On Wed, 30 Sep 1998 10:32:53 +0200 Martin Ortseifer
<ortseife at mpip-mainz.mpg.de> wrote:
> in my studies of cellbiologie, exactly mitosis, I am confronted with two
> terms, to which I haven't yet seen any definition or explanation. So,
> what is meant by:
Amitosis is the division of a eukaryotic nucleus in two
or more parts without the formation of a metaphase plate or
typical mitotic apparatus. An example is the division of
the ciliate macronucleus, which although it involves
Microtubules, is not mitosis (see Walker and Goode
The micronucleus in the same cells divide mitotically, with
microtubules attaching to kinetochores and going thru
metaphase and anaphase.
Endomitosis, on the other hand, is the duplication of the
chromosomes within the nucleus, but no nuclear division
occurs, thus the number of chromosomes per nucleus doubles.
They go thru prophase but no MA forms and no metaphase,
anaphase or telophase. See Dan Mazia's wonderful "chapter"
in The Cell, Vol 3.
Dept. of Biology
University of Maryland
College Park 20742
dg0 at umail.umd.edu