Showing papers on "Dosage compensation published in 1979"
TL;DR: In addition to its effect on sexual differentiation, Sxl M#1 reduces the size of haplo-X imaginal disc and histoblast derivatives in general in a cell autonomous fashion, suggesting that there is no single localized “lethal focus” for this mutation.
105 citations
TL;DR: 6-phosphogluconate dehydrogenase (6PGD) is sex-linked in Heliconius butterflies, and this confirms that sex- linked genes in lepidoptera, as in birds, are not dosage-compensated.
Abstract: 6-phosphogluconate dehydrogenase (6PGD) is sex-linked in Heliconius butterflies. Within each of two species tested, the specific activity of 6PGD in males (the homogametic sex) is approximately twice that in females. This confirms that sex-linked genes in lepidoptera, as in birds, are not dosage-compensated. This absence of dosage compensation may be the basis for the frequent female-limitation of mimicry, and explains the peculiarity that the loci involved are never sex-linked, whereas male-limited sexual characters can be both sex-linked and autosomal.
63 citations
TL;DR: Dosage compensation represents a system which can be used to study the control of gene activity in eukaryotes and is reported on, that of the X-linked α-chain gene of Drosophila larval serum protein-1.
Abstract: IN many species of higher organisms there is compensation for the different number of ‘doses’ of X-linked genes in the two sexes. This can be demonstrated by studies on enzymes which show that the level of activity of an X-linked enzyme is the same in the sex with one chromosome as in the sex with two. Dosage compensation therefore represents a system which can be used to study the control of gene activity in eukaryotes. Dosage compensation in Drosophila melanogaster has been extensively reviewed1, and although it has been studied mainly in adult flies it does occur in larval stages2–5 and in cultured cells6. The one published example of an X-linked gene which does not show complete dosage compensation is the white-eosin mutant7 where there is more pigment in the eye of the female homozygote than in the eye of the male hemizygote. Here we report a second example, that of the X-linked α-chain gene of Drosophila larval serum protein-1.
48 citations
Journal Article•
TL;DR: A regulatory mechanism for dosage compensation by X chromosome inactivation appears to be operating in Gryllotalpa, what is believed to be the first cytogenetic demonstration of such a mechanism outside mammals.
Abstract: In Gryllotalpa the cell cycle duration in the hepatic caecae in vivo is about 12.5 h and of various phases are, G2 + P about 10 h, S about 2.5--3.5 h, and G1 appears negligible or absent. These estimates of the cell cycle are the only ones available in Gryllotalpidae. In the female Gryllotalpa, as in mammals, there is asynchronous DNA replication between the two euchromatic arms of the two X chromosomes. The other arm is constitutively heterochromatized and as expected is late replicating. Thus, a regulatory mechanism for dosage compensation by X chromosome inactivation appears to be operating in Gryllotalpa. This we believe, is the first cytogenetic demonstration of such a mechanism outside mammals.
11 citations