BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Genomic analyses of the evolution and loss of distyly in Linum rev
 eal convergent evolution at the molecular level - Prof. Tanja Slotte (Stoc
 kholm University)
DTSTART:20230614T120000Z
DTEND:20230614T130000Z
UID:TALK199231@talks.cam.ac.uk
CONTACT:Thea Edith Kongsted
DESCRIPTION:Supergenes govern multi-trait balanced polymorphisms in a wide
  range of systems\, yet our understanding of their origins and evolution r
 emains incomplete. The reciprocal placement of stigmas and anthers in pin 
 and thrum floral morphs of distylous species constitutes an iconic example
  of a balanced polymorphism governed by a supergene\, the distyly S-locus.
  Recent studies have shown that the _Primula_ and _Turnera_ distyly superg
 enes are both hemizygous in thrums\, but it remains unknown if hemizygosit
 y is pervasive among distyly S-loci. As hemizygosity has major consequence
 s for supergene evolution and loss\, clarifying whether this genetic archi
 tecture is shared among distylous species is critical. We aimed to charact
 erize the genetic architecture and evolution of the distyly supergene in _
 Linum_ by generating a chromosome-level genome assembly of _Linum_ _tenue_
 \, followed by the identification of the S-locus using population genomic 
 data. We show that hemizygosity and thrum-specific expression of S-linked 
 genes\, including a pistil-expressed candidate gene for style length\, are
  major features of the Linum S-locus. Structural variation is likely instr
 umental for recombination suppression\, and although the non-recombining d
 ominant haplotype has accumulated transposable elements\, S-linked genes a
 re not under relaxed purifying selection. Genomic analyses of additional d
 istylous _Linum_ species further identify shared presence-absence variatio
 n at the S-locus\, indicating that hemizygosity in thrums is a general fea
 ture of _Linum_ S-loci. Finally\, we investigate the genetic causes and ge
 nomic consequences of breakdown of distyly\, resulting in homostylous and 
 largely self-fertilizing species. Our findings reveal remarkable convergen
 ce in the genetic architecture and evolution of independently derived dist
 yly supergenes\, and shed new light on the evolution and loss of an iconic
  floral polymorphism.
LOCATION:Part II Lecture Theatre\, Department of Zoology
END:VEVENT
END:VCALENDAR