Re: "Zygote"
Camilla, you're really digging up my old embryology class! :-) I think
the zygote is a special entity in that it consists of the merged sperm and
egg before it begins to split into the cells that then form the blastula. I
would think that the zygote could only exist as such until it starts
dividing into the undifferentiated cells that make up the blastula. I guess
I'm going to have to get to a library and find a text on embryology.
In my days we didn't call it an embryo until the cells had differentiated
and migrated into their relative positions..... i.e. the "tadpole" stage...
Whatdya think?
Bill
*****************************
-----Original Message-----
From: Camilla Flintermann [mailto:[log in to unmask]]
Sent: Thursday, October 05, 2000 11:22 AM
To: [log in to unmask]
Subject: Re: Stem Cells = "Blastula" ?
Well, my embryology class was a looooong time ago---and you may be right,
but the stage I have seen cited is the zygote, a "cell produced by the
union of egg and spern":(acc. to Tabers' Medical Encyclopedia) which I
think would be even earlier than a blastula? Is this correct?
>Stem Cells = "Blastula" ?
>
>Is it not true that the best undifferentiated cells are to be found in the
>blastula phase of development?
>
>If I remember my college embryology from 35 years ago, (and if they haven't
>completely changed the field of embryology since then), the egg and sperm
>come together, begin to split and form a hollow sphere made up of cells....
>a blastula. At this stage the individuals cells can become anything,
>depending on chemical and other conditions and influences ("tropisms") to
>which they may become exposed.
>
>If the blastula is the best source of stem cells, then should the questions
>not be focused on the use of blastulas, not embryos. What say you?
>
>Bill
>PWP, New Jersey
Camilla Flintermann, CG for Peter 82/70/55
Oxford, Ohio
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