Ychromosoommarkers

Y-chromosome markers are genetic loci on the Y chromosome used to trace paternal ancestry and support forensic and population genetic studies. They include single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs), which differ in mutation rate and informativeness.

Most of the Y chromosome is non-recombining, known as the non-recombining region of the Y (NRY). Because NRY markers are inherited largely as a single block from father to son, they form paternal lineages that can be traced across generations. A small region called the pseudoautosomal region (PAR) does recombine with the X chromosome and is not typically used for standard Y-chromosome haplotyping.

Y-SNPs define stable haplogroups and provide information about deep ancestry and paternal lineages. They mutate slowly, making them useful for broad population structure, historical inferences, and aligning individuals within a phylogenetic tree of human populations.

Y-STRs mutate more rapidly and are widely used for forensic identification, paternity testing, and genealogical studies. A panel of several Y-STR loci yields a haplotype that can differentiate between unrelated lineages and help resolve recent paternal connections, though close male relatives may share identical or very similar profiles.

Analytical methods typically involve PCR amplification and capillary electrophoresis. Data are compared against reference databases such as the Y-chromosome reference databases and haplogroup trees to interpret lineage and population information.

Limitations include confinement to the male line, potential sharing of haplotypes among patrilineal relatives, and challenges in mixtures or populations with limited marker diversity. Forensic and genealogical inferences require careful statistical context and corroborating evidence.