Greetings of peace, Prof. Leonardo.
Thank you for your questions. Here are our responses:
Question 1
The medial and intermediate epiblasts refer to the regions of the horizontal strip cut from the center of the epiblast which are sections the researchers conducted their study to determine their specification. This horizontal strip of epiblast tissue was dissected into three sections: two intermediate regions, and one medial region. One of the findings of this paper by Prasad et al. (2020) provides evidence that the medial region of the horizontal strip of avian epiblast leads to neural specification, while the intermediate region leads to a neural crest cell fate.
Question 2
Yes. In this model proposed by the authors, we can say that the neural crest cells as a fourth germ layer. As stated in the study itself, they proposed that the neural crest cells are a “segregated populations of cells with cell fates distinct from others”.
Question 3
No. Since the epiblast is only formed through ingression of cells prior to gastrulation and is only observed in birds, reptiles and mammals. In amphibians, there is no epiblast formed, and the three germ layers are derived from involution of cells that forms into a blastopore.
Thank you.
Thank you for your questions. Here are our responses:
Question 1
The medial and intermediate epiblasts refer to the regions of the horizontal strip cut from the center of the epiblast which are sections the researchers conducted their study to determine their specification. This horizontal strip of epiblast tissue was dissected into three sections: two intermediate regions, and one medial region. One of the findings of this paper by Prasad et al. (2020) provides evidence that the medial region of the horizontal strip of avian epiblast leads to neural specification, while the intermediate region leads to a neural crest cell fate.
Question 2
Yes. In this model proposed by the authors, we can say that the neural crest cells as a fourth germ layer. As stated in the study itself, they proposed that the neural crest cells are a “segregated populations of cells with cell fates distinct from others”.
Question 3
No. Since the epiblast is only formed through ingression of cells prior to gastrulation and is only observed in birds, reptiles and mammals. In amphibians, there is no epiblast formed, and the three germ layers are derived from involution of cells that forms into a blastopore.
Thank you.