Identification of Spermatozoa by Tissue-Specific Differential DNA Methylation Using Bisulfite Modification and Pyrosequencing

• NCJ Number: 248803
• Journal: Electrophoresis Volume: 35 Issue: 21-22 Dated: 2014 Pages: 3079-3086
• Author(s): Kuppareddi Balamurugan; Robin Bombardi; George Duncan; Bruce McCord
• Date Published: November 2014
• Length: 8 pages
• Grant Number(s): 2012-DN-BX-K018
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored)
• Award: Body fluid Identification using epigenetic methylation markers and pyrosequencing

Annotation

This study assessed the application of epigenetic markers as a forensic tool for the determination of semen present in sexual assault cases.

Abstract

A series of genetic loci were screened in order to identify certain epigenetic markers displaying differential methylation that can allow semen to be differentiated from blood, buccal cells, skin epidermis, and vaginal epithelial cells. Of the different loci tested, a panel of six markers, DACT1, USP49, DDX4, Hs_INSL6_03, Hs_ZC3H12D_05, and B_SPTB_03 were identified to contain tissue-specific differential methylation. Samples ranging from 9-21 for each tissue type were collected and subjected to bisulfite modification. The bisulfite modified DNA was amplified by PCR, and analyzed by pyrosequencing to quantitate the level of methylation at each marker. All six markers successfully differentiated semen samples from the other four tissue types analyzed. Sperm DNA was hypomethylated in all but one marker, B_SPTB_03, where this marker showed hypermethylation. Mean methylation percentages for semen samples were statistically significant from mean methylation. (Publisher abstract)