Author:
Romero Julianna Kesselring,Bittencourt Eloisa Auler,Soares-Vieira José Arnaldo,Pacheco Ana Claudia,Soares Alexandre Learth,Iwamura Edna Sadayo Miazato
Abstract
AbstractTo understand stored evidence and the insertion in genetic databases is important in forensic investigations. Blood, pre- and post-vasectomy semen from 90 fertile male individuals, aged 24 to 45, were donated for research after informed consent. The semen samples were stored in the form of 30 µL stains on cotton fabric, for 16 years at room temperature in the laboratory. As well as the seminal fluid post vasectomy stains, which were performed after microscopy analyzes and certainty of the absence of spermatozoon. The pre vasectomy stains contained mainly haploid spermatozoon and the post vasectomy stains diploid epithelial cells and leukocytes. DNA extraction was performed with magnetic resin, followed by quantification and analysis of degradation of DNA. In this study we analyze these genetic profiles of DNA from stains on cotton fabric, using two Short Tandem Repeat multiplex systems, the PowerPlex Fusion 6C and Y23. Electrophoresis was performed on a 3500xL and analyzed using the Gene Mapper ID-X software. The genetic profiles of the 90 individuals were fully amplified in pre-vasectomy and partially in post-vasectomy stain samples, using the both multiplex systems. The results provide information about 0.25 cm2 semen stains on cotton fabric from 90 individuals, correlating concentration, degradation, and allele analysis. It also provides an understanding of the cells present in semen stains and the implications of individual factors. In the stains of post-vasectomy samples the small quantity of DNA was one of the limiting factors, in addition to degradation. Considering that all evaluations were carried out in a laboratory that has a quality control certificate and audited for being part of the national genetic profile database, the results were very consistent. Many aspects of the semen samples stored in the form of stains on cotton fabric have been clarified. The performance and sensitivity of the amplification systems used in the genotyping of azoospermic individuals were assessed. Conclusions: Genetic profiles were satisfactorily amplified in pre-vasectomy stain samples, and partially amplified in post-vasectomy stain samples, stored for almost two decades at room temperature in a tropical country. The small amount of DNA was one of the limitations in post-vasectomy stain samples, in addition to degradation and fragmentation. There are no publications in the literature on PowerPlex Fusion 6C and Y23 analyses using blood, sperm, and seminal fluids of the same individual, much less in the form of stains. This study can serve as a benchmark for the tracking analyses of stored samples. In addition, it anticipates a few social issues related to the analysis of post-vasectomy samples in forensic cases, most notably sex crimes.
Funder
Fundação de Amparo a Pesquisa do Estado de São Paulo
Publisher
Springer Science and Business Media LLC
Reference39 articles.
1. Amankwaa, A. O. & McCartney, C. The effectiveness of the UK national DNA database. Forensic Sci. Int. 21, 45–55 (2019).
2. Perepechina, I. O. Forensic DNA registration in the Russian Federation: background and the current state. Forensic Sci. Int. Genet. Suppl. Ser. 7(1), 688–689 (2019).
3. da Silva Junior, R. C., Wirz, L. N., Solares Reyes, E. & Del Moral Stevenel, M. A. Development of DNA databases in Latin America. Forensic Sci. Int. 316, 110540 (2020).
4. Prinz, M. Advantages and disadvantages of Y-short tandem repeat testing in forensic casework. Forensic Sci. Rev. 15(2), 191–198 (2003).
5. Johnson, C. L., Giles, R. C., Warren, J. H., Floyd, J. I. & Staub, R. W. Analysis of non-suspect samples lacking visually identifiable sperm using a Y-STR 10-plex. J. Forensic Sci. 50(5), 1116–1118 (2005).