Sunday, January 2, 2011
Haplogroups to Haplotypes
As discussed in a previous post (Terms, Terms, and more Terms), a haplotype is defined by as series of changes among several nucleotides in a row. Since the changes occure side by side, they are called "Short Tandem Repeat" or STRs. At the biochemical level where these changes occur and have been identified, there has been applied a naming system. [Human Gene Nomenclature Committee] This naming system includes an address (locus); a DYS # (DNA, Y-chromosome, [unique] segment); and an "allele" value. [An allele is one side of the DNA double helix.]
The figure to the right is an addition to "The Gene Tree-Haplogroups", showing the number of haplotypes for each of the haplogroups. At the top, the number of haplotypes in each haplogroup is shown along the approximate time frame. At the bottom, the number of haplotypes are given under the haplogroup in which they are derived. Haplogroup E has the greatest number of haplotypes at 58! Haplogroup J is second in number of haplotypes (34), followed by haplogroup O (31) and haplogroup R (29). My JONES DNA belongs to haplogroup R. Certainly, it is an interest "Gene Tree"!