Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.
RESUMEN.Se analizaron aspectos reproductivos de la raya eléctrica Narcine bancroftii, capturada como bycatch con una red playera de cerco en dos playas del sector de El Rodadero, Santa Marta, Caribe colombiano. Los ejemplares fueron sexados, pesados y medidos, se identificó su estado de desarrollo gonadal mediante características morfológicas externas e internas. Se evaluó la condición reproductiva con el comportamiento de los índices biológicos (gonadosomático IGS y hepatosomático IHS) y la talla a la madurez sexual (l 50% ). Los resultados obtenidos mostraron que el IGS tiene un máximo anual entre septiembre y diciembre cuando probablemente ocurre la cópula. El IHS presentó su mayor valor en enero, cuando termina su periodo reproductivo. La talla media de madurez en hembras fue de 32,2 cm y en machos de 20,2 a 22,9 cm. El período de gestación es de cuatro meses y las crías nacen de febrero a abril. Palabras clave: raya eléctrica, reproducción, fecundidad, mar Caribe, Colombia.Reproduction of the electric ray Narcine bancroftii (Torpediniformes: Narcinidae) in Santa Marta, Colombian Caribbean ABSTRACT. This paper provides information about reproductive aspects of the electric ray Narcine bancroftii, caught as bycatch with beach seines in two beaches of El Rodadero, Santa Marta, Colombian Caribbean, between August (2005) and October (2006). The electric rays obtained were separate by sex, weighed and measured; the development of reproductive stage was identified by external and internal characteristics. The reproductive condition was determinate by (gonadosomatic GSI and hepatosomatic HSI) indexes and the size at sexual maturity (l 50% ). The results showed that the GSI has one peak at year between September and December when probably the copulation carried out, the HSI presented its highest value in January, which corresponds to the end of the reproductive period. The size at sexual maturity was 32.2 cm in females and it was between 20.2 and 22.9 cm in males. We propose that the gestation period extends during four months, starting with the birth of individuals in February and finishing in April.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.