Segregation Distortion In An F2 Population May Not Be Trasmitted In A Multi-Parental Population That Included The Same Parents
Date
2016-05
Authors
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Publisher
University of Delaware
Abstract
This study concerns the analysis of responsive allelic variation associated with
phenotypic change. Examination of selection response through the lens of allele
frequency change, a common approach for associating regions of a genome with
changes in phenotypes, may be biased by non-random segregation or segregation
distortion. That is, specific alleles appearing to change rapidly in frequency in a
population could be due to distortion; however, these alleles may not be important
drivers for the observed selection response (i.e. a false positive association). I have
begun examining genetic properties of F2 populations derived from the initial crosses
of a TROPICal Synthetic (TROPICS) population of maize. Here, I present results
from one cross, CML341 x CML373, for which I constructed a genetic map from
genotyping-by-sequencing marker data that showed near perfect chromosomal
localization relative to the physical map. About 80% of the markers across the genome
displayed higher levels of heterozygosity than expected but 98.6% of these did not
exhibit statistically significant deviation; thus, there was significance in the total
number of markers that exhibited deviation. Non-random distortion was found in
multiple genomic regions that did not co-localize with previously mapped
gametophytic or gametic factors in maize that are known to underlie distortion. The
methods from this study will be used to examine the remaining F2 populations
corresponding to parents of the TROPICS in order to inform analyses on allele
frequency change in this population.
Description
Keywords
plant science, segregation distortion