Faculty Opinions recommendation of hMSH4-hMSH5 recognizes Holliday Junctions and forms a meiosis-specific sliding clamp that embraces homologous chromosomes.

Author(s):  
Janet Stavnezer
2004 ◽  
Vol 15 (3) ◽  
pp. 437-451 ◽  
Author(s):  
Timothy Snowden ◽  
Samir Acharya ◽  
Charles Butz ◽  
Mark Berardini ◽  
Richard Fishel

2005 ◽  
Vol 33 (6) ◽  
pp. 1451-1455 ◽  
Author(s):  
M.C. Whitby

Homologous recombination (HR) is required to promote both correct chromosome segregation and genetic variation during meiosis. For this to be successful recombination intermediates must be resolved to generate reciprocal exchanges or ‘crossovers’ between the homologous chromosomes (homologues) during the first meiotic division. Crossover recombination promotes faithful chromosome segregation by establishing connections (chiasmata) between the homologues, which help guide their proper bipolar alignment on the meiotic spindle. Recent studies of meiotic recombination in both the budding and fission yeasts have established that there are at least two pathways for generating crossovers. One pathway involves the resolution of fully ligated four-way DNA junctions [HJs (Holliday junctions)] by an as yet unidentified endonuclease. The second pathway appears to involve the cleavage of the precursors of ligated HJs, namely displacement (D) loops and unligated/nicked HJs, by the Mus81-Eme1/Mms4 endonuclease.


Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.


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