Project description:This study evaluates genetic and phenotypic variation in the intermediate altitude Calchaquí population living in the Calchaquí Valleys of the Argentinean Andes in the town of Cachi at 2300 m. This study attempts to pinpoint evolutionary mechanisms underlying adaptation to moderate hypoxia at a intermediate altitude.
Project description:This study evaluates genetic and phenotypic variation in the high altitude Colla population living in the Argentinean Andes above 3500 m. They were compared to the Wichí population living in the nearby lowlands of the Gran Chaco region. This study attempts to pinpoint evolutionary mechanisms underlying adaptation to hypobaric hypoxia. We have genotyped 25 individuals from both populations for 730,525 SNPs.
Project description:This study evaluates genetic and phenotypic variation in the intermediate altitude Calchaquà population living in the Calchaquà Valleys of the Argentinean Andes in the town of Cachi at 2300 m. This study attempts to pinpoint evolutionary mechanisms underlying adaptation to moderate hypoxia at a intermediate altitude. DNA from 24 saliva samples of CalchaquÃes living at 2300 m in Cachi in the Province of Salta in Argentina was genotyped.
Project description:This study evaluates genetic and phenotypic variation in the high altitude Colla population living in the Argentinean Andes above 3500 m. They were compared to the Wichà population living in the nearby lowlands of the Gran Chaco region. This study attempts to pinpoint evolutionary mechanisms underlying adaptation to hypobaric hypoxia. We have genotyped 25 individuals from both populations for 730,525 SNPs. DNA from 25 saliva samples from Collas living >3500 m and 25 saliva samples from Wichà living <500 m from the Province of Salta in Argentina was genotyped
Project description:Understanding molecular mechanism associated with high altitude exposure during acclimatization/adaptation/maladaptation. Data reveals specific components of the complex molecular circuitry underlying high altitude pulmonary edema. Individualized outcome prediction were constructed through expression profiling of 39400 genes in sea level sojourners who were acclimatized to high altitude and grouped as controls (n=14), high altitude natives (n=14) and individuals who developed high altitude pulmonary edema within 48-72 hours after air induction to high altitude (n=17).
Project description:High-altitude adaptation is a representative example of vertebrates getting adapted to harsh and extreme environments. To investigate the miRNA expression alterations of goats that were induced by high altitude stress, we performed comparative miRNA transcriptome analysis on six hypoxia-sensitive tissues (heart, kidney, liver, lung, skeletal muscle and spleen) in two indigenous goat populations from distinct altitudes (600 m and 3000 m). We obtained the expression of 1391 mature miRNAs and identified 138 differentially expressed miRNAs between altitudes. Combined with tissue specificity analysis, we illustrated alterations of expression levels between altitudes and among tissues, which suggested the coexisting tissue-specific and tissue-conserved mechanism for hypoxia adaptation. Notably, the interplay between DE miRNA and DE target genes strongly indicated post-transcriptional regulation in HIF-1 signaling pathway, insulin signaling pathway and p53 signaling pathway, which might play a significant role in high altitude adaptation in domestic goats. These results provide insights into the complicated miRNA expression pattern and regulatory mechanism of high altitude adaptation in domestic goats.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.