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Sex determination using biochemical methods from dentition

Namitha D

Assistant Professor, Department of Biochemistry, Adichunchanagiri University, B G Nagara, Nagamangala Taluk, Mandya District, India

E-mail : bhuvaneswari.bibleraaj@uhsm.nhs.uk

MG Shivaramu

Professor, Department of Forensic Medicine, Principal, Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, B G Nagara, Nagamangala Taluk, Mandya District, India

Vijay Kumar AG

Associate Professor, Department of Forensic Medicine, Adichunchanagiri University, B G Nagara, Nagamangala Taluk, Mandya District, India

Kumar U

Professor and Head, Department of Forensic Medicine, Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, B G Nagara, Nagamangala Taluk, Mandya District, India

DOI: 10.15761/DOMR.1000391

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Abstract

PCR is a method of amplifying small quantities of relatively short target sequences of DNA using sequence-specific oligonucleotide primers and thermostable Taq DNA polymerase. The teeth can withstand high temperature and are used for personal identification in forensic medicine. In the case of few teeth or missing dental records, there is not enough information to identify the person. The dental pulp enclosed by the hard tissue is not influenced by temperature unlike the buccal mucous membrane, saliva, and calculus. Barr bodies, F-bodies, SRY gene, AMEL gene can be studied to determine sex from these samples. A thorough knowledge and usage of the appropriate evidence from forensic scene enables proper identification of the individual.

Key words

sex determination, biochemical methods, dentition

Introduction

PCR is a method of amplifying small quantities of relatively short target sequences of DNA using sequence-specific oligonucleotide primers and thermostable Taq DNA polymerase.[1]

The teeth can withstand high temperature and are used for personal identification in forensic medicine. In the case of few teeth or missing dental records, there is not enough information to identify the person. The dental pulp enclosed by the hard tissue is not influenced by temperature unlike the buccal mucous membrane, saliva, and calculus.[2]

In a study by Tsuchimochi et al., they used Chelex method to extract DNA from the dental pulp and amplified it with PCR and typing at Y chromosomal loci to determine the effects of temperature on the sex determination of the teeth.

Hanaoka and Minaguchi conducted a study to determine sex from blood and teeth by PCR amplification of the alphoid satellite family using amplification of X-specific (131 bp) and Y-specific (172 bp) sequences in males and Y-specific sequences in females. It was shown to be a useful method in determining the sex of an individual.[3]

Sivagami et al. prepared DNA from teeth by ultrasonication and subsequent PCR amplification and obtained 100% success in determining the sex of the individual.[4]

Sex determination from the f-bodies

Y chromosome contains F-bodies. These F-bodies can be used to identify sex. Various studies have been undertaken to identify F-bodies from pulpal tissue. Caspersson et al. [5] suggested that F-bodies can be applicable in forensic for sex determination. Dried blood stains, saliva, hair, and extracted dental pulp can serve as a sample for the test. Seno and Ishizu [6] carried out the detection of Y chromosome in the nuclei of dental pulp. Their study result was that over 30% of the male pulpal tissue showed positivity for F-bodies. F-bodies could be examined even in teeth as old as 5 months after extraction. Nayar et al. [7] in their study of pulp tissue in sex determination using fluorescent microscopy concluded that sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries within enamel or up to half the way of dentin. Teeth with caries involving pulp cannot used for sex determination.

Sex determining region "Y" gene

The abbreviation of SRY is the sex determining region "Y" gene. These gene codes for the sex-determining region Y protein, which is responsible for further development as male. Females have 2X chromosomes (46XX), and males have 1X and 1Y chromosome (46XY). SRY is located on the short (p) arm of the Y chromosomes at the position 11.3. Therefore, SRY gene can be used as a sex-typing marker in forensic samples. Many studies have shown the amplified SRY gene in various samples to determine sex. False positive results can be attained in certain syndromes, maternal-fetal microchimerism, and dissimilar sex between donor and recipient during transplantation (chimerism). George et al. [8] identified gender by amplification of SRY gene using real-time PCR from isolated epithelial cells of the removable partial denture. They concluded that saliva-stained acrylic dentures can act as a source of forensic DNA and co-amplification of SRY gene with other routine sex-typing markers will give unambiguous gender identification. Reddy et al. [9] studied the epithelial cells adherent to toothbrush as a source of DNA for sex determination using real-time PCR. All male sample in their study showed positive results and out of 15 female samples four were wrongly identified as males.

Sex determination from the enamel protein - amelogenin gene

Amelogenin (AMEL) is a major matrix proteins found in the human enamel involving Amelogenesis. Developing human enamel has about 30% protein, 90% of which are AMELs. AMEL gene is involved in the formation of AMEL. AMEL X gene is present in 106 bps and AMEL Y is present in 112 bps of the DNA. It has a different signature (or size and pattern of the nucleotide sequence) in male and female enamel.
The AMEL gene that encodes for female AMEL is located on the X chromosome and AMEL gene that encodes for male AMEL is located on the Y chromosome. The female has two identical AMEL genes or alleles, whereas the male has two different AMEL genes. This can be used to determine the sex of the remains with very small samples of DNA.

Sex determination from barr bodies

Sex can also be determined by the study of X and Y chromosomes in the cells that are not undergoing active division. Presence or absence of X chromosome can be studied from buccal smears, skin biopsy, blood, cartilage, hair root sheath, and tooth pulp. After death, it persists for variable periods depending upon the humidity and temperature in which tissue has remained. X chromatin and intra-nuclear structure is also known as Barr body as it was first discovered by Barr et al. It is present as a mass usually lying against the nuclear membrane in the females.[10] In a study carried out by Das et al. [11] it has been shown that up to a period of 4 weeks after death we can determine the sex accurately from the study of X and Y chromosomes keeping in view the variation of temperature and humidity.

Whittaker et al. [12] determined sex from necrotic pulp tissue stained by quinacrine mustard using fluorescent Y chromosome test for maleness and claimed that up to 5 weeks sex determination can be done with high degree of accuracy. It was found that in cases after fires, high impact crashes and explosions fragmentation and thermal trauma renders other methods impossible to determine the sex of the remains except the above said method from pulp. Pulp tissue cells become embedded firmly into the dried fibrosis matrix. Duffy et al. [13] have shown that Barr bodies and F bodies of Y chromosomes are preserved in dehydrated pulp tissues up to 1-year and pulp tissues retain sex diagnostic characteristics when heated up to 100C for 1 h.

Conclusion

Barr bodies, F-bodies, SRY gene, AMEL gene can be studied to determine sex from these samples. A thorough knowledge and usage of the appropriate evidence from forensic scene enables proper identification of the individual.

References

  • 1. Tsuchimochi, T., 2002. Chelating resin-based extraction of DNA from dental pulp and sex determination from incinerated teeth with Y-chromosomal alphoid repeat and short tandem repeats, Am J Forensic Med Pathol, 23,268–71.
  • 2. Hemanth, M., Sex determination using dental tissue, Med Leg Update, 12, 2.
  • 3. Hanaoka, Y., 1996. Sex determination from blood and teeth by PCR amplification of the alphoid satellite family, J Forensic Sci, 41, 855–8.
  • 4. Sivagami, A.V.,2000. A simple and cost-effective method for preparing DNA from the hard tooth tissue, and its use in polymerase chain reaction amplification of amelogenin gene segment for sex determination in an Indian population, Forensic Sci Int, 110, 107–15.
  • 5.Caspersson, T.,1970. Analysis of human metaphase chromosome set by aid of DNA-binding fluorescent agents, Exp Cell Res, 62, 490-2.
  • 6.Seno, M., 1973. Sex identification of a human tooth, Int J Forensic Dent, 1, 8-11.
  • 7.Nayar, A., 2014. Pulp tissue in sex determination: A fluorescent microscopic study, J Forensic Dent Sci ,6,77-80.
  • 8.George, R., 2010. Isolation of epithelial cells from acrylic removable dentures and gender identification by amplification of SRY gene using real time PCR, J Forensic Dent Sci, 2,32-6
  • 9. Reddy, V.S., 2011. Isolation of epithelial cells from tooth brush and gender identification by amplification of SRY gene, J Forensic Dent Sci, 3, 27-32.
  • 10. Barr, M.L.,1950. The morphology of the nerve cell nucleus, according to sex, Anat Rec, 107,283-4.
  • 11. Das, N., 2004. Sex determination from pulpal tissue, J Indian Acad Forensic Med, 26, 50-4.
  • 12. Whittaker, D.K., 1975. Sex determination from necrotic pulpal tissue, Br Dent J, 139, 403-5.
  • 13. Duffy, J.B., 1991. Isolation of tooth pulp cells for sex chromatin studies in experimental dehydrated and cremated remains. Forensic Sci Int, 49, 127-41.

Editorial Information

Founding Editor-in-Chief

Shigeru Watanabe
Meikai University Japan

Editor-in-Chief

Vagner Rodrigues
Federal University of Minas Gerais

Article Type

Review Article

Publication history

Received: March 03, 2021
Accepted: March 15, 2021
Published: March 17, 2021

Copyright

©2021 Namitha D. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation

Namitha D, MG Shivaramu, Vijay Kumar AG, Kumar U (2021) Sex determination using biochemical methods from dentition. Dent Oral Maxillofac Res 7: DOI: 10.15761/DOMR.1000391

Corresponding author

Dr. Kumar U

Professor and Head, Department of Forensic Medicine, Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, B G Nagara, Nagamangala Taluk, Mandya District, India

E-mail : bhuvaneswari.bibleraaj@uhsm.nhs.uk

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