BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Heterochrony and developmental system drift as the forces shaping 
 spiralian development - Dr Chema Martin-Duran (Queen Mary\, University of 
 London)
DTSTART:20230510T120000Z
DTEND:20230510T130000Z
UID:TALK199216@talks.cam.ac.uk
CONTACT:Nadine Randel
DESCRIPTION:Animals with bilateral symmetry (i.e.\, Bilateria) show the hi
 ghest diversity of body plans. Remarkably\, nearly half of these body plan
 s occur in a large clade of invertebrates termed Spiralia\, which exhibits
  a unique mode of development termed spiral cleavage as the ancestral and 
 defining feature. How spiral cleavage is controlled and how it generates s
 uch a diversity of adult morphologies despite its seeming conservation is 
 unknown but fundamental to our understanding of animal development and evo
 lution. To investigate these questions\, my lab has established the “bas
 al” annelid Owenia fusiformis as a tractable research system. In this sp
 ecies\, the FGF receptor triggers the ERK signalling pathway to specify a 
 dorsoposterior fate in the cell that acts as the axial organiser. This eve
 nt triggers a cascade that involves Notch and BMP signalling and transcrip
 tional regulators involved in trunk mesoderm and dorsoposterior developmen
 t. In other annelids\, however\, the dorsoventral specification does not d
 epend on the FGF-ERK-BMP axis but on Activin/Nodal\, which appears to cont
 rol cell differentiation along the animal-vegetal axis in O. fusiformis. N
 otably\, this transition to Activin/Nodal coincides with a shift from cond
 itional to maternally-regulated autonomous development and the accelerated
  formation of adult characters\, such as a segmented trunk. Together\, our
  work reveals widespread developmental system drift and heterochronic shif
 ts in axial patterning and organogenesis in Spiralia and during spiral cle
 avage\, without these implying\, paradoxically\, major alterations in the 
 early patterns of zygotic divisions.
LOCATION:Part II Lecture Theatre\, Department of Zoology
END:VEVENT
END:VCALENDAR