RESUMO
In general snakes show differentiate anatomical, biological and behavioral particularities compared to other species. Basic information about the snakes anatomy, physiology and reproductive biology is scarce in several species, making the reproduction a challenge. Thus, the present work aims to evaluate morphological aspects of the Corallus hortulanus testes, correlating these findings with environmental factors and reproductive aspects. The testes of three specimens of Corallus hortulanus were cut to a thickness of 3µm in microtome, stained with 1% toluidine blue, photo documented and described. Seasonality was observed in the sperm production of Corallus hortulanus, with the presence of mature spermatozoa in the wettest and hottest periods of the year, as well as the largest testicular volume in these periods.
Assuntos
Estações do Ano , Testículo , Masculino , Testículo/anatomia & histologia , Testículo/fisiologia , Animais , Reprodução/fisiologia , Espermatozoides/fisiologia , Espermatozoides/citologia , Colubridae/anatomia & histologia , Colubridae/fisiologiaRESUMO
Snakes represent a wide and diverse group of species and have anatomical particularities, such as the renal sexual segment (RSS), a structure located in the kidneys and formed from the hypertrophy of the urinary ducts and nephrons. This study aims at describing the histological aspects of the RSS of Boa constrictor, Epicrates cenchria and Corallus hortulanus, all of which are Brazilian snake species from the Boidae family. The reproductive system and kidneys of five male specimens of E. cenchria, three male specimens of C. hortulanus and two male specimens of B. constrictor were obtained. Tissue samples were processed histologically and different stains used (Toluidine Blue, Alcian Blue and Periodic Acid Schiff). The histological evaluation of the RSS of E. cenchria, C. hortulanus and B. constrictor shows that the RSS in these species varies when comparing individuals in the reproductive period with those which are not. It also allows for the observation of the segment's secretory activity in animals in the reproductive stage (mature sperm in the lumen of the seminiferous tubules) as well as in those which are not. Finally, the histological evaluation also reveals the variation of the secretion product in individuals in the reproductive period, in those which are not, and also among individuals within the same reproductive stage.
Assuntos
Boidae , Rim , Animais , Masculino , Rim/anatomia & histologia , Brasil , Boidae/anatomia & histologia , Túbulos Seminíferos/anatomia & histologia , Espermatozoides/citologiaRESUMO
Four genera of the Boidae family are found in Brazil: Eunectes, Corallus, Epicrates, and Boa. Male copulatory organs in snakes are located inside the tail and are called hemipenes. They are double structures in an inverted position that are exposed during copulation. This study describes the macroscopic and histological aspects of hemipenes in Boidae snakes. One Boa constrictor, three Epicrates cenchria, one Corallus hortulanus hemipenes, and one fragment of the muscular retractor penis magnus (m. retractor penis magnus) from Eunectes murinus were included in this study. The structures were evaluated macroscopically and photo-documented using a stereo microscope. Tissue fragments were included in glycol methacrylate plastic resin, cut into 3-µm-thick slices, and stained with 1% toluidine blue for microscopic evaluation. The macroscopic analysis showed that the arrangement and diameter occupied by the m. retractor penis magnus in the hemipenis and the internal and external cavernous bodies differ between species. The histological analysis showed that the hemipenis of B. constrictor, E. cenchria, and C. hortulanus has stratified epithelium in the external portion supported by dense connective tissue with blood vessels and muscle tissue. Although the literature reports the presence of skeletal musculature in the hemipenis, striated musculature with a centrally located nucleus in the fibre bundle, typical of cardiac musculature in mammals, was observed in the studied species.
Assuntos
Boidae , Masculino , Animais , Boidae/fisiologia , Brasil , MamíferosRESUMO
The follicular development and reproductive characteristics of four species of oviparous lizards in the Tropidurus torquatus group were anatomically and histologically evaluated. We measured specimens, recorded the number of follicles and eggs, and removed the right ovary of each individual, which we processed according to histological routine and photo-documented. For all species, ovaries were divided into a cortical germinal bed, where oogonia and stage I oocytes are located, and a medullar stroma, where the remaining follicular developmental stages occur. Microscopic analysis did not show differences in ovarian follicle development for the four species of the T. torquatus group. The only measurement that presented significant variation throughout follicular development was the thickness of the granulosa layer in stage VII follicles. Regarding snout-tovent length at sexual maturity, few variations were observed among the species, with the smallest length recorded for T. oreadicus. Clutch size was higher for T. itambere and T. torquatus species, with a maximum of five and six eggs in the oviducts, respectively. Tropidurus oreadicus and T. hispidus had a maximum of five and six follicles, respectively, but neither species presented eggs in the oviducts. In addition, the reproductive activity varied among the four lizard species of the T. torquatus group. Finally, besides the morphological characteristics observed among these species, this is the first study to report data on the germinal bed, number of ovarian follicles, corpus luteum, and follicular atresia in relation to reproductive activity.
Assuntos
Lagartos/fisiologia , Folículo Ovariano/fisiologia , Reprodução/fisiologia , Animais , Brasil , Feminino , Lagartos/classificação , Especificidade da EspécieRESUMO
The hoary fox Lycalopex vetulus (Lund, 1842) is a small canid, endemic to Brazil, belonging to the Canidae family, widely distributed in the country, occurring records in different regions and habitats. The objective of this study is to describe morphologically the testicles and epididymal ducts of hoary fox. The animals, coming from the zoo of Federal University of Mato Grosso, Brazil, had died by natural causes. The male reproductive system was dissected to collect the testicles. The samples were fragmented and histologically examined. Microscopically, the testes were coated by the vaginal and albuginea tunic, formed by modeled dense connective tissue with large amount of collagen fibers. Into the organ, convoluted seminiferous tubules were surrounded by a basement membrane characterized by the presence of myoid and Sertoli cells and germinative epithelium composed by Between the seminiferous tubules, interstitial tissue composed of connective tissue, blood and lymph vessels and Leydig cells in polyhedral shape was present. The epididymal ducts showed pseudostratified columnar epithelium with secretory cells, in which stereocilia located on a basement membrane filled by myoid cells were found. The structures observed by us are very similar to those described for other mammals.(AU)
A raposa-do-campo Lycalopex vetulus (Lund, 1842) é um canídeo de pequeno porte, endêmico do Brasil, pertencente a família Canidae, com ampla distribuição no país, ocorrendo registros em várias regiões e habitats diferentes. Com base nessa informação, o objetivo deste trabalho é caracterizar morfologicamente os testículos e ductos epididimários da raposa-do-campo. O animal, oriundo do zoológico da Universidade Federal de Mato Grosso, Brasil, veio a óbito por causas naturais e o sistema reprodutor masculino foi dissecado para coleta dos testículos. As amostras retiradas foram fragmentadas e histológicamente examinadas. A partir das análises microscópicas dos testículos foram identificados: a túnica vaginal e albugínea, formada por tecido conjuntivo denso modelado, com grande quantidade de fibras colágenas; túbulos seminíferos enovelados e revestidos por epitélio germinativo e células de Sertoli, envolvidos por uma membrana basal com presença de células mioides; tecido intersticial entre os túbulos seminíferos constituído de tecido conjuntivo, vasos sanguíneos e linfáticos, e células de Leydig em formato poliédrico. Os ductos epididimários apresentaram epitélio cilíndrico pseudoestratificado com células secretoras dos quais projetam estereocílios, situados sobre uma membrana basal repleta por células mióides. As estruturas por nós observadas possuem muita semelhança com as demais descrições para mamíferos.(AU)
Assuntos
Testículo , Raposas , Genitália Masculina , Túbulos Seminíferos , Células de Sertoli , Membrana Basal , Tecido Conjuntivo , Canidae , Estereocílios , Células Intersticiais do TestículoRESUMO
Tropidurus comprises a Neotropical genus of lizard that currently has about 30 species widely distributed in the South American. Among these species, Tropidurus torquatus, which has the characteristic of great physiological plasticity, occupying a variety of habitats in open areas and urbanized environments. Considering this, the aim of the study was to investigate the germinative cells and spermatogenesis of a population of T. torquatus in an urban area under Cerrado Biome influences to understand how to establish the temporal development of germinative cells and spermatogenesis during a period of one year. Individuals were obtained in the Zoological Collection of Vertebrates at the Universidade Federal de Mato Grosso (UFMT), and the germinative cells and full spermatogenesis were described with light microscopy. Tropidurus torquatus presented germ cells with similar characteristics already documented for the other species of lizards and reptiles. Spermatogonia type A and B, primary and secondary spermatocytes, and spermatids were present in almost all months evaluated. The gonadosomatic ratio presented its highest value in October, moment in which spermatogenesis presented all the germinative cells and spermatozoa in the lumen, of the seminiferous tubules. In the seasonal climate of the Cerrado Biome, we observe discontinuous spermatogenesis in T. torquatus with the production of spermatozoa in almost every month of the year, however with sperm storage in the epididymis during the phase of testicular regression.
O gênero de lagartos neotropicais Tropidurus tem cerca de 30 espécies amplamente distribuídas no continente sul-americano. Entre essas espécies, Tropidurus torquatus é a que apresenta grande plasticidade fisiológica, ocupando uma variedade de hábitats em áreas abertas e ambientes urbanizados. Considerando isso, o objetivo do estudo foi investigar as células germinativas e a espermatogênese de uma população de T. torquatus em uma área urbana sob a influência do Bioma Cerrado para entender como é estabelecido o desenvolvimento temporal das células germinativas e a espermatogênese durante o período de um ano. Indivíduos foram obtidos na Coleção Zoológica de Vertebrados da Universidade Federal de Mato Grosso (UFMT). A caracterização das células germinativas e da espermatogênese foi realizada através de microscopia de luz. Tropidurus torquatus apresentou células germinativas com características similares às já documentadas para outras espécies de lagartos e répteis. Espermatogônias do tipo A e B, espermatócitos primários e secundários e espermátides estiveram presentes praticamente em todos os meses. A razão gonadossomática apresentou seu valor máximo em outubro, momento em que a espermatogênese apresentou todas as células germinativas e espermatozoides no lúmen do túbulo seminífero. No clima sazonal do Bioma Cerrado observamos espermatogênese descontínua em T. torquatus com a produção de espermatozoides em quase todos os meses do ano, porém com estocagem nos epidídimos durante a fase de regressão testicular.
Assuntos
Espermatogênese , Ecossistema , Pradaria , Células Germinativas , LagartosRESUMO
The pampas cat Leopardus colocolo (Molina, 1782) is a species of the Felidae family, widely distributed in South America, included on CITES Appendix II and classified as Near Threatened on the IUCN Red List, with population trend decreasing. Based on this information, the objective of this study is to describe morphologically the testes and epididymal ducts of pampas cat. The animal, coming from the Federal University of Mato Grosso Zoo, Brazil, had died after anesthesia procedure and the male reproductive system was dissected to collect the testicles. The samples taken were fragmented and histologically examined. From the microscopic analysis of the testes were identified: vaginal and tunica albuginea, formed by dense connective tissue modeled with large amount of collagen fibers. The tunica albuginea fibrous septa emits into the body. The seminiferous tubules are coiled and coated internally by spermatogenic epithelium consisting of Sertoli cells, surrounded by a basement membrane in the presence of myoid cells. The interstitial tissue between the seminiferous tubules, is composed of loose connective tissue, blood and lymph vessels, and Leydig cells in polyhedral shape. The epididymal ducts showed pseudostratified columnar epithelium with secretory cells of which stereocilia design, situated on a basement membrane filled by myoid cells. This epithelium has principal and basal cells, the main cell design stereocilia toward the lumen of the epididymal duct.(AU)
O gato-palheiro Leopardus colocolo (Molina, 1782) é uma espécie da família Felidae, com ampla distribuição na América do Sul. Está incluido no Appendix II da CITES e classificada como Próxima da Extinção na Lista Vermelha da IUCN, apresentando população em decrescimo. Com base nessas informações o objetivo deste estudo é caracterizar morfologicamente os testículos e ductos epididimários de L. colocolo. O animal, oriundo do Zoológico da Universidade Federal de Mato Grosso, Brasil, veio a óbito após procedimento anestésico e o sistema reprodutor masculino foi dissecado para coleta dos testículos. As amostras retiradas foram fragmentadas e histologicamente examinadas. A partir das análises microscópicas dos testículos foram identificados: a túnica vaginal e albugínea, formada por tecido conjuntivo denso modelado, com grande quantidade de fibras de colágeno. A túnica albugínea emite septos fibrosos para o interior do órgão. Os túbulos seminíferos são enovelados e revestidos internamente por epitélio estratificado constituído por células espermatogênicas e células somáticas de Sertoli, envolvidos por uma membrana basal com presença de células mioides. O tecido intersticial, entre os túbulos seminíferos, é constituído de tecido conjuntivo do tipo frouxo com vasos sanguíneos e linfáticos, e células de Leydig em formato poliédrico. Os ductos epididimários apresentaram epitélio cilíndrico pseudoestratificado com células secretoras dos quais projetam estereocílios, situados sobre uma membrana basal repleta por células mióides. Este epitélio apresenta células principais e basais, cujas células principais projetam estereocílios em direção ao lúmen do ducto epididimário.(AU)
Assuntos
Animais , Masculino , Epididimo/anatomia & histologia , Felidae/anatomia & histologia , Epitélio Seminífero/anatomia & histologia , Testículo/anatomia & histologia , Pesos e Medidas Corporais/veterináriaRESUMO
Fish belonging to the family Rivulidae possess one of the most complex reproductive systems. Rivulus, a genus of freshwater fish in the Rivulidae family, was recently reclassified into five genera, including Melanorivulus. Its type species, M. punctatus, is widely distributed and probably represents a species complex. The ultrastructure of sperm has been broadly used in systematics, and we hereby describe the ultrastructural features of spermatogenesis in M. punctatus. Ten M. punctatus males were collected from the reservoir of Parque Estadual da Quineira, municipality of Chapada dos Guimarães, Mato Grosso, Brazil, and prepared for analysis by light microscopy and transmission electron microscopy. M. punctatus undergoes cystic spermatogenesis. Its cysts consist of groups of germ cells that are in synchronous development and are surrounded by cytoplasmic projections of Sertoli cells. With the breakdown of the cysts, the spermatozoa are released and their maturation is completed in the duct, where part of the cytoplasmic material is discarded through the vesicles. The mature spermatozoon is characterized by a spherical head with homogeneously condensed chromatin, a symmetric midpiece consisting of a pair of perpendicular centrioles, a ring of mitochondria, several vesicles, and one flagellum medial to the nucleus. Early stages of spermatogenesis show no peculiarities; however, in spermiogenesis, we observed that the spermatids remain interconnected by cytoplasmic bridges and have pockets of residual cytoplasm. The sperm is of the aquasperm type and is similar to that observed in the members of the family Rivulidae. The spermatozoa have a single flagellum that consists of a classic axoneme (9+2), as found in most groups of fish, despite the lateral extensions.
Assuntos
Ciprinodontiformes/anatomia & histologia , Espermatogênese , Espermatozoides/ultraestrutura , Animais , Brasil , Masculino , Microscopia Eletrônica de Transmissão , Células de Sertoli/ultraestrutura , Cabeça do Espermatozoide/ultraestrutura , Cauda do Espermatozoide/ultraestrutura , Espermátides/ultraestruturaRESUMO
The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulus aff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male gonads presented themselves as capable of reproducing, characterized by the presence of undifferentiated and differentiated spermatogonia, spermatocytes organized into cysts, spermatids in cysts whose wall was thicker and the spermatozoa was free in the lumen and the duct. This can indicate a continuous reproductive cycle with split spermiation. The females had gonads in the development stage from May to September with undifferentiated and differentiated oogonias and early oocytes always facing the lumen, abundant pre-vitellogenic and vitellogenic oocytes and some atresias. In the phase capable of spawning, observed from October to March, the mature oocytes are abundant, there are many post-ovulatory complexes and some atresia in advanced stage. The regression, observed in some individuals from February to April, is characterized by ovaries with many atresias and post-ovulatory complexes. The same results were found in the quantitative assessments. Therefore, it may be characterized as discontinuous cycle with split spawning. Thus, the reproductive cycle of this species can be characterized as continuous for males and discontinuous for females, which have a most intense phase of reproduction from October to March. However, both have fractional release of gametes.
A compreensão do ciclo reprodutivo possibilita entender quais são as mudanças morfológicas que se desenvolvem na gônada neste período. Assim, muitos estudos têm sido realizados no intuito de descrever e classificar as fases de desenvolvimento gonadal e dos estados reprodutivos dos peixes da região Neotropical. Com esse objetivo foram coletados espécimes de Melanorivulus aff. punctatus em um represamento permanente em Chapada dos Guimarães, Mato Grosso, Brasil. As gônadas foram preparadas para análise à microscopia de luz. A ovogênese e a espermatogênese foram descritas e caracterizados os estágios de desenvolvimento gonadal, juntamente com as avaliações de razão gonadossomática, contagem de células germinativas e verificação de variação de ovócitos maduros em fêmeas. Durante todo o ano as gônadas masculinas apresentaram-se como aptas a reprodução, caracterizadas pela presença de espermatogônias indiferenciadas e diferenciadas, espermatócitos organizados em cistos, espermátides em cistos com parede mais espessa e espermatozoides livres no lúmen e no ducto. Isso pode indicar um ciclo reprodutivo contínuo com espermiação parcelada. As fêmeas apresentaram gônadas em estágio de desenvolvimento de maio a setembro, com ovogônias indiferenciadas e diferenciadas e ovócitos iniciais sempre voltados para o lúmen, ovócitos pré-vitelogênicos e vitelogênicos abundantes e algumas atresias. Na fase de apto a desova, observada de outubro a março, os ovócitos maduros são abundantes, há muitos complexos pós ovulatórios e algumas atresias em estágio avançado. A fase de regressão, constatada em alguns indivíduos de fevereiro a abril, é caracterizada por ovários com muitas atresias e complexos pós-ovulatórios. Os mesmos resultados foram encontrados nas avaliações quantitativas realizadas. Logo, pode-se caracterizar o ciclo como descontínuo com desova parcelada. Assim, o ciclo reprodutivo desta espécie pode ser caracterizado como contínuo para machos e descontínuo para fêmeas, que apresentam uma fase mais intensa de reprodução de outubro a março. Porém, ambos possuem liberação de gametas parcelada.
Assuntos
Animais , Gônadas/fisiologia , Peixes/anatomia & histologia , Fenômenos Reprodutivos Fisiológicos , Comportamento Reprodutivo , Contagem de Células/veterinária , Oócitos/crescimento & desenvolvimento , Reprodução/fisiologiaRESUMO
The Sertoli cell contributes to spermatogenesis acting in the differentiation of germ cells and being the only somatic cells present in the germinal compartment. So that spermatogenesis is primarily dependent of Sertoli-Sertoli and Sertoli-germ cell interactions once Sertoli cells provide critical factors necessary for a successful differentiation of germ cells to sperm. In teleost fish the cytoplasmic extensions of Sertoli cells support the cysts that remain closed until spermiogenesis. The number of Sertoli cells determines the testicular size, the number of testicular germ cells and the production capacity of spermatozoa. Our objective was to describe the morphology and the cytoarchitectonical dynamic of Sertoli cells in Melanorivulus punctatus, which were collected in the municipality of Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were extracted and prepared according to histological routine for light microscopy and transmission electron microscopy. Sertoli cells have cytoplasmic extensions which provide the conformation of cysts in the interior of the lobes. These cells possess a polymorphic nucleus with a well-defined nuclear envelope and a prominent and eccentric nucleoli. Each cyst is sustained for more than one Sertoli cell and the cysts seem to share the Sertoli cells with each other regardless the stage of development of germ cells within these cysts. This disposal promotes a reticulated arrangement of Sertoli cells. The Sertoli cells lining the ducts assume rectangular shape with rounded nucleus. Thus, the morphological characteristics of Sertoli cells observed did not differ from what has been described for other teleosts. Despite the similarity in the morphology of these cells, we observed that its disposal in the extension of the gonad seems to differ from what is described for fish. The arrangement by which the cytoplasmic extensions of Sertoli cells connect the ends of lobes prevents the proliferation of spermatogonia on the lobe side walls and are only observed in the end of the lobes, which ensures the testicular characteristic-lobular restricted in Atherinomorpha.
Assuntos
Ciprinodontiformes , Células de Sertoli/ultraestrutura , Testículo/ultraestrutura , Animais , Brasil , Masculino , Microscopia Eletrônica de TransmissãoRESUMO
The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission electron microscopy. No variations were observed when the diameter of the seminiferous tubules and the thickness of the interstitial tissue were studied. However, changes in spermatogenesis were conspicuous and indicated that the reproductive cycle of D. minutus in Chapada dos Guimarães is discontinuous and seems related to variations in air temperature and rainfall.
Assuntos
Anuros/fisiologia , Estações do Ano , Espermatogênese/fisiologia , Testículo/ultraestrutura , Animais , Masculino , Microscopia Eletrônica de Transmissão , Microscopia de PolarizaçãoRESUMO
The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission electron microscopy. No variations were observed when the diameter of the seminiferous tubules and the thickness of the interstitial tissue were studied. However, changes in spermatogenesis were conspicuous and indicated that the reproductive cycle of D. minutus in Chapada dos Guimarães is discontinuous and seems related to variations in air temperature and rainfall.
Assuntos
Animais , Masculino , Anuros/fisiologia , Estações do Ano , Espermatogênese/fisiologia , Testículo/ultraestrutura , Microscopia Eletrônica de Transmissão , Microscopia de PolarizaçãoRESUMO
The construction of dams causes major impacts on fauna by changing or eliminating irreversibly their habitats. The resulting changes lead to deep potential modifications on reproductive biology and population structure of lizards, snakes and amphisbaenas. The reservoir in the Multiple Use Area of Manso (APM-Manso) is located near to Chapada dos Guimarães National Park, in Mato Grosso State. We analyzed comparatively the male gonads of Anolis meridionalis, Colobosaura modesta, Cercosaura ocellata, Cnemidophorus ocellifer, Hoplocercus spinosus, Bachia bresslaui, Mabuya frenata, Micrablepharus atticolus and Tropidurus oreadicus, from APM-Manso, aiming to verify possible changes in the reproductive success according to environmental changes. Before the impoundment A. meridionalis, Colobosaura modesta, Cercosaura ocellata, M. atticolus and T. oreadicus showed up reproductive. However, during the impoundment period they presented changes in seminiferous tubules, evidenced by the absence of spermatids and spermatozoids. B. bresslaui and M. frenata had no differences in the seminiferous tubules before and after the impoundment, being reproductive in both moments. The damming and the formation of the lake of Manso reservoir may have interfered on the reproduction of some lizards species, especially if the reproductive cycle is regulated by the rainfall of the habitat.
RESUMO
The construction of dams causes major impacts on fauna by changing or eliminating irreversibly their habitats. The resulting changes lead to deep potential modifications on reproductive biology and population structure of lizards, snakes and amphisbaenas. The reservoir in the Multiple Use Area of Manso (APM-Manso) is located near to Chapada dos Guimarães National Park, in Mato Grosso State. We analyzed comparatively the male gonads of Anolis meridionalis, Colobosaura modesta, Cercosaura ocellata, Cnemidophorus ocellifer, Hoplocercus spinosus, Bachia bresslaui, Mabuya frenata, Micrablepharus atticolus and Tropidurus oreadicus, from APM-Manso, aiming to verify possible changes in the reproductive success according to environmental changes. Before the impoundment A. meridionalis, Colobosaura modesta, Cercosaura ocellata, M. atticolus and T. oreadicus showed up reproductive. However, during the impoundment period they presented changes in seminiferous tubules, evidenced by the absence of spermatids and spermatozoids. B. bresslaui and M. frenata had no differences in the seminiferous tubules before and after the impoundment, being reproductive in both moments. The damming and the formation of the lake of Manso reservoir may have interfered on the reproduction of some lizards species, especially if the reproductive cycle is regulated by the rainfall of the habitat.
A construção de barragens tem ocasionado grandes impactos sobre a fauna ao alterar ou eliminar seus habitats de forma irreversível. Alterações decorrentes exercem profundas modificações potenciais na biologia reprodutiva e na estrutura populacional de lagartos, serpentes e anfisbenas. O reservatório da Área de Aproveitamento Múltiplo de Manso (APM-Manso) localiza-se próximo ao Parque Nacional da Chapada dos Guimarães, em Mato Grosso. Foram analisadas comparativamente as gônadas masculinas de Anolis meridionalis, Colobosaura modesta, Cercosaura ocellata, Cnemidophorus ocellifer, Hoplocercus spinosus, Bachia bresslaui, Mabuya frenata, Micrablepharus atticolus e Tropidurus oreadicus, da APM-Manso com o objetivo de verificar se houve alterações no sucesso reprodutivo das mesmas de acordo com as modificações ocorridas no ambiente. Antes do represamento A. meridionalis, Colobosaura modesta, Cercosaura ocellata, M. atticolus e T. oreadicus apresentavam-se reprodutivas. No entanto, durante o período de represamento apresentaram alterações nos túbulos seminíferos evidenciadas pela ausência de espermátides e espermatozóides. B. bresslaui e M. frenata não apresentaram diferenças em seus túbulos seminíferos antes ou depois do represamento, estando reprodutivas em ambos os momentos. O represamento e a formação do lago do Manso pode ter interferido na reprodução de algumas espécies de lagartos, principalmente se o ciclo reprodutivo for regulado a partir da pluviosidade do habitat.
Assuntos
Animais , Reprodução , Histologia , LagartosRESUMO
Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T. oreadicus, T. itambere, T. spinulosus and T. Guarani species, collected in different places in the Mato Grosso state, Brazil. The reproductive period is synchronous for males and females and occurs in September, October and November. Reproductive males were characterized. In the testes are seminiferous tubules with germ cells at different stages of spermatogenesis, with a high epithelium, at present light, free spermatozoa in the lumen and reduction of interstitial tissue. For females, the reproduction peak occurs when the oviduct epithelium is high with secretions and basal nucleus. These months are characterized in the sampled areas over a period of heavy rain and high temperatures. The decline of reproductive period was observed in both sexes, between April and August. Low reproduction in males is characterized by ample light, absence of sperm, only germ cells in the early stages of spermatogenesis are observed (a few spermatogonia and spermatocytes) and interstitial tissue wide. In females, the period of reproductive decline is marked by the absence of unicellular glands in the oviduct epithelium, with higher affinity with the dye. This period corresponds to low rainfall periods and lower temperatures. We propose an analysis of zoological samples; this is a proposal ...
Estrategia reproductiva es el conjunto de adaptaciones que promueven la manera más eficiente para una población a sobrevivir en las condiciones específicas de un entorno particular. Comprender esta adaptación es importante y puede identificarse en algunas poblaciones como indicador de cambios ambientales. La espermatogénesis puede ser un proceso biológico medible de estas adaptaciones en escalas espaciales y temporales. Se analizó la morfología de los testículos y oviductos de las especies de lagartijas que componen el género Tropidurus, teniendo en cuenta la amplia distribución geográfica y las relaciones simpátricas. Para el análisis hemos eliminado los testículos de los machos y la parte media de los oviductos de hembras de las especiesTropidurus Etheridge, T. oreadicus, T. itambere, T. spinulosus y T. Guarani recolectadas en diferentes lugares en el estado de Mato Grosso, Brasil. El período reproductivo es sincrónico para machos y hembras, y se produce durante septiembre, octubre y noviembre. Se caracterizaron como machos reproductores por testículos con túbulos seminíferos con células germinales en distintas etapas de la espermatogénesis, un epitelio muy alto, un lumen reducido, numerosos espermatozoides libres en el lumen y tejido intersticial redicudo. En hembras el pico reproductivo se produce cuando los canales de conducción de gametos poseen un epitelio alto, secretor y con núcleos basales. Estos meses son caracterizados en las zonas muestreadas por fuertes lluvias y altas temperaturas. La disminución del período reproductivo se observó en ambos sexos, entre abril y agosto. La baja reproducción en machos se caracteriza por un lumen ancho, ausencia de espermatozoides, presencia de células germinales sólo en las primeras etapas de la espermatogénesis (espermatogonias y pocos espermatocitos) y tejido intersticial amplio. En las mujeres, el período de baja reproducción está marcado por la ausencia de glándulas unicelulares en el epitelio de...
Assuntos
Animais , Gônadas/anatomia & histologia , Lagartos/anatomia & histologia , Oviductos/anatomia & histologia , Adaptação Biológica , Brasil , Lagartos/fisiologia , Chuva , Reprodução , Estações do Ano , TemperaturaRESUMO
Fever of unknown origin remains a diagnostic challenge with up to 50% of unexplained cases. Adult-onset Still disease typically present high fever, arthralgia, rash, pharyngitis and serositis, lymphadenopathy and hepatosplenomegaly, inflammatory markers and hepatic enzymes elevation and negative immunological study. The authors present a 46-year old man with previous admissions for fever of unknown origin with a 3-week history of fever and systemic symptoms. The study disclosed anaemia, inflammatory markers and hepatic enzymes elevation, splenomegaly and negative serological and immunological studies. The patient posteriorly presented polyarthralgias and cutaneous rash. The introduction of corticotherapy resolved symptoms and laboratories alterations. Adult-onset Still disease is a heterogeneous and rare disease and the lack of serologic markers as a true gold standard makes diagnosis difficult.
Assuntos
Febre de Causa Desconhecida/etiologia , Doença de Still de Início Tardio/complicações , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A morfologia bucal interna das larvas de Eupemphix nattereri, Physalaemus albonotatus, P. centralis, P. cuvieri, Leptodactylus furnarius, L. fuscus, L. petersii e L. podicipinus são descritas e comparadas utilizando microscopia eletrônica de varredura. A larva de E. nattereri apresenta muitas diferenças quando comparada à larvas de anuros do gênero Physalaemus. As larvas de P. albonotatus, P. centralis e P. cuvieri apresentam semelhanças em sua morfologia bucal interna, tais como o número de papilas infralabiais e papilas laterais à crista mediana. P. centralis difere na quantidade de papilas pós-nasais e papilas da arena do teto bucal. Entre as larvas de Leptodactylus é possível perceber um padrão na distribuição e quantidade das estruturas bucais internas (papilas infralabiais e linguais, papilas das arenas do assoalho e teto bucal, crista mediana, papilas laterais da crista e papilas pós-nasais) nos grupos de espécies. Os caracteres da morfologia bucal larvária podem ser úteis quando utilizados conjuntamente com outros dados auxiliando na compreensão das relações sistemáticas da ordem Anura.
The internal buccal morphology of the tadpoles of Eupemphix nattereri, Physalaemus albonotatus, P. centralis, P. cuvieri, Leptodactylus furnarius, L. fuscus, L. petersii and L. podicipinus are described and compared using scanning electron microscopy. The tadpole of E. nattereri has major differences when compared to other tadpoles of the Physalaemus genus. The tadpoles of P. albonotatus, P. centralis and P. cuvieri present similarities in internal buccal morphology, such as the number of the infralabial and lateral ridge papillae, but P. centralis differ in the number of the post-narial and buccal roof arena papillae. Among the tadpoles of the Leptodactylus species is possible to observe patterns, in distribution and quantity of the internal buccal structures (infralabial and lingual papillae, buccal floor and roof arena papillae, median ridge, lateral ridge papillae and postnarial papillae) in the species groups. The characteristics of the internal buccal morphology may be useful when used together with other data helping in comprehension of the systematic of the order Anura.
Assuntos
Anfíbios , Anatomia Comparada , Anuros , Anatomia/classificação , Comportamento Alimentar , Larva/anatomia & histologia , Larva/classificaçãoRESUMO
Spermiogenesis involves a series of cellular modifications, culminating in the production of a highly specialized cell, the spermatozoon. To reassess the peculiarities of this process, specimens of the lizard Iguana iguana were collected in the Pantanal, Mato Grosso do Sul state, Brazil; the testis and ducts were processed according to routine methods for light, scanning and transmission electron microscopy. After nuclear condensation and elongation, the cytoplasm and organelles flow towards the basal area, below the nucleus. An infolding occurs at the nuclear base, where the middle piece is implanted. This area contains a centriole pair, with the proximal one perpendicular and the distal one parallel to the nuclear axis. The distal centriole can be functionally compared to the basal corpuscle at the axoneme base. The mitochondria, that are round or elongated with transverse cristae, initially organized around the centriole in continuous rings; later they alternate with dense bodies. Thus the dense bodies are apparently formed by mitochondrial modification with deposition of dense material. In I. iguana the formation of dense bodies is one of the last events of spermiogenesis. Marking the transition between middle piece and flagellum is the annulus. This structure blocks the displacement of mitochondria from the middle piece during flagellar movement. Halfway down the middle piece, a fibrous sheath is formed by the accumulation of an amorphous layer surrounding the axoneme, and this structure is the axonemic complex. In the spermatozoa of I. iguana, the flagellar end piece is reduced in diameter, because the fibrous sheath terminates and only the typical axonemal microtubule pattern (9+2) is present. A large amount of cytoplasm is observed around spermatozoa in the seminiferous tubule lumen, suggesting that these are immature spermatozoa. Structural modifications occur during their passage through the reproductive tract...
A espermiogênese envolve uma série de modificações celulares, culminando na formação de uma célula altamente especializada, o espermatozóide. Para re-avaliarmos as peculiaridades desse processo, espécimes do lagarto Iguana iguana foram coletados no Pantanal, estado de Mato Grosso do Sul, Brasil; os testículos e ductos foram retirados e processados de acordo com a rotina para microscopia de luz e eletrônica de transmissão e varredura. Após a condensação e alongamento do núcleo, o citoplasma e as organelas se deslocam para região basal abaixo do núcleo. Nessa região basal do núcleo é implantada a peça intermediária. Essa área contém um par de centríolos, sendo um proximal e perpendicular e um distal paralelo ao eixo maior do núcleo. O centríolo distal pode ser comparado funcionalmente ao corpúsculo basal na base do axonema. As mitocôndrias são redondas ou alongadas com cristas transversais, organizadas em torno dos centríolos em anéis contínuos; esses anéis são alternados por corpos densos. Esses corpos densos são aparentemente formados por mitocôndrias modificadas com deposição de material denso. Em I. iguana a formação desses corpos densos é um dos últimos eventos da espermiogênese. O que marca a transição entre a peça intermediária e o flagelo é o annulus. Esta estrutura obstrui o deslocamento das mitocôndrias da peça intermediária durante o movimento flagelar. A peça intermediária apresenta uma parte incompleta formada pelo acúmulo de uma camada amorfa que cerca o axonema chamada de bainha fibrosa, o conjunto dessas estruturas é o complexo axonêmico. No espermatozóide de I. iguana a peça final flagelar tem o diâmetro reduzido, com o término da bainha fibrosa permanecendo um típico padrão axonêmico de microtúbulos (9+2). Uma quantidade grande de citoplasma é observada em torno dos espermatozóides no lúmen dos túbulos seminíferos, sugerindo que estes são espermatozóides imaturos. As modificações estruturais ocorrem durante a sua passagem através...
Assuntos
Animais , Iguanas , Lagartos , Reprodução , EspermatogêneseRESUMO
The objective of this work was to make a comparative analysis of germ cell organization at different stages of cellular differentiation in adult males of Dendropsophus nanus (Boulenger, 1889), Pseudis limellum (Cope, 1862), P. paradoxa (Linnaeus, 1758), and Scinax acuminatus (Cope, 1862), belonging to the family Hylidae; and Leptodactylus chaquensis (Cei, 1950) and L. podicipinus (Cope, 1862), belonging to the family Leptodactylidae, collected in the Pantanal and in Serra da Bodoquena, Mato Grosso do Sul State, Brazil. The testes were removed and fixed, dehydrated in a graded series of ethanol, and embedded in methacrylate glycol resin (Historesin Leica®). The sections were stained by 1% toluidine blue and observed under light microscope. It was detected that all individual of the Hylidae family show, throughout the year, the presence of all germ cell types of spermatogenesis. However, all Leptodactylidae family individuals only show the presence of all germ cell types during the rainy season. The variations of characteristics in seminiferous epithelium organization, as well as the evident difference in the amount of spermatozoa inside the tubules, are evidence that the anurans in this work show different forms of spermatogenesis development throughout the year: the cycle is continuous for the Hylidae family, and discontinuous with explosive release of spermatozoa for the Lept
O objetivo deste trabalho foi analisar e comparar a organização das células germinativas em diferentes estádios de diferenciação celular nos machos adultos de Dendropsophus nanus (Boulenger, 1889), Pseudis limellum (Cope, 1862), Pseudis paradoxa (Linnaeus, 1758) e Scinax acuminatus (Cope, 1862), pertencentes à família Hylidae, e de Leptodactylus chaquensis (Cei, 1950) e L. podicipinus (Cope, 1862), pertencentes à família Leptodactylidae, coletados no Pantanal e na serra da Bodoquena, no Estado do Mato Grosso do Sul, Brasil. Os testículos foram retirados, fixados, desidratados em uma série alcoólica e incluídos em resina plástica do tipo methacrilato glicol (Historesin Leica®); cortados a 3 µm, corados com azul de toluidina 1% e observados no microscópio de luz. Constatou-se que os indivíduos da família Hylidae apresentam, em todas as épocas do ano, presença de todas as células de linhagem germinativa da espermatogênese. Já os indivíduos da família Leptodactylidae apresentam todas as células da linhagem germinativa somente no período chuvoso. As variações das características na organização dos epitélios seminíferos, assim como da evidente diferença na quantidade de espermatozoides no interior dos túbulos, demonstram que os anuros estudados apresentam diferentes formas de desenvolvimento da espermatogênese ao longo do ano: de forma cíclica para os da família Hylidae e acíclica, c
RESUMO
The spermatogenesis of Pseudis limellum, from the Southern Pantanal, Brazil, was studied from July 1995 to May 1996, through histological sections of the testis. The cells could be differentiated as: primary spermatogonia, large cells, generally with bilobed nucleus; secondary spermatogonia, smaller cells, with darker cytoplasm, chromatin of radial form; primary and secondary spermatocytes, differentiated according to the different stages of the nucleus during the successive cells divisions. Furthermore, we observed cells in process of morphologic differentiation: rounded spermatids much smaller, with nucleus containing chromatin in compacting process and cytoplasm reduction; elongated spermatids, generally parallel organized in well defined bundles, with the anterior region directed toward the periphery of the seminiferous tubule and the tail directed toward the lumen. Spermatozoa are free in the lumen of the seminiferous tubule. All the cells are organized as cysts, which are supported by a large amount of Sertoli cells. The spermatogenesis in P. limellum is very similar to that of other anurans, but peculiarities were observed regarding the organization of the germ cells, the great amount of free Sertoli cells in the lumen of testis collected in May, and the long cytoplasmatic extensions of the cells bearing pigments and involving the seminiferous tubule. The diameter of the seminiferous tubule (SD) exhibited an annual mean of 251.79 +/- 37.57 microm. Spermatozoa number by seminiferous tubule (SN) exhibited an annual mean of 306.66 +/- 39.83, also with higher and lower values at each month. Variations in SD and SN were not significantly correlated with climatic variables. In this species, reproduction occurs throughout the year in ponds and flooded areas, despite the seasonal climate of the Pantanal. Although males varied in their annual reproductive activity, they were considered potentially reproductive in all months throughout the year.