A simple and inexpensive molecular method for sexing and identification of the forensic samples of elephant origin

The population of the Asian elephant is being dramatically reduced due to poaching of the ivory from the male. As poaching occurs in remote forests, it often takes weeks or longer for it to be discovered and it is therefore often very difficult to determine the sex of the decomposed body. Data suggest that in the recent past, over 2000 male elephants have been poached in South India. We have developed a technique based on molecular markers to determine that the carcass is an elephant and that it is a male. Using DNA sequence information from Genbank, we have developed two primer pairs: one for the mitochondrial DNA (mtDNA) and the other for the sex-determining region of Y chromosome (SRY) gene of the Indian elephant. After PCR amplification of known elephant DNA, we found that the mtDNA was common in both males and females, whereas the SRY-specific amplicon was observed only in the male.     

Integration of the AmpFlSTR Identifiler PCR Amplification Kit with SRY-specific primers for gender identification

Dropout of the amelogenin Y-specific allele due to an interstitial deletion of the Yp involving the amelogenin Y locus (AMELY) can cause misidentification of sex genotype with potentially serious consequences in personal identification processes and criminal investigations. Inclusion of additional sex-defining markers in forensic DNA typing kits is therefore advisable. In this study, the co-amplification of the sex-determining region Y (SRY) gene and 16 STR loci included in the AmpFlSTR Identifiler PCR Amplification Kit was evaluated. Combination of SRY and Identifiler primers did not compromise the amplification outcome and generated a 90 bp male-specific SRY fragment, showing a reproducible peak height ratio in comparison with the AMELY peak. The SRY peak was detectable in presence of amounts of template DNA as low as 125 pg, and in mixed samples with a male/female DNA ratio of 1:100.     

Validation of SRY Marker for Forensic Casework Analysis

Abstract:  Determining the gender of the source of forensic DNA evidence is based on the amelogenin test. However, at times the assay may not be indicative of gender assignment, because of deletions at the amelogenin site. Previously, we described successful coamplification of a marker residing within the SRY gene with the short tandem repeat markers from two commercially available human identification kits. The study herein addresses the validation of primers for the target SRY gene regarding specificity, sensitivity, and robustness. Among 115 unrelated male Slovenians no null allele was observed. Repeatable and reliable results were obtained from as little as 25 pg of template DNA, indicating a high sensitivity of detection for the assay. No polymerase chain reaction product was observed even at a concentration of 10 ng/μL of template female DNA. Additionally, the male specific marker could be detected in mixed male and female samples down to a ratio of 1:16.     

联合应用STR和SRY基因分型技术分析性分化异常者

目的对Amelogenin分型结果为“X,X”的一名“男孩”进行性别确认。方法采用STR检测和SRY基因检测技术进行分析。结果孩子STR、X-STR的检验结果符合女性性别特征,SRY基因检测结果为阴性。结论应用STR、X-STR检测和SRY基因检测技术可以确证“男孩”Amelogenin基因座结果为“X,X”,推断其患有“46,XX”男性性反转综合症。