CHARACTERIZATION OF A HUMAN ALPHOID SATELLITE DNA-SEQUENCE - POTENTIAL USE IN ASSESSING GENETIC DIVERSITY IN INDIAN POPULATIONS

Sequence analysis of a human repetitive DNA sequence (pTRF5.6) reveale d considerable homology (76%) to the alphoid consensus sequence. Genom ic blots of StuI-digested human DNA, hybridized to pTRF5.6, generated a ladder of bands with each band corresponding to oligodeoxyribonucleo tide of an approx. 170-bp repeat, indicating a tandemly arrayed organi zation of this repeat element within the genome. Genomic hybridization analyses of unrelated individuals belonging to various geographical r egions of India, using this alphoid satellite probe, revealed polymorp hic bands ranging between 2 and 9 kb. Along with an individual-specifi c band pattern, several isomorphic bands below 2 kb were also evident. There was very little of genetic variability between populations, sug gestive of low polymorphism at the inter-population level. Our result suggest that alphoid satellite sequence probe can be used in assessing the genetic diversity of various ethnic groups/populations belonging to different geographical regions.