To understand how cytokinesis is regulated during mitosis, we tested cyclin-p34cdc2 for myosin-II kinase activity, and investigated the mitotic-specific phosphorylation of myosin-II in lysates of Xenopus eggs. Purified cyclin-p34cdc2 phosphorylated the regulatory light chain of cytoplasmic and smooth muscle myosin-II in vitro on serine-1 or serine-2 and threonine-9, sites known to inhibit the a...

In many eukaryotes, condensins I and II associate with chromosomes in an ordered fashion during mitosis and play nonoverlapping functions in their assembly and segregation. Here we report for the first time the spatiotemporal dynamics and functions of the two condensin complexes during meiotic divisions in mouse oocytes. At the germinal vesicle stage (prophase I), condensin I is present in the ...

Although the mRNA that encodes progesterone receptor membrane component 1 (PGRMC1) is present in mammalian oocytes, nothing is known about either PGRMC1's expression pattern or function in oocytes during maturation, fertilization, and subsequent embryonic development. As PGRMC1 associates with the mitotic spindle in somatic cells, we hypothesized that PGRMC1 is involved in oocyte maturation (me...

In this article we describe a system we have constructed that provides for automated karyotyping of metaphase spreads. The software system Athena – based upon the Macintosh II computer and a Data Translation's frame grabber – is written entirely in C and consists of approximately 200 Kbytes of executable code. While Athena does not provide (at this time) facilities for automated metaphase findi...

With the advent of commercial electron microscopes, it was discovered by M.J. Moses (1956) and D.W. Fawcett (1956) that chromosomes at prophase of meiosis have welldefined axial elements that synapse homologously to form the synaptonemal complex, SC. This arrangement would appear to be eminently suited to the analysis of chromosome structure and function because each bivalent is distinct and th...

Heterocyclic scaffold has been under discovery due to their considerable therapeutic and medicinal importance. One of such heterocycles 2-pyrimidinone, while not naturally occurring, are receiving increased attention because of their wide-ranging biological activity like, an efficient inhibitor of DNA synthesis in E. coli, inhibitors of the enzyme cytidinedeaminase, and as metaphase inhibitors....