Dosage compensation is less effective in birds than in mammals
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چکیده
منابع مشابه
Dosage compensation is less effective in birds than in mammals
BACKGROUND In animals with heteromorphic sex chromosomes, dosage compensation of sex-chromosome genes is thought to be critical for species survival. Diverse molecular mechanisms have evolved to effectively balance the expressed dose of X-linked genes between XX and XY animals, and to balance expression of X and autosomal genes. Dosage compensation is not understood in birds, in which females (...
متن کاملDosage compensation in mammals.
Many organisms show major chromosomal differences between sexes. In mammals, females have two copies of a large, gene-rich chromosome, the X, whereas males have one X and a small, gene-poor Y. The imbalance in expression of several hundred genes is lethal if not dealt with by dosage compensation. The male-female difference is addressed by silencing of genes on one female X early in development....
متن کاملDosage compensation in birds
The Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess "dosage compensation" systems to eq...
متن کاملSex-biased microRNA expression in mammals and birds reveals underlying regulatory mechanisms and a role in dosage compensation.
Sexual dimorphism depends on sex-biased gene expression, but the contributions of microRNAs (miRNAs) have not been globally assessed. We therefore produced an extensive small RNA sequencing data set to analyze male and female miRNA expression profiles in mouse, opossum, and chicken. Our analyses uncovered numerous cases of somatic sex-biased miRNA expression, with the largest proportion found i...
متن کاملX chromosome dosage compensation: how mammals keep the balance.
The development of genetic sex determination and cytologically distinct sex chromosomes leads to the potential problem of gene dosage imbalances between autosomes and sex chromosomes and also between males and females. To circumvent these imbalances, mammals have developed an elaborate system of dosage compensation that includes both upregulation and repression of the X chromosome. Recent advan...
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ژورنال
عنوان ژورنال: Journal of Biology
سال: 2007
ISSN: 1475-4924
DOI: 10.1186/jbiol53