A DNA test to sex most birds.
Birds are difficult to sex. Nestlings rarely show sex-linked morphology and we estimate that adult females appear identical to males in over 50% of the world's bird species. This problem can hinder both evolutionary studies and human-assisted breeding of birds. DNA-based sex identification provides a solution. We describe a test based on two conserved CHD (chromo-helicase-DNA-binding) genes that are located on the avian sex chromosomes of all birds, with the possible exception of the ratites (ostriches, etc.; Struthioniformes). The CHD-W gene is located on the W chromosome; therefore it is unique to females. The other gene, CHD-Z, is found on the Z chromosome and therefore occurs in both sexes (female, ZW; male, ZZ). The test employs PCR with a single set of primers. It amplifies homologous sections of both genes and incorporates introns whose lengths usually differ. When examined on a gel there is a single CHD-Z band in males but females have a second, distinctive CHD-W band.
Griffiths
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Molecular Laboratory, DEEB, Glasgow University, UK. R.Griffiths@bio.gla.ac.uk
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D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D001717:Birds / Q000235:genetics*; D002645:Chickens / Q000235:genetics; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics*; D004587:Electrophoresis, Agar Gel / Q000662:veterinary; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005260:Female; D007438:Introns / Q000235:genetics; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA / Q000662:veterinary; D012689:Sequence Homology, Nucleic Acid; D012730:Sex Chromosomes / Q000737:chemistry / Q000235:genetics*; D012732:Sex Determination Analysis / Q000662:veterinary*
D030161:Avian Proteins; C489845:CHD-W protein, Gallus gallus; C489846:CHD-Z protein, Gallus gallus; C489844:Chd1 protein, mouse; D017931:DNA Primers; D004268:DNA-Binding Proteins; D004247:DNA