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1.
J Insect Physiol ; 150: 104570, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37806552

RESUMEN

Mating induces behavioral and physiological changes in female insects-collectively referred to as the female post-mating response (PMR)-that facilitate the production of progeny. PMRs are elicited by transfer of male-derived seminal components during mating, but are altered by other factors, including adult age. Increased female age is often accompanied by declines in fertility. However, mating shortly after emergence also impacts fertility in the insect model Drosophila melanogaster. Here, we determined the age post-emergence when females of the vector mosquito Aedes aegypti can be inseminated and blood-feed. We next examined fecundity, fertility, and the storage of sperm in the female reproductive tract in "young" (30-41 hours-old) and "old" (2- and 3-week-old) females, finding that blood-feeding began at 14 hours, and mating at ∼24 hours post-emergence. Although young females consumed smaller blood quantities and stored fewer sperm, they were similarly fertile to 4-day-old controls. Old females, however, suffered significant declines in fecundity by 2 weeks of age. Our results show that female Ae. aegypti start to become sexually receptive 1 day after their emergence, but can ingest blood much sooner, suggesting that mating is not a prerequisite to blood-feeding, and that females can ingest an arbovirus infected blood-meal shortly after emergence.


Asunto(s)
Aedes , Dengue , Masculino , Femenino , Animales , Aedes/fisiología , Drosophila melanogaster , Semen , Mosquitos Vectores/fisiología , Fertilidad , Inseminación , Espermatozoides/fisiología
2.
Insect Sci ; 30(4): 1183-1190, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36395351

RESUMEN

Promiscuous mating systems provide the opportunity for females to bias fertilization toward particular males. However, distinguishing between male sperm competition and active female sperm choice is difficult for species with internal fertilization. Nevertheless, species that store and use sperm of different males in different storing structures and species where females are able to expel all or part of the ejaculates after copulation may be able to bias fertilization. We report a series of experiments aimed at providing evidence of female sperm choice in Euxesta eluta (Hendel), a species of ulidiid fly that expels and consumes ejaculates after copulation. We found no evidence of greater reproductive success for females mated singly, multiply with the same male, or mated multiply with different males. Female E. eluta possesses two spherical spermathecae and a bursa copulatrix for sperm storage, with a ventral receptacle. There was no significant difference in storing more sperm in spermathecae 24 h after copulation than immediately after copulation. Females mated with protein-fed males had greater reproductive success than similar females mated to protein-deprived males. Protein-fed females prevented to consume the ejaculate, retained more sperm when mated to protein-fed males than when mated to protein-deprived males. Our results suggest that female E. eluta can exert control of sperm retention of higher quality males through ejaculate ejection.


Asunto(s)
Dípteros , Masculino , Femenino , Animales , Semen , Espermatozoides , Copulación , Reproducción , Conducta Sexual Animal
3.
Front Genet ; 12: 795669, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34899871

RESUMEN

Bumblebee queens have remarkable spermathecae that store sperm for year-round reproduction. The spermathecal gland is regarded as a secretory organ that could benefit sperm storage. Queen mating provokes substantial physiological, behavioral, and gene expression changes. Here, the transcriptomes of spermathecae were compared between virgins and mated queens of the bumblebee, Bombus terrestris L., at 24 h post mating. Differentially expressed genes were further validated by real time quantitative PCR and immunofluorescence assay. In total, the expression of 11, 069 and 10, 862 genes were identified in virgins and mated queens, respectively. We identified that 176 differentially expressed genes between virgin and mated queen spermathecae: 110 (62.5%) genes were upregulated, and 66 (37.5%) genes were downregulated in mated queens. Most of the differentially expressed genes validated by RT-qPCR were concentrated on immune response [i.e., leucine-rich repeat-containing protein 70 (35.8-fold), phenoloxidase 2 (41.9-fold), and defensin (4.9-fold)] and sperm storage [i.e., chymotrypsin inhibitor (6.2-fold), trehalose transporter Tret1 (1.7-, 1.9-, 2.4-, and 2.4-fold), and heterogeneous nuclear ribonucleoprotein A3 (1.2-, and 2.6-fold)] functions in the spermathecae of mated queens. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) was hypothesized to promote the mating behavior according to RT-qPCR and immunofluorescence assay. The expression levels of most upregulated immune genes were decreased significantly at 3 days post mating. In conclusion, the external sperm transfer into spermathecae led to the significantly upregulated immune response genes in bumblebees. These gene expression differences in queen spermathecae contribute to understanding the bumblebee post mating regulatory network.

4.
Front Zool ; 18(1): 19, 2021 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-33902650

RESUMEN

BACKGROUND: Mating generally occurs after individuals reach adulthood. In many arthropods including spiders, the adult stage is marked by a final moult after which the genitalia are fully developed and functional. In several widow spider species (genus Latrodectus), however, immature females may mate a few days before they moult to adulthood, i.e. in their late-subadult stage. While the "adult" mating typically results in cannibalism, males survive the "immature" mating. During both "immature" and "adult" matings, males leave parts of their paired copulatory organs within female genitalia, which may act as mating plugs. To study potential costs and benefits of the two mating tactics, we investigated female genital morphology of the brown widow spider, L. geometricus. Light microscopy, histology and micro-computed tomography of early-subadult, late-subadult and adult females were conducted to determine the overall pattern of genital maturation. We compared genitalia of mated late-subadult and adult females to reveal potential differences in the genitalic details that might indicate differential success in sperm transfer and different environments for sperm storage and sperm competition. RESULTS: We found that the paired sperm storage organs (spermathecae) and copulatory ducts are developed already in late-subadult females and host sperm after immature mating. However, the thickness of the spermathecal cuticle and the staining of the secretions inside differ significantly between the late-subadult and adult females. In late-subadult females mating plugs were found with higher probability in both spermathecae compared to adult females. CONCLUSIONS: Sperm transfer in matings with late-subadult females follows the same route as in matings with adult females. The observed differences in the secretions inside the spermathecae of adult and late-subadult females likely reflect different storage conditions for the transferred sperm which may lead to a disadvantage under sperm competition if the subadult female later re-mates with another male. However, since males mating with late-subadult females typically transfer sperm to both spermathecae they might benefit from numerical sperm competition as well as from monopolizing access to the female sperm storage organs. The assessment of re-mating probability and relative paternity will clarify the costs and benefits of the two mating tactics in light of these findings.

5.
BMC Evol Biol ; 20(1): 159, 2020 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-33256600

RESUMEN

BACKGROUND: Sperm storage plays a key role in the reproductive success of many sexually-reproducing organisms, and the capacity of long-term sperm storage varies across species. While there are theoretical explanations for why such variation exists, to date there are no controlled empirical tests of the reproductive consequences of additional long-term sperm storage. While Dipterans ancestrally have three long-term sperm organs, known as the spermathecae, Drosophila contain only two. RESULTS: We identified a candidate gene, which we call spermathreecae (sp3), in which a disruption cause the development of three functional spermathecae rather than the usual two in Drosophila. We used this disruption to test the reproductive consequences of having an additional long-term sperm storage organ. Compared to females with two spermathecae, females with three spermathecae store a greater total number of sperm and can produce offspring a greater length of time. However, they did not produce a greater total number of offspring. CONCLUSIONS: Thus, additional long-term sperm storage in insects may increase female fitness through extending the range of conditions where she produces offspring, or through increasing the quality of offspring via enhanced local sperm competition at fertilization.


Asunto(s)
Drosophila melanogaster/anatomía & histología , Drosophila melanogaster/citología , Espermatozoides/fisiología , Animales , Femenino , Masculino , Reproducción/fisiología , Espermatozoides/citología , Factores de Tiempo
6.
Integr Comp Biol ; 2020 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-32805033

RESUMEN

Most arachnid fertilization occurs internally, allowing for a variety of post-copulatory mechanisms to take place. Females are expected to exert some level of control over sperm fate when 1) the point of gametic fusion is particularly distant from the point of oogenesis, 2) the time of syngamy is significantly later than the time of mating, 3) sperm are non-motile, and/or 4) the morphology of females allows for selective containment of sperm. Many of these conditions are met in Opiliones (a.k.a. "harvesters," "harvestmen," or "daddy-longlegs"), where we have evidence of sexual antagonism, multiple mating, and delayed oviposition for a number of species. We used confocal laser scanning microscopy to capture and analyze images of harvester spermathecae, structures within the genitalia of female arthropods that store and maintain sperm after copulation. Spermathecal morphology may have critical function in controlling seminal movement. We anticipated that species with previously identified traits associated with sexual antagonism would also have thicker and/or relatively more complex spermathecae. We examined spermathecal morphology in thirteen species of Leiobunum and one species of Hadrobunus, which were collected from North America and Japan. Our results show that eight species had structures consisting of a single chamber with no or partial invagination, and the remainder had multiple cuticular invaginations producing 2-3 lumina within the spermathecae. Using phylogenetic multivariate comparative methods, we estimated a trend towards cross-correlation between conflict and spermathecal traits. Some, but not all, of the species with thicker, more complex spermathecae had morphological traits associated with sexual conflict (larger body size, thicker genital muscle). In conclusion, we discuss methods to elucidate spermathecal mechanism and sperm precedence in these species. Confocal microscopy allowed us to visualize internal structures difficult to interpret with two-dimensional brightfield microscopy, a technique that could be applied to the characterization of internal reproductive structures in other arthropods.

7.
Saudi J Biol Sci ; 26(7): 1581-1586, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31762630

RESUMEN

The current study aimed to investigate the important reproductive biology and morphology of A.m. jemenitica queens and drones through measuring the weight of virgin and mated queens, size and weight of spermathecae, weight of ovaries, number of ovarioles, quantity and viability of semen in queen and drones. Accordingly, the average weights of 0.139 ±â€¯0.01 g and 0.143 ±â€¯0.013 g recorded for virgin and mated queens respectively. The sizes of spermathecae were 1.248 ±â€¯0.103 mm and 1.25 ±â€¯0.022 mm for virgin and mated queens respectively. The mean weight of ovaries was 0.013 ±â€¯0.003 g and the numbers of ovarioles varied from 124 to 163 with the mean of 142.9 ±â€¯9.47 and with no significant difference between virgin and mated queens. The average number of stored sperm per spermathecae of mated queen was estimated to be 4.202 ±â€¯0.613 million with the viability of 80.39%. The average number of sperm per drone recorded was 8,763,950 ±â€¯1,633,203.15 with viability of 79.54 ±â€¯6.70%. In general, the current study revealed that the values recorded for reproductive biology and morphological characters of A. m. jemenitica queens and drones were relatively lower than values recorded for other Apis mellifera races. This mainly could be associated with the body size of the race which is known to be the smallest race among A. mellifera races. Moreover, the harsh environmental conditions of the regions, high temperature, low humidity and limited resources may have contributed for the smaller biological and morphological values. The information will serve as a base in future selection and breeding of program of the race.

8.
J Med Entomol ; 56(2): 334-340, 2019 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-30668724

RESUMEN

The mosquitoes Aedes aegypti (L.) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) are ecologically similar species that have evolved independently in their native ranges, Ae. aegypti in Africa and Ae. albopictus in Asia. Where their invasive ranges overlap, interspecific mating is facilitated by both species swarming to mate around bloodmeal hosts during daylight. Here, we test hypotheses to account for variation in spermathecal filling in females of Ae. aegypti and Ae. albopictus, particularly, the effect of mosquito size on the number of spermathecae containing sperm after intraspecific and interspecifc matings of these two species. Results show that significantly more spermathecae contained sperm in large than in small Ae. albopictus females, but there was no effect of Ae. aegypti female body size on the average number of spermathecae filled. Among inseminated females, there was no effect of male size or cross-type on number of spermathecae with sperm. Differences in the effect of female size on the number of spermathecae that store sperm in Ae. aegypti and Ae. albopictus imply differences in the mating biology of these two species.


Asunto(s)
Aedes/fisiología , Conducta Sexual Animal/fisiología , Animales , Tamaño Corporal , Femenino , Hibridación Genética , Masculino , Especificidad de la Especie
9.
Bull Entomol Res ; 109(4): 544-549, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30514413

RESUMEN

The coffee berry borer, Hypothenemus hampei (Ferrari), can survive in residual coffee berries during the inter-harvest period, while new fructification only appears 2-3 months after the last harvest. The dispersal of colonizing females is an adaptation that enables the life cycle of the species to go ahead whenever his flight aptitude allows. This paper focuses on accurately determining the rate of inseminated females ready to reproduce when emerging from residuals berries to colonize new ones, which constitutes a characteristic of the live cycle far from common in Curculionidae. We dissected females caught in traps baited with a mixture of alcohols during the inter-harvest season, females from infested residual berries collected from branches, and virgin females obtained from pupae reared individually in the laboratory. After microscopic preparation with Giemsa stain, spermathecae were observed to identify the physiological status of each specimen. Out of the females found in the traps, 98.4% displayed recent and abundant insemination and 1.6% sporadic insemination. In contrast, in residual berries, most of females were recently inseminated (84.5%), followed by virgin females (10.5%) and older inseminated females (5%). In addition, the flight tests of the virgin females were negative. These results indicate that all colonizing females were inseminated, ready for flying and oviposition, females inside residual berries showed different physiological status, and virgin females could not migrate since they could not flight. The large number of inseminated females inside the residual berries, and the capacity of migrating females to colonize and reproduce, suggest that it is necessary to control residual berries and use traps to stop the dispersal and reproduction of this pest.


Asunto(s)
Coffea/crecimiento & desarrollo , Producción de Cultivos , Gorgojos/fisiología , Animales , Femenino , Inseminación , México , Reproducción , Estaciones del Año
10.
J Econ Entomol ; 111(1): 491-494, 2018 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-29182772

RESUMEN

The monitoring of a pest population often relies on the identification of individuals from traps. For area-wide programs utilizing the sterile insect technique, the further identification of the mated status of females found in traps is of utmost importance. For the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), this is usually verified through the assessment of sperm in the spermathecae. However, this can be misleading for species where there are other sperm storage organs such as the ventral receptacle. Here, we studied the relative importance of sperm storage in the ventral receptacle compared to the spermathecae for females from 5 to 18 d of age. Furthermore, we studied how sperm can be identified in the ventral receptacle or spermathecae after females were recovered from traps. We found no effect of female age on likelihood of sperm storage. Sperm could be identified in both sperm storage organs at 7 or 14 d after females had been placed in traps. We found that the ventral receptacle is a more reliable indicator of female mated status. Thus, we propose that if no sperm are found in the spermathecae, program managers should revise the ventral receptacle before assuming that females are not mated. This test may also be relevant to other pest tephritids that store even more sperm in the ventral receptacle than C. capitata.


Asunto(s)
Ceratitis capitata/fisiología , Conducta Sexual Animal , Espermatozoides/fisiología , Factores de Edad , Animales , Femenino , Control de Insectos , Masculino , Reproducción , Factores de Tiempo
11.
Acta Trop ; 176: 440-445, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28859957

RESUMEN

Trypanosoma cruzi, the etiological agent of Chagas disease, is transmitted by triatomines that have been described in a large number of studies. Most of those studies are related to external morphology and taxonomy, but some biochemical, genetic and physiological studies have also been published. There are a few publications in the literature about the internal organs of Triatominae, for instance the spermathecae, which are responsible for storing and maintaining the viability of the spermatozoids until the fertilization of the oocytes. This work aims to study the spermathecae of twelve species of triatomines obtained from the Triatominae Insectarium of the Faculty of Pharmaceutical Sciences, UNESP, Araraquara, using optical microscopy and scanning electron microscopy. The spermathecae of the twelve species studied showed three morphological patterns: a) P. herreri sn, P. lignarius, P. megistus, Triatoma brasiliensis, T. juazeirensis, T. sherlocki and T. tibiamaculata have spermathecae with a thin initial portion and an oval-shaped final portion; b) R. montenegrensis, R. nasutus, R. neglectus, R. pictipes and R. prolixus have tubular and winding spermathecae; c) T. infestans has oval spermathecae. In addition to the three morphological patterns, it was noted that each of the twelve species has particular features that differentiate them.


Asunto(s)
Genitales/anatomía & histología , Insectos Vectores/anatomía & histología , Triatominae/anatomía & histología , Animales , Enfermedad de Chagas/transmisión , Femenino , Triatoma/anatomía & histología
12.
Bull Environ Contam Toxicol ; 99(3): 297-302, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28748329

RESUMEN

High honey bee losses around the world have been linked in part by the regular use of neonicotinoids in agriculture. In light of the current situation, the aim of this study was to investigate the effects of thiamethoxam on the development of the reproductive system and physiology in the honey bee queen. Two experimental groups of honey bee queen larvae were treated with thiamethoxam during artificial rearing, applied via artificial feed in two cycles. In the first rearing cycle, honey bee larvae received a single treatment dose (4.28 ng thiamethoxam/queen larva on the 4th day after larvae grafting in artificial queen cells), while the second honey bee queen rearing cycle received a double treatment dose (total of 8.56 ng thiamethoxam/queen larva on the 4th and 5th day after larvae grafting in artificial queen cells). After emerging, queens were anesthetized and weighed, and after mating with drones were anesthetized, weighed, and sectioned. Ovary mass and number of stored sperm were determined. Body weight differed between untreated and treated honey bee queens. The results also show a decrease in the number of sperm within honey bee queen spermathecae that received the double thiamethoxam dose.


Asunto(s)
Abejas , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Nitrocompuestos/toxicidad , Oxazinas/toxicidad , Tiazoles/toxicidad , Animales , Femenino , Larva/efectos de los fármacos , Masculino , Reproducción/efectos de los fármacos , Espermatozoides/fisiología , Tiametoxam
13.
J Morphol ; 278(7): 907-918, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28401572

RESUMEN

Sperm storage within the female reproductive tract has been reported as a reproductive strategy in several species of vertebrates and invertebrates. However, the morphological structures that allow for sperm to be stored and kept viable for long periods are relatively unknown in osteichthyes. We use histological and stereological tools to identify and quantify sperm storage structures (spermathecae) in 12 species of viviparous Poeciliidae. We found spermathecae in nine species, six of which exhibit superfetation (the ability of females to simultaneously carry within the ovary two or more broods of embryos at different stages of development). These spermathecae are folds of ovarian tissue that close around spermatozoa. We compared the number and size (volume) of spermathecae between species with and without superfetation. Species that exhibit superfetation had a significantly higher number of spermathecae than species that do not exhibit this reproductive strategy. In addition, we found that the mean volume of spermathecae and total volume of spermathecae present in the ovary are marginally higher in species with superfetation. Our results contribute to the understanding of the morphological structures that allow for sperm storage in viviparous osteichthyes and suggest a positive relationship between superfetation and the capacity of females to store sperm.


Asunto(s)
Ciprinodontiformes/anatomía & histología , Espermatozoides/citología , Superfetación , Animales , Femenino , Análisis de los Mínimos Cuadrados , Masculino , Ovario/citología , Filogenia , Embarazo , Especificidad de la Especie
14.
Insects ; 8(1)2017 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-28287438

RESUMEN

The spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), is an emerging invasive pest, which attacks a wide variety of fruits and berries. Although previous studies have focused on different aspects of D. suzukii reproductive biology, there are no protocols available for determining the mating status of D. suzukii females and drosophilids in general. In this study, a step-by-step protocol for tissue dissection, isolating spermathecae, and determining the mating status of females was developed specifically for D. suzukii. This protocol is an effective and relatively quick method for determining female mating status. It has important applications from exploring reproductive output of D. suzukii females to understanding the biology of D. suzukii winter morph, which presumably plays the main role in the overwintering of this invasive species. We demonstrated applicability of this protocol for both field collected flies and flies reared in the lab, including fly specimens stored on a long-term basis.

15.
G3 (Bethesda) ; 7(5): 1417-1427, 2017 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-28258114

RESUMEN

Spermathecae are glandular organs in the insect female reproductive tract that play essential roles in insect reproduction; however, the molecular mechanism involved in their development is largely unknown. Drosophila spermathecae consist of class-III secretory units, in which each secretory cell (SC) discharges its products to the central lumen through an end-apparatus and a canal. Secretory unit formation in Drosophila spermathecae utilizes a fixed cell lineage, in which each secretory unit precursor (SUP) divides to produce one pIIb cell and one pIIa cell. The former differentiates into an apical cell (AC), whereas the latter divides again to produce an SC and a basal cell (BC). It is unclear how each cell acquires its identity and contributes to secretory unit formation. Here, we demonstrate that Notch signaling is required and sufficient for the specification of lumen epithelial precursors (LEPs; vs. SUPs), pIIb (vs. pIIa), and SCs (vs. BCs) sequentially. To our surprise, Notch activation in LEPs and SCs apparently utilizes different ligand mechanisms. In addition, Notch signaling both suppresses and activates transcription factors Hindsight (Hnt) and Cut during spermathecal lineage specification, supporting the notion that Notch signaling can have opposite biological outcomes in different cellular environments. Furthermore, LEP-derived epithelial cells (ECs) and ACs show distinct cellular morphology and are essential for securing secretory units to the epithelial lumen. Our work demonstrates, for the first time, the dynamic role of Notch signaling in binary cell fate determination in Drosophila spermathecae and the role of ECs and ACs in secretory unit formation.


Asunto(s)
Diferenciación Celular , Linaje de la Célula , Proteínas de Drosophila/metabolismo , Ovario/metabolismo , Receptores Notch/metabolismo , Transducción de Señal , Animales , Drosophila/embriología , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Femenino , Ovario/citología , Ovario/embriología , Receptores Notch/genética
16.
Rev. bras. entomol ; 61(1): 1-5, Jan.-Mar. 2017. graf
Artículo en Inglés | LILACS | ID: biblio-843705

RESUMEN

ABSTRACT The genus Neogriphoneura Malloch, 1924 is currently composed of 11 species with New World distribution. Neogriphoneura timida Curran, 1942 is recorded for the first time in South America, with occurrences in Brazil, Colombia and Trinidad and Tobago; and new Central American records are presented: Belize, Honduras and Mexico. Here we redescribe the species and present, for the first time, illustrations of the male terminalia and female spermathecae, and discuss the main diagnostic characteristics of external morphology. A brief discussion about the postcopulatory sexual selection in this species is proposed based on morphology of the spermathecae.

17.
Biol Lett ; 11(9): 20150527, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26382076

RESUMEN

Previous research has documented low frequencies of interspecific mating in nature between the invasive vectors Aedes aegypti and Aedes albopictus. It is also known that heterospecific male accessory gland substances transferred during mating sterilize A. aegypti but not A. albopictus females, leading to satyrization, a form of reproductive interference. This paper demonstrates that satyrization of A. aegypti by A. albopictus may occur without evidence of successful insemination. Our results show that A. aegypti females, previously exposed to A. albopictus males, are rendered refractory to subsequent conspecific mating even though their spermathecae contain no heterospecific sperm. Additional experiments demonstrating transfer of labelled semen from A. albopictus males to A. aegypti females and low production of viable eggs of females housed with conspecific males, following exposure to A. albopictus males, confirm higher incidences of satyrization than expected, based on heterospecific insemination rates. We conclude that frequencies of satyrization based on detection of interspecific sperm in spermathecae may underestimate the impact of this form of reproductive interference.


Asunto(s)
Aedes/fisiología , Especies Introducidas , Animales , Femenino , Insectos Vectores , Masculino , Isótopos de Nitrógeno , Reproducción/fisiología , Conducta Sexual Animal , Especificidad de la Especie
18.
Mol Phylogenet Evol ; 83: 7-19, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25463017

RESUMEN

Earthworms belonging to the family Lumbricidae are extremely abundant in terrestrial temperate regions. They affect soil properties and nutrient cycling, thus shaping plant community composition and aboveground food webs. Some lumbricids are also model organisms in ecology and toxicology. Despite the intense research efforts dedicated to lumbricids over the last 130years, the evolutionary relationships and taxonomic classification of these organisms are still subject to great debate. Resolution of their systematics is hampered by the structural simplicity of the earthworm body plan and the existence of cryptic species. We sampled 160 earthworm specimens belonging to 84 lumbricid species (28 genera) and 22 Lumbricoidea outgroups, sequenced two nuclear genes, four mitochondrial genes and seven mitochondrial tRNAs and examined 22 morphological characters. We then applied a combination of phylogenetic methods to generate the first robust genus-level phylogeny of the Lumbricidae. Our results show that the current Lumbricidae classification and the underlying hypotheses of character evolution must be revised. Our chronogram suggests that lumbricids emerged in the Lower Cretaceous in the holarctic region and that their diversification has been driven by tectonic processes (e.g. Laurasia split) and geographical isolation. Our chronogram and character reconstruction analysis reveal that spermathecae number does not follow a gradual pattern of reduction and that parthenogenesis arose from sexual relatives multiple times in the group; the same analysis also indicates that both epigeic and anecic earthworms evolved from endogeic ancestors. These findings emphasize the strong and multiple changes to which morphological and ecological characters are subjected, challenging the hypothesis of character stasis in Lumbricidae.


Asunto(s)
Evolución Biológica , Oligoquetos/clasificación , Filogenia , Animales , Teorema de Bayes , Genes Mitocondriales , Funciones de Verosimilitud , Modelos Genéticos , Oligoquetos/anatomía & histología , ARN de Transferencia/genética , Análisis de Secuencia de ADN
19.
J Morphol ; 275(9): 1027-40, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24788235

RESUMEN

Female genital morphology of secondarily haplogyne spiders has been poorly studied, hampering the analysis of its possible phylogenetic significance. We conduct a comparative morphological study of 12 species of the secondarily haplogyne spider genus Glenognatha Simon, 1887 using scanning electron microscopy. Representatives of the closely related genera Pachygnatha Sundevall, 1823 and Dyschiriognatha Simon, 1893 were also examined. The female genitalia of Glenognatha, Dyschiriognatha, and Pachygnatha species examined are composed of a spiracle-shape gonopore, a membranous chamber, a pair of copulatory ducts (CD) leading to spermathecae and a large uterus externus (UE). The most significant variation among Glenognatha species, previously unregistered within Araneoidea, is related with the absence or presence of CD and spermathecae. In addition, several characters as the form and distribution of long stem gland ductules and compartmentalization of the UE may be important for phylogenetic inference at species and generic level. Our results corroborate the close relationship between Dyshiriognatha and Glenognatha. A table with potentially informative female genitalic characters for phylogenetic inference within Glenognatha is provided. Understanding the general structure of the female genitalia in secondarily haplogyne taxa is a crucial step in order to propose characters for phylogenetic inference and to understand its possible functional significance.


Asunto(s)
Arañas/anatomía & histología , Animales , Femenino , Genitales Femeninos/anatomía & histología , Masculino , Microscopía Electrónica de Rastreo , Filogenia
20.
J Insect Physiol ; 60: 1-6, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24188987

RESUMEN

Mating between relatives usually decreases genetic quality of progeny as deleterious recessive alleles are expressed in inbred individuals. Inbreeding degrades sperm traits but its effects on sperm storage and fate within females are currently unknown. We quantified the relationship between the degrees of inbreeding relevant to natural populations (f=0, 0.25 and 0.50) and the number of sperm inseminated and stored, sperm swimming speed, long-term sperm viability while in storage, pattern of sperm precedence, mating latency, and offspring viability of female Drosophila melanogaster. The use of transgenic flies that have either red or green fluorescent sperm heads allowed us to distinguish two ejaculates in the female reproductive tract and facilitated quantification of sperm storage and use traits. We found no inbreeding depression in either long- or short-term sperm storage ability. The most inbred females exhibited significantly longer mating latency, which could be explained by males preferring to mate with outbred females. On the other hand, as no evidence for cryptic male choice in the form of ejaculate tailoring of sperm number was found, the most inbred females might just be less eager to mate. We also found no evidence that the degree of maternal inbreeding influenced offspring viability. Comparison with a contemporaneous study of male inbreeding consequences for ejaculate quality suggests that inbreeding depression is more severe in males than in females in our study population.


Asunto(s)
Drosophila melanogaster/fisiología , Endogamia , Conducta Sexual Animal/fisiología , Espermatozoides/fisiología , Animales , Animales Modificados Genéticamente , Femenino , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes , Masculino , Reproducción , Proteína Fluorescente Roja
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