scholarly journals The genomic landscape of Mexican Indigenous populations brings insights into the peopling of the Americas

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Humberto García-Ortiz ◽  
Francisco Barajas-Olmos ◽  
Cecilia Contreras-Cubas ◽  
Miguel Ángel Cid-Soto ◽  
Emilio J. Córdova ◽  
...  

AbstractThe genetic makeup of Indigenous populations inhabiting Mexico has been strongly influenced by geography and demographic history. Here, we perform a genome-wide analysis of 716 newly genotyped individuals from 60 of the 68 recognized ethnic groups in Mexico. We show that the genetic structure of these populations is strongly influenced by geography, and our demographic reconstructions suggest a decline in the population size of all tested populations in the last 15–30 generations. We find evidence that Aridoamerican and Mesoamerican populations diverged roughly 4–9.9 ka, around the time when sedentary farming started in Mesoamerica. Comparisons with ancient genomes indicate that the Upward Sun River 1 (USR1) individual is an outgroup to Mexican/South American Indigenous populations, whereas Anzick-1 was more closely related to Mesoamerican/South American populations than to those from Aridoamerica, showing an even more complex history of divergence than recognized so far.

2016 ◽  
Vol 48 (1) ◽  
Author(s):  
Arianna Manunza ◽  
Antonia Noce ◽  
Juan Manuel Serradilla ◽  
Félix Goyache ◽  
Amparo Martínez ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoyun Bin ◽  
Rui Wang ◽  
Youyi Huang ◽  
Rongyao Wei ◽  
Kongyang Zhu ◽  
...  

Sui people, which belong to the Tai-Kadai-speaking family, remain poorly characterized due to a lack of genome-wide data. To infer the fine-scale population genetic structure and putative genetic sources of the Sui people, we genotyped 498,655 genome-wide single-nucleotide polymorphisms (SNPs) using SNP arrays in 68 Sui individuals from seven indigenous populations in Guizhou province and Guangxi Zhuang Autonomous Region in Southwest China and co-analyzed with available East Asians via a series of population genetic methods including principal component analysis (PCA), ADMIXTURE, pairwise Fst genetic distance, f-statistics, qpWave, and qpAdm. Our results revealed that Guangxi and Guizhou Sui people showed a strong genetic affinity with populations from southern China and Southeast Asia, especially Tai-Kadai- and Hmong-Mien-speaking populations as well as ancient Iron Age Taiwan Hanben, Gongguan individuals supporting the hypothesis that Sui people came from southern China originally. The indigenous Tai-Kadai-related ancestry (represented by Li), Northern East Asian-related ancestry, and Hmong-Mien-related lineage contributed to the formation processes of the Sui people. We identified the genetic substructure within Sui groups: Guizhou Sui people were relatively homogeneous and possessed similar genetic profiles with neighboring Tai-Kadai-related populations, such as Maonan. While Sui people in Yizhou and Huanjiang of Guangxi might receive unique, additional gene flow from Hmong-Mien-speaking populations and Northern East Asians, respectively, after the divergence within other Sui populations. Sui people could be modeled as the admixture of ancient Yellow River Basin farmer-related ancestry (36.2–54.7%) and ancient coastal Southeast Asian-related ancestry (45.3–63.8%). We also identified the potential positive selection signals related to the disease susceptibility in Sui people via integrated haplotype score (iHS) and number of segregating sites by length (nSL) scores. These genomic findings provided new insights into the demographic history of Tai-Kadai-speaking Sui people and their interaction with neighboring populations in Southern China.


2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Jessica Nye ◽  
Mayukh Mondal ◽  
Jaume Bertranpetit ◽  
Hafid Laayouni

Abstract After diverging, each chimpanzee subspecies has been the target of unique selective pressures. Here, we employ a machine learning approach to classify regions as under positive selection or neutrality genome-wide. The regions determined to be under selection reflect the unique demographic and adaptive history of each subspecies. The results indicate that effective population size is important for determining the proportion of the genome under positive selection. The chimpanzee subspecies share signals of selection in genes associated with immunity and gene regulation. With these results, we have created a selection map for each population that can be displayed in a genome browser (www.hsb.upf.edu/chimp_browser). This study is the first to use a detailed demographic history and machine learning to map selection genome-wide in chimpanzee. The chimpanzee selection map will improve our understanding of the impact of selection on closely related subspecies and will empower future studies of chimpanzee.


2020 ◽  
Author(s):  
Ardalan Naseri ◽  
Degui Zhi ◽  
Shaojie Zhang

AbstractRuns of homozygosity (ROH) segments, contiguous homozygous regions in a genome were traditionally linked to families and inbred populations. However, a growing literature suggests that ROHs are ubiquitous in outbred populations. Still, most existing genetic studies of ROH in populations are limited to aggregated ROH content across the genome, which does not offer the resolution for mapping causal loci. This limitation is mainly due to a lack of methods for efficient identification of shared ROH diplotypes. Here, we present a new method, ROH-DICE, to find large ROH diplotype clusters, sufficiently long ROHs shared by a sufficient number of individuals, in large cohorts. ROH-DICE identified over 1 million ROH diplotypes that span over 100 SNPs and shared by more than 100 UK Biobank participants. Moreover, we found significant associations of clustered ROH diplotypes across the genome with various self-reported diseases, with the strongest associations found between the extended HLA region and autoimmune disorders. We found an association between a diplotype covering the HFE gene and haemochromatosis, even though the well-known causal SNP was not directly genotyped nor imputed. Using genome-wide scan, we identified a putative association between carriers of an ROH diplotype in chromosome 4 and an increase of mortality among COVID-19 patients. In summary, our ROH-DICE method, by calling out large ROH diplotypes in a large outbred population, enables further population genetics into the demographic history of large populations. More importantly, our method enables a new genome-wide mapping approach for finding disease-causing loci with multi-marker recessive effects at population scale.


2017 ◽  
Author(s):  
Behrooz Darbani ◽  
Douglas B. Kell ◽  
Irina Borodina

ABSTRACTTransporter proteins mediate the translocation of substances across the membranes of living cells. We performed a genome-wide analysis of the compositional reshaping of cellular transporters (the transportome) across the kingdoms of bacteria, archaea, and eukarya. We show that the transportomes of eukaryotes evolved strongly towards a higher energetic efficiency, as ATP-dependent transporters diminished and secondary transporters and ion channels proliferated. This change has likely been important in the development of tissues performing energetically costly cellular functions. The transportome analysis also indicated seven bacterial species, includingNeorickettsia risticiiandNeorickettsia sennetsu, as likely origins of the mitochondrion in eukaryotes, due to the restricted presence therein of clear homologues of modern mitochondrial solute carriers.


2021 ◽  
Author(s):  
Rania Jbir Koubaa ◽  
Mariem Ayadi ◽  
Mohamed Najib Saidi ◽  
Safa Charfeddine ◽  
Radhia Gargouri Bouzid ◽  
...  

Abstract As antioxidant enzymes, catalase (CAT) protects organisms from oxidative stress via the production of reactive oxygen species (ROS). These enzymes play important roles in diverse biological processes. However, little is known about the CAT genes in potato plants despite its important economical rank of this crop in the world. Yet, abiotic and biotic stresses severely hinder growth and development of the plants which affects the production and quality of the crop. To define the possible roles of CAT genes under various stresses, a genome-wide analysis of CAT gene family has been performed in potato plant.In this study, the StCAT gene’s structure, secondary and 3D protein structure, physicochemical properties, synteny analysis, phylogenetic tree and also expression profiling under various developmental and environmental cues were predicted using bioinformatics tools. The expression analysis by RT-PCR was performed using commercial potato cultivar. Three genes encoding StCAT that code for three proteins each of size 492 aa, interrupted by seven introns have been identified in potatoes. StCAT proteins were found to be localized in the peroxisome which is judged as the main H2O2 cell production site during different processes. Many regulating cis-elements related to stress responses and plant hormones signaling were found in the promoter sequence of each gene. The analysis of motifs and phylogenetic trees showed that StCAT are closer to their homologous in S. lycopersicum and share a 41% – 95% identity with other plants’ CATs. Expression profiling revealed that StCAT1 is the constitutively expressive member; while StCAT2 and StCAT3 are the stress-responsive members.


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