| Abstract Detail
Comparative Genomics/Transcriptomics Bentz, Philip [1], Carey, Sarah [2], Harkess, Alex [2], Leebens-Mack, Jim [3]. Modeling the stepwise evolution of sex chromosomes in the genus Asparagus. There is much debate about whether the origin of sex chromosomes in hermaphroditic ancestral lineages is driven by a single 'master regulator gene' that determines sex; or via two linked genes that independently evolve sex-determining function, each separately affecting male and female function. Further, sex chromosome evolution is thought to be a progressive process, beginning with selection for linkage between the sex-determining gene(s) and additional sexually antagonistic genes, and punctuated by stepwise changes in genetic content within the non-recombining sex-determining region (SDR). These stepwise changes in ancestral sex chromosomes may be evident as 'evolutionary strata' in the SDR of extant sex chromosomes, as each stepwise addition of gene content is more similar to its ancestral autosomal homolog than are previously established strata. We will use the dioecious garden asparagus (Asparagus officinalis) and close relatives in the genus Asparagus as a model to investigate the origins and stepwise evolution of sex chromosomes. Garden asparagus is quickly becoming a model for studying dioecy and sex chromosome evolution, partly due to its hypothesized recent evolution of sex chromosomes. Traditional methods for detecting stepwise changes in gene content (evolutionary strata) on sex chromosomes compare KS between homologous X- and Y-linked genes on sex chromosomes. However, this traditional approach cannot be applied in this system, because no X- and Y-linked homolog gene pairs are found in the garden asparagus SDR. We will overcome this by developing a novel phylogenetic approach to test for the existence of evolutionary strata in the SDR of different species of Asparagus. Testing for strata in the SDR of diverse species of Asparagus will provide further insight into whether stepwise changes in gene content is universally a key feature of sex chromosome evolution.
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1 - University Of Georgia, Department Of Plant Biology, 120 Carlton Street, Athens, GA, 30602, United States
2 - HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
3 - University Of Georgia, Plant Biology, 2101 Miller Plant Sciences, Athens, GA, 30602, United States
Keywords:
phylogenetics
sex chromosomes
Dioecy
evolutionary strata
asparagus
sex-determination
genomics.
Presentation Type: Poster
Session: P1, Comparative Genomics/Transcriptomics Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1GT006
Abstract ID:657
Candidate for Awards:None |
