Postcopulatory reproductive processes: The role of female and male reproductive genes and proteins in speciation and sexual selection
Al-Wathiqui, Nooria.
2016
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Abstract: Sexual selection is a powerful force that drives the evolution of
reproductive traits and continues after mating is completed. Postcopulatory sexual
selection involves molecular interactions between the male ejaculate and the female
reproductive tract; these interactions are mediated by male seminal fluid proteins (SFPs),
transferred in the male ejaculate, and female reproductive ... read moreproteins (FRPs), secreted by the
female reproductive tract. SFPs have been characterized in numerous species and shown to
affect female behavior and physiology. However, they have been poorly studied in species
where males transfer a packaged ejaculate, called a spermatophore. Many insects transfer
spermatophores, yet the implication of this type of ejaculate transfer for postcopulatory
interactions is unclear. Furthermore, we understand little about FRPs and their roles in
postcopulatory sexual selection. Not only are female proteins potential mediators of sexual
selection, but may play a role in reproductive isolation due to their potential for rapid
evolution. Here, I used a combination of RNA sequencing, proteomics, and metabolomics to
characterize SFPs and FRPs in the spermatophore-transferring taxa: Ostrinia nubilalis
moths, Tribolium castaneum beetles, and Photinus pyralis fireflies to determine how
reproductive genes, proteins, and metabolites differentially regulate postcopulatory
interactions between the sexes in different ecological contexts. First, I used these
methods to identify male and female reproductive genes that could be mediating a
postmating, prezygotic barrier acting between O. nubilalis strains. I found that ECB males
differentially express peptidases and odorant binding proteins between strains. After
mating within- and across-strain, females of O. nubilalis also differentially expressed
several reproductive genes, many of which are novel. In T. castaneum, I used experimentally
enforced monandry to examine how relaxed postcopulatory sexual selection could influence
reproductive gene expression. Monandrous males showed a shift in gene expression that
indicated they may be increasing sperm or production of eggs in female mates. Finally, in
P. pyralis fireflies I characterized the composition of the male spermatophore, which I
found contains a number of peptidases and proteins related to the immune response. Across
all three taxa, I found that both sexes express peptidases that may be important mediators
of postcopulatory sexual interactions in these spermatophore-producing
species.
Thesis (Ph.D.)--Tufts University, 2016.
Submitted to the Dept. of Biology.
Advisor: Sara Lewis.
Committee: Erik Dopman, Laura Sirot, Frances Chew, Colin Orians, and Stephen Fuchs.
Keywords: Evolution & development, and Ecology.read less - ID:
- mg74qz46w
- Component ID:
- tufts:21177
- To Cite:
- TARC Citation Guide EndNote
