scholarly journals Male-Female Interactions and the Evolution of Postmating Prezygotic Reproductive Isolation among Species of the Virilis Subgroup

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Nada Sagga ◽  
Alberto Civetta
Keyword(s):  
Reproductive Isolation ◽  
Egg Laying ◽  
Sperm Transfer ◽  
Geographic Locations ◽  
Future Studies ◽  
Egg Hatchability ◽  
Fertilization Rates ◽  
Postzygotic Barriers ◽  
Storage Organs

Reproductive isolation reduces breeding between species. Traditionally, prezygotic and postzygotic barriers to reproduction have been broadly studied, but in recent years, attention has been brought to the existence of barriers that act after copulation but before fertilization. Here, we show that when D. virilis females from different geographic locations mate with D. novamexicana males, egg laying is normal, but fertilization rates are severely reduced, despite normal rates of sperm transfer. This reduction in fertilization is probably due to lower retention of heterospecific sperm in female storage organs one-to-two days after copulation. An inspection of egg hatchability in crosses between females and males from other virilis subgroup species reveals that isolation due to poor egg hatchability likely evolved during the diversification of D. virilis/D. lummei from species of the novamexicana-americana clade. Interestingly, the number of eggs laid by D. virilis females in heterospecific crosses was not different from the numbers of eggs laid in conspecific crosses, suggesting that females exert some form of cryptic control over the heterospecific ejaculate and that future studies should focus on how female and female-sperm interactions contribute to the loss or active exclusion of heterospecific sperm from storage.

scholarly journals Expression of Mst89B and CG31287 is Needed for Effective Sperm Storage and Egg Fertilization in Drosophila

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 289
Author(s):  
Gurman Grewal ◽  
Bahar Patlar ◽  
Alberto Civetta
Keyword(s):  
Germ Line ◽  
Sperm Storage ◽  
Mature Sperm ◽  
Sperm Production ◽  
Cytogenetic Map ◽  
Egg Hatchability ◽  
Storage Organs ◽  
Competitive Success ◽  
Paternity Success ◽  
And Storage

In Drosophila, male reproductive fitness can be affected by any number of processes, ranging from development of gametes, transfer to and storage of mature sperm within the female sperm storage organs, and utilization of sperm for fertilization. We have previously identified the 89B cytogenetic map position of D. melanogaster as a hub for genes that effect male paternity success when disturbed. Here, we used RNA interference to test 11 genes that are highly expressed in the testes and located within the 89B region for their role in sperm competition and male fecundity when their expression is perturbed. Testes-specific knockdown (KD) of bor and CSN5 resulted in complete sterility, whereas KD of CG31287, Manf and Mst89B, showed a breakdown in sperm competitive success when second to mate (P2 < 0.5) and reduced fecundity in single matings. The low fecundity of Manf KD is explained by a significant reduction in the amount of mature sperm produced. KD of Mst89B and CG31287 does not affect sperm production, sperm transfer into the female bursa or storage within 30 min after mating. Instead, a significant reduction of sperm in female storage is observed 24 h after mating. Egg hatchability 24 h after mating is also drastically reduced for females mated to Mst89B or CG31287 KD males, and this reduction parallels the decrease in fecundity. We show that normal germ-line expression of Mst89B and CG31287 is needed for effective sperm usage and egg fertilization.

scholarly journals Functional morphology of immature mating in a widow spider

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lenka Sentenská ◽  
Aileen Neumann ◽  
Yael Lubin ◽  
Gabriele Uhl
Keyword(s):  
Sperm Competition ◽  
Storage Conditions ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Costs And Benefits ◽  
Micro Computed Tomography ◽  
Mating Tactics ◽  
Adult Females ◽  
Storage Organs ◽  
Widow Spider

Abstract 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.

scholarly journals Baccharis dracunculifolia DC (Asteraceae) leaf and flower essential oils to control Rhipicephalus microplus Canestrini (Arachnida: Ixodidae) in the free-living stage

2020 ◽  
Vol 9 (10) ◽  
pp. e5049108788
Author(s):  
Luciane Neris Cazella ◽  
Herika Line de Marko de Oliveira ◽  
Wanessa de Campos Bortolucci ◽  
Isabelle Luiz Rahal ◽  
Irinéia Paulina Baretta ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Biological Activities ◽  
Probit Analysis ◽  
Rhipicephalus Microplus ◽  
Acaricidal Activity ◽  
Egg Laying ◽  
Ex Situ ◽  
Egg Hatchability

Baccharis dracunculifolia, native to Brazil and the main source of “green propolis”, has been reported with several biological activities, and may be a source of bovine tick control substituting synthetic acaricides. Objective: to evaluate the in vitro and ex situ acaricidal activity of B. dracunculifolia leaf and flower essential oils against Rhipicephalus microplus. Methodology: the essential oils were extracted by hydrodistillation and analyzed by a gas chromatography coupled to mass spectrometry; the acaricidal activity of the essential oil was evaluated in vitro against adult females and against the egg hatchability; moreover, the acaricidal activity against tick larvae was evaluated in vitro and ex situ. Results: the major class of the essential oils was oxygenated sesquiterpene (55.1% leaves 50.4% flowers) and the main compounds were (21.5% leaves; 20.6% flowers) and spathulenol (21.8% leaves; 20.3% flowers). The essential oil at 500 mg/mL was effective to control egg hatchability with a reduction of egg laying capacity and decrease of number of adult ticks and larvae. The larvicidal activity of the essential oil had LC99.9 from 35 to 37 mg/mL by probit analysis, and the essential oil from 11 to 14 mg/mL presented 85 to 95% of treatment efficiency in the ex situ test. Conclusion: B. dracunculifolia leaf and flower essential oils are stable and have application potential to control bovine ticks.

Typification for reliable application of subspecific names within Peridinium cinctum (Peridiniales, Dinophyceae)

Phytotaxa ◽  
2019 ◽  
Vol 424 (3) ◽  
pp. 147-157 ◽  
Author(s):  
CORINNA ROMEIKAT ◽  
ALEJANDRO IZQUIERDO LÓPEZ ◽  
CHRISTINE TIETZE ◽  
JULIANE KRETSCHMANN ◽  
MARC GOTTSCHLING
Keyword(s):  
Morphological Variation ◽  
Dna Sequences ◽  
Related Species ◽  
Original Material ◽  
Full Spectrum ◽  
Closely Related Species ◽  
Geographic Locations ◽  
Future Studies ◽  
Unicellular Organisms ◽  
Peridinium Cinctum

The application of scientific names is determined by means of nomenclatural types, and every name has to be typified properly. The concept has limitations for unicellular organisms, because original material frequently consists of drawings and/or inadequately preserved physical material. Peridinium cinctum is an abundant freshwater microalga and variable in both morphology and genotype. Morphological variation is mainly expressed in its epithecal conformation: shape deviations of plates, plate rearrangements, plate fusion and plate additions. Different epithecal conformations were traditionally described as either varieties of P. cinctum or were established as closely related species. Despite this, relations between varieties, ribotypes and geographic locations were oversighted, and the full spectrum of plate variation in P. cinctum is still not well represented. For this reason, we sampled localities in Germany and Poland, from which varieties of P. cinctum were described a century ago. We cultivated monoclonal strains, exhibiting two distinct ITS ribotypes, and assessed their epithecal variation of morphology. Based on ca 2,500 observations of individual cells we report a plethora of both plate and suture deviations from the archetypical epithecal conformation of P. cinctum. Morphologies corresponding to previously described varieties were rare, even at their type localities. Nevertheless, we found morphologies consistent with protologues in four cases and use this material for epitypification. These varieties are now linked to specific DNA sequences, allowing reliable application of scientific names for future studies.

Interspecific Hybridization Between Common Ragweed (Ambrosia artemisiifolia) and Giant Ragweed (A. trifida)

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 633-636 ◽  
Author(s):  
Gilles Vincent ◽  
Mario Cappadocia
Keyword(s):  
Ambrosia Artemisiifolia ◽  
Eastern Canada ◽  
Common Ragweed ◽  
Future Studies ◽  
Suitable Material ◽  
Culture Techniques ◽  
Hybrid Plants ◽  
Giant Ragweed ◽  
Postzygotic Barriers ◽  
Embryo Culture Techniques

Common ragweed [Ambrosia artemisiifoliaL. # AMBEL (2n=36)] and giant ragweed[A. trifidaL. # AMBTR (2n=24)] are two abundant annuals that are widespread throughout northeastern North America. They are also the main cause of hay fever in Eastern Canada. The formation of a hybrid between the two species has been reported only once and just one type of hybrid was recovered; namely, common ragweed × giant ragweed. In order to create additional suitable material for future studies of the biochemical features characterizing the allergenic pollen, the production of reciprocal hybrids between common and giant ragweed was attempted. A number of hybrid plants derived from crosses of the type common ragweed × giant ragweed were easily obtained; the reciprocal crosses, however, failed to produce viable plants. In this last case, evidence of postzygotic barriers of interspecific incompatibility were shown by the presence of underdeveloped embryos contained in the few seeds recovered. Embryo culture techniques, therefore, were used in order to bypass such barriers. By this method fifteen plants of hybrid constitution survived to maturity.

scholarly journals The evolution of strong reproductive isolation between sympatric intertidal snails

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190545 ◽  
Author(s):  
Sean Stankowski ◽  
Anja M. Westram ◽  
Zuzanna B. Zagrodzka ◽  
Isobel Eyres ◽  
Thomas Broquet ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Biological Diversity ◽  
Demographic History ◽  
Egg Laying ◽  
Female Reproduction ◽  
Open Questions ◽  
Geographical Separation ◽  
Short Period ◽  
Littorina Arcana ◽  
Subsequent Effect

The evolution of strong reproductive isolation (RI) is fundamental to the origins and maintenance of biological diversity, especially in situations where geographical distributions of taxa broadly overlap. But what is the history behind strong barriers currently acting in sympatry? Using whole-genome sequencing and single nucleotide polymorphism genotyping, we inferred (i) the evolutionary relationships, (ii) the strength of RI, and (iii) the demographic history of divergence between two broadly sympatric taxa of intertidal snail. Despite being cryptic, based on external morphology, Littorina arcana and Littorina saxatilis differ in their mode of female reproduction (egg-laying versus brooding), which may generate a strong post-zygotic barrier. We show that egg-laying and brooding snails are closely related, but genetically distinct. Genotyping of 3092 snails from three locations failed to recover any recent hybrid or backcrossed individuals, confirming that RI is strong. There was, however, evidence for a very low level of asymmetrical introgression, suggesting that isolation remains incomplete. The presence of strong, asymmetrical RI was further supported by demographic analysis of these populations. Although the taxa are currently broadly sympatric, demographic modelling suggests that they initially diverged during a short period of geographical separation involving very low gene flow. Our study suggests that some geographical separation may kick-start the evolution of strong RI, facilitating subsequent coexistence of taxa in sympatry. The strength of RI needed to achieve sympatry and the subsequent effect of sympatry on RI remain open questions. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

scholarly journals Noncompetitive Gametic Isolation between Sibling Species of Cricket: A Hypothesized Link between Within-Population Incompatibility and Reproductive Isolation between Species

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jeremy L. Marshall ◽  
Nicholas DiRienzo
Keyword(s):  
Reproductive Isolation ◽  
Sibling Species ◽  
Reproductive Tract ◽  
Egg Laying ◽  
Female Reproductive Tract ◽  
Common Mechanism ◽  
Species Divergence ◽  
Genetic Pathway ◽  
Genetic Tests

Postmating, prezygotic phenotypes are a common mechanism of reproductive isolation. Here, we describe the dynamics of a noncompetitive gametic isolation phenotype (namely, the ability of a male to induce a female to lay eggs) in a group of recently diverged crickets that are primarily isolated from each other by this phenotype. We not only show that heterospecific males are less able to induce females to lay eggs but that there are male by female incompatibilities in this phenotype that occur within populations. We also identify a protein in the female reproductive tract that correlates with the number of eggs that she was induced to lay. Functional genetic tests using RNAi confirm that the function of this protein is linked to egg-laying induction. Moreover, the dysfunction of this protein appears to underlie both within-population incompatibilities and between-species divergence—thus suggesting a common genetic pathway underlies both. However, this is only correlative evidence and further research is needed to assess whether or not the same mutations in the same genes underlie variation at both levels.

scholarly journals Postzygotic Isolation Evolves before Prezygotic Isolation between Fresh and Saltwater Populations of the Rainwater Killifish, Lucania parva

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Genevieve M. Kozak ◽  
Arthur B. Rudolph ◽  
Beatrice L. Colon ◽  
Rebecca C. Fuller
Keyword(s):  
Reproductive Isolation ◽  
Fresh Water ◽  
Salt Water ◽  
Postzygotic Isolation ◽  
Hybrid Inviability ◽  
Prezygotic Isolation ◽  
Divergent Natural Selection ◽  
Postzygotic Barriers ◽  
Species Population ◽  
Stable Populations

Divergent natural selection has the potential to drive the evolution of reproductive isolation. The euryhaline killifish Lucania parva has stable populations in both fresh water and salt water. Lucania parva and its sister species, the freshwater L. goodei, are isolated by both prezygotic and postzygotic barriers. To further test whether adaptation to salinity has led to the evolution of these isolating barriers, we tested for incipient reproductive isolation within L. parva by crossing freshwater and saltwater populations. We found no evidence for prezygotic isolation, but reduced hybrid survival indicated that postzygotic isolation existed between L. parva populations. Therefore, postzygotic isolation evolved before prezygotic isolation in these ecologically divergent populations. Previous work on these species raised eggs with methylene blue, which acts as a fungicide. We found this fungicide distorts the pattern of postzygotic isolation by increasing fresh water survival in L. parva, masking species/population differences, and underestimating hybrid inviability.

Assortative mating and divergent male courtship behaviours between two cryptic species of nine-spined sticklebacks (genus Pungitius)

Behaviour ◽  
2016 ◽  
Vol 153 (15) ◽  
pp. 1879-1911 ◽  
Author(s):  
Yu-ichiro Meguro ◽  
Hiroshi Takahashi ◽  
Yoshiyasu Machida ◽  
Hokuto Shirakawa ◽  
Michelle R. Gaither ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Cryptic Species ◽  
Assortative Mating ◽  
Brackish Water ◽  
Courtship Behaviour ◽  
Water Type ◽  
Male Courtship ◽  
Future Studies ◽  
Kinematic Analyses

Assortative mating based on ecologically divergent traits is a major driver of speciation among three-spined sticklebacks, however, little is known about reproductive isolation and variations in courtship behaviour among nine-spined sticklebacks. Here we demonstrate assortative mating and divergent courtship behaviours between two cryptic species of nine-spined sticklebacks using no-choice mate trials and kinematic analyses. Strong assortative mating was demonstrated in our tank experiments, highlighting the importance of prezygotic reproductive isolation in these species. Kinematic analyses showed that the freshwater type exhibited aggressive courtship behaviour with frequent ‘Attacking’ and spent more time exhibiting displacement activities. In contrast, the brackish-water type demonstrated a higher frequency of the ‘Zigzag-dance’ and ‘Nest-showing’. Our study highlights the value of nine-spined sticklebacks as a comparative system for the study of speciation and paves the way for future studies on the role of courtship behaviours and assortative mating in the evolution of sticklebacks.

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