Dosage compensation in Drosophila: the X-chromosomal binding of MSL-1 and MLE is dependent on Sxl activity.
In Drosophila, dosage compensation, i.e. the equalization of levels of X-linked gene products in the two sexes, is achieved by the hypertranscription of most X-linked genes in males relative to females. The products of at least four genes, collectively termed male-specific lethal (msl) genes, are required for this process and, at least in the case of three of them, mediate this function through an association with the X chromosome in males. We have studied some of the parameters that affect the association of the msl-1 gene product and found that its presence is dependent on the wild-type function of the other three genes, leading to the conclusion that these gene products contribute to the formation of a multi-subunit complex. Furthermore, the X-chromosomal association of the msl-1 and mle gene products is negatively correlated with the level of function of the master regulatory gene Sxl and can assume either a mosaic or a uniform distribution in the tissues of mutant XX individuals. Surprisingly, we also found that the association of these two msl gene products with the two X chromosomes in females of certain mutant genotypes does not result in the hypertranscription of X-linked genes or in any apparent reduction in viability.
Hilfiker
A
A
Department of Biology, Emory University, Atlanta, GA 30322.
Yang
Y
Y
Hayes
D H
DH
Beard
C A
CA
Manning
J E
JE
Lucchesi
J C
JC
D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004303:Dosage Compensation, Genetic; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D005260:Female; D017344:Genes, Insect / Q000235:genetics; D005804:Genes, Lethal / Q000235:genetics; D006657:Histones / Q000032:analysis / Q000378:metabolism; D007301:Insect Hormones / Q000032:analysis / Q000378:metabolism*; D008297:Male; D009154:Mutation / Q000502:physiology; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism*; D011485:Protein Binding; D016601:RNA-Binding Proteins; D012469:Salivary Glands / Q000737:chemistry; D014157:Transcription Factors / Q000032:analysis / Q000378:metabolism*; D014960:X Chromosome
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006657:Histones; D007301:Insect Hormones; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C067777:Sxl protein, Drosophila; D014157:Transcription Factors; C070837:mle protein, Drosophila; C082132:msl-1 protein, Drosophila; D004247:DNA; D004265:DNA Helicases