Re: Could you help me to know more about all the kinds of mitosis

I'm not familiar with many of these terms, except endomitosis, which I 
suspect is also called "closed mitosis" to distinguish it from the typical 
"open mitosis" of plant and animals cells.  (I suspect that some of these 
terms are not widely used).  However, I can tell you about some of the 
variations of mitosis off the top of my head.  The strangest types of 
mitosis are found in certain protists (single-celled eucaryotes).

In a number of protists (eugenoids, dinoflagellates) the nucl. env. remains 
intact.  At least two things can happen to pull apart the 2 groups of 
chromosomes:  microtubules form inside the nucleus (euglenoids, fungi) -or-  
the nucleus is penetrated by fingers of cytoplasm that grow into tunnels, 
containing microtubules, stretching from one side of the nucleus to the 
other.   The chromosomes attach to the inner membrane of the nuclear 
envelope, and are pulled apart by sliding along the microtubules (unlike 
normal mitosis, there is no direct contact between chromosome and 
microtubule).

Another variation in mitosis is the nature and origin of spindle 
microtubules.  In addition to the typical centrioles at each end of the 
spindle, one finds a larger MTOC (microtubule organizing center) in diatoms 
(described beautifully by Jeremy Pickett-Heaps) where the spindle 
microtubules are all parallel to each other, and a large, banded, polar 
spindle body that forms on the nuclear envelope in fungal cells.

Finally, something called "amitosis" involves the macronucleus of ciliates.
The macronucleus, oddly enough, is made from a much much smaller 
micronucleus that replicates its DNA repeatedly, then cuts it into tiny 
gene-sized bits, each of which is given 2 telomeres.  So, it is clearly 
impossible to line up and sort a million mini-chromosomes!  During cell 
division, a replication band sweeps from one end of the macronucleus to the 
other, then it simply pinches in two.

Some protists have a nucleus associated with 4 flagellae and a complex 
microtubular ribbon (the Trichomonads, part of the parabasalians) and they 
must have their own special mitotic routine. If you can find a good 
university library, this info is published in journals like Protistologica, 
Journal of Protozoology, etc..  If you need more info, I could fax you a few 
pages from a protistology book by O. Roger Anderson that discusses such 
variations (it is not terribly easy to understand without pictures) if you 
contact me directly: djacobson@whitworth.edu.  Also, feel free to send a 
follow up query to the Mad scientists network.

Cheers,
Dean Jacobson