PATERNAL LOSS (PAL): A MEIOTIC MUTANT IN DROSOPHILA MELANOGASTER CAUSING LOSS OF PATERNAL CHROMOSOMES

作者：Bruce S. Baker · 发表于：Genetics · 年份：1975 · DOI：10.1093/genetics/80.2.267 · 被引用次数：83 · 研究领域：Chromosomal and Genetic Variations、Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities、Plant Reproductive Biology

The effects of a male-specific meiotic mutant, paternal los (pal), in D. melanogaster have been examined genetically. The results indicate the following: (1) When homozygous in males, pal can cause loss, but not nondisjunction, of any chromosome pair. The pal-induced chromosome loss produces exceptional progeny that apparently failed to receive one, or more, paternal chromosomes and, in addition, mosaic progeny during whose early mitotic divisions one or more paternal chromosomes were lost. (2) Only paternally derived chromosomes are lost. (3) Mitotic chromosome loss can occur in homozygous pal+progeny of pal males. (4) Chromosomes differ in their susceptibility to pal-induced loss. The site responsible for the insensitivity vs. sensitivity of the X chromosome to pal mapped to the basal region of the X chromosome at, or near, the centromere. From these results, it is suggested that pal+acts in male gonia to specify a product that is a component of, or interacts with, the centromeric region of chromosomes and is necessary for the normal segregation of paternal chromosomes. In the presence of pal, defective chromosomes are produced and these chromosomes tend to get lost during the early cleavage divisions of the zygote. (5) The loss of heterologous chromosome pairs is not independent; there are more cases of simultaneous loss of two chromosomes than expected from independence. Moreover, an examination of cases of simultaneous somatic loss of two heterologs reveals an asymmetry ...