scholarly journals Testing potential mechanisms of conspecific sperm precedence in Drosophila pseudoobscura

2021 ◽  
Author(s):  
Brooke Peckenpaugh ◽  
Dean M. Castillo ◽  
Leonie C. Moyle
Keyword(s):  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Sister Species ◽  
Copulation Duration ◽  
Drosophila Pseudoobscura ◽  
Sperm Precedence ◽  
Conspecific Male ◽  
Testing Potential

AbstractDrosophila pseudoobscura females that co-occur with sister species D. persimilis show elevated fertilization by conspecific sperm when they mate with both a heterospecific and a conspecific male. This phenomenon, known as conspecific sperm precedence (CSP), has evolved as a mechanism to avoid maladaptive hybridization with D. persimilis. In this study, we assessed pericopulatory (during mating) and postcopulatory (after mating) traits in crosses with sympatric or allopatric D. pseudoobscura females and conspecific or heterospecific males to evaluate potential mechanisms of CSP in this system. We observed shorter copulation duration in crosses with sympatric females, but found no difference in quantity of sperm transferred or female reproductive tract toxicity between sympatry and allopatry. Our data also support the hypothesis that parasperm, a short, sterile sperm morph, can protect fertile eusperm from the D. pseudoobscura female reproductive tract, though it is unclear how this might affect patterns of sperm use in sympatry vs. allopatry. Overall, these results suggest that copulation duration could potentially contribute to the elevated CSP observed in sympatry.

scholarly journals Conspecific sperm precedence in Callosobruchus subinnotatus (Coleoptera: Bruchidae): mechanisms and consequences

2007 ◽  
Vol 274 (1612) ◽  
pp. 983-988 ◽  
Author(s):  
Paul F Rugman-Jones ◽  
Paul E Eady
Keyword(s):  
Sexual Selection ◽  
Gene Flow ◽  
Sperm Competition ◽  
Reproductive Tract ◽  
Callosobruchus Maculatus ◽  
Female Reproductive Tract ◽  
Sperm Precedence ◽  
Male And Female ◽  
Mating Order ◽  
Callosobruchus Subinnotatus

Conspecific sperm precedence (CSP) has been identified as an important post-copulatory, pre-zygotic mechanism that can act to reduce gene flow between populations. The evolution of CSP is thought to have arisen as a by-product of male and female coevolution in response to intraspecific post-copulatory sexual selection. However, little is known about the mechanisms that generate CSP. When Callosobruchus subinnotatus females copulate with both C. subinnotatus and Callosobruchus maculatus males, regardless of mating order, the majority of eggs are fertilized by conspecific sperm. The low number of heterospecific fertilizations does not result from general differences in the viability of sperm in the female reproductive tract, as heterospecific sperm fertilized equivalent numbers of eggs as conspecific sperm in the absence of sperm competition. Instead, CSP results from disadvantages to heterospecific sperm that are manifest only when in competition with conspecific sperm. CSP in C. subinnotatus appears to result from two, not mutually exclusive, mechanisms. First, conspecific sperm are better able to displace heterospecific sperm from female storage. Second, conspecific sperm achieve disproportionately higher numbers of fertilizations relative to their proportional representation in the fertilization set. Thus, we provide evidence of differential sperm use from the female spermatheca.

scholarly journals Within-population sperm competition intensity does not predict asymmetry in conpopulation sperm precedence

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200071 ◽  
Author(s):  
Martin D. Garlovsky ◽  
Leeban H. Yusuf ◽  
Michael G. Ritchie ◽  
Rhonda R. Snook
Keyword(s):  
Sexual Selection ◽  
Gene Flow ◽  
Sperm Competition ◽  
Reproductive Tract ◽  
Fertilization Success ◽  
Female Reproductive Tract ◽  
Sperm Precedence ◽  
Arms Races ◽  
Postcopulatory Sexual Selection ◽  
The Face

Postcopulatory sexual selection can generate evolutionary arms races between the sexes resulting in the rapid coevolution of reproductive phenotypes. As traits affecting fertilization success diverge between populations, postmating prezygotic (PMPZ) barriers to gene flow may evolve. Conspecific sperm precedence is a form of PMPZ isolation thought to evolve early during speciation yet has mostly been studied between species. Here , we show conpopulation sperm precedence (CpSP) between Drosophila montana populations. Using Pool-seq genomic data we estimate divergence times and ask whether PMPZ isolation evolved in the face of gene flow. We find models incorporating gene flow fit the data best indicating populations experienced considerable gene flow during divergence. We find CpSP is asymmetric and mirrors asymmetry in non-competitive PMPZ isolation, suggesting these phenomena have a shared mechanism. However, we show asymmetry is unrelated to the strength of postcopulatory sexual selection acting within populations. We tested whether overlapping foreign and coevolved ejaculates within the female reproductive tract altered fertilization success but found no effect. Our results show that neither time since divergence nor sperm competitiveness predicts the strength of PMPZ isolation. We suggest that instead cryptic female choice or mutation-order divergence may drive divergence of postcopulatory phenotypes resulting in PMPZ isolation. This article is part of the theme issue ‘Fifty years of sperm competition’.

scholarly journals Within-population sperm competition intensity does not predict asymmetry in conpopulation sperm precedence

2020 ◽  
Author(s):  
Martin D. Garlovsky ◽  
Leeban H. Yusuf ◽  
Michael G. Ritchie ◽  
Rhonda R. Snook
Keyword(s):  
Sexual Selection ◽  
Gene Flow ◽  
Reproductive Isolation ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Sperm Precedence ◽  
Arms Races ◽  
Fertilisation Success ◽  
Postcopulatory Sexual Selection ◽  
Postmating Prezygotic Isolation

ABSTRACTPostcopulatory sexual selection can generate coevolutionary arms races between the sexes resulting in the rapid coevolution of reproductive phenotypes. As traits affecting fertilisation success diverge between populations postmating prezygotic barriers to gene flow may evolve. Conspecific sperm precedence is a form of such isolation thought to evolve early during speciation yet has mostly been studied between species. Here we show conpopulation sperm precedence between Drosophila montana populations. Using genomic data to estimate divergence times and patterns of gene flow between populations, we show gene flow has played a considerable role during divergence. We find conpopulation sperm precedence is asymmetric and is concordant with asymmetry in non-competitive postmating prezygotic reproductive isolation. These results suggest these phenomena have a shared mechanism, but we show that this asymmetry is unrelated to the strength of postcopulatory sexual selection acting within populations. We tested whether overlapping foreign and coevolved ejaculates within the female reproductive tract altered fertilisation success but found no effect. Our results show that neither time since divergence nor sperm competitiveness predicts the strength of postmating prezygotic reproductive isolation. We suggest that divergence of postcopulatory phenotypes resulting in postmating prezygotic isolation is potentially driven by cryptic female choice, or mutation order divergence.

scholarly journals Mating duration and prolonged post-copulatory associations in Arrenurus water mites (Actinotrichida: Parasitengonina: Hydrachnidiae)

2021 ◽  
Author(s):  
Mariusz Wiecek ◽  
Jacek Dabert ◽  
Heather Proctor
Keyword(s):  
Reproductive Tract ◽  
Conflicts Of Interest ◽  
Female Reproductive Tract ◽  
Sperm Transfer ◽  
Copulation Duration ◽  
Water Mites ◽  
Genital Morphology ◽  
Male Control ◽  
Mating Duration

Conflicts of interest between the sexes over control of mating can be reflected in various aspects of morphology and behaviour, including structure of genitalia and copulation duration. In Arrenurus water mites (Hydrachnidia: Arrenuridae) there are two main patterns of sperm transfer that differ in degree of potential male control of sperm uptake by females. In some species, males are equipped with an intromittent organ (the "petiole") that is used to forcefully insert sperm into the female reproductive tract. In others, males lack an intromittent organ and females appear to push sperm into their reproductive opening themselves. Theory suggests that the amount of time spent in courtship after sperm transfer should differ between males with and without an intromittent structure. We predicted that male Arrenurus able to push sperm into the female's reproductive tract (petiolate males) should spend less time courting females after transferring sperm than apetiolate males, which may have to "convince" females to take up their sperm. Here, we examined durations of mating for 10 species of Arrenurus with males that differ in genital morphology: six species with males equipped with a well developed petiole (= "petiolate" species) and four species with males that either completely lack a petiole or have a minute peg-like petiole that does not appear to function as an intromittent organ (= "apetiolate" species). We tested whether males of petiolate species spend less time in the stage of courtship that takes place after sperm transfer (= "post-transfer courtship") than apetiolate males. In contrast to our prediction, we found that species with well developed petioles spent significantly more time in post-transfer behaviours than species lacking petioles. The possible function of protracted post-transfer courtship in the genus Arrenurus is discussed.

Effect of Contraceptive Steroids on the Endometrium of Guinea Pig: SEM study

1977 ◽  
Vol 35 ◽  
pp. 668-669
Author(s):  
Mai M. Said ◽  
Ramesh K. Nayak ◽  
Randall E. McCoy
Keyword(s):  
Guinea Pig ◽  
Reproductive Tract ◽  
Three Dimensional ◽  
Female Reproductive Tract ◽  
Human Female ◽  
Surface Ultrastructure ◽  
Transmission Electron ◽  
Sem Study ◽  
Uterine Mucosa ◽  
Group 1

Burgos and Wislocki described changes in the mucosa of the guinea pig uterus, cervix and vagina during the estrous cycle investigated by transmission electron microscopy. More recently, Moghissi and Reame reported the effects of progestational agents on the human female reproductive tract. They found drooping and shortening of cilia in norgestrel and norethindrone- treated endometria. To the best of our knowledge, no studies concerning the effects of mestranol and norethindrone given concurrently on the three-dimensional surface features on the uterine mucosa of the guinea pig have been reported. The purpose of this study was to determine the effect of mestranol and norethindrone on surface ultrastructure of guinea pig uterus by SEM.Seventy eight animals were used in this study. They were allocated into two groups. Group 1 (20 animals) was injected intramuscularly 0.1 ml vegetable oil and served as controls.

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

The application of electron microscopy to diagnosis in gynecologic neoplasms and tumor-like conditions

1984 ◽  
Vol 42 ◽  
pp. 102-105
Author(s):  
Lawrence M. Roth
Keyword(s):  
Electron Microscopy ◽  
Reproductive Tract ◽  
Malignant Tumors ◽  
Frozen Section ◽  
Cost Effective ◽  
Female Reproductive Tract ◽  
Ultrastructural Examination ◽  
Specific Diagnosis ◽  
Potential Value ◽  
Gynecologic Neoplasms

The female reproductive tract may be the site of a wide variety of benign and malignant tumors, as well as non-neoplastic tumor-like conditions, most of which can be diagnosed by light microscopic examination including special stains and more recently immunoperoxidase techniques. Nevertheless there are situations where ultrastructural examination can contribute substantially to an accurate and specific diagnosis. It is my opinion that electron microscopy can be of greatest benefit and is most cost effective when applied in conjunction with other methodologies. Thus, I have developed an approach which has proved useful for me and may have benefit for others. In cases where it is deemed of potential value, glutaraldehyde-fixed material is obtained at the time of frozen section or otherwise at operation. Coordination with the gynecologic oncologist is required in the latter situation. This material is processed and blocked and is available if a future need arises.

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