University of Pittsburgh Department of Biological Sciences Presents:
Dr. Maureen Neiman
University of Iowa
Sex in the Wild (and Especially in New Zealand)
Why sexual reproduction (sex) is so common remains a hotly debated topic. Direct study of the costs and benefits of sex requires comparison between otherwise similar sexual and asexual forms. From this perspective, Potamopyrgus antipodarum, a New Zealand freshwater snail, is a powerful system to apply to the problem of sex because phenotypically and ecologically similar sexual and obligate asexual individuals and lineages frequently coexist in nature. Many hypotheses for the maintenance of sex focus on whether and how sexual vs. asexual reproduction influences important properties of genome evolution, like the spread of beneficial alleles and the clearance of harmful mutations. Accordingly, my students and I, along with several other collaborators, are leading a genome project for P. antipodarum. In this seminar, I will discuss how we have used these new genomic resources to address the sex question. How the genomes of sexual vs. asexual lineages manage the accumulation of deleterious mutations is a key component of many hypotheses for sex. I will address the extent to which asexual P. antipodarum lineages might be accumulating harmful mutations at a higher rate than sexual counterparts and whether these mutations might cause enough harm to contribute to the maintenance of sex. A second project focuses on the evolution of repetitive elements in sexual vs. asexual P. antipodarum. Repetitive elements are a major source of variation in genome structure, are often harmful, and are expected to be affected by reproductive mode. The third project that I will present focuses on how genes and traits used primarily or exclusively for sexual reproduction, like meiosis-specific genes and sperm, evolve in an asexual context. While all of these projects are still ongoing, our data do suggest that sexual reproduction has important consequences for genome evolution that could influence the maintenance of sex and the success (or lack thereof) of asexual lineages.
Monday, March 26, 2018
169 Crawford Hall
11:00 A.M.
10:50 A.M. refreshments
Host: Dr. Tia-Lynn Ashman