title: Heterochromatin and multiple inversions in a Drosophila chromosome.
abstract: A chromosomal polymorphism is described from a Maui (Hawaii) population of D. disjuncta. The acquisition of an extra heterochromatic segment in a mitotic chromosome is specifically associated with the presence of multiple inversions in the same chromosome. This suggests the possible effect of a chromosomal break-point within the area of centromeric heterochromatin in causing an increase in the amount of repetitive DNA. The possibility exists that the extra heterochromatin may play a role in the suppression of gene recombination in a certain region of the chromosome and/or in strengthening pairing of the inversion-laden chromosome with its normal homologue. This may reduce the changes of sterility due to nondisjunction during meiosis.
mesh_terms: D000818:Animals; D002869:Chromosome Aberrations; D007446:Chromosome Inversion; D002875:Chromosomes; D004330:Drosophila; D005724:Ganglia / Q000166:cytology; D006570:Heterochromatin; D008938:Mitosis; D012469:Salivary Glands / Q000166:cytology
chemical_list: D006570:Heterochromatin