Abstracts (first author)
Like father like son? Nongenetic paternal effects reinvigorate the possibility of telegony
Telegony, a belief that was once widely accepted but now largely dismissed, is the hypothesis that offspring occasionally inherit characters from a previous mate of their mother. Although telegony seems unfeasible under Mendelian laws of inheritance, mounting empirical evidence for nongenetic inheritance mechanisms reinvigorates the hypothesis. In the neriid fly, Telostylinus angusticollis, fathers transmit their environmentally-acquired condition to offspring: large fathers that are reared on a high-quality larval diet produce larger offspring. Males show no obvious forms of paternal investment or care, and thus the mechanism mediating the effect of paternal condition on offspring body size is not known. As a first step towards disentangling whether the effect is borne by the sperm itself or by accessory-gland products (ACPs) in the seminal fluid, we mated females initially to a male in high or low condition and then remated the female to a new male in high or low condition two weeks later. Interestingly, offspring size and viability were determined by the condition of the first male, with no effect of the condition of the second mate. Genetic tests confirm this result holds even when the second male is the biological father of the offspring. These findings suggest the paternal effect is mediated by ACPs, and provide a compelling case for reassessing the possibility of telegony as a valid phenomenon.