Abstract Detail

Insights into the diversity of plant sex chromosomes

Carey, Sarah [1], Rifkin, Joanna [2].

Insights into the diversity of plant sex chromosomes.

The diversity of plant reproduction is extraordinary. Botanists have extensively explored how plants coevolve with pollinators to facilitate mating, how they allocate resources to male and female function, and mechanisms of avoiding and adapting to widely varying levels of inbreeding. Although the first identification of plant sex chromosomes occurred over a century ago, the importance of plant sex chromosomes is only now being appreciated in context with other aspects of plant sexual diversity. Sex chromosomes in plants also span a wide range of diversity, which is ideally suited to explore the extreme genomic environment of a recombination-suppressed sex chromosome. 
For plants which express sex in their diploid stage, sex chromosomes are either XY or ZW, depending on which is the heterogametic sex. But some plants express sex (or mating-type) in the haploid, not diploid stage of their life cycle (UV chromosomes and MT loci). Polyploidy can occur in diploid and haploid-dominant systems, and the effects of these events on dioecy can vary. The age and degree of divergence between sex chromosomes also vary widely, as do the genome and chromosome sizes of plants with sex chromosomes. All of these forms of variation can alter the effective population size, efficacy of selection, patterns of repetitive sequence accumulation, structural variation, and mutational spectra of an essential and sometimes sizeable region of the genome. In addition, although sex chromosomes are less common in plants than in animals, they have arisen independently and sometimes repeatedly in almost every major clade of land plants as well as in green, red, and brown algaes. Because dioecy is rare in plants, these independent origins of sex chromosomes also generally have close relatives without sex chromosomes. This allows comparisons of “replicate” chromosomes in different genomic environments. 
For these reasons, plant sex chromosomes offer ideal models for testing general patterns and mechanisms in sex chromosome evolution, as well as how those patterns and mechanisms change depending on different aspects of plant genomes. The speakers we have invited to this symposium reflect this breadth and diversity in their research. They use a variety of theoretical and empirical approaches to dissect the genomic contents and evolutionary history of sex chromosomes in systems from across the tree of green plants. Given the fundamental nature of the evolutionary questions addressed and the wide array of systems and approaches, this symposium will be of broad interdisciplinary interest to all botanists.

1 - University of Florida, Department of Biology, Gainesville, FL, USA
2 - 25 Willlcocks St, Toronto, M5S3B2, Canada

none specified

Presentation Type: Symposium Presentation
Session: SY5, Insights into the diversity of plant sex chromosomes
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 10:00 AM
Number: SY5SUM
Abstract ID:944
Candidate for Awards:None

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