Dosage compensation regulatory proteins and the evolution of sex chromosomes in Drosophila.
In the fruitfly Drosophila melanogaster, the four male specific lethal (msl) genes are required to achieve dosage compensation of the male X chromosome. The MSL proteins are thought to interact with cis-acting sites that confer dosage compensation to nearby genes, as they are detected at hundreds of discrete sites along the length of the polytene X chromosome in males but not in females. The histone H4 acetylated isoform, H4Ac16, colocalizes with the MSL proteins at a majority of sites on the D. melanogaster X chromosome. Using polytene chromosome immunostaining of other species from the genus Drosophila, we found that X chromosome association of MSL proteins and H4Ac16 is conserved despite differences in the sex chromosome karyotype between species. Our results support a model in which cis-acting regulatory sites for dosage compensation evolve on a neo-X chromosome arm in response to the degeneration of its former homologue.
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
J R
JR
Bone
M I
MI
Kuroda
D000818:Animals; D015153:Blotting, Western; D002868:Chromosomal Proteins, Non-Histone; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004303:Dosage Compensation, Genetic; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012730:Sex Chromosomes; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C070837:mle protein, Drosophila; C082132:msl-1 protein, Drosophila; D004265:DNA Helicases