1. Uncoupling of DNA and histone synthesis prior to prophase I of meiosis in the cricket Grillus (Acheta) domesticus L
- Author
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N.A. Liapunova, Antropova En, Yu.F. Bogdanov, and A.I. Sherudilo
- Subjects
Insecta ,biology ,DNA synthesis ,Chromosome ,Cell Biology ,DNA ,biology.organism_classification ,Molecular biology ,Cell biology ,Histones ,chemistry.chemical_compound ,Meiosis ,Histone ,chemistry ,Acheta ,Spectrophotometry ,Homologous chromosome ,biology.protein ,Feulgen stain - Abstract
Using double wavelength cytospectrophotometry of Feulgen staining, fast green staining according to Alfert and Geschwind at pH 8.2 and bromphenol blue staining at pH 8.2, the authors have studied DNA and histone content per nucleus at various stages of spermatogenesis in the cricket. Uncopuling of DNA and histone synthesis was found to occur during premeiotic interphase. While DNA synthesis is terminated or almost terminated prior to the leptotene-zygotene stage, histone synthesis is far from termination. Zygotene nuclei contain 4C DNA and only 3C of histone. The 4C level of histone is reached only at pachytene-diplotene. The histone/DNA ratio stays constant during other stages of meiosis. It is suggested that histone deficiency in chromosome during homologous pairing and also changes in chemical properties of histone may cause pairing to start. This suggestion resumes, but in much modified form, the “precocity theory of meiosis” proposed by Darlington and the new “histone deficiency hypothesis” is developed.
- Published
- 1968