Linear differentiation of the C-band pattern of the W chromosome in snakes and birds.
Evidence is presented from C-banding studies that the W chromosome of eleven species of snakes is not homogeneous in nature but is differentiated linearly into alternating lighter and darker C positive regions. The same is true of the W chromosome of at least some birds. There is evidence from the literature indicating a similar differentiation of the Y chromosome of some mammals and here the intermediate C positive regions are deficient in highly repetitive DNA. The significance of heterochromatinization as a means of generating differentiated sex chromosomes is discussed in the light of these findings.
D000818:Animals; D001001:Anura / Q000235:genetics*; D005075:Biological Evolution; D001717:Birds / Q000235:genetics*; D002871:Chromosome Banding; D004261:DNA Replication; D005260:Female; D008297:Male; D012730:Sex Chromosomes / Q000648:ultrastructure*; D012911:Snakes / Q000235:genetics*; D013045:Species Specificity