The fluid-filled perivitelline space overlays the vitelline membrane, which surrounds the yolk and the blastoderm
, which will become the developing embryo.
The blastomeres ultimately form a blastoderm
and a germ disk, from which the embryonic nauplius stage develops (Ishikawa, 1885; Weldon, 1887; Brooks and Herrick, 1891; Nair, 1949; Klann and Scholtz, 2014).
The gastrula phase began from 20-40 h after post fertilization and 2 days after post fertilization, germ ring surrounding the margin of the blastoderm
; it is the main characteristics of this phase and embryonic protection layer stretched from germ ring towards the animal pole and form the neural tube.
The entire blastoderm
was harvested as mentioned previously and then dissociated in tubes containing PBS at room temperature .
This allowed the blastoderm
to float upward and take a position over the yolk sac just beneath the shell.
The gastrulation stage ends when the blastoderm
completely covers the yolk, characterizing the 100% epiboly stage, which is marked by the presence of primary germ layers (endoderm, mesoderm and ectoderm) and the embryonic axis, giving rise to the subsequent stage characterized by organogenesis (Wolpert et al., 2000).
One had arrested growth at early vascularised blastoderm
Effects of Zinc deficiency on the chick embryo blastoderm
. Acta Anat (Basel).
The egg-white quality and the distance between the blastoderm
and the eggshell remain constant during longer periods in young poultries (SANTOS et al., 2009).
Wrth i'r bl gael ei ffurfio mae'r celloedd yn tueddu i ymledu ar y tu allan i'r bl ac mae'r celloedd yma'n cael eu galw'n blastoderm
, gan adael ceudod yn y canol.
In Drosophila, segmentation results from a simultaneous subdivision of the blastoderm
. Arthropods use the segment-polarity-genes known from Drosophila in their segmentation.
In chicken embryos, myostatin expression can be detected as early as the blastoderm
stage (Kocamis et al., 1999).
The chosen embryonic stages were: eggs at 0 d old; 1 d old (i.e., about the time the blastoderm
is formed); 8 d old [i.e, blastokinesis is established (Jones 1964)].
The egg which were incubated for 11 h our showed distract evidences of cleavage, especially superficial cleavage, resulting in the formation of uniform monocellular blastoderm
At midblastula, cells of the blastoderm
become mobile and spread over the yolk in the process known as epiboly.