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The relationship between ethnicity and biology is of interest to anthropologists, biomedical scientists, and historians in understanding how human groups are constructed. Ethnic self-identification in recently admixed groups such as Hispanics, African Americans, and Native Americans (NA) is likely to be complex due to the heterogeneity in individual admixture proportions and social environments within these groups. This study examines the relationships between self-identified ethnicity, self-estimated admixture proportions, skin pigmentation, and genetic marker estimated admixture proportions. These measures were assessed using questionnaires, skin color measurements, and genotyping of a panel of 76 ancestry informative markers, among 170 Hispanics and NAs from New Mexico, a state known for its complex history of interactions between people of NA and European (EU) ancestry. Results reveal that NAs underestimate their degree of EU admixture, and that Hispanics underestimate their degree of NA admixture. Within Hispanics, genetic-marker estimated admixture is better predicted by forehead skin pigmentation than by self-estimated admixture. We also find that Hispanic individuals self-identified as 'half-White, half Hispanic' and 'Spanish' have lower levels of NA admixture than those self-identified as 'Mexican' and 'Mexican American.' Such results highlight the interplay between culture and biology in how individuals identify and view themselves, and have implications for how ethnicity and disease risk are assessed in a medical setting. KEY WORDS ethnic identity; New Mexico; genetic ancestry

Perilipin (PLIN) is the major protein surrounding lipid droplets in adipocytes and regulates adipocyte metabolism by modulating the interaction between lipases and triacylglycerol stores. Associations between PLIN gene polymorphisms and obesity risk have been described, but interactions with dietary macronutrients require further attention. We examined whether dietary macronutrients (e.g. carbohydrates and fats) modulated the associations of the common PLIN 11482G > A (rs894160) single nucleotide polymorphism with obesity. We studied a population-based sample of Caribbean-origin Hispanics (n = 920, aged 45-74 y) living in the Boston area. Obesity measures (waist and hip circumference, BMI) did not differ between GG subjects and carriers of the A allele (GA and AA). In multivariate linear regression models, we found a significant interaction between complex carbohydrate intake as a continuous variable and PLIN 11482 G > A genotype for waist circumference (P = 0.002). By dichotomizing complex carbohydrate intake, we found significantly different effects across PLIN 11482G > A genotypes. When complex carbohydrate intake was < 144 g/d, waist circumference was larger in PLIN 11482G > A carriers (P = 0.024). Conversely, when complex carbohydrate intake was [greater than or equal to] 144 g/d, waist and hip circumferences were less in PLIN 11482G > A carriers (P < 0.05). These interactions were not found for simple sugars or total carbohydrates. We identified a significant gene-diet interaction associated with obesity at the PLIN locus. In subjects with higher complex carbohydrate intake, the minor allele was protective against obesity, whereas in subjects with lower carbohydrate intake, the minor allele was associated with increased obesity. These interactions may be relevant to dietary management of obesity.

A study to compare the extent Hispanics, African Americans and Asian Americans as carriers of the tumor suppressor gene BRCA1 compared to white non-Hispanics with and without Ashkenazi Jewish ancestry is conducted. Results reveal that the mutated gene was highest in Hispanics and Asian Americans displayed the lowest.

A genomewide admixture mapping (AM) panel for Hispanic/Latino populations is described. The AM panel has 2,120 ancestry markers and the main criteria for marker selection were both high information content for Native American/European ancestry and small frequency differences between the Mesoamerican and South American samples.

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1741-3729.2006.00403.x Byline: Sampson Lee Blair (*), Jose A Cobas (*) Keywords: bilingualism; gender differences; Latino families; status attainment; young adults Abstract: Abstract: Previous studies have demonstrated that bilingualism among Latinos in the United States may not necessarily result in negative status attainment consequences. Such studies have typically overlooked gender differences in the consequences of bilingualism. Using data from the National Education Longitudinal Study (N= 866 females; 737 males), we analyzed gender differences in how bilingualism among Latino families (as experienced in childhood and adolescence) may affect the status attainment of young adults. Results indicated that females were more substantially affected by language use and ability in the family context than males. The findings suggest that gender roles within Latino families are interwoven with the effects of bilingualism. Practice and policy implications include how schools and educators must address the gendered nature of bilingualism. Article note: (*) Sampson Lee Blair is an Associate Professor in the Department of Sociology, 430 Park Hall, The State University of New York, Buffalo, NY 14260-4140 (slblair@buffalo.edu). Jose A. Cobas is a Professor in the Department of Sociology at Arizona State University, Tempe, AZ 85287-4802 (cobas@asu.edu).

Recent studies have demonstrated widespread pesticide exposures in pregnant women and in children. Plasma paraoxonase 1 (PON1) plays an important role in detoxification of various organophosphates. The goals of this [...]

Although it is well established that Hispanics generally have a mixed Native American, African, and European ancestry, the dynamics of admixture at the foundation of Hispanic populations is heterogeneous and poorly documented. Genetic analyses are potentially very informative for probing the early demographic history of these populations. Here we evaluate the genetic structure and admixture dynamics of a province in northwest Colombia (Antioquia), which prior analyses indicate was founded mostly by Spanish men and native women. We examined surname, Y chromosome, and mtDNA diversity in a geographically structured sample of the region and obtained admixture estimates with highly informative autosomal and X chromosome markers. We found evidence of reduced surname diversity and support for the introduction of several common surnames by single founders, consistent with the isolation of Antioquia after the colonial period. Y chromosome and mtDNA data indicate little population substructure among founder Antioquian municipalities. Interestingly, despite a nearly complete Native American mtDNA background, Antioquia has a markedly predominant European ancestry at the autosomal and X chromosome level, which suggests that, after foundation, continuing admixture with Spanish men (but not with native women) increased the European nuclear ancestry of Antioquia. This scenario is consistent with historical information and with results from population genetics theory. genetic history | migration latinos | Founder effect | cultural selection

Latinos are the largest minority population in the United States. Although usually classified as a single ethnic group by researchers, Latinos are heterogeneous from cultural, socioeconomic, and genetic perspectives. From a cultural and social perspective, Latinos represent a wide variety of national origins and ethnic and cultural groups, with a full spectrum of social class. From a genetic perspective, Latinos are descended from indigenous American, European, and African populations. We review the historical events that led to the formation of contemporary Latino populations and use results from recent genetic and clinical studies to illustrate the unique opportunity Latino groups offer for studying the interaction between racial, genetic, and environmental contributions to disease occurrence and drug response. doi:10.2105/AJPH. 2005.068668)