Talk:Mammalian embryogenesis

When couples at fertility clinics freeze "embryos" for later use, what stage are these embryos in? Are they morula? blastocyst? embryoblast? other? Thanks! :-)

Embryos are frozen at the 6-8 cell stage (morula) stage--nixie 00:57, 27 May 2005 (UTC)


 * What's it called between the ages of 9-49 cells? And when - exactly - does it become a human 'embryo proper' rather than merely a 'blastocyst'? Is this at 151 cells? Maybe 152? This 'blastocyst' label is a smokescreen used to cloud the issue and justify controversial experiments.--CJ 4 July 2005 17:24 (UTC)

The terminology has been around alot longer than the stem cell debate.--nixie 5 July 2005 00:00 (UTC)

Has it Nixie? For how long? Can you answer my questions that i asked earlier regarding the precise stages of the embryo? If you read Michael Mulkay's The Embryo Research Debate (1997) it documents the rise of terms such as 'pre-embryo' and 'blastocyst' as being particular products of the IVF debate. If you would like to disagree with this then please feel free to provide references.--CJ 5 July 2005 00:16 (UTC)


 * Yes, it has, I can find papers if you want. I mean zygote, morula and blastocyst, I have never heard about "pre-embryo" (what would it be?). One cell embryo (and it is embryo already, not pre-anything) is a zygote, later morula and then blastocyst (blastocyst stage starts when a cavity appears among cells). Blastocyst is "embryo proper" as well as morula is. Look at the entry below "4-16 cells" 69.86.188.219 02:48, 16 July 2007 (UTC)an

stem cell question
From where does the term "stem cell" actually derive?
 * Not sure about that. It's a good question though! Can anyone provide an answer? Just a little note to the questioner, it's customary for users to sign their posts on the discussion page. This makes it easier to read the flow of the discussion.--Nicholas 15:00, 2 August 2005 (UTC)

4 to 16 cells
I thought at 4 to 16 cells it was still a blastula?

Hi there, Blastula is a term used for non-mammalian embryos and represents the stage when an embryo form a hollow sphere. The blastocyst is the mammalian equivalent to that stage. Up to the 8 cell stage, the stage of the embryo is usually defined by the number of cells (e.g. 4-cell-stage. The stages when the embryo is a "ball of cells" are referred to as Morula. Around the 8 cell stage, cells of the mammalian embryo upregulate expression of adhesion proteins on the cell surface which leads to a compaction of the 8-cell-embryo (now called: compacted morula). After division of the cells of the compacted morula, some cells end up in the entre of this compacted ball whereas some cells form the outer layer. The cells of the outer layer (called trophectoderm) seal of the inside of the ball. Pump-like proteins in the trophectoderm facilitate the the expansion of an inner cavity (called blastocoel). The appearance of the blastocoel marks the blastocyst stage.

CG

Beyond the cavity formation
The article suddenly stops at the formation of the amniotic and yolk sacs it would seem... is there a reason for this or has no one gotten around to writing about the trilaminar embryo, folding and preliminary organogenesis? I have just started writing the trilaminar embry page and realized there is no article (that I can find) which explains how an embryo comes to be three-layered. I also noticed there is no Human Embryogenesis article, which would make a perfect resting place for this sort of information. Anyone interested in helping with such an article should head over to the page for discussion, cheers -- Serephine / talk - 08:32, 22 April 2006 (UTC)

Question: "Invading" the endometrium
Is "invade" the verb used in technical scientific discussions? Thank you. --Dpr 00:41, 22 June 2007 (UTC)

Merging
Mammalian embryogenesis is already well covered in Embryogenesis - this page adds nothing and its inclusion is unnecessary Shall merge Iztwoz (talk) 20:54, 27 July 2014 (UTC)