C-heterochromatin during synapsis and recombination in grey cockroach Nauphoeta cinerea spermatogenesis

Autor: O. S. Kornienko, L. V. Vysotskaya, A. M. Gusachenko
Rok vydání: 2009
Předmět:
Zdroj: Scopus-Elsevier
ISSN: 1990-5203
1990-519X
DOI: 10.1134/s1990519x09030110
Popis: The behavior of large, distal, C-heterochromatic blocks in the spermatogenesis of the grey cockroach Nauphoeta cinerea was investigated by light and electron microscopy. In early meiotic prophase I, heterochromatic blocks of some autosomes are involved in the nonhomologous association and form a chromocenter. Fluorescent in situ hybridization (FISH) with a ribosomal DNA (rDNA) probe revealed the signal on only two pairs of middle chromosomes not engaged in the chromocenter formation; therefore, ectopic conjugation was not caused by the formation of a nucleolus. Analysis showed that chromocentric heterochromatin does not participate (functionally or spatially) in basic meiotic events. Heterochromatin does not participate in the formation of a bouquet, initiation of homologous synapsis, or recombination events. The chromocenter disintegrates at the end of the pachytene when synapsis is totally completed. Heterochromatin polymorphism results in asymmetric synaptonemal complexes (SCs) with different degrees of synaptic adjustment. The axis of the sex univalent (male sex determination is XO) is split in various sites, regardless of heterochromatin localization.
Databáze: OpenAIRE
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