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1.
Birth Defects Res ; 116(6): e2347, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38822636

RESUMO

BACKGROUND: Measurement of rat anogenital distance (AGD) dates to at least 1912. Increased interest in endocrine disrupting chemicals and the use of AGD as a biomarker for fetal androgen effects have increased the number of studies with this endpoint in recent decades. A literature review revealed different landmarks, methods of measurement, and methods to adjust for body weight differences. AGD is often reported to hundredths of millimeters and as such, deserves precision in all these aspects. This paper presents recommendations for the measurement and analysis of rodent AGD. METHODS: Literature and regulatory guidance documents that mentioned or measured rodent AGD were reviewed. Four adjustment methods were evaluated using available online data from three rat studies each with two generations of offspring. RESULTS: Tabulation of studies reveals that species/stocks and time of data collection, but more importantly anatomical landmarks and methods of measurement have produced a variety of results which are difficult to compare. Not all studies have adjusted for test article effects on body weight (and thus size). The four adjustment methods were fairly comparable. CONCLUSION: Recommendations are as follows. A microscopic method should be used to measure AGD of late rodent fetuses and early postnatal pups. The caudal edge of the genital tubercle and the cranial edge of the anus are clear and identifiable landmarks. The simplest adjustment is to divide individual AGDs by the cube root of animals' body weight. These recommendations will help ensure data consistency and accuracy, and facilitate meaningful comparisons across laboratories and chemical classes.


Assuntos
Canal Anal , Animais , Ratos , Canal Anal/anatomia & histologia , Canal Anal/embriologia , Feminino , Masculino , Gravidez , Roedores/anatomia & histologia , Peso Corporal , Feto/anatomia & histologia , Genitália/anatomia & histologia , Genitália/embriologia
2.
J Obes ; 2024: 7204607, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38831961

RESUMO

Obesity is a complex chronic disease characterized by excess body fat (adipose) that is harmful to health and has been a major global health problem. It may be associated with several diseases, such as nonalcoholic fatty liver disease (NAFLD). Polyunsaturated fatty acids (PUFA) are lipid mediators that have anti-inflammatory characteristics and can be found in animals and plants, with capybara oil (CO) being a promising source. So, we intend to evaluate the hepatic pathophysiological alterations in C57Bl/6 mice with NAFLD, caused by obesity, and the possible beneficial effects of OC in the treatment of this disease. Eighteen 3-month-old male C57Bl/6 mice received a control or high-fat diet for 18 weeks. From the 15th to the 18th week, the animals received treatment-through orogastric gavage-with placebo or free capybara oil (5 g/kg). Parameters inherent to body mass, glucose tolerance, evaluation of liver enzymes, percentage of hepatic steatosis, oxidative stress, the process of cell death with the apoptotic biomarkers (Bax, Bcl2, and Cytochrome C), and the ultrastructure of hepatocytes were analyzed. Even though the treatment with CO was not able to disassemble the effects on the physiological parameters, it proved to be beneficial in reversing the morphological and ultrastructural damage present in the hepatocytes. Thus, demonstrating that CO has beneficial effects in reducing steatosis and the apoptotic pathway, it is a promising treatment for NAFLD.


Assuntos
Apoptose , Fígado , Hepatopatia Gordurosa não Alcoólica , Óleos , Roedores , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/terapia , Masculino , Animais , Camundongos , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Hepatócitos/ultraestrutura , Óleos/farmacologia , Óleos/uso terapêutico , Obesidade/complicações , Apoptose/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/ultraestrutura , Oxirredutases/metabolismo , Ativação Enzimática/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
3.
PLoS One ; 19(6): e0304763, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38848416

RESUMO

Identifying the factors that favor group living is central to studies of animal social behavior. One demographic parameter that is expected to substantially shape spatial and social relationships is population density. Specifically, high population densities may favor group living by constraining opportunities to live alone. In contrast, low densities may allow individuals to spread out within the habitat, leading to a reduction in the prevalence or size of social groups. Abrupt changes in density following natural catastrophic events provide important opportunities to evaluate the effects of population density on patterns of spatial and social organization. As part of long-term studies of the behavioral ecology of a population of highland tuco-tucos (Ctenomys opimus) at Monumento Natural Laguna de los Pozuelos, Jujuy Province, Argentina, we monitored the demographic and behavioral consequences of a flood that inundated our study site during December 2012. Unlike most species of Ctenomys studied to date, highland tuco-tucos are group living, meaning that multiple adults share burrow systems and nest sites. Despite a post-flood reduction in population density of ~75%, animals present on the study site during the 2013 breeding season continued to live in multi-adult social units (groups). No differences between pre- and post-flood home range sizes were detected and although between-unit spatial overlap was reduced in 2013, overlap within social units did not differ from that in pre-flood years. Animals assigned to the same social unit in 2013 had not lived together during 2012, indicating that post-flood groups were not simply the remnants of those present prior to the flood. Collectively, these findings indicate that group living in highland tuco-tucos is not driven by the density of conspecifics in the habitat. In addition to enhancing understanding of the adaptive bases for group living in Ctenomys, our analyses underscore the power of catastrophic events to generate insights into fundamental aspects of social behavior.


Assuntos
Densidade Demográfica , Comportamento Social , Animais , Argentina , Ecossistema , Comportamento Animal/fisiologia , Inundações , Roedores/fisiologia , Feminino , Masculino
4.
Infect Genet Evol ; 121: 105602, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38734397

RESUMO

Hepatitis E, caused by the hepatitis E virus (HEV), is a global public health issue. Low similarity between the gene sequences of mouse and human HEV led to the belief that the risk of human infection was low. Recent reports of chronic and acute hepatitis E caused by murine HEV infection in humans in Hong Kong have raised global concerns. Therefore, it is crucial to investigate the epidemiology and prevalence of HEV in China. We comprehensively analyzed different rodent HEV strains to understand rocahepevirus occurrence in Hubei Province, China. The HEV positivity rate for was 6.43% (73/1136). We identified seven near-full-length rocahepevirus strains and detected rat HEV antigens in tissues from different mouse species. HEV has extensive tissue tropism and a high viral load in the liver. We highlight the genetic diversity of HEVs in rodents and underscore the importance of paying attention to their variation and evolution.


Assuntos
Vírus da Hepatite E , Hepatite E , Filogenia , Vírus da Hepatite E/genética , Vírus da Hepatite E/classificação , Animais , China/epidemiologia , Hepatite E/epidemiologia , Hepatite E/veterinária , Hepatite E/virologia , Prevalência , Camundongos , Roedores/virologia , Ratos , Animais Selvagens/virologia , Variação Genética
5.
Am Nat ; 203(6): 629-643, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38781527

RESUMO

AbstractPopulation-level variation in rodent tail structures has been variously attributed to facilitating social communication, locomotion, thermoregulation, and predator avoidance. Little is known, however, about the applicability of these ecological and social correlates to explaining the tremendous interspecific diversity of this appendage. To investigate the potential drivers of rodent tail morphology at a macroevolutionary level, we first carefully reviewed the literature and constructed a list of major hypotheses regarding this variation. We then compiled a database of 11 different tail traits related to length, color, texture, and ecological characteristics for 2,101 species of rodents (order Rodentia) and examined their key evolutionary correlates. Using Bayesian phylogenetic mixed models across the entire order and additionally within the five rodent suborders, we found that tail length is correlated with both temperature (Allen's rule) and locomotory mode, that black tips are more common in brightly lit environments, that naked tails are often found in warmer climates, that fluffy-tipped tails are more common in smaller and/or arboreal species, that prehensility is predominant in arboreal species and/or species with longer tails, and that tail autotomy is more common in open environments. Most of our tested predictions, largely drawn from population-level studies, are not recapitulated across the entire order, potentially indicating a role of local ecological context in shaping tail morphology.


Assuntos
Evolução Biológica , Roedores , Cauda , Animais , Cauda/anatomia & histologia , Roedores/anatomia & histologia , Roedores/fisiologia , Filogenia , Teorema de Bayes
6.
PLoS Negl Trop Dis ; 18(5): e0012159, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38739673

RESUMO

BACKGROUND: Rodents are recognized as the hosts of many vector-borne bacteria and protozoan parasites and play an important role in their transmission and maintenance. Intensive studies have focused on their infections in vectors, especially in ticks, however, vector-borne bacterial and protozoan infections in rodents are poorly understood although human cases presenting with fever may due to their infection have been found. METHODS: From May to October 2019, 192 wild rodents were trapped in wild environment of Guangxi Province, and the spleen samples were collected to reveal the presence of vector-borne bacterial and protozoan infections in them. The microorganisms in rodents were identified by detecting their DNA using (semi-)nested PCR. All the PCR products of the expected size were subjected to sequencing, and then analyzed by BLASTn. Furthermore, all the recovered sequences were subjected to nucleotide identity and phylogenetic analyses. RESULTS: As a result, 192 rodents representing seven species were captured, and Bandicota indica were the dominant species, followed by Rattus andamanensis. Based on the (semi-)nested PCR, our results suggested that Anaplasma bovis, Anaplasma capra, Anaplasma ovis, Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis", "Candidatus E. hainanensis", "Candidatus E. zunyiensis", three uncultured Ehrlichia spp., Bartonella coopersplainsensis, Bartonella tribocorum, Bartonella rattimassiliensis, Bartonella silvatica, two uncultured Bartonella spp., Babesia microti and diverse Hepatozoon were identified in six rodent species. More importantly, six species (including two Anaplasma, two Bartonella, "Ca. N. mikurensis" and Bab. microti) are zoonotic pathogens except Anaplasma bovis and Anaplasma ovis with zoonotic potential. Furthermore, dual infection was observed between different microorganisms, and the most common type of co-infection is between "Ca. N. mikurensis" and other microorganisms. Additionally, potential novel Bartonella species and Hepatozoon species demonstrated the presence of more diverse rodent-associated Bartonella and Hepatozoon. CONCLUSIONS: The results in this work indicated great genetic diversity of vector-borne infections in wild rodents, and highlighted the potential risk of human pathogens transmitted from rodents to humans through vectors.


Assuntos
Variação Genética , Roedores , Animais , China/epidemiologia , Roedores/microbiologia , Roedores/parasitologia , Filogenia , Animais Selvagens/parasitologia , Animais Selvagens/microbiologia , Anaplasma/genética , Anaplasma/isolamento & purificação , Anaplasma/classificação , Doenças Transmitidas por Vetores/transmissão , Doenças Transmitidas por Vetores/microbiologia , Doenças Transmitidas por Vetores/parasitologia , Doenças Transmitidas por Vetores/epidemiologia , Bartonella/genética , Bartonella/isolamento & purificação , Bartonella/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/classificação , Ratos
7.
Int J Mol Sci ; 25(10)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38791125

RESUMO

The brain is the central organ of adaptation to stress because it perceives and determines threats that induce behavioral, physiological, and molecular responses. In humans, chronic stress manifests as an enduring consistent feeling of pressure and being overwhelmed for an extended duration. This can result in a persistent proinflammatory response in the peripheral and central nervous system (CNS), resulting in cellular, physiological, and behavioral effects. Compounding stressors may increase the risk of chronic-stress-induced inflammation, which can yield serious health consequences, including mental health disorders. This review summarizes the current knowledge surrounding the neuroinflammatory response in rodent models of chronic stress-a relationship that is continually being defined. Many studies investigating the effects of chronic stress on neuroinflammation in rodent models have identified significant changes in inflammatory modulators, including nuclear factor-κB (NF-κB) and toll-like receptors (TLRs), and cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6. This suggests that these are key inflammatory factors in the chronic stress response, which may contribute to the establishment of anxiety and depression-like symptoms. The behavioral and neurological effects of modulating inflammatory factors through gene knockdown (KD) and knockout (KO), and conventional and alternative medicine approaches, are discussed.


Assuntos
Modelos Animais de Doenças , Doenças Neuroinflamatórias , Estresse Psicológico , Animais , Humanos , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/etiologia , Estresse Psicológico/metabolismo , Roedores , Doença Crônica , Citocinas/metabolismo , NF-kappa B/metabolismo , Inflamação/metabolismo
8.
J Comp Neurol ; 532(6): e25631, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38813760

RESUMO

The plains vizcacha, Lagostomus maximus, is a precocial hystricomorph rodent with a gyrencephalic brain. This work aimed to perform a time-lapse analysis of the embryonic brain cortical development in the plains vizcacha to establish a species-specific temporal window for corticogenesis and the gyrencephaly onset. Additionally, a comparative examination with evolutionarily related rodents was conducted. Embryos from 40 embryonic days (ED) until the end of pregnancy ( ∼ $\sim $ 154 ED) were evaluated. The neuroanatomical examination determined transverse sulci at 80 ED and rostral lateral and caudal intraparietal sulci around 95 ED. Histological examination of corticogenesis showed emergence of the subplate at 43 ED and expansion of the subventricular zone (SVZ) and its division into inner and outer SVZs around 54 ED. The neocortical layers formation followed an inside-to-outside spatiotemporal gradient beginning with the emergence of layers VI and V at 68 ED and establishing the final six neocortical layers around 100 ED. A progressive increment of gyrencephalization index (GI) from 1.005 ± 0.003 around 70 ED, which reflects a smooth cortex, up to 1.07 ± 0.009 at the end of gestation, reflecting a gyrencephalic neuroanatomy, was determined. Contrarily, the minimum cortical thickness (MCT) progressively decreased from 61 ED up to the end of gestation. These results show that the decrease in the cortical thickness, which enables the onset of neocortical invaginations, occurs together with the expansion and subdivision of the SVZ. The temporal comparison of corticogenesis in plains vizcacha with that in relative species reflects a prenatal long process compared with other rodents that may give an evolutionary advantage to L. maximus as a precocial species.


Assuntos
Córtex Cerebral , Roedores , Animais , Córtex Cerebral/crescimento & desenvolvimento , Roedores/anatomia & histologia , Feminino , Gravidez , Neurogênese/fisiologia , Neocórtex/crescimento & desenvolvimento
9.
Pediatr Transplant ; 28(4): e14788, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38766977

RESUMO

BACKGROUND: Partial heart transplantation delivers growing heart valve implants by transplanting the part of the heart containing the necessary heart valve only. In contrast to heart transplantation, partial heart transplantation spares the native ventricles. This has important implications for partial heart transplant biology, including the allowable ischemia time, optimal graft preservation, primary graft dysfunction, immune rejection, and optimal immunosuppression. AIMS: Exploration of partial heart transplant biology will depend on suitable animal models. Here we review our experience with partial heart transplantation in rodents, piglets, and non-human primates. MATERIALS & METHODS: This review is based on our experience with partial heart transplantation using over 100 rodents, over 50 piglets and one baboon. RESULTS: Suitable animal models for partial heart transplantation include rodent heterotopic partial heart transplantation, piglet orthotopic partial heart transplantation, and non-human primate partial heart xenotransplantation. DISCUSSION: Rodent models are relatively cheap and offer extensive availability of research tools. However, rodent open-heart surgery is technically not feasible. This limits rodents to heterotopic partial heart transplant models. Piglets are comparable in size to children. This allows for open-heart surgery using clinical grade equipment for orthoptic partial heart transplantation. Piglets also grow rapidly, which is useful for studying partial heart transplant growth. Finally, nonhuman primates are immunologically most closely related to humans. Therefore, nonhuman primates are most suitable for studying partial heart transplant immunobiology and xenotransplantation. CONCLUSIONS: Animal research is a privilege that is contingent on utilitarian ethics and the 3R principles of replacement, reduction and refinement. This privilege allows the research community to seek fundamental knowledge about partial heart transplantation, and to apply this knowledge to enhance the health of children who require partial heart transplants.


Assuntos
Transplante de Coração , Modelos Animais , Transplante Heterólogo , Transplante de Coração/métodos , Animais , Suínos , Papio , Humanos , Rejeição de Enxerto/imunologia , Transplante Heterotópico , Ratos , Modelos Animais de Doenças , Roedores
10.
Cells ; 13(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38727278

RESUMO

Spermatogenesis involves a complex process of cellular differentiation maintained by spermatogonial stem cells (SSCs). Being critical to male reproduction, it is generally assumed that spermatogenesis starts and ends in equivalent transcriptional states in related species. Based on single-cell gene expression profiling, it has been proposed that undifferentiated human spermatogonia can be subclassified into four heterogenous subtypes, termed states 0, 0A, 0B, and 1. To increase the resolution of the undifferentiated compartment and trace the origin of the spermatogenic trajectory, we re-analysed the single-cell (sc) RNA-sequencing libraries of 34 post-pubescent human testes to generate an integrated atlas of germ cell differentiation. We then used this atlas to perform comparative analyses of the putative SSC transcriptome both across human development (using 28 foetal and pre-pubertal scRNA-seq libraries) and across species (including data from sheep, pig, buffalo, rhesus and cynomolgus macaque, rat, and mouse). Alongside its detailed characterisation, we show that the transcriptional heterogeneity of the undifferentiated spermatogonial cell compartment varies not only between species but across development. Our findings associate 'state 0B' with a suppressive transcriptomic programme that, in adult humans, acts to functionally oppose proliferation and maintain cells in a ready-to-react state. Consistent with this conclusion, we show that human foetal germ cells-which are mitotically arrested-can be characterised solely as state 0B. While germ cells with a state 0B signature are also present in foetal mice (and are likely conserved at this stage throughout mammals), they are not maintained into adulthood. We conjecture that in rodents, the foetal-like state 0B differentiates at birth into the renewing SSC population, whereas in humans it is maintained as a reserve population, supporting testicular homeostasis over a longer reproductive lifespan while reducing mutagenic load. Together, these results suggest that SSCs adopt differing evolutionary strategies across species to ensure fertility and genome integrity over vastly differing life histories and reproductive timeframes.


Assuntos
Espermatogônias , Humanos , Animais , Masculino , Espermatogônias/citologia , Espermatogônias/metabolismo , Células-Tronco Germinativas Adultas/metabolismo , Células-Tronco Germinativas Adultas/citologia , Diferenciação Celular/genética , Espermatogênese/genética , Transcriptoma/genética , Adulto , Camundongos , Feto/citologia , Testículo/citologia , Testículo/metabolismo , Roedores , Ratos , Análise de Célula Única
11.
Front Endocrinol (Lausanne) ; 15: 1390203, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38803478

RESUMO

Vasopressin and oxytocin are well known and evolutionarily ancient modulators of social behavior. The distribution and relative densities of vasopressin and oxytocin receptors are known to modulate the sensitivity to these signaling molecules. Comparative work is needed to determine which neural networks have been conserved and modified over evolutionary time, and which social behaviors are commonly modulated by nonapeptide signaling. To this end, we used receptor autoradiography to determine the distribution of vasopressin 1a and oxytocin receptors in the Southern giant pouched rat (Cricetomys ansorgei) brain, and to assess the relative densities of these receptors in specific brain regions. We then compared the relative receptor pattern to 23 other species of rodents using a multivariate ANOVA. Pouched rat receptor patterns were strikingly similar to hamsters and voles overall, despite the variation in social organization among species. Uniquely, the pouched rat had dense vasopressin 1a receptor binding in the caudate-putamen (i.e., striatum), an area that might impact affiliative behavior in this species. In contrast, the pouched rat had relatively little oxytocin receptor binding in much of the anterior forebrain. Notably, however, oxytocin receptor binding demonstrated extremely dense binding in the bed nucleus of the stria terminalis, which is associated with the modulation of several social behaviors and a central hub of the social decision-making network. Examination of the nonapeptide system has the potential to reveal insights into species-specific behaviors and general themes in the modulation of social behavior.


Assuntos
Encéfalo , Receptores de Ocitocina , Receptores de Vasopressinas , Animais , Receptores de Ocitocina/metabolismo , Receptores de Vasopressinas/metabolismo , Masculino , Encéfalo/metabolismo , Roedores/metabolismo , Ratos , Especificidade da Espécie , Autorradiografia , Arvicolinae/metabolismo , Ocitocina/metabolismo , Cricetinae , Comportamento Social , Feminino
12.
Zoology (Jena) ; 164: 126171, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38761613

RESUMO

Estrogens, acting through their receptors (ERα and ERß), regulate cell turnover in the pituitary gland, influencing cell proliferation and apoptosis across various species. However, their role in pituitary processes in seasonally reproducing animals remains poorly understood. This study aims to investigate the influence of estrogens, through the expression of their specific receptors, on the apoptosis of PD cells in relation to sexual maturity, the reproductive cycle, and pregnancy in a seasonal reproductive rodent (Lagostomus maximus maximus). ERα and caspase-3-cleaved (CASP3c) immunoreactive (-ir) cells were identified through immunohistochemistry. Apoptotic cells were detected using the TUNEL technique, with quantitative analysis facilitated by image analysis software, alongside measurement of serum estradiol levels using radioimmunoassay The immunostaining pattern for ERα included nuclear (ERαn) and cytoplasmic (ERαc) staining. In male viscachas, ERα expression significantly increases from immature to adult animals, correlating with the rise in serum estradiol levels and a decrease in the percentage of apoptotic cells. During the gonadal regression period in adult males, a decrease in the number of ER-ir cells and serum levels of estradiol corresponds with an increase in the number of apoptotic cells. In females, serum levels of estradiol peaked during mid-pregnancy, coinciding with a significant decrease in the number of apoptotic cells in the PD. Simultaneously, the percentage of ERαn-ir cells reaches its maximum value during late pregnancy, indicating the need to maintain the protective action of this gonadal hormone throughout the extensive pregnancy in these rodents. Regional ERα receptor expression and apoptotic cells appear to be associated with distinct PD cell populations and their hormonal responses. Finally, elevated estradiol levels coincide with diminished apoptotic cells in the male reproductive cycle and during pregnancy, suggesting an antiapoptotic role of estradiol in this species.


Assuntos
Apoptose , Estrogênios , Hipófise , Roedores , Animais , Feminino , Masculino , Roedores/fisiologia , Estrogênios/metabolismo , Estrogênios/sangue , Hipófise/metabolismo , Gravidez , Regulação da Expressão Gênica , Estradiol/sangue , Estradiol/metabolismo
13.
PLoS One ; 19(5): e0301685, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38748697

RESUMO

Amblyomma ticks are vectors of both Rickettsia rickettsii and R. parkeri in the Americas, where capybaras (Hydrochoerus hydrochaeris) are the main hosts in urban areas, thus contributing to the transmission of spotted fever. Herein, we studied: (i) the seasonal dynamics and abundance of ticks in areas where capybaras live, (ii) the effect of environmental variables on tick abundance, and (iii) the presence of Rickettsia-infected ticks. Between September 2021 and September 2022, we sampled ticks using cloth-dragging at 194 sites on the shore of Lake Paranoá in Brasília, Brazil. We measured environmental data (season, vegetation type, canopy density, temperature, humidity, and presence or vestige of capybara) at each site. Nymphs and adults were morphologically identified to the species level, and a selected tick sample including larvae was subjected to genotypic identification. We investigated Rickettsia-infected ticks by PCR (gltA, htrA, ompB, and ompA genes) and associations between tick abundance and environmental variables using Generalized Linear Models. A total of 30,334 ticks (96% larvae) were captured. Ticks were identified as Amblyomma, with A. sculptum comprising 97% of the adult/nymphs. Genotype identification of a larval sample confirmed that 95% belonged to A. dubitatum. Seasonal variables showed significant effects on tick abundance. Most larvae and nymphs were captured during the early dry season, while the adults were more abundant during the wet season. Vegetation variables and the presence of capybaras showed no association with tick abundance. Rickettsia parkeri group and R. bellii were identified in A. dubitatum, while A. sculptum presented R. bellii. We conclude that: (i) Amblyomma ticks are widely distributed in Lake Paranoá throughout the year, especially larvae at the dry season, (ii) the abundance of Amblyomma ticks is explained more by climatic factors than by vegetation or presence of capybaras, and (iii) A. dubitatum ticks are potential vectors of R. parkeri in Brasília.


Assuntos
Amblyomma , Rickettsia , Estações do Ano , Animais , Rickettsia/genética , Rickettsia/isolamento & purificação , Brasil , Amblyomma/microbiologia , Ninfa/microbiologia , Larva/microbiologia , Infecções por Rickettsia/transmissão , Infecções por Rickettsia/microbiologia , Vetores Aracnídeos/microbiologia , Roedores/microbiologia , Roedores/parasitologia , Meio Ambiente
14.
Sci Rep ; 14(1): 11220, 2024 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755206

RESUMO

The corpus luteum (CL) is a transient endocrine gland that plays a crucial role in establishing and maintaining pregnancy. Although autophagy and apoptosis have been suggested as cooperative mechanisms, their interaction within the CL of pregnant mammals has not been thoroughly investigated. To understand the collaborative function of autophagy and apoptosis in the CL, we analyzed both mechanisms during pregnancy in the South American plains vizcacha, Lagostomus maximus. This rodent undergoes a decline in progesterone levels during mid-gestation, a reactivation of the hypothalamus-hypophysis-gonadal axis, and the incorporation of new functional secondary CL. Our analysis of autophagy markers BECLIN 1 (BECN1), SEQUESTOSOME1 (SQSTM1), Microtubule-associated protein light chain 3 (LC3B), and lysosomal-associated membrane protein 1 (LAMP1) and anti- and pro-apoptotic markers BCL2 and ACTIVE CASPASE 3 (A-C3) revealed interactive behaviors between both processes. Healthy primary and secondary CL exhibited positive expression of BECN1, SQSTM1, LC3B, and LAMP1, while regressed CL displayed enhanced expression of these autophagy markers along with nuclear A-C3. Transmission electron microscopy revealed a significant formation of autophagic vesicles in regressed CL during full-term pregnancy, whereas healthy CL exhibited a low number of autophagy vesicles. The co-localization between LC3B and SQSTM1 and LC3B with LAMP1 was observed in both healthy and regressed CL during pregnancy, while co-localization of BECN1 and BCL2 was only detected in healthy CL. LC3B and ACTIVE CASPASE 3 co-localization were detected in a subset of luteal cells within the regressing CL. We propose that autophagy could act as a survival mechanism in the CL, allowing the pregnancy to progress until full-term, while also serving as a mechanism to eliminate remnants of regressed CL, thereby providing the necessary space for subsequent follicular maturation.


Assuntos
Apoptose , Autofagia , Corpo Lúteo , Roedores , Feminino , Animais , Gravidez , Corpo Lúteo/metabolismo
15.
Cryo Letters ; 45(2): 134-138, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38557992

RESUMO

BACKGROUND: Examining semen cryopreservation in Calomys laucha offers valuable insights for reproductive research and species conservation. OBJECTIVE: To determine the most effective sugar for the cryopreservation of C. laucha semen. MATERIALS AND METHODS: Using 36 epididymides from C. laucha, semen samples were diluted in a 3% skimmed milk medium supplemented with one of four sugars (glucose, fructose, lactose, or sucrose) at a concentration of 0.3 M. These mixtures underwent a conditioning phase at 37 degree C for 10 min, cooled to -80 degree C for another 10 min, and were subsequently stored in liquid nitrogen. RESULTS: Upon thawing, samples treated with lactose and glucose solutions show superior sperm motility, achieving 8.2% and 10.0% respectively, in contrast to the fructose (2.0%) and sucrose (4.1%) mixtures. Furthermore, samples preserved in glucose registered the highest sperm penetration rates, reaching 44.9%. CONCLUSION: Our findings suggest that a cryopreservation medium containing 0.3 M glucose can contribute to the safeguarding C. laucha rodent semen. https://doi.org/10.54680/fr24210110612.


Assuntos
Preservação do Sêmen , Sêmen , Animais , Masculino , Criopreservação , Lactose , Roedores , Motilidade dos Espermatozoides , Glucose/farmacologia , Frutose , Sacarose/farmacologia , Espermatozoides , Crioprotetores
16.
J Pineal Res ; 76(3): e12950, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38558122

RESUMO

Homeobox genes encode transcription factors that are widely known to control developmental processes. This is also the case in the pineal gland, a neuroendocrine brain structure devoted to nighttime synthesis of the hormone melatonin. Thus, in accordance with high prenatal gene expression, knockout studies have identified a specific set of homeobox genes that are essential for development of the pineal gland. However, as a special feature of the pineal gland, homeobox gene expression persists into adulthood, and gene product abundance exhibits 24 h circadian rhythms. Recent lines of evidence show that some homeobox genes even control expression of enzymes catalyzing melatonin synthesis. We here review current knowledge of homeobox genes in the rodent pineal gland and suggest a model for dual functions of homeobox gene-encoded transcription factors in developmental and circadian mature neuroendocrine function.


Assuntos
Melatonina , Glândula Pineal , Animais , Glândula Pineal/metabolismo , Genes Homeobox , Melatonina/metabolismo , Roedores/genética , Roedores/metabolismo , Fatores de Transcrição/metabolismo , Ritmo Circadiano
17.
Environ Monit Assess ; 196(4): 407, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38561512

RESUMO

Small mammals have a short lifetime and are strictly associated with their environment. This work aimed to use histopathology to assess the health of Holochilus chacarius in a rice agroecosystem in the Pantanal of Mato Grosso do Sul. During necropsy, fragments of the lung, kidney, skin, liver, and reproductive system of 33 animals were collected and submitted to histological processing. Tissue damages were evaluated as mild, moderate, and severe and arranged in a matrix for further statistical analysis. Furthermore, we used generalized linear models to verify the influence of tissue changes on the body condition, obtained by a regression between body mass and length. In the lungs, we found an intense inflammatory infiltrate associated with anthracosis that had a negative influence on the body's condition. Also, we observed degenerative and inflammatory changes in the liver, kidneys, skin, and reproductive system that ranged from mild to moderate. The histopathological lesions observed in this study may be associated with environmental alterations of anthropic origin such as the exposure to soot from wildfires and heavy metals, evidenced by lesions in the lung, kidney, and liver. The present study provided a histopathological matrix as a new approach that allows to classify and quantify the tissue alterations. Tissue changes when associated with body condition demonstrated to be an effective tool to assess the health of small free-living mammals, showing that these animals can be used as bioindicators of environmental condition.


Assuntos
Oryza , Roedores , Animais , Arvicolinae , Áreas Alagadas , Monitoramento Ambiental , Sigmodontinae
18.
Front Neural Circuits ; 18: 1286111, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638163

RESUMO

Cognitive control of behavior is crucial for well-being, as allows subject to adapt to changing environments in a goal-directed way. Changes in cognitive control of behavior is observed during cognitive decline in elderly and in pathological mental conditions. Therefore, the recovery of cognitive control may provide a reliable preventive and therapeutic strategy. However, its neural basis is not completely understood. Cognitive control is supported by the prefrontal cortex, structure that integrates relevant information for the appropriate organization of behavior. At neurophysiological level, it is suggested that cognitive control is supported by local and large-scale synchronization of oscillatory activity patterns and neural spiking activity between the prefrontal cortex and distributed neural networks. In this review, we focus mainly on rodent models approaching the neuronal origin of these prefrontal patterns, and the cognitive and behavioral relevance of its coordination with distributed brain systems. We also examine the relationship between cognitive control and neural activity patterns in the prefrontal cortex, and its role in normal cognitive decline and pathological mental conditions. Finally, based on these body of evidence, we propose a common mechanism that may underlie the impaired cognitive control of behavior.


Assuntos
Encéfalo , Roedores , Animais , Humanos , Idoso , Córtex Pré-Frontal/fisiologia , Neurônios/fisiologia , Cognição/fisiologia
19.
Anat Histol Embryol ; 53(3): e13043, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38666620

RESUMO

Capybara is considered the largest living rodent and is widespread distributed in the South America and in the Brazilian territory. The purpose of this study was to provide the anatomical description of the brain in the capybara (Hydrochoerus hydrochaeris) using magnetic resonance imaging (MRI). Brains of ten normal capybaras were imaged and sectioned in the anatomical studies. MRI was acquired on 0.25 Tesla equipment, promoting good-quality images capable to identify and classify the main anatomical structures of clinical interest. MRI reference images were validated by comparing them with gross anatomical sections. The capybara sulci and gyri were named for its similar location and orientation to those described in the previous descriptions in the capybara and in the domestic dog. Capybaras presented prominent cerebral sulcus and gyrus in relation to other caviomorph rodents, but in reduced number when compared to domestic animals and other wild mammals such as elephants and giraffes. The findings of this study indicate that the shape of the capybara brain is remarkably similar to that of the caviomorph rodents with a higher neocortilization. The capybara rhinencephalon was well-developed implying a good sense of smell. Due to this development of the rhinencephalon, we can suggest that capybara brain is a macrosmatic brain. The MRI and gross anatomical sections of capybara brain may help veterinary researchers and clinicians increase the accuracy of brain MRI scans interpretation in these animals.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Roedores , Animais , Roedores/anatomia & histologia , Imageamento por Ressonância Magnética/veterinária , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Masculino , Feminino
20.
Sci Rep ; 14(1): 8956, 2024 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637569

RESUMO

As known "ecosystem engineers", beavers influence river hydrology, geomorphology, biochemistry, and biological assemblages. However, there is a lack of research regarding the effects of beaver activities on freshwater meiofauna. In this study, we investigated the taxonomic and functional composition of the benthic copepod assemblage of a segment of the Tiber River (Italy) where a beaver dam, created about 7 weeks before our survey, had formed a semi-lentic habitat upstream and a lotic habitat downstream of the dam. We also analyzed the copepod assemblage before and after a flood event that destroyed the beaver dam, providing a unique opportunity to observe changes in a naturally reversing scenario. Our analyses revealed that, while the taxonomic composition and functional traits of the copepod assemblage remained largely unchanged across the recently formed semi-lentic and lotic habitats, substantial differences were evident between the dammed and undammed states. The dammed state showed lower copepod abundances, biomass, and functionality than the undammed one. These results highlight the role of beaver dams in changing the composition and functionality of meiofaunal assemblages offering insights into the dynamic interactions within aquatic ecosystems.


Assuntos
Copépodes , Ecossistema , Animais , Roedores , Rios , Biomassa
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