First gene on the avian W chromosome (CHD) provides a tag for universal sexing of non-ratite birds.
The avian W chromosome shares many features with the mammalian Y chromosome: it is small, mostly heterochromatic, and filled with large repetitive arrays. No gene so far been assigned to the W chromosome in any bird species and, as a practical consequence, a general tag for avian gender identification on the molecular level is lacking. Here I describe the isolation of a chicken homologue to the mouse chromo-helicase-DNA binding (CHD) gene which encodes a protein involved in global regulation of transcriptional activation on the chromatin level. The avian CHD gene exists in two genomic copies, one of which termed CHD-W) was located on the W chromosome in all non-ratio species investigated. The gene displays extreme levels of sequence conservation since chicken CHD-W and mouse CHD are 82.9% and 95.6% identical at the nucleotide and amino acid level respectively. Molecular sexing can be accomplished in probably all non-ratite birds by hybridizing Southern blots with CHD probes, PCR-based gender identification is also demonstrated. A general system for avian sexing should facilitate many studies of behaviour, evolutionary ecology, genetics, and evolution.
Ellegren
H
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Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala Biomedical Centre, Sweden.
D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D001717:Birds / Q000235:genetics*; D002645:Chickens / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005796:Genes; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012730:Sex Chromosomes / Q000235:genetics*; D012732:Sex Determination Analysis / Q000379:methods*; D013045:Species Specificity
D030161:Avian Proteins; C489845:CHD-W protein, Gallus gallus; C489844:Chd1 protein, mouse; D017931:DNA Primers; D004268:DNA-Binding Proteins