Month: September 2022

FEMALE SPERM STORAGE. “Some of this transition to storing sperm is regulated by interactions between SFPs and innervated stretches of the reproductive tract. Later, in order for fertilization to occur, both female secretions and male SFPs are required. Perhaps the most compelling evidence of synergy comes from recent studies demonstrating a stepwise seminal fluid proteolytic cascade with diverse effects on reproductive processes that requires both male and female contributions.” (SFPs = male seminal fluid proteins). http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

SEXUAL CONFLICT. “The female reproductive tract also acts as an arena for sexual conflict – the optimal outcome of sexual interactions is likely to differ between males and females. First, sperm and SFPs have presumably been selected to increase the male's success in direct sperm competition with the sperm of other males within the female reproductive tract. This function of SFPs is supported by the fact that males transfer more SFPs during mating if another male is present, implying a greater risk of sperm competition.” (SFPs = male seminal fluid proteins). http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

INFLUENCES ON PATERNITY. “Some of the female response to mating may exist to influence the outcome of this competition via cryptic female choice, but males would be selected to overcome this. Consistent with this notion, paternity is known to be affected by both male and female genotype, often in a nonadditive way.” http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

FEMALE MATING BEHAVIOR. “SFPs influence female behaviour or physiology in a way that makes her less likely to mate again. This is advantageous to the male, but may be disadvantageous to the female – females in insects usually experience a net benefit from multiple mating.” (SFPs = male seminal fluid proteins). http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

FEMALE COSTS. “SFPs inflict direct costs on females in terms of reduced lifetime reproduction or lifespan. Even if some of those costs are compensated by improved offspring quality, the majority of evidence suggests strong net costs for females upon receipt of SFPs; thus, selection should favour a female response that counteracts this effect.” (SFPs = male seminal fluid proteins). http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

MOLECULAR ARMS RACE. “Molecular evolutionary patterns support this role for sexual conflict, as the family of SFP genes (comprising at least 140 members) are rapidly evolving at the sequence level. The female side of this putative arms race, involving primarily proteases expressed in the reproductive tract, also shows evidence of rapid evolution and a signature of strong selection.” (SFPs = male seminal fluid proteins). http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

TESTABLE HYPOTHESIS. “One way to test the extent to which male and female contributions are operating cooperatively or antagonistically is to study how they evolve if sexual selection is experimentally eliminated. Removing female choice and competition for mates eliminates sexual conflict – any amount of harm to females would become detrimental to the reproductive success of both sexes.” http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

METHODS. “To address this question, we eliminated sexual selection by enforcing monogamy in populations of Drosophila melanogaster for 65 generations and then measured the expression of male seminal fluid protein genes and genes involved in the female response to mating. In the absence of sperm competition, male and female reproductive interests are perfectly aligned and any antagonism should be reduced by natural selection.” http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

ALTERNATIVE HYPOTHESES. “We tested alternative predictions based on the hypotheses that the male–female interactions these genes mediate are mostly synergistic, regulating the switch of female physiology to reproduction, or mostly antagonistic, driven by sexual conflict. The broad pattern of evolutionary change in the expression of genes involved in this interaction, evident in both males and females from populations maintained under enforced monogamy, supports a prevailing role for sexual conflict.” http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn

GENETIC FLARE. “Males from monogamous populations showed reduced expression of seminal fluid protein genes, 16% less on average than in polygamous males. Further, we identified 428 genes that responded to mating in females.” http://onlinelibrary.wiley.com/doi/10.1111/jeb.12763/full View in LinkedIn