Inbreeding depression in male reproductive traits

Inbreeding frequently leads to inbreeding depression, a general reduction in trait values and loss of fitness, and it appears that some sexually selected traits are especially sensitive to inbreeding, but sperm may be an exception. Additionally, because inbreeding depression is always in the direction of low fitness, it can reveal the direction of past selection acting on trait values. Here, we experimentall manipulate levels of inbreeding in a beetle (Tribolium castaneum) by full-sib mating for six generations. This breeding design allowed us to track the effects of increasing homozygosity on male reproductive traits (sperm and testes size), male size and lifespan, and reproductive output within inbred families, and on the heritability of these traits. All traits measured showed significant inbreeding depression and heritabilities tended to increase with inbreeding. Since inbreeding resulted in shorter sperm and smaller testes, it suggests that longer sperm and larger testes confer hig..., , , # Inbreeding depression in male reproductive traits Vasudeva, R.1*, Sales, K.2, Gage, M.J.G.†, and Hosken, D.J.3* Summary: This study investigates the consequences of inbreeding on male reproductive traits and survival. Overall, we initiated small independent populations from an outbred stock and from this we carried out full-sib matings for six consecutive generations. We tracked many life history traits linked to fitness (reproductive success). This work constitutes 29 data files (.csv), image files (.jpg) overall that are linked to the findings of this study; ‘.csv’ format and an Rscript file. RV with help of members of the group initiated the small populations and was responsible for data collection, curation and KS, MJGG helped maintain the lines for six months due to RV’s absence. RV collected much of this data, imaged the traits, measured them and carried out the preliminary analysis. Lifespan of the study species is long for a small beetle, we tracked individuals until deat...,