chick lab - society for developmental biology · chick cheap, easy to obtain fertilized eggs easy...

Chick Lab

Lee Niswander HHMI/ U Colorado Health Sciences Center

lee.niswander@uchsc.edu

Chick

Cheap, easy to obtain fertilized eggsEasy to work with on bench with dissecting microscopeSimilar development to human (flat disc)Genome - 1 x 109 bp (1/3 size of mouse and human); genome sequenceRapid functional tests

Microsurgery (cut & paste) to define cell interactionsMolecular manipulation - gain and loss of functionImaging, cell tracking

Fertilization

Hamburger and Hamilton Staging Stage 2 Stage 4

Early somite/heart fields

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

HH Stage 7

HH Stage 14HH Stage 10

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Hensen’s node as an embryonic organizer

Prospective mesoderm cells ingress through the primitive streak in a rostral-caudalorder that presages their medial to lateral position after ingression

Node (most rostral) primitive streak= midline tissue

Rostral (anterior) primitive streak= paraxial (somite) tissue

Middle streak movements

Rapid lateral movement, pause, then back toward regressing node Lateral plate mesoderm

Yan, Dormann, Munsterberg and Weijer; Developmental Cell 3, 425-437, 2002

Caudal streak movements

Lateral and caudal movement

extraembryonicmesoderm

Cell autonomous or mediated by surrounding tissues?

Control Anterior streak to anterior streak

Anterior streakto caudal streak

Streak cells are attracted to FGF4

SU5402 = FGF inhibitor

Embryonic Polarity

Left-right

India ink

In Ovo Electroporation

In Ovo Electroporation

+ -

enhancer driven

constitutive promoter

RNAi