A polycystin-1 controls postcopulatory reproductive selection in mice

Abstract

Pkdrej, a member of the polycystin-1 gene family, is expressed only in the male germ line. Male mice that are homozygous for a targeted mutation in the Pkdrej allele (Pkdrej tm/tm ) are fertile in unrestricted mating trials, but exhibit lower reproductive success when competing with wild-type males in sequential mating trials and in artificial insemination of mixed-sperm populations. Following mating, sperm from Pkdrej tm/tm mice require >2 h longer than those of wild-type males to be detected within the egg/cumulus complex in the oviduct. Sperm from mice of both genotypes are able to capacitate in vitro. However, one of the component processes of capacitation, the ability to undergo a zona pellucidaevoked acrosome reaction, develops more slowly in sperm from Pkdrej tm/tm animals than in sperm from wild-type males. In contrast, a second component process of capacitation, the transition to hyperactivated flagellar motility, develops with a similar time course in both genotypes. These two behavioral consequences of capacitation, exocytotic competence and altered motility, are therefore differentially regulated. These data suggest that Pkdrej controls the timing of fertilization in vivo through effects on sperm transport and exocytotic competence and is a factor in postcopulatory sexual selection.capacitation ͉ evolution ͉ fertilization ͉ polycystin ͉ sexual selection

Genome engineering uncovers 54 evolutionarily conserved and testis-enriched genes that are not required for male fertility in mice

“…For example, Pkdrej KO mice have been produced previously, and their litter size was normal, consistent with the present study (36). However, detailed analyses showed that Pkdrej KO males exhibit lower reproductive success compared with WT males in sequential mating trials, suggesting that Pkdrej is important in postcopulatory sexual selection (36).…”

Aquaporin3 is a sperm water channel essential for postcopulatory sperm osmoadaptation and migration

“…Under physiological condition, before reaching the eggs, sperm must successfully migrate through the uterine-oviduct junction, where most of the sperm were blocked out and stayed in the uterine cavity. By checking the number of sperm that arrived in the egg/cumulus complex after time-defined copulation [28], we found a significant decrease in sperm/egg ratio in the Aqp3-null male ( Figure 4D and 4E), supporting the idea that the impaired in vivo fertilization in the Aqp3 -/-male is due to reduced sperm number that migrated to oviduct. Moreover, in vitro sperm transwell migration assay demonstrated that the Aqp3-null sperm showed decreased ability in passing through the mesh pores of membrane filter that mimicked the barrier of uterine-oviduct junction ( Figure 4F-4H and Supplementary information, Figure S4), which further justified our hypothesis.…”

Fitness Assays Reveal Incomplete Functional Redundancy of the HoxA1 and HoxB1 Paralogs of Mice

“…This is likely due to the competitive nature of house mice, which vigorously compete with one another over resources. Differences in physiological performance that are too cryptic, diffuse, or subtle to cause gross defects may nonetheless lower fitness in a competitive environment and this concept has driven the use of fitness assays in Drosophila, RNA virus, and yeast communities (e.g., Shabalina et al 1997;Thatcher et al 1998;Lauring et al 2012); unfortunately, similar approaches have not been adopted by those working with vertebrate model systems (with the notable exception of genes involved in sperm function or competition, e.g., Sutton et al 2008). In addition to the Hoxb1 A1 phenotypes herein, OPAs have revealed adversities associated with three other genetic treatments, including cousin-and sibling-level inbreeding and bearing the selfish genetic element known as the t complex, which had escaped detection for decades (Meagher et al 2000;Carroll et al 2004;Ilmonen et al 2008).…”