In article <334D7CBB.4169 at bcc.orst.edu>, morrisk at bcc.orst.edu wrote:
> Michael J. Bumbulis wrote:
> >
> > Here's a question for someone in the know about Giardia.
> > They have two nuclei, right? Well, do the two nuclei
> > contain different sets of chromosomes? And during mitosis,
> > do all the chromosomes mix or are the contents of each nucleus
> > separated independently?
>
The nuclei remain seperate, so there is no mixing. One would assume that
the two nuclei contain the same sets of chromosomes, since any parasite
lacking a whole chromosome would probably be weeded out of the population
pretty smartly. Alternatively, a chromosome that is useless would also
probably be strongly selected against.
However, what is inside the nuclei is still pretty mysterious. We're not
even sure what the ploidy of Giardia is (ie whether they have two sets of
chromosomes, or 20). There have beem extimates ranging up to higher
numbers than that, and solving this problem is high on the list for Giardia
genetics.
Cheers, Mark
