Genetic Evidence Supports the Multiethnic Character of Teopancazco, a Neighborhood Center of Teotihuacan, Mexico (AD 200-600)

Multiethnicity in Teopancazco, Teotihuacan, is supported by foreign individuals found in the neighborhood center as well as by the diversity observed in funerary rituals at the site. Studies of both stable and strontium isotopes as well as paleodietary analysis, suggest that the population of Teopancazco was composed by three population groups: people from Teotihuacan, people from nearby sites (Tlaxcala-Hidalgo-Puebla), and people from afar, including the coastal plains. In an attempt to understand the genetic dynamics in Teopancazco we conducted an ancient DNA (aDNA) analysis based on mtDNA. Our results show that the level of genetic diversity is consistent with the multiethnicity phenomenon at the neighborhood center. Levels of genetic diversity at different time periods of Teopancazco's history show that multiethnicity was evident since the beginning and lasted until the collapse of the neighborhood center. However, a PCA and a Neighbor-Joining tree suggested the presence of a genetically differentiated group (buried at the Transitional phase) compared to the population from the initial phase (Tlamimilolpa) as well as the population from the final phase (Xolalpan) of the history of Teopancazco. Genetic studies showed no differences in genetic diversity between males and females in the adult population of Teopancazco, this data along with ample archaeological evidence, suggest a neolocal post-marital pattern of residence in Teopancazco. Nevertheless, genetic analyses on the infant population showed that the males are significantly more heterogeneous than the females suggesting a possible differential role in cultural practices by sex in the infant sector. Regarding interpopulation analysis, we found similar indices of genetic diversity between Teopancazco and heterogeneous native groups, which support the multiethnic character of Teopancazco. Finally, our data showed a close genetic relationship between Teopancazco and populations from the "Teotihuacan corridor" and from Oaxaca and the Maya region, in agreement with previous archaeological evidence

Genetic history of Classic Period Teotihuacan burials in Central Mexico

The ancient city of Teotihuacan was a great urban and ceremonial center, whose population grew exceptionally in the Classic Period (300 – 700 AC). Settlement patterns, culture and burials have indicated an occupation that consisted of groups of neighboring apartment compounds or barrios. We investigated the genetics of three apartment compounds in the Teotihuacan Valley through ancient DNA analysis to prove multiethnicity during the Classic Period. Amerindian mitochondrial haplogroups were identified in 10 burials from San Francisco Mazapa, 7 from San Sebastian Xolalpan, and 19 human bone tools from La Ventilla. These samples had a wide genetic diversity. Differences in genetic structures were slight but significant (p< 0.001) between the three households and 7 ancient populations from Central and Southern Mexico by FST analysis between the three barrios studied, and Xaltocan (post-conquest) was congruent with the number of migrants estimated. Tlailotlacan, another household of Teotihuacan, was different following a small interaction with Mazapa, Xolalpan and La Ventilla. Through the estimation of immigrants, the three households studied seem to have come into contact with Mayans from Xcaret in Yucatan, and this coincides with archaeological data reported. Genetic data could indicate that migration and less genetic drift may possibly lead to a more effective role in the Teotihuacan groups, suggesting that interchange with other groups was not only for commercial, service or governmental purposes, which implicated demographic integration and genetic fusion, culminating in multiethnicity during the Classic Period in Teotihuacan. Further studies can be directed to examine others households.La ciudad de Teotihuacan tuvo un gran crecimiento poblacional durante el Período Clásico (300-700 AC, del inglés after Christ), cuando alcanzó el desarrollo urbano y llegó a ser un centro ceremonial de gran importancia. Los patrones de asentamiento, cultura y los entierros excavados muestran una ocupación organizada en barrios. En este estudio se realiza el análisis genético, por medio del ADN antiguo, de tres barrios ubicados en el Valle de Teotihuacan con el objetivo de identificar patrones de multietnicidad durante el Período Clásico. Se identificaron los haplogrupos mitocondriales amerindios en 10 individuos de San Francisco Mazapa, 7 de San Sebastián Xolalpan y 19 residuos de herramientas óseas de La Ventilla. Estos barrios mostraron diversidad genética. El análisis de FST reveló poca estructura genética, pero estadísticamente significativa (p<0.001), entre los barrios estudiados, en comparación con 7 poblaciones antiguas del centro y sur de México. En los análisis, Xaltocan fue congruente con el número de migrantes estimado. Tlailotlacan, otro barrio de Teotihuacan, tuvo una relación pequeña con los barrios estudiados. La estimación de migrantes mostró que pudieron tener contacto con mayas de Xcaret en Yucatán, en coincidencia con los datos arqueológicos reportados. Los datos genéticos podrían señalar que la migración y poca deriva genética jugaron un papel importante entre los grupos teotihuacanos, lo que sugiere intercambio con otros grupos por propósitos de comercio, servicios o gubernamentales, lo cual implica integración y fusión genética que determina multietnicidad en Teotihuacan durante el período Clásico. Estos resultados pueden ser corroborados por estudios en otros barrios de Teotihuacan y con futuros análisis de secuenciación.Asociación de Antropología Biológica de la República Argentina (AABRA

Genetic history of Classic Period Teotihuacan burials in Central Mexico

The ancient city of Teotihuacan was a great urban and ceremonial center, whose population grew exceptionally in the Classic Period (300 – 700 AC). Settlement patterns, culture and burials have indicated an occupation that consisted of groups of neighboring apartment compounds or barrios. We investigated the genetics of three apartment compounds in the Teotihuacan Valley through ancient DNA analysis to prove multiethnicity during the Classic Period. Amerindian mitochondrial haplogroups were identified in 10 burials from San Francisco Mazapa, 7 from San Sebastian Xolalpan, and 19 human bone tools from La Ventilla. These samples had a wide genetic diversity. Differences in genetic structures were slight but significant (p< 0.001) between the three households and 7 ancient populations from Central and Southern Mexico by FST analysis between the three barrios studied, and Xaltocan (post-conquest) was congruent with the number of migrants estimated. Tlailotlacan, another household of Teotihuacan, was different following a small interaction with Mazapa, Xolalpan and La Ventilla. Through the estimation of immigrants, the three households studied seem to have come into contact with Mayans from Xcaret in Yucatan, and this coincides with archaeological data reported. Genetic data could indicate that migration and less genetic drift may possibly lead to a more effective role in the Teotihuacan groups, suggesting that interchange with other groups was not only for commercial, service or governmental purposes, which implicated demographic integration and genetic fusion, culminating in multiethnicity during the Classic Period in Teotihuacan. Further studies can be directed to examine others households.La ciudad de Teotihuacan tuvo un gran crecimiento poblacional durante el Período Clásico (300-700 AC, del inglés after Christ), cuando alcanzó el desarrollo urbano y llegó a ser un centro ceremonial de gran importancia. Los patrones de asentamiento, cultura y los entierros excavados muestran una ocupación organizada en barrios. En este estudio se realiza el análisis genético, por medio del ADN antiguo, de tres barrios ubicados en el Valle de Teotihuacan con el objetivo de identificar patrones de multietnicidad durante el Período Clásico. Se identificaron los haplogrupos mitocondriales amerindios en 10 individuos de San Francisco Mazapa, 7 de San Sebastián Xolalpan y 19 residuos de herramientas óseas de La Ventilla. Estos barrios mostraron diversidad genética. El análisis de FST reveló poca estructura genética, pero estadísticamente significativa (p<0.001), entre los barrios estudiados, en comparación con 7 poblaciones antiguas del centro y sur de México. En los análisis, Xaltocan fue congruente con el número de migrantes estimado. Tlailotlacan, otro barrio de Teotihuacan, tuvo una relación pequeña con los barrios estudiados. La estimación de migrantes mostró que pudieron tener contacto con mayas de Xcaret en Yucatán, en coincidencia con los datos arqueológicos reportados. Los datos genéticos podrían señalar que la migración y poca deriva genética jugaron un papel importante entre los grupos teotihuacanos, lo que sugiere intercambio con otros grupos por propósitos de comercio, servicios o gubernamentales, lo cual implica integración y fusión genética que determina multietnicidad en Teotihuacan durante el período Clásico. Estos resultados pueden ser corroborados por estudios en otros barrios de Teotihuacan y con futuros análisis de secuenciación.Asociación de Antropología Biológica de la República Argentina (AABRA

Genetic history of Classic Period Teotihuacan burials in Central Mexico

The ancient city of Teotihuacan was a great urban and ceremonial center, whose population grew exceptionally in the Classic Period (300 – 700 AC). Settlement patterns, culture and burials have indicated an occupation that consisted of groups of neighboring apartment compounds or barrios. We investigated the genetics of three apartment compounds in the Teotihuacan Valley through ancient DNA analysis to prove multiethnicity during the Classic Period. Amerindian mitochondrial haplogroups were identified in 10 burials from San Francisco Mazapa, 7 from San Sebastian Xolalpan, and 19 human bone tools from La Ventilla. These samples had a wide genetic diversity. Differences in genetic structures were slight but significant (p< 0.001) between the three households and 7 ancient populations from Central and Southern Mexico by FST analysis between the three barrios studied, and Xaltocan (post-conquest) was congruent with the number of migrants estimated. Tlailotlacan, another household of Teotihuacan, was different following a small interaction with Mazapa, Xolalpan and La Ventilla. Through the estimation of immigrants, the three households studied seem to have come into contact with Mayans from Xcaret in Yucatan, and this coincides with archaeological data reported. Genetic data could indicate that migration and less genetic drift may possibly lead to a more effective role in the Teotihuacan groups, suggesting that interchange with other groups was not only for commercial, service or governmental purposes, which implicated demographic integration and genetic fusion, culminating in multiethnicity during the Classic Period in Teotihuacan. Further studies can be directed to examine others households.La ciudad de Teotihuacan tuvo un gran crecimiento poblacional durante el Período Clásico (300-700 AC, del inglés after Christ), cuando alcanzó el desarrollo urbano y llegó a ser un centro ceremonial de gran importancia. Los patrones de asentamiento, cultura y los entierros excavados muestran una ocupación organizada en barrios. En este estudio se realiza el análisis genético, por medio del ADN antiguo, de tres barrios ubicados en el Valle de Teotihuacan con el objetivo de identificar patrones de multietnicidad durante el Período Clásico. Se identificaron los haplogrupos mitocondriales amerindios en 10 individuos de San Francisco Mazapa, 7 de San Sebastián Xolalpan y 19 residuos de herramientas óseas de La Ventilla. Estos barrios mostraron diversidad genética. El análisis de FST reveló poca estructura genética, pero estadísticamente significativa (p<0.001), entre los barrios estudiados, en comparación con 7 poblaciones antiguas del centro y sur de México. En los análisis, Xaltocan fue congruente con el número de migrantes estimado. Tlailotlacan, otro barrio de Teotihuacan, tuvo una relación pequeña con los barrios estudiados. La estimación de migrantes mostró que pudieron tener contacto con mayas de Xcaret en Yucatán, en coincidencia con los datos arqueológicos reportados. Los datos genéticos podrían señalar que la migración y poca deriva genética jugaron un papel importante entre los grupos teotihuacanos, lo que sugiere intercambio con otros grupos por propósitos de comercio, servicios o gubernamentales, lo cual implica integración y fusión genética que determina multietnicidad en Teotihuacan durante el período Clásico. Estos resultados pueden ser corroborados por estudios en otros barrios de Teotihuacan y con futuros análisis de secuenciación.Asociación de Antropología Biológica de la República Argentina (AABRA

Neonate Human Remains: A Window of Opportunity to the Molecular Study of Ancient Syphilis

Ancient DNA (aDNA) analysis can be a useful tool in bacterial disease diagnosis in human remains. However, while the recovery of Mycobacterium spp. has been widely successful, several authors report unsuccessful results regarding ancient treponemal DNA, casting doubts on the usefulness of this technique for the diagnosis of ancient syphilis. Here, we present results from an analysis of four newborn specimens recovered from the crypt of “La Ermita de la Soledad” (XVI–XVII centuries), located in the province of Huelva in the southwest of Spain. We extracted and analyzed aDNA in three independent laboratories, following specific procedures generally practiced in the aDNA field, including cloning of the amplified DNA fragments and sequencing of several clones. This is the most ancient case, reported to date, from which detection of DNA from T. pallidum subspecies pallidum has been successful in more than one individual, and we put forward a hypothesis to explain this result, taking into account the course of the disease in neonate individuals

Sex Determination in Highly Fragmented Human DNA by High-Resolution Melting (HRM) Analysis

<div><p>Sex identification in ancient human remains is a common problem especially if the skeletons are sub-adult, incomplete or damaged. In this paper we propose a new method to identify sex, based on real-time PCR amplification of small fragments (61 and 64 bp) of the third exon within the amelogenin gene covering a 3-bp deletion on the AMELX-allele, followed by a High Resolution Melting analysis (HRM). HRM is based on the melting curves of amplified fragments. The amelogenin gene is located on both chromosomes X and Y, showing dimorphism in length. This molecular tool is rapid, sensitive and reduces the risk of contamination from exogenous genetic material when used for ancient DNA studies. The accuracy of the new method described here has been corroborated by using control samples of known sex and by contrasting our results with those obtained with other methods. Our method has proven to be useful even in heavily degraded samples, where other previously published methods failed. Stochastic problems such as the random allele drop-out phenomenon are expected to occur in a less severe form, due to the smaller fragment size to be amplified. Thus, their negative effect could be easier to overcome by a proper experimental design.</p></div

Melting temperature curve profiles produced by male and female samples in a HRM analysis.

<p>HRM analysis starts with a PCR amplification of the amelogenin gen. The amplification is in the presence of <i>EvaGreen</i> a saturating dye which presents high fluorescence when bound to dsDNA. Amplification is followed by a High Resolution Melting analysis (HRM) in the <i>LightCycler 480 Real-Time PCR Instrument</i> (Roche Applied Science). A dissociation curve analysis displays the different melting temperature of products from the X and Y chromosome.</p

Genetic Evidence Supports the Multiethnic Character of Teopancazco, a Neighborhood Center of Teotihuacan, Mexico (AD 200-600)

Multiethnicity in Teopancazco, Teotihuacan, is supported by foreign individuals found in the neighborhood center as well as by the diversity observed in funerary rituals at the site. Studies of both stable and strontium isotopes as well as paleodietary analysis, suggest that the population of Teopancazco was composed by three population groups: people from Teotihuacan, people from nearby sites (Tlaxcala-Hidalgo-Puebla), and people from afar, including the coastal plains. In an attempt to understand the genetic dynamics in Teopancazco we conducted an ancient DNA (aDNA) analysis based on mtDNA. Our results show that the level of genetic diversity is consistent with the multiethnicity phenomenon at the neighborhood center. Levels of genetic diversity at different time periods of Teopancazco's history show that multiethnicity was evident since the beginning and lasted until the collapse of the neighborhood center. However, a PCA and a Neighbor-Joining tree suggested the presence of a genetically differentiated group (buried at the Transitional phase) compared to the population from the initial phase (Tlamimilolpa) as well as the population from the final phase (Xolalpan) of the history of Teopancazco. Genetic studies showed no differences in genetic diversity between males and females in the adult population of Teopancazco, this data along with ample archaeological evidence, suggest a neolocal post-marital pattern of residence in Teopancazco. Nevertheless, genetic analyses on the infant population showed that the males are significantly more heterogeneous than the females suggesting a possible differential role in cultural practices by sex in the infant sector. Regarding interpopulation analysis, we found similar indices of genetic diversity between Teopancazco and heterogeneous native groups, which support the multiethnic character of Teopancazco. Finally, our data showed a close genetic relationship between Teopancazco and populations from the "Teotihuacan corridor" and from Oaxaca and the Maya region, in agreement with previous archaeological evidence

Principal Component Analysis based on mitochondrial haplogroups frequencies.

<p><b>TEO</b> (Teopancazco), <b>TEO-TLAM</b> (<i>Tlamimilolpa</i> period), <b>TEO-XOL</b> (<i>Xolalpan</i> period), <b>TEO-TRAN</b> (<i>Transitional</i> phase), <b>PIMA</b> (Pima, Aridoamerica), <b>ZAP</b> (Zapotec, Oaxaca), <b>OTO</b> (Otomi, Hidalgo)<b>, OTO I</b> (Otomi, Hidalgo)<b>, OTO II</b> (Otomi, Hidalgo)<b>, NAH</b> (Nahua, Veracruz)<b>, NAH I</b> (Nahua, Veracruz)<b>, NAH II</b> (Nahua, Puebla), <b>NAH III</b> (Nahua, Hidalgo), <b>MAY</b> (Maya, Xcaret), <b>MAY II</b> (Maya, Yucatán), <b>MAY III</b> (Maya, Campeche), <b>MAY IV</b> (Maya, Quintana Roo), <b>TEPE</b> (Tepehua, Hidalgo), <b>HUA</b> (Huastec, Hidalgo) <b>MIXT</b> (Mixtec, Oaxaca), <b>MIXT II</b> (Mixtec, Oaxaca).</p

Genetic Diversity (<i>Ĥ</i>a) found in males and females (adults and infants).

<p>N, sample size.</p><p>Genetic Diversity (<i>Ĥ</i>a) found in males and females (adults and infants).</p