Abstract Detail

Insights into the diversity of plant sex chromosomes

Rifkin, Joanna [1], Beaudry, Felix [2], Humphries, Zoë  [2], Choudhury, Baharul [2], Wright, Stephen [2], Barrett, Spencer [2].

A role for pre-existing recombination suppression in the evolution of a plant neo-sex chromosome.

Sex chromosomes are believed to evolve through the gradual stepwise loss of recombination between homologs. However, recombination rates vary widely along chromosomes across the tree of life, and evolve dynamically. We investigate recombination rates in an old and new sex chromosome in the dioecious plant Rumex hastatulus, which has a karyotype polymorphic for a Robertsonian fusion leading to a neo sex chromosome in some populations. We find that recombination suppression is widespread on both the sex chromosomes and the autosomes. The neo sex likely had low recombination rates before becoming a sex chromosome through a Robertsonian fusion, and has experienced further subsequent loss of recombination. This is consistent with growing theoretical and empirical evidence that pre-existing recombination suppression may be important in the evolution of sex chromosomes in plants.

1 - 25 Willlcocks St, Toronto, M5S3B2, Canada
2 - University of Toronto, 25 Willcocks St, Toronto, ON, M5S 3B2, Canada

Keywords:
sex chromosome
Rumex
recombination
angiosperm.

Presentation Type: Symposium Presentation
Session: SY5, Insights into the diversity of plant sex chromosomes
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 12:30 PM
Number: SY5006
Abstract ID:293
Candidate for Awards:Margaret Menzel Award