Different Classes Of Y Chromosome Genetic Markers

Two broad categories of DNA markers have been used to examine Y chromosome diversity: bi-allelic loci, which exhibit two possible alleles, and multi-allelic loci. Results from typing the lower resolution bi-allelic markers are classified into haplogroups while multi-allelic results are characterized as haplotypes (de Knijff 2000).

Bi-allelic markers include single nucleotide polymorphisms (Y-SNPs) and an Alu element insertion (see Chapter 8). The Y-Alu polymorphism (YAP) was the first discovered Y chromosome bi-allelic marker (Hammer 1994). Bi-allelic markers are sometimes referred to as unique event polymorphisms (UEPs) because of their low mutation rates (~10-8 per generation). Approximately 250 bi-allelic Y chromosome markers have been characterized (Y Chromosome Consortium 2002, Butler 2003).

Y chromosome multi-allelic markers include two minisatellites and over 200 short tandem repeat (Y-STR) markers (Butler 2003, Kayser et al. 2004). These multi-allelic loci can be used to differentiate Y chromosome haplotypes with fairly high resolution due to their higher mutation rates. Minisatellite loci have mutation rates as high as 6-11% per generation (Jobling et al. 1999) while the average mutation rate for Y-STRs is ~0.2% per generation (Kayer et al. 2000, Dupuy et al. 2004).

Y-STR MARKERS

Was this article helpful?

0 0
Stammering Its Cause and Its Cure

Stammering Its Cause and Its Cure

This book discusses the futility of curing stammering by common means. It traces various attempts at curing stammering in the past and how wasteful these attempt were, until he discovered a simple program to cure it. The book presents the life of Benjamin Nathaniel Bogue and his struggles with the handicap. Bogue devotes a great deal of text to explain the handicap of stammering, its effects on the body and psychology of the sufferer, and its cure.

Get My Free Ebook


Post a comment