The human Y chromosome contains highly informative markers for making historical inferences about the pre-Columbian peopling of Americas. However, the scarcity of these markers has limited its use in the inference of shared ancestry and past migrations relevant to the origin of the culturally and biologically diverse Native Americans. To identify new single nucleotide polymorphisms (SNPs) and increase the phylogenetic resolution of the major haplogroup Q found in the Americas, we have performed a search for new polymorphisms based on sequencing divergent Y chromosomes identified by microsatellite haplotype analysis. Using this approach, a new Y-SNP (SA01) has been identified in the Andean populations of South America, allowing for the detection of a new sublineage of Q1a3a. This sublineage displays a less complex phylogeographic network of associated microsatellites and more restricted geographic occurrence, and is given the designation Q1a3a4. This result indicates that our approach can be successfully used to identify sublineages of interest in a specific region that allow the investigation of particular histories of human populations.

BackgroundWe reasoned that by identifying genetic markers on human X chromosome regions where recombination is rare or absent, we should be able to construct X chromosome genealogies analogous to those based on Y chromosome and mitochondrial DNA polymorphisms, with the advantage of providing information about both male and female components of the population.Methodology/Principal FindingsWe identified a 47 Kb interval containing an Alu insertion polymorphism (DXS225) and four microsatellites in complete linkage disequilibrium in a low recombination rate region of the long arm of the human X chromosome. This haplotype block was studied in 667 males from the HGDP-CEPH Human Genome Diversity Panel. The haplotypic diversity was highest in Africa (0.992±0.0025) and lowest in the Americas (0.839±0.0378), where no insertion alleles of DXS225 were observed. Africa shared few haplotypes with other geographical areas, while those exhibited significant sharing among themselves. Median joining networks revealed that the African haplotypes were numerous, occupied the periphery of the graph and had low frequency, whereas those from the other continents were few, central and had high frequency. Altogether, our data support a single origin of modern man in Africa and migration to occupy the other continents by serial founder effects. Coalescent analysis permitted estimation of the time of the most recent common ancestor as 182,000 years (56,700–479,000) and the estimated time of the DXS225 Alu insertion of 94,400 years (24,300–310,000). These dates are fully compatible with the current widely accepted scenario of the origin of modern mankind in Africa within the last 195,000 years and migration out-of-Africa circa 55,000–65,000 years ago.Conclusions/SignificanceA haplotypic block combining an Alu insertion polymorphism and four microsatellite markers on the human X chromosome is a useful marker to evaluate genetic diversity of human populations and provides a highly informative tool for evolutionary studies.

The hypothalamic-pituitary-adrenal (HPA) axis is an important hormonal mechanism of the human body and is extremely programmable during embryonic and fetal development. Analyzing its development in this period is the key to understanding in fact how vulnerabilities of congenital diseases occur and any other changes in the phenotypic and histophysiological aspects of the fetus. The environment in which the mother is exposed during the gestational period can influence this axis. Knowing this, our objective was to analyze in recent research the possible impact of epigenetic programming on the HPA axis and its consequences for fetal development. This review brought together articles from two databases: ScienceDirect and PUBMED researched based on key words such as "epigenetics, HPA axis, cardiovascular disease, and circulatory problems" where it demonstrated full relevance in experimental and scientific settings. A total of 101 articles were selected following the criteria established by the researchers. Thus, it was possible to verify that the development of the HPA axis is directly related to changes that occur in the cardiovascular system, to the cerebral growth and other systems depending on the influence that it receives in the period of fetal formation. K E Y W O R D Sepigenetic, gestational period, hormonal mechanism, HPA

Mucopolysaccharidosis (MPS) IVA is a rare autosomal recessive disease with a highly variable distribution worldwide. Discrepancies in the incidence of MPS IVA among populations of different ethnicities are mostly attributed to founder effects. Demographic and clinical data from 28 MPS IVA patients, followed at a single center, and ancestry (Y chromosome and mitochondrial markers) of a subsample of 17 patients, most with the p.Ser341Arg (c.1023C>G) mutation were analyzed. Parental consanguinity was observed in 15/20 couples; a rare homozygous N-acetylgalactosamine-6-sulfatase (GALNS) mutation was found in 7/16 families with intra-familial phenotypic heterogeneity. Paternal ancestry was 94.2% (16/17) European, 5.8%(1/17) African, and 0% Amerindian. The European paternal haplogroups R1a, R1b, and R* accounted for 94.2% (16/17) of the patients. The R1b haplogroup, identified in 59% (10/17) of the patients, is frequently found in populations from the Iberian Peninsula. European, Amerindian, and African maternal ancestry was observed in 46.9% (8/17), 35.4% (6/17), and 17.7% (3/17) of the patients, respectively. Study of a cluster of MPS IVA patients from Northeastern Brazil, with high parental consanguinity and phenotypic heterogeneity showed predominantly European parental ancestry. This ancestry finding corroborates historical data on the local settlement, formed predominantly by European men.