[Increased mitotic crossing over of heterochromatin in the first cleavage division of Drosophila melanogaster].
It is shown that, although no compaction of paracentromeric heterochromatin occurs during the first cleavage division in Drosophila melanogaster, the frequency of mitotic crossing-over in corresponding chromosome regions is increased, as compared to that in euchromatin. Because a similar situation is observed at later stages of Drosophila development, at which compact chromatin regions become well-manifested, it is concluded that the effect of heterochromatin on the frequency of crossing-over does not depend on its packing. A positive correlation between crossing-over events in paracentromeric heterochromatin and euchromatin was observed. This effect is probably due to the formation of a continuous region of somatic synapsis, which facilitates the process of mitotic crossing-over. On this basis, it is proposed that the effect of heterochromatin on mitotic crossing-over is associated with preferential chromosome pairing in the corresponding regions.
Omel'ianchuk
L V
LV
Volkova
E I
EI
D000818:Animals; D003434:Crossing Over, Genetic; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D008297:Male; D008938:Mitosis; D051381:Rats
D006570:Heterochromatin
Povyshennyĭ mitoticheskiĭ korssingover v geterokhromatine v pervom delenii drobleniia u Drosophila melanogaster.