In this paperwe review use of different types of X and Y chromosome marker for determiningsex in forensic investigation. This aim to provide an overview of how X and Ymarker are still being used in forensic laboratories. Advanced applications ofvarious DNA analysis methods are used for determining sex.
There arevarious types of markers for sex determination like Amelogenin, SRY (Sexdetermination Region Y), TSPY(Y-encoded Testis Specific Protein), LocusDXYS156, STS (Steroid Sulphatse). F-bodies are also used in sex determination.F- bodies contain Y chromosome. It is used to identify sex from pulpal tissue.The formation of amelogenin is involved in AMEL gene.
In female AMEL Xgene islocated on 106bps and in male AMEL gene is located on 112 bps of DNA.SRY is thesex determination region Ygene. These genes codes for the sex determiningregion Protein which is responsible for further development as male.
TSPY(Y-encoded Testis specific Protein) located distal and proximal of AMELY. TSPY hasproposal of non allelic homologous recombination between TSPY respect as themechanism for some Y chromosome determination. STS (Steroid Sulphatse) islocated on the X chromosome.
STS marker is different from other marker.DXYS156marker is locate on both X and Y chromosome and used for sex determination. Y chromosomeis the male specific part of human used in forensic DNA analysis.
By analyzing thetrace material present in the mixture of male and female by specific tool i.e.-STRmarker. Previously sex determination was performed by the investigation of leukocytenuclear drumstick, sex chromatin or fluorescence of the Y chromosome and thusit is possible to perform sex determination through chromosome specificmarkers.
Testing of X chromosome marker can be valuable inparticular situations, like, deficiency kinship cases. X- Chromosome ShortTandem Repeats(X-STRs) are widely used in forensic genetics, while the use of Xchromosome single- nucleotide polymorphisms (X-SNPs) is still limited. Theanalysis of Autosomal and Chromosome Y marker can complement by the chromosomeX genotyping and also especially in kinship testing.
Over 40 X STR markers havebeen characterized till date.Introduction – Sexdetermination is utmost important in the identification of missing person andsexual assault or rape cases. Through molecular analysis investigator canidentify the sex of particular individual. Normally female has two Xchromosomes and male has one X chromosome and one Y chromosome. Y chromosome onthe whole is much successful method for identifying sex of an individual anddetermining the ratio of male and female DNA in mixed forensic sample. For aDNA profile to be got into US National DNA Index System(NDIS), which isnational level of the Combined DNA Index System(CODIS).