Filicidal ring-Y chromosomes in D. melanogaster.

Heterochromatin position effects on circularized sex chromosomes cause filicidal embryonic lethality in Drosophila melanogaster Authors:

Heterochromatin position effects on circularized sex chromosomes cause filicidal embryonic lethality in Drosophila melanogaster.

Some circularized X-Y chromosomes in Drosophila melanogaster are mitotically unstable and induce early embryonic lethality, but the genetic basis is unknown. Our experiments suggest that a large region of X-linked satellite DNA causes anaphase bridges and lethality when placed into a new heterochromatic environment within certain circularized X-Y chromosomes. These results reveal that repetitiv...

Induced Loss of a Ring and a Telomeric Chromosome in Drosophila Melanogaster.

ING chromosomes are potentially useful for studying the process of rejoining R after chromosome breakage, since a certain portion of the restitutions should produce dicentric ring chromosomes or interlocked rings rather than structurally normal chromosomes. The relevance of ring chromosomes studies to problems of induced chromosome breakage in Drosophila melanogaster sperm has been recognized f...

Lack of Spontaneous Sister Chromatid Exchanges in Somatic Cells of DROSOPHILA MELANOGASTER.

Neural ganglia of wild type third-instar larvae of Drosophila melanogaster were incubated for 13 hours at various concentrations of BUdR (1, 3, 9, 27 micrograms/ml). Metaphases were collected with colchicine, stained with Hoechst 33258, and scored under a fluorescence microscope. Metaphases in which the sister chromatids were clearly differentiated were scored for the presence of sister-chromat...

Surprising differences in the variability of Y chromosomes in African and cosmopolitan populations of Drosophila melanogaster.

The nonrecombining Drosophila melanogaster Y chromosome is heterochromatic and has few genes. Despite these limitations, there remains ample opportunity for natural selection to act on the genes that are vital for male fertility and on Y factors that modulate gene expression elsewhere in the genome. Y chromosomes of many organisms have low levels of nucleotide variability, but a formal survey o...