Lectures - avian hypoblast/Visceral endoderm formation

what is the first thing that happens in the formation of the avian hypoblast

some of the AP epiblast cells delaminate and migrate towards yolk through sub germinal cavity and stick to each other and become hypoblast cells

Describe the avian hypoblast

1st layer of cells

delaminated from AP

forms below AP epiblast

what is hypothesized with the avian hypoblast

hypothesized that hypoblast cells anterior to embryo give rise to primordial germ cells and moves them from epiblast to germinal crescent

what does the avian hypoblast not do

does not: contribute to embryo or extraembryonic membranes

what is created with avian hypoblast formation

another fluid filled cavity between epiblast and hypoblast - blastocoel

where is the blastocoel in avian layers

between epiblast and hypoblast

where is the sub germinal cavity in avian layers

between hypoblast and yolk

what is the avian epiblast

former blastoderm

comprised of AP, dorsal most MZ and AO cells

what is the avian blastula made up of

structure composed of epiblast and hypoblast

in the avian blastula how many fluid cavities exist

2, sub germinal cavity and the blastocoel

is the avian hypoblast transitory

yes

what is the general purpose of the hypoblast

prepares embryo for explosion of cellular complexity

the avian blastula is

bilaminar

define bilaminar

has 2 true layers

avian hypoblast is made of cells from

AP only

what specifically is the avian epiblast made of

dorsal most cells from AP, MZ, and AO