while studying embryology of Holobatrachus tigerinus (Rana tigerina), in cleaving fertilized egg, i found third cleavage furrow to running vertically. while in B. stomaticus and other amphibians found in Pakistan and India it is always horizontal, dividing the zugotic egg unequally in eight cells, upper four dark micromeres, and lower whitish megameres.
However, in H. tigerinus fourth cleavage was horizontal resulting in micromeres and megameres. my observation was published:
Khan, M. S. 1969. A normal table of Rana tigerina Daudin. 1. Early development (Stages 1-27). Pakistan J. Sci. 21:36-50.
since i have not received any comment on my paper. i will be happy if some body shares his/her experience.
I have not conducted such studies but gone through some articles on the subject and all such articles were describing the third cleavage furrow running horizontally dividing the zygotic egg unequally in eight cells, upper four micromeres and lower megameres.
Your finding is surprising !
There are some frog species, the embryos of which are characterized by the vertical furrow of third cleavage. Examples: Gastrotheca riobambae and Eleutherodactulus coqui fron Neotropics, Ascaphus truei from north America, Philoria (Kyarranus) sphagnicolus from Australia, Rhacophorus arboreus from Japan (and several species of urodele amphibians).
Important question for me: at what stage of development is there a loss of blastomere division synchrony in the animal half of Hoplobatrachus tigerinus embryo? At 8-16-celled stage or considerably later? Could you please send me your paper on Hoplobatrachus development published in Pakistan J. Sci. (1969)?
Thanks.
dear dr Alexey
i am sorry i visited the page today and found your comments. thanks for the names of amphibians where third cleavage runs vertical. please, see the paper attached
- Badges
- Science topic
- Similar topics
- Biological Science
- Anatomy