Open AccessSpreading Synaptonemal Complexes from the Grasshopper Chorthippus Jacobsi : Pachytene and Zygotene Observations
Author(s) -
Santos J. L.,
Cerro A. L. Del,
Díez M.
Publication year - 1993
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1993.00235.x
Subject(s) - biology , pairing , meiosis , chromosome pairing , synaptonemal complex , bivalent (engine) , centromere , grasshopper , zoology , genetics , chromosome , ecology , physics , chemistry , superconductivity , organic chemistry , quantum mechanics , gene , metal
Pachytene and zygotene stages have been analysed on silver stained spreads of synaptonemal complexes (SCs) from Chorthippus jacobsi spermatocytes. SC lengths are compared to those obtained from C‐banded mitotic metaphases. The pattern of meiotic pairing initiation and progression is described. In the submetacentric bivalents it is initiated from both chromosomal ends whereas in acrocentric bivalents two potential pairing initiation points are located in the long arms, the short arms remaining as late pairing regions. In addition, some interstitial pairing initiation points also occur, particularly in the L and M4–M5 bivalent groups. Shorter chromosomes commence and finish pairing relatively early. Interlockings form and are mostly resolved throughout zygotene. The estimated mean number of interlockings is 1.6 at zygotene as opposed to 0.17 at early–mid pachytene.