title: Dosage compensation: do birds do it as well?
abstract: In birds males carry ZZ and females ZW sex chromosomes, and it has been proposed that there is no dosage compensation in the expression of sex-linked genes. However, recent data suggest the opposite, indicating that male and female birds might demonstrate similar levels of expression of Z-linked genes. If they do, the equalization between the sexes is probably not achieved by inactivation of one of the male Z chromosomes. Other possible mechanisms include the transcription of Z-linked genes being upregulated in females or downregulated in males, or equalization at the translation stage in either sex. A recently identified hypermethylated region on the Z chromosome, with similarities to the X inactivation centre on the mammalian X chromosome, might play a part in this process or have a role in avian sex determination.
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden. Hans.Ellegren@ebc.uu.se
authors.forename: Hans
authors.initials: H
authors.lastname: Ellegren
mesh_terms: D000818:Animals; D001717:Birds / Q000235:genetics*; D019175:DNA Methylation; D004303:Dosage Compensation, Genetic; D005260:Female; D008040:Genetic Linkage; D008297:Male; D008322:Mammals / Q000235:genetics; D008957:Models, Genetic; D012730:Sex Chromosomes / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: C110547:DMRT1 protein; D014157:Transcription Factors