Y- STRs are Short Tandem Repeats found on the male-specific Y Chromosome. The coding genes, mostly found on the short arm of the Y Chromosome, are vital to male sex determination, spermatogenesis and other male-related functions. The Y-STRs are polymorphic among unrelated males and are inherited through the paternal line with little change through generations.
Uses of Y-STR:
- Y-STRs have been used by forensic laboratories to examine sexual assault evidence. In a sexual assault case, evidence such as vaginal swabs will contain both female and male DNA.
- Y-STR is also used for non-sexual assault cases where mixed samples are collected from evidence. Sometimes, regular STR will cause the masking effect if there is a minimal quantity of male DNA in the combined sample.
- The Y-STR system is especially helpful when there is more than one assailant. The mixed pattern in the evidence can help to identify those males responsible for the assault.
Y-STR Male Paternal Lineage DNA Test:
Y-STR testing determines whether two males share the same paternal lineage. The Y-STR paternal lineage DNA test is based on the fact that the Y chromosome is passed from father to son relatively unchanged through many generations. Only males can undergo Y-STR testing because females do not possess a Y chromosome. Y-STR’s are used to establish a biological relationship. In scenarios where the father is dead or not available for testing, this test can be used to build a biological relationship between the alleged male members.