Sex determination by polymerase chain reaction on mummies discovered at Taklamakan desert in 1912

A novel method of male sex identification of human ancient skeletal remains

Sex identification of ancient individuals is important to understand aspects of the culture, demographic structure, religious practices, disease association, and the history of the ancient civilizations. Sex identification is performed using anthropometric measurements and molecular genetics techniques, including quantification of the X and Y chromosomes. These approaches are not always reliable in subadult, or fragmented, incomplete skeletons or when the DNA is highly degraded. Most of the methods include the identification of the male and female sexes, but the absence of a specific marker for the males does not mean that the sample obtained was from a female. This study aims (1) to identify new male-specific regions that allow male identification; (2) to contrast the effectiveness of these markers against AMELX/AMELY and anthropometric measurement procedures; and (3) to test the efficacy of these markers in archaeological samples. For the first two aims, we used known sex samples, and for the third aim, we used samples from different archaeological sites. A novel molecular technique to identify male-specific regions by amplification of TTTY7, TSPY3, TTTY2, and TTTY22 genes of the human Y chromosome was developed. The results showed amplification of the specific DNA regions of Y chromosome in male individuals, with no amplification being observed in any of the female samples, confirming their specificity for male individuals. This approach complements the current procedures, such as the AMELX/AMELY test and anthropometric principle.

Sex selection in late Iberian infant burials: Integrating evidence from morphological and genetic data

OBJECTIVE

The aim of this study was to analyze the infant burials found inside Iberian homes in relation to a possible case of sex selection.

METHODS

The study included the remains of 11 infant individuals buried under the 10 houses excavated in the late Iberian village of Camp de les Lloses (Tona, Barcelona, Spain). Sex was determined using genetic analysis.

RESULTS

Our results showed that almost all the burials were females. However, the age interval of death was wide enough to weaken the premise of infanticide, and the burials probably represent cases of natural death.

DISCUSSION

Infanticide in its different forms has long been argued as an explanation for the infant remains found throughout various burial sites. Many authors thought that infanticide, mainly femicide, was the main method of population control in ancient times. However, there is no anthropological evidence (age distribution and sex analyzed genetically) to support the intentional killing of females in this or in other cases. We hypothesized that there was a positive selection for females to be buried inside the houses, probably related to their benefactor roles.

Molecular sex identification of dry human teeth specimens from Sokoto, Northwestern Nigeria

BACKGROUND

The advent of molecular techniques has revolutionized the ability of scientists to estimate the sex of individuals. Forensic odontology plays an important role in establishing the sex of victims with bodies mutilated beyond recognition due to major disaster. The genetic difference between males and females is defined by the presence or absence of the Y-chromosome. The use of alphoid-repeat primers in sex estimation was first applied on dried blood. Generally, the X, Y alphoid repeats blind test attest to the accuracy of genetic testing, and also point the potential for occasional error in morphometric sexing.

AIM

To estimate genetic sex of dry human teeth specimens from Sokoto, Northwestern Nigeria, using polymerase chain reaction (PCR).

MATERIALS AND METHODS

A single-blind study of DNA analysis for sex estimation of nine dry human teeth specimens from Sokoto, Northwestern Nigeria, through PCR, using alphoid repeats primers, was undertaken.

RESULTS

The genetic sex of each group of the teeth samples were accurately (100%) identified. For each group of teeth, PCR Sensitivity = 100%, Specificity = 0%, Predictive value of positive test = 100%, Predictive value of negative test = 0%, False positive rate = 0%, False negative rate = 0%, Efficiency of test = 100%. Fisher's exact probability test P = 1. Z-test: z- and P values were invalid.

CONCLUSION

This study has demonstrated the successful use of alphoid-repeat primers in genetic sex identification of human dry teeth samples from Sokoto, Northwestern Nigeria. This is the first known study estimating the sex of human dry teeth specimens by means of PCR in Nigeria. There is need for further studies in Nigeria to complement the findings of this study.

Cultured human epithelium: human umbilical cord blood stem cells differentiate into keratinocytes under in vitro conditions

BACKGROUND

Stem cells have the capacity to renew or to give rise to a specialized cell types. Human umbilical cord blood (HUCB) has been explored as an alternative source of stem cells. However, its potential to differentiate into cells of other tissues is still under discussion. The aim of our study was to evaluate if HUCB stem cells could differentiate into epithelial cells under in vitro conditions.

METHODS

Human keratinocytes derived from adult female skin donors, were isolated and cultured on fibrin glue/fibroblast gels-control group. In the umbilical cord blood cell group, male umbilical cord blood cells were added at a 1:10 ratio to keratinocytes and co-cultured on the fibrin glue/fibroblasts gel. After 15 days of culture, the sheets were analyzed by use of histochemistry and FISH. DNA was extracted and evaluated by use of polymerase chain reaction (PCR) for detection of Y-chromosome-specific sequences.

RESULTS

In both groups a regular epithelial sheet consisting of three to four layers of cells was formed. Using PCR and FISH, in the umbilical cord blood cell group the presence of Y-chromosome-specific sequences in the cultured keratinocytes could be detected. In the control group, no Y-chromosome-specific sequences could be detected.

CONCLUSION

Our findings indicate that umbilical cord blood stem cells differentiate into epithelial cells under in vitro conditions and thereby, might serve as a starting material for isolation and expansion of cells for transplantation in patients with large skin defects.

Exploration of anthropological specimens by GC-MS and chemometrics

Anthropological specimens combine a variety of unfavorable characteristics, rendering their evaluation an analytical challenge. Their remarkable status is primarily based on two characteristics: (i) these very rare samples of human origin are testimonies of human history and are, therefore, available only in minute amounts for analytical purposes, and (ii) the analysis of these samples is extremely limited by the decomposition of molecules, which are easily detected in living organisms, such as nucleic acids and proteins, but are subject to rapid post-mortem decay. In this article, we review the methods and results of archaeometry, emphasizing the role of MS combined with chemometrics. Focusing on experimental results for fatty acid profiles, specimens from mummies from different civilizations were compared. Considering in particular the Tyrolean Iceman, the application of chemometric methods to GC-MS data recovers essential information about the preservation and the storage conditions of mummies.

Paleodermatoses: lessons learned from mummies

Mummies, the preserved remains of living beings from former times, bear witness across millennia to the maladies plaguing humankind. Disease, older than humanity, is better understood when examined in the context of history. Paleopathology, literally meaning "ancient suffering", is the study of disease through evaluation of ancient remains. This area of increasing medical interest offers insights into the management of public health issues and disease epidemiology. This article provides an introduction and overview to paleodermatology, the branch of dermatology concerned with the evaluation of diseases associated with the integument by examination of ancient human remains. Mummy sources, how they were made and used throughout history, and the multidisciplinary approach used to study skin diseases found in mummies is briefly described. Despite pervasive pseudopathology, a remarkable array of diseases are well substantiated in the paleorecord, including infectious, heritable, nutritional, hormonal, acquired, iatrogenic, and neoplastic disorders. Legitimate ethical concerns have been raised in the use of human remains for any purpose, with the lack of informed consent eliciting accusations of exploitation. While these studies are undertaken with certain risks, such as the acquisition of potentially dangerous or extinct infections, paleodermatology offers a unique and historical perspective on the afflictions of the skin and the way of all flesh.