Abstract Detail

Population Genetics/Genomics

Kollar, Leslie [1], Eppley, Sarah [2], Rosenstiel, Todd [3], Gall, Elliott T. [4], McDaniel, Stuart [5].

Genetic conflict in an ancient interaction between moss and microarthropods.

A central goal in evolution is to understand the mechanisms that maintain genetic variation for fitness. Across much of the tree of life, males and females are differentiated in many non-reproductive traits, presumably because selection favors different trait optima in each sex. Thus, an allele that increases fitness in one sex can be deleterious in the opposite sex, a form of genetic conflict called sexual antagonism. The role of sexual antagonism in maintaining variation for fitness depends upon the degree to which males and females respond similarly to an allelic substitution (i.e., the cross-sex correlation) and the difference in optimum phenotypes between the sexes, both poorly understood quantities. An experimentally tractable trait under sexually antagonistic selection is volatile organic compound (VOC) profile in moss. Analogous to flowering plant-pollinator mutualisms, female C. purpureus gametophytes emit abundant VOCs to attract sperm-dispersing microarthropods, which significantly increase fertilization rates in moss. Male mosses produce fewer VOCs than female mosses, suggesting that VOC production may be costly. Here, I used a common greenhouse experiment with 46 haploid-sibling families, each comprising at least three male and three female offspring to estimate the cross-sex correlation for VOC production and several other life history traits in the moss, Ceratodon purpureus. We found that many compounds are positively correlated in females whereas in males fewer are positively correlated and one compound is negatively correlated with many compounds. This lays the foundation for identifying biochemical pathways which could be under genetic conflict. Additionally, we were able to demonstrate that there is additive genetic variation for several VOCs and other life history traits, and determined how much of that variation is on autosomes versus sex chromosomes. Next, I plan to conduct competitive mating experiments in controlled mesocosms to identify traits linked with female and male reproductive success.

1 - University of Florida, Biology Department, Gainesville, FL, 32611, USA
2 - Portland State University, Biology, PO Box 751, Portland, OR, 97207, United States
3 - Biology, 1719 SW 10th Ave., SB2 Room 246, Portland, OR, 97207, United States
4 - Portland State University, Engineering Department, Portland, OR, 97202, USA
5 - Biology Department, University Of Florida, Gainesville, FL, 32611, United States

Keywords:
Sexual selection
Genetic conflict
Volatile organic compounds
microarthropods
bryophytes
Dimorphism.

Presentation Type: Oral Paper
Session: POPGEN2, Population Genetics/Genomics II
Location: Tucson H/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 1:30 PM
Number: POPGEN2001
Abstract ID:675
Candidate for Awards:Margaret Menzel Award