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From: mikes@tekecs.TEK.COM (Michael Sellers)
Newsgroups: sci.med
Subject: Re: sex and color
Message-ID: <7858@tekecs.TEK.COM>
Date: Fri, 7-Nov-86 15:12:16 EST
Article-I.D.: tekecs.7858
Posted: Fri Nov  7 15:12:16 1986
Date-Received: Sat, 8-Nov-86 18:34:31 EST
References: <2302@bucse.bu-cs.BU.EDU>
Organization: Tektronix Inc., Wilsonville, OR
Lines: 27

In article <2302@bucse.bu-cs.BU.EDU>, gasp@bu-cs.BU.EDU (Isaac Kohane) writes:
> Well, it seems that women can in fact see more than men.
> [...]
> Now, as we all know, women have twice as much X chromosome as men do.
> Therefore, if there are multiple alleles (versions of that gene at
> that locus) for the red pigment (as is suggested by recent experiments
> in this area), then a women could have one allele on one X chromosome,
> and another allele on the second X chromosome. Each allele would have
> a different peak absorption wavelength. It might be then, that some
> women are in fact quadrichromatic. What do they see that we don't? :-)

If I remember correctly, the second X chromosome in females sits unused in
the nucleus (it never "unbundles" in interphase like the rest of the 
chromosomes do).  These are called "Barr bodies", after the guy who 
discovered them.  If my recollection is correct, then this would seem to 
imply that females do not benefit from anything on the "extra" X chromosome.
Can anyone closer to a genetics text confirm or deny my remembrance?

[It seems I have to put some extra text in here so that the news software will
agree to send it.  Seems my ratio of old to new text isn't quite what it 
should be.  Welcome  to net.big-brother. :-(]

-- 
			   Mike Sellers
     UUCP: {...your spinal column here...}!tektronix!tekecs!mikes

    "In a quiet moment, you can just hear them brain cells a-dyin'"