Unilinear molecular markers (mtDNA and Y Chromosome): application to the study of human and animal populations

The progress of molecular biology allowed the study of genetic variation from the phenotypic traits with mendelian transmission (e.g. blood groups, allozymes, etc.) to the genotypic polymorphisms (e.g. microsatellites, nucletidic changes in DNA sequences, etc.). In particular, the uniparental molecular markers (maternally inerithed as mitochondrial DNA and paternally inherited as Ychromosome) drew the attention of scholars as a profitable tool for studying the phylogeography and the population genetics of the species. Thus genetic markers within mitochondrial DNA (mtDNA) and Y chromosome, whose transmission is uniparental and not recombinant, represent a very useful tools for phylogenetic and phylogeographic studies. mtDNA offers the possibility to individuate regions where even sequences of moderate length are evolutionary informative. In this work, I used mtDNA marker to analyze populations of Sardinian humans, Atlantic interstitial flatworms, and Mediterranean syngnathid fish. The Non Recombinant Region of Y chromosome (NRY) contains, together with several short tandem repeated (STRs), about 500 single nuclear polymorphisms (SNPs) characterized by low mutation rates, that may be analysed to infer on the molecular phylogeny of populations. In this work, we used NRY marker to analyze human peopling of Sardinia , enclosed into an Euro-Mediterranean framework and to perform a complete review of human Y chromosome haplogroups worldwide distribution.