Meeting Abstract

P3-119   -   Do testosterone and haemosporidian blood parasites predict sperm telomere length in Song Sparrows (Melospiza melodia)? Ross, KV*; Talbott, KM; Wolf, SE; Ketterson, ED; Indiana University, Bloomington, IN; Indiana University, Bloomington, IN ; Indiana University, Bloomington, IN ; Indiana University, Bloomington, IN kvross@iu.edu

Haemosporidians are common vector-borne blood parasites found in songbird populations throughout the world. Some studies suggest that haemosporidians can affect the reproductive success of their hosts. However, it is unclear whether haemosporidian infections can impact multiple generations. Sperm telomere length is a possible mechanism that could connect the effects of the parental infection to offspring. Telomeres are the regions of DNA on the ends of chromosomes that provide protection and stability. In general, telomere length is positively associated with organism health. In humans, longer telomeres in sperm are associated with increased fertilization rates and higher embryo quality. Previous studies have shown that sperm count and motility are reduced in hosts infected with haemosporidian blood parasites and that higher levels of testosterone are associated with higher parasite loads. Therefore, we investigated the relationship between circulating testosterone levels, haemosporidian blood parasite loads and sperm telomere length in Song Sparrows (Melospiza melodia). We collected blood and sperm samples from breeding-condition Song Sparrows captured near Bloomington, Indiana. Then, we used qPCR to determine telomere length in DNA extracted from sperm, enzyme-linked immunosorbent assays to quantify circulating testosterone levels in plasma, and blood smear microscopy to determine parasite loads. We predict that higher levels of circulating testosterone and higher parasite loads will be associated with shorter telomere lengths. We will discuss the results of this project in the context of parasite impacts on host reproduction.