DNA sequencing and genotyping profile of the microsatellites of Y-STRs of the Beer-Alsabaa bedouins of Jordan as part of the Arabian genome project since 1995

In humans, the Y chromosome spans 58 million base pairs and represents approximately 0.38% of the total DNA in a human cell. The human Y chromosome contains 86 genes,1 many of the genes on Y-chromosome are involved in male sexual determination and development.2 The bulk of the Y chromosome which does not recombine is called the non-recombining region of the Y chromosome (NRY), which is composed of the DNA segments known as Short Tandem Repeats (STRs). The STRs polymorphism are categorized by length of the repeated units such as Di nucleotide (CA), Trinucleotide (TAT), Tetra nucleotide (TTTA), Pentanucleotide (TAAAA), Hexa nucleotide (AGAGAT),3,4 (Figure 1). As Y-chromosome is paternally inherited as haploid Y-DNA segment and passed down from father to son unchanged from generation to another except by the gradual accumulation of mutations, the STRs of the Y chromosome have proved to be a very powerful tool in tracing movements of males in human population history.5 The applications of Y-STRs are becoming increasingly important because of their male specificity and the informativeness of the haplotypes they define and also provide useful discriminating power in individual identification and the geographical differentiation of Y haplotypes of the male genetic map.6