Ancestral resurrection of anthropoid estrogen receptor ß demonstrates functional consequences of positive selection.

Anthropoid primates arose during the Eocene approximately 55 million years ago (mya), and extant anthropoids share a most recent common ancestor ∼40mya. Paleontology has been very successful at describing the morphological phenotypes of extinct anthropoids. Less well understood is the molecular biology of these extinct species as well as the phenotypic consequences of evolutionary variation in their genomes. Here we resurrect the most recent common ancestral anthropoid estrogen receptor ß gene (ESR2) and demonstrate that the function of this ancestral estrogen receptor has been maintained during human descent but was altered during early New World monkey (NWM) evolution by becoming a more potent transcriptional activator. We tested hypotheses of adaptive evolution in the protein coding sequences of ESR2, and determined that ESR2 evolved via episodic positive selection on the NWM stem lineage. We separately co-transfected ESR2 constructs for human, NWM, and the anthropoid ancestor along with reporter gene vectors and performed hormone binding dose response experiments that measure transactivation activity. We found the transactivation potentials of the ancestral and human sequences to be significantly lower (p<0.0001 in each comparison) than that of the NWM when treated with estradiol, the most prevalent estrogen. We conclude the difference in fold activation is due to positive selection in the NWM ERß ligand binding domain. Our study validates inferential methods for detecting adaptive evolution that predict functional consequences of nucleotide substitutions and points a way toward examining the functional consequences of positive Darwinian selection.

Prevalence of overweight and obesity in older Mexican adults and its association with physical activity and related factors: An analysis of the study on global ageing and adult health.

OBJECTIVES: The obesity epidemic in Mexico is increasing and represents a considerable public health challenge. The population aged 50 years and older is also increasing and is not exempt from the obesity rise. We aimed to determine the current prevalence of Body Mass Index (BMI) categories in a sample of Mexicans aged 50 years and older and to test the associations of BMI with physical activity categories and related factors. METHODS: Data from 2,032 individuals aged 50 years and older who participated in SAGE Wave 1 (2009-2010) were analyzed. Representativeness of the sample was obtained by using weighted data. Descriptive statistics, chi square tests, simple regression analysis, and multiple regression analysis were performed in relation to BMI, self-reported physical activity categories, and several variables, including demographic characteristics and selected risk factors for non-communicable diseases. RESULTS: Among older adults, 0.6% was found to be underweight, 21.4% normal weight, 49.4% overweight, and 28.7% obese. It was also found that practicing vigorous intensity physical activity (-1.32) and being 80 years or older (-2.73) were significantly associated (P < 0.05) with a lower mean BMI (28.3). In contrast, being in the lowest income quintile (1.35), and living in urban areas (0.86) were significantly associated with a higher mean BMI. CONCLUSIONS: The study results contribute to the current understanding of obesity etiology in Mexico, and moreover confirm that overweight and obesity are current public health problems that must be addressed in specific subgroups of older adults.

Elephant transcriptome provides insights into the evolution of eutherian placentation.

The chorioallantoic placenta connects mother and fetus in eutherian pregnancies. In order to understand the evolution of the placenta and provide further understanding of placenta biology, we sequenced the transcriptome of a term placenta of an African elephant (Loxodonta africana) and compared these data with RNA sequence and microarray data from other eutherian placentas including human, mouse, and cow. We characterized the composition of 55,910 expressed sequence tag (i.e., cDNA) contigs using our custom annotation pipeline. A Markov algorithm was used to cluster orthologs of human, mouse, cow, and elephant placenta transcripts. We found 2,963 genes are commonly expressed in the placentas of these eutherian mammals. Gene ontology categories previously suggested to be important for placenta function (e.g., estrogen receptor signaling pathway, cell motion and migration, and adherens junctions) were significantly enriched in these eutherian placenta-expressed genes. Genes duplicated in different lineages and also specifically expressed in the placenta contribute to the great diversity observed in mammalian placenta anatomy. We identified 1,365 human lineage-specific, 1,235 mouse lineage-specific, 436 cow lineage-specific, and 904 elephant-specific placenta-expressed (PE) genes. The most enriched clusters of human-specific PE genes are signal/glycoprotein and immunoglobulin, and humans possess a deeply invasive human hemochorial placenta that comes into direct contact with maternal immune cells. Inference of phylogenetically conserved and derived transcripts demonstrates the power of comparative transcriptomics to trace placenta evolution and variation across mammals and identified candidate genes that may be important in the normal function of the human placenta, and their dysfunction may be related to human pregnancy complications.