cloning problems

We like to put on that we know so much, when in reality we know so little!

http://www.iol.co.za/index.php?click_id=31&art_id=qw1050018123411B224&set_id=1

Successful human cloning is 'impossible'

April 11 2003 at 01:42AM
Quickwire

Washington - Successful human cloning is currently impossible because of basic
flaws in the embryonic development of primates, according to details of a
study published on Thursday in the journal Science.

The study by a team of researchers from the Pittsburgh Development Centre
observed basic molecular structures that blocked normal cell development
despite using four different techniques of nuclear transfer.

"The chromosomes do not split properly,", said Dr Gerald P. Schatten, senior
author of the study. "From the very first cell division, development is
inappropriate in vital ways."

The study's use of DNA imaging and analysis of basic cell structure revealed
that while cell division continued in a superficially normal manner,
chromosomal problems existed within each individual cell.

'We may discover how to make it work. It just doesn't work now' Problems with the mitotic spindle, which is among the key structures involved
in cell division, were named as one of the key flaws in human cloning. The
mitotic spindle functions to precisely align and separate chromosomes.

However, in cells originating as a result of nuclear-transfer, examination of
spindle configuration revealed chaotic structures and unequal chromosome
counts. Even the most basic proteins involved in spindle formation were
absent or inadequate, the study said.

"Current techniques such as those used to create Dolly the sheep, mice and
other domestic animals do not work in non-human primates," added Schatten. "I
don't want to say that this will never happen. Given enough time and
materials, we may discover how to make it work. It just doesn't work now." -
Sapa-DPA