Paternal lineages and forensic parameters based on 23 Y-STRs (Powerplex® Y23) in Mestizo males from Mexico City

Genetic Diversity and Forensic Parameters of 27 Y-STRs in Two Mestizo Populations from Western Mexico

BACKGROUND

Analyzing Y-chromosome short tandem repeats (Y-STRs) is essential in forensic genetics and population studies. The Yfiler™ Plus kit, which includes 27 Y-STR markers, enhances the discrimination power for forensic and kinship applications. However, this genetic system has not been analyzed in Mexican populations, which limits its application and representativeness in international databases.

OBJECTIVES

We wished to examine the genetic diversity and forensic parameters of the 27 Y-STRs included in the YFiler™ Plus kit in two populations from Western Mexico (Jalisco and Michoacán).

METHODS

Male DNA samples were amplified using the Yfiler™ Plus kit, followed by a fragment analysis via capillary electrophoresis (CE). The haplotype frequencies and forensic parameters were calculated. The haplogroups of all samples were predicted, and the distribution and percentages of ancestries were determined. The Rst genetic distances, including reference populations, were calculated and graphically represented in a multidimensional scaling (MDS) plot.

RESULTS

A total of 224 haplotypes were identified in all of the samples, of which 98.66% corresponded to unique haplotypes. Bi- and tri-allelic patterns were observed in both populations. The observed discriminatory capacity was 98.4% for Jalisco and 98.9% for Michoacán, while the haplotype diversity values were 0.9998 and 0.9997, respectively. The most frequent haplogroup was R1b, followed by Q, representing the European and Native American ancestries, in both populations.

CONCLUSIONS

This study is the first to report the haplotype diversity and forensic parameters of the 27 Y-STRs included in the Yfiler™ Plus kit in Mexican populations. These findings confirm the forensic utility of these markers for human identification, biological relationship testing, and criminal investigations, reinforcing their applicability in forensic casework.

Population expansion, larger, and more homogeneous native American ancestry among Mexican mestizo populations based on 10 X-chromosome STR loci (X-STR decaplex system)

OBJECTIVE

To evaluate the genetic diversity, admixture, genetic relationships, and sex-biased demographic processes in Mexican Mestizo (admixed) populations based on 10 X-chromosome STRs (X-STRs).

METHODS

We analyzed the X-STRs Decaplex system in 104 Mexican Native Americans to obtain the ancestral reference needed to complete the demographic analyses above mentioned. We included reported Iberian and Latin American (admixed) populations from Central and South America, as well as datasets from Mexican Mestizos based on Y-linked STRs (Y-STRs), autosomal STRs (A-STRs), and mtDNA.

RESULTS

Higher X-linked Native American ancestry was observed among Latin American populations regarding that reported from A-STRs and Y-STRs. The interpopulation differentiation based on ancestry among Mexican Mestizos diminished according to the inheritance pattern: Y-STRs (highest), A-STRs, X-STRs, and mtDNA (lowest). This finding is related to the peculiar admixture process that occurred during and after the Spanish Conquest of Mexico (and most of Latin America), involving a large number of Spanish men (Y-chromosomes) with a lesser proportion of X-chromosomes than autosomes; besides to the limited number of Spanish women (XX) arrived in the Americas in subsequent and shorter periods. Population expansion was detected in Mexican Mestizos from all the country, except those from the southeast region characterized by elevated indigenous ancestry, marginalization, and poorness.

CONCLUSIONS

Population growth was detected in most Mexican Mestizos, besides more homogeneous and larger Native American ancestry based on X-linked inheritance than that based on autosomal STRs and Y-STRs.

Circum-Mediterranean influence in the Y-chromosome lineages associated with prostate cancer in Mexican men: A Converso heritage founder effect?

Prostate cancer is the second most common neoplasia amongst men worldwide. Hereditary susceptibility and ancestral heritage are well-established risk factors that explain the disparity trends across different ethnicities, populations, and regions even within the same country. The Y-chromosome has been considered a prototype biomarker for male health. African, European, Middle Eastern, and Hispanic ancestries exhibit the highest incidences of such neoplasia; Asians have the lowest rates. Nonetheless, the contribution of ancestry patterns has been scarcely explored among Latino males. The Mexican population has an extremely diverse genetic architecture where all the aforementioned ancestral backgrounds converge. Trans-ethnic research could illuminate the aetiology of prostate cancer, involving the migratory patterns, founder effects, and the ethnic contributions to its disparate incidence rates. The contribution of the ancestral heritage to prostate cancer risk were explored through a case-control study (152 cases and 372 controls) study in Mexican Mestizo males. Seventeen microsatellites were used to trace back the ancestral heritage using two Bayesian predictor methods. The lineage R1a seems to contribute to prostate cancer (ORadjusted:8.04, 95%CI:1.41-45.80) development, whereas E1b1a/E1b1b and GHIJ contributed to well-differentiated (Gleason ≤ 7), and late-onset prostate cancer. Meta-analyses reinforced our findings. The mentioned lineages exhibited a connection with the Middle Eastern and North African populations that enriched the patrilineal diversity to the southeast region of the Iberian Peninsula. This ancestral legacy arrived at the New World with the Spanish and Sephardim migrations. Our findings reinforced the contribution of family history and ethnic background to prostate cancer risk, although should be confirmed using a large sample size. Nonetheless, given its complex aetiology, in addition to the genetic component, the lifestyle and xenobiotic exposition could also influence the obtained results.

Personalized medicine and nutrition in hepatology for preventing chronic liver disease in Mexico

Chronic liver disease is a global health issue. Patients with chronic liver disease require a fresh approach that focuses on the genetic and environmental factors that contribute to disease initiation and progression. Emerging knowledge in the fields of Genomic Medicine and Genomic Nutrition demonstrates differences between countries in terms of genetics and lifestyle risk factors such as diet, physical activity, and mental health in chronic liver disease, which serves as the foundation for the implementation of Personalized Medicine and Nutrition (PerMed-Nut) strategies. Most of the world's populations have descended from various ethnic groupings. Mexico's population has a tripartite ancestral background, consisting of Amerindian, European, and African lineages, which is common across Latin America's regional countries. The purpose of this review is to discuss the genetic and environmental components that could be incorporated into a PerMed-Nut model for metabolic-associated liver disease, viral hepatitis B and C, and hepatocellular carcinoma in Mexico. Additionally, the implementation of the PerMed-Nut approach will require updated medicine and nutrition education curricula. Training and equipping future health professionals and researchers with new clinical and investigative abilities focused on preventing liver illnesses in the field of genomic hepatology globally is a vision that clinicians and nutritionists should be concerned about.

Y chromosome diversity in Aztlan descendants and its implications for the history of Central Mexico

Native Mexican populations are crucial for understanding the genetic ancestry of Aztec descendants and coexisting ethnolinguistic groups in the Valley of Mexico and elucidating the population dynamics of the prehistoric colonization of the Americas. Mesoamerican societies were multicultural in nature and also experienced significant admixture during Spanish colonization of the region. Despite these facts, Native Mexican Y chromosome diversity has been greatly understudied. To further elucidate their genetic history, we conducted a high-resolution Y chromosome analysis with Chichimecas, Nahuas, Otomies, Popolocas, Tepehuas, and Totonacas using 19 Y-short tandem repeat and 21 single nucleotide polymorphism loci. We detected enormous paternal genetic diversity in these groups, with haplogroups Q-MEH2, Q-M3, Q-Z768, Q-L663, Q-Z780, and Q-PV3 being identified. These data affirmed the southward colonization of the Americas via Beringia and connected Native Mexicans with indigenous populations from South-Central Siberia and Canada. They also suggested that multiple population dispersals gave rise to Y chromosome diversity in these populations.

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Enormous Y chromosome diversity observed in Native Mexican populations.

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Haplogroups Q-MEH2, Q-M3, Q-Z768, Q-L663, Q-Z780, and Q-PV3 were identified.

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Patterns of Y chromosome diversity not shaped by ethnicity, geography, or language.

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Multiple population dispersals contributed to Y chromosome diversity in Mexico.

"Distribution of paternal lineages in Mestizo populations throughout Mexico: an in silico study based on Y-STR haplotypes"

The Mexican-Mestizo population arose following European contact with the Americas due to the admixture of principally Spaniards, Native Americans, and Africans around 500 years ago. Because the paternal lineage distribution of the Mexican population has been poorly investigated, this study inferred the haplogroups of ten populations based on 1859 haplotypes (Y-STR data) using two haplogroup predictor programs. In the Mexican population sample, we found predominantly European ancestry (50.1%), followed by Native American (32.5%), Eurasian (13.4%), African (2.1%), East African-South Eurasian (1.3%), and Asian (0.6%) ancestries. In general, our results support a contrary north-to-south gradient throughout the Mexican territory of European and Native-American ancestries, respectively. Moreover, the presence of West-European R1b and Sub-Saharan African E1b1a haplogroups agrees with historical and genetic data of gene flow during the European conquest. This study represents the effort to analyze these paternal lineages on a large scale by taking advantage of Y-STR haplotype data to determine the distribution and ancestry proportions in this country.