On the Origin and Evolution of <i>Drosophila</i> New Genes during Spermatogenesis by Qianwei Su, Huangyi He, Qi Zhou

“…We reveal that new genes, particularly those produced by retrotransposition, tend to exhibit an expression shift toward late spermatogenesis compared with their parental copies, probably due to the more intensive sperm competition or sexual conflict. Our results dissect the complex factors including age, the origination mechanisms and the chromosomal locations that influence the new gene origination and evolution in testes, and identify new gene cases that show divergent cell-level expression patterns from their progenitors for future functional studies.…”
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Proteins involved in motility and sperm-egg interaction evolve more rapidly in mouse spermatozoa. by Alberto Vicens, Lena Lüke, Eduardo R S Roldan

“…Adaptive evolution of proteins involved in motility could be driven by sperm competition, since this selective force is known to increase the proportion of motile sperm and their swimming velocity. …”
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Bundle formation of sperm: Influence of environmental factors by Paula Morcillo i Soler, Carlos Hidalgo, Zoltán Fekete, Zoltán Fekete, Laszlo Zalanyi, Laszlo Zalanyi, Islam S. M. Khalil, Marc Yeste, Marc Yeste, Veronika Magdanz, Veronika Magdanz

“…Cooperative behaviour of sperm is one of the mechanisms that plays a role in sperm competition. It has been observed in several species that spermatozoa interact with each other to form agglomerates or bundles. …”
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The evolution of a female genital trait widely distributed in the Lepidoptera: comparative evidence for an effect of sexual coevolution. by Víctor Sánchez, Blanca Estela Hernández-Baños, Carlos Cordero

“…In many lepidopterans, females become temporarily unreceptive after mating and the length of this refractory period is inversely related to the amount of spermatophore remaining in their genital tracts. Sperm competition can select for males that delay female remating by transferring spermatophores with thick spermatophore envelopes that take more time to be broken. …”
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Multi-copy gene family evolution on the avian W chromosome by Rogers, TF, Pizzari, T, Wright, AE

“…The reasons for this remain elusive with a number of recent studies implicating meiotic drive, sperm competition, genetic drift and gene conversion in the expansion of gene families. …”

The benefits of male ejaculate sex peptide transfer in Drosophila melanogaster. by Fricke, C, Wigby, S, Hobbs, R, Chapman, T

“…In matings with virgin females, SP transfer increased mating productivity and delayed remating and hence the onset of sperm competition. In already mated females, SP transfer did not elevate absolute progeny production, but did increase intermating intervals and hence the period over which a male could gain paternity. …”

Intraspecific variation in male mating strategies in an African ground squirrel (Xerus inauris) by Mary Beth Manjerovic, Eric A. Hoffman, Christopher L. Parkinson, Jane M. Waterman

“…Our findings suggest that differences in resource availability affect female distribution, which ultimately leads to intraspecific variation in male reproductive tactics and sexual morphology. Sperm competition, assessed by reproductive morphometrics, was more pronounced in our high resource site where females were distributed evenly across the landscape, whereas dominance seemed to be an important determinant of success in our low resource site where females were more aggregated. …”
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The evolution of centriole degradation in mouse sperm by Sushil Khanal, Ankit Jaiswal, Rajanikanth Chowdanayaka, Nahshon Puente, Katerina Turner, Kebron Yeshitela Assefa, Mohamad Nawras, Ezekiel David Back, Abigail Royfman, James P. Burkett, Soon Hon Cheong, Heidi S. Fisher, Puneet Sindhwani, John Gray, Nallur Basappa Ramachandra, Tomer Avidor-Reiss

“…Here, we test the hypothesis that this transition occurred through a cascade of evolutionary changes to the proteins, structure, and function of sperm centrioles and was possibly driven by sperm competition. We found that the final steps in this cascade are associated with a change in the primary structure of the centriolar inner scaffold protein FAM161A in rodents. …”
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Copulatory behaviour in the Bonelli´s Eagle: Assessing the paternity assurance hypothesis. by José E Martínez, Iñigo Zuberogoitia, José M Escarabajal, Ginés J Gómez, José F Calvo, Antoni Margalida

“…A possible explanation could be related to the low number of extra-pair encounters observed (opportunities for which appear to be rare), although the gradual increase in within-pair copulations during the female fertile period is consistent with the sperm competition hypothesis. The results are discussed based on the signalling hypothesis, which proposes that raptors signal territory ownership to conspecifics, and possibly to other raptor species, by copulating frequently and conspicuously in the defended nesting area.…”
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How much multiple paternity should we expect? A study of birds and contrast with mammals by F. Stephen Dobson, Hannah E. Correia, Ash Abebe

“…The generally low probability of multiple paternity in birds might be produced by a variety of factors, including behaviors that reflect sexual selection (extreme mate guarding or unifocal female choice) and sperm competition (e.g., precedence effects favoring fertilization by early or late matings).…”
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Sexual selection on bushcricket genitalia operates in a mosaic pattern by Nadja C. Wulff, Gerlind U. C. Lehmann

“…Several theories have been proposed for the sexual selection forces driving the evolution of internal genitalia, especially sperm competition, sexually antagonistic coevolution (SAC), and cryptic female choice (CFC). …”
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Mating plugs in polyandrous giants: which sex produces them, when, how and why? by Matjaž Kuntner, Matjaž Gregorič, Shichang Zhang, Simona Kralj-Fišer, Daiqin Li

“…BACKGROUND: Males usually produce mating plugs to reduce sperm competition. However, females can conceivably also produce mating plugs in order to prevent unwanted, superfluous and energetically costly matings. …”
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Quantifying the costs of pre‐ and postcopulatory traits for males: Evidence that costs of ejaculation are minor relative to mating effort by Meng‐Han Joseph Chung, Michael D. Jennions, Rebecca J. Fox

“…These minor costs occur despite the fact that G. holbrooki has very high levels of sperm competition and multiple mating by both sexes, which is usually associated with elevated levels of sperm production. …”
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Population and colony-level determinants of tertiary sex ratio in the declining barn swallow. by Nicola Saino, Maria Romano, Diego Rubolini, Manuela Caprioli, Roberto Ambrosini, Giuseppe Boncoraglio, Luca Canova

“…Dispersal and settling site decisions can have major consequences on fitness via the effects of local TSR on mating and sperm competition. Breeding barn swallows are highly philopatric while natal dispersal is high and, together with mortality, is the main determinant of colony TSR. …”
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Testing the Role of Natural and Sexual Selection on Testes Size Asymmetry in Anurans by Shengnan Chen, Ying Jiang, Long Jin, Wenbo Liao

“…We also found that the postcopulatory sperm competition (e.g., residual testes size) was positively associated with the degree of testes asymmetry. …”
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Cooperation and Coordination in Socially Monogamous Birds: Moving Away From a Focus on Sexual Conflict by Simon C. Griffith

“…For example, differential allocation in socially monogamous birds can be explained from an entirely cooperative perspective, as can much behavior that is currently associated with sperm competition and the conflict over paternity. With over 80% of avian species forming socially monogamous bonds that are often life-long and can last for many decades, we need to redress the balance, and focus more attention on the benefits that both males and females gain from establishing, and maintaining socially monogamous partnerships. …”
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The reproductive behavior of Neotropical dung beetles by Carmen Huerta, Magdalena Cruz-Rosales, Patricia González-Vainer, Ivette Chamorro-Florescano, José D. Rivera, José D. Rivera, Mario E. Favila

“…Dung beetles display complex reproductive behaviors involving sexual findings, sexual recognition, fighting for mates and food used for nesting, sperm competition, and parental care. Over the past 40 years, significant advances have been made regarding the knowledge of various aspects of the sexual and nesting behavior of Neotropical dung beetles. …”
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Experimental evolution under hyper-promiscuity in Drosophila melanogaster by Perry, J, Wigby, S, Joag, R, Hosken, D, Weddell, N, Radwan, J

“…Results: We found that males from the high mating frequency SPR- populations evolved decreased ability to inhibit the receptivity of their mates and decreased copulation duration, in line with predictions of decreased per-mating investment with increased sperm competition. Unexpectedly, SPR- population males also evolved weakly increased sex peptide (SP) gene expression. …”

Genetically engineered insects with sex-selection and genetic incompatibility enable population suppression by Ambuj Upadhyay, Nathan R Feltman, Adam Sychla, Anna Janzen, Siba R Das, Maciej Maselko, Michael Smanski

“…Further we show that SSIMS males remain competitive with wild-type males for reproduction with wild-type females, including at the level of sperm competition.…”
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A behavioral and genetic study of multiple paternity in a polygamous marine invertebrate, Octopus oliveri by Heather Ylitalo, Thomas A. Oliver, Iria Fernandez-Silva, James B. Wood, Robert J. Toonen

“…We saw no evidence of direct sperm competition in Octopus oliveri, but larger males produced significantly more offspring. …”
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