SCI/TECH: Platypus sex is XXXXX-rated

The world's weirdest animal just got weirder! A new Australian research shows that the egg laying platypuses have five pairs of sex chromosomes. Interestingly, one of the pairs contains XX/XY system (male heterogamety) found in mammals, but another resembles ZZ/ZW system (female heterogamety) found in birds. Platypuses with the elements of two diverse groups of animals might suggest an evolutionary link. As Jennifer Viegas from Discovery News says, "Previously it was believed that sex systems for mammals and birds evolved completely independently from each other. If the current research holds true, all mammals, including humans, may hold a bit of unexpected bird history from the distant past."



Platypus (Ornithorhynchus anatinus) belongs to a primate group of mammals known as monotremes. There are two other species in this group; long and short beaked echidnas. Scientists are planning to study these members of the group also in order to see if they use the same system as platypuses.

I think this is amazing news. It would be interesting to find out if an ancestral mammal had a sex chromosomal system of ZZ/ZW.

I wonder why platypuses need so many sex chromosomes.

Related News Links:
www.theaustralian.news.com.au
www.nature.com
dsc.discovery.com

www.nature.com


[edit on 25-10-2004 by Banshee]

First off...this is cool. Not that it's a definite link between birds and humans, but it's interesting nonetheless.

I wonder if there are any platypuses that express any variations except XXXXXXXXXX XYXYXYXYXY. Would it make a difference for a five-paired sex determinant gene to be off by a pair? I guess we'll find out.

This is amazing news. Does anyone have any information on the other species similar to the platypus? Hopefully research will show something exciting from them as well!

As an aside, you just know someone out there is completely bummed out by the true nature of this article...

Damn.

When i saw xxxxx rated platypus sex, i thought it was a discovery that platypuses have been observed in leather masks and chains mating with mechanical devices.........

I didnt think it was possible but it looks like there can be such a thing as a Quadsexual

"...primate group of mammals... "

I think the right word here is primitive, not primate.

Echidna can taste good, quite gamey, but it's important to have a strong constitution for afterwards.

I think the most interesting part of the finding was:

The largest X chromosome, with homology to the human X chromosome, lies at one end of the chain, and a chromosome with homology to the bird Z chromosome lies near the other end. This suggests an evolutionary link between mammal and bird sex chromosome systems, which were previously thought to have evolved independently. (Source)

Correction: "...primate group of mammals... " (first post).
Primitive is the correct word instead of primate.
Thanks Off_The_Street for pointing that out.

I don't think that this necessarily means that mammals have bird dna, more likely that, since mammals and reptiles share a common ancestor, that these chromosomes that are homologous to bird chromosomes are 'primitive' for mammals and birds. This means that other mammals lost the extra sex chromosomes, while birds retained it. The bird lineage and mammal lineage seperated a long long time ago tho, so I don't see why they'd say mammals have 'bird history'. It isn't bird history, the chromosomes must've existed long long before birds were around.

Extremey interesting none the less.

hmmm

what resembles the ZZ/ZW system?

Where do you get a sex drive, and staying power strong enough to satisfy this many genomes. I have enough trouble satisfying Mine and my wifes.