The Seminal fluid proteome of the polyandrous Red junglefowl offers insights into the molecular basis of fertility, reproductive ageing and domestication.
Seminal fluid proteins (SFPs) are emerging as fundamental contributors to sexual selection given their role in post-mating reproductive events, particularly in polyandrous species where the ejaculates of different males compete for fertilisation. SFP identification however remains taxonomically limited and little is known about avian SFPs, despite extensive work on sexual selection in birds. We characterize the SF proteome of the polyandrous Red junglefowl, Gallus gallus, the wild species that gave rise to the domestic chicken. We identify 1,141 SFPs, including proteins involved in immunity and antimicrobial defences, sperm maturation, and fertilisation, revealing a functionally complex SF proteome. This includes a predominant contribution of blood plasma proteins that is conserved with human SF. By comparing the proteome of young and old males with fast or slow sperm velocity in a balanced design, we identify proteins associated with ageing and sperm velocity, and show that old males that retain high sperm velocity have distinct proteome characteristics. SFP comparisons with domestic chickens revealed both qualitative and quantitative differences likely associated with domestication and artificial selection. Collectively, these results shed light onto the functional complexity of avian SF, and provide a platform for molecular studies of fertility, reproductive ageing, and domestication.
Center for Reproductive Evolution, Department of Biology, Syracuse University, US.
Kirill
K
Borziak
Edward Grey Institute, Department of Zoology, University of Oxford, UK.
Aitor
A
Álvarez-Fernández
Drosophila Genetic Resource Center, Kyoto Institute of Technology, Saga Ippongi-cho, Ukyo-ku, Kyoto 616-8354, Japan.
Timothy
T
L Karr
Edward Grey Institute, Department of Zoology, University of Oxford, UK.
Tommaso
T
Pizzari
Center for Reproductive Evolution, Department of Biology, Syracuse University, US.
Steve
S
Dorus
D000375:Aging; D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D002645:Chickens / Q000235:genetics / Q000502:physiology*; D000071278:Domestication; D004591:Electrophoresis, Polyacrylamide Gel; D005298:Fertility / Q000235:genetics*; D008297:Male; D025341:Principal Component Analysis; D020543:Proteome / Q000235:genetics*; D012661:Semen / Q000378:metabolism; D029589:Seminal Plasma Proteins / Q000235:genetics / Q000378:metabolism*; D013081:Sperm Motility / Q000235:genetics; D013094:Spermatozoa / Q000502:physiology; D053719:Tandem Mass Spectrometry
D030161:Avian Proteins; D020543:Proteome; D029589:Seminal Plasma Proteins