00:01
Hello everyone in this question we will be discussing about the formation of the mesodermal layer in sea urchin.
00:10
So here we have one animal pole and the vegetal pole here.
00:16
So this animal pole has two genes, the an1 and an2, which here forms the ectoderm.
00:26
And the vegetal pole here has vg1 and vg2.
00:33
So here this vg1 basically is the oral ectoderm and this forms the hindgut that is the endoderm and the vg2 here forms the mid gut as well as the foregut and this here has the non -skeletal mesoderm that is known as the secondary mesoderm.
01:06
So here basically the gene hesc is present in all the nucleus except the micromere.
01:21
The large micromeres are the primary mesenkind cells that forms the skeletogenic mesenchime in which the fate is autonomous.
01:38
And the small micromere forms the primordial germ cell.
01:46
So here basically these are present in all the nucleus except the micromere.
01:51
So this hesc basically inhibits the skeleton forming mesen kind.
01:59
The specification of the micromere begins before the fertilization...