BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:How to reduce body size: dimorphic development of the bone-eating 
 Osedax (Annelida) - Katrine Worsaae (University of Copenhagen)
DTSTART:20221012T120000Z
DTEND:20221012T130000Z
UID:TALK178523@talks.cam.ac.uk
CONTACT:Nadine Randel
DESCRIPTION:Timing is crucial\, especially during early development of ani
 mals. The theoretical evolutionary process termed progenesis is accepted a
 s the prevailing evolutionary route to underdeveloped (paedomorphic) life 
 forms with retained larval appearance\, e.g.\, salamanders\, most meiofaun
 al groups\, and many dwarf males. Progenesis proposedly starts with an acc
 elerated sexual maturation (compared to the ancestor) leading to an early 
 and synchronous offset of somatic development (in the descendant). This ev
 olutionary process is challenging to investigate since most microscopic me
 tazoan lineages are old and lack close macroscopic relatives for compariso
 n. However\, the dimorphic bone devouring worms of Osedax (Siboglinidae\, 
 Annelida) have both macroscopic females and microscopic dwarf males\; the 
 latter potentially being an outcome of progenesis. The embryos of Osedax a
 re genetically similar and sexual differentiation of the competent larvae 
 seemingly depend on environmental cues. Whereas adequate bone substrate & 
 exposure to bacterial symbionts seem to trigger metamorphosis into females
 \, exposure to cospecific female hormones seem to trigger metamorphosis in
 to dwarf males. The life cycle and development of Osedax therefore offer a
  unique experimental insight into the detailed morphogenesis and epigeneti
 c regulation underlying their symbiotic relationship (in females) and prog
 enesis (in males).\n            Using traditional immunochemistry labellin
 g and CLSM we have reconstructed distinct anatomical stages during the lar
 val and juvenile development of Osedax japonicus to serve as a basis for i
 nterpretation of molecular expression patterns. We found striking similari
 ties in the nervous system\, musculature\, ciliation and chaetae between l
 ate larval and adult male stages\, which support male dwarfism to be the o
 utcome of an early offset of somatic development (=progenesis). In our ong
 oing research we now seek to align and couple genetic expressions with ana
 tomical changes during development in order to characterize genetic key pl
 ayers in Osedax development and life cycle.
LOCATION:Online
END:VEVENT
END:VCALENDAR