In article <M_Doherty-1107960941210001 at db428.niaid.nih.gov>,
M_Doherty at NIH.gov (M. Doherty) wrote:
> In article <4s263a$9ii at news.aimnet.com>, xyzzyx at aimnet.com (xyzzyx) wrote:
>> > Is it possible to distinguish a male sperm from a female sperm,
> immunologically?
>> No - Only male cells will display the (male specific) H-Y antigen, but
> this is apparently not expressed in sperm.
>> There is an easier way however. If you can see a sperm, you can safely
> assume it is male, since females don't make sperm - they make eggs :-)
>> If on the other hand, you mean whether the sperm carries an X chromosome
> (thus giving rise to a girl) or a Y (giving rise to a boy) the way it is
> currently done is to allow several egges to be fertilised, grow into a 16
> or 32 cell embryo and extract a couple of cells for genotyping.
>Actually, if you simply want to know wether it's a 'female or male' sperm
(it should more correctly read whether the sperm carries a X or Y chomosome)
this is (most amazingly) possible with flow cytometry - although
probably not all machines. Just have a look in Nature/Science/Immunology
Today, there were some time ago some advertisments from a cytometer
producing company (that was formerly called 'partec' if I am right).
They show a DNA staining of Bull sperm. You clearly see two peaks due
to the fact that the X chromosome is somewhat bigger than the Y. And
remember, this difference is resolved in the background of all the other
chromosomes. Quite amazing.
If one could get a good 'live stain', that would be the way to define
the sex beforehand - hopefully nobody ever does this in humans !
jorg
kirberg at nki.nl