My degree is peanuts really - BS in molecular bio. I worked in a research lab for a couple of years, and the main model they used to study gene regulation was early embryogenesis. So I had to understand fairly well, and plenty of time to contemplate about, the extremely fine points of what's needed for a creature to start developing from a single cell.
It's really cool - the original body pattern is laid out by a gradient of proteins and RNA, which were already produced by and arranged across the ovum before fertilization. So the very first steps of development depend on maternal genes, not the embryo's own genes. There's interaction between zygotic and maternal genes at the time the embryo's genes start to get expressed. I am just guessing that this makes exact cloning of extinct creatures (using only DNA) virtually impossible, unless they are terrifically closely related to the surrogate / egg donor species.
I admit to talking out my ass about immunology of pregnancy, and a little bit about making functional chromosomes from ancient DNA. I know that the way DNA is "packaged" with proteins can affect how genes get expressed, so I was speculating that that'd be another obstacle to cloning extinct species.
|Because this message is archived you cannot respond to it.|