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El objetivo de este trabajo es determinar los parámetros sanguíneos y la presencia de parásitos en una población salvaje de tortugas deslizantes (Trachemys scripta emolli), durante la estación seca de 2013, en el Refugio de Vida Silvestre Caño Negro, Costa Rica. Utilizando redes, los individuos fueron capturados de diferentes huecos. Se tomó muestras de sangre para determinar los parámetros químicos de esta y el hematocrito, así como los valores morfológicos y las condiciones corporales. Además, se recolectaron muestras de heces y ectoparásitos. El IC del hematocrito 95.0 % fue [14 7091, 18 7356] y no se encontraron diferencias significativas entre los sexos. Los IC del 95 % para los parámetros de la química sanguínea fueron: AST (U/L) [87 6214, 148 929], CK (U/L) [1439.2, 2487.08], AU (umol/L) [68.22, 90.43], GLU (mmol/L) [4.26, 5.47], PHOS [0.46, 0.61], Ca (mmol/L) [1.99, 2.15], PT (g/L) [22.16, 24.44], K (mmol/L) [3.31, 3.83 ] y Na (mmol/L) [127.92, 130.93]. También se obtuvo 21 muestras de heces, de las cuales 10 fueron positivas para parásitos (23.8 % Strongyloides, 14.3 % Ascaridia, 9.5 % Coccidia y 9.5 % Pentastomida). Una sanguijuela de la familia Rhynchobdellidae fue el único ectoparásito encontrado (Placobdella sp.). Ninguno de los individuos estaba enfermo o presentaba abscesos en relación con sus atributos morfológicos. Según los resultados, el manejo empleado no representa un riesgo para esta población de reptiles The objective of this study was to determinate blood parameters and the presence of parasites in a wild population of tortugas deslizantes (Trachemys scripta emolli) during the dry season of 2013 in the Caño Negro Wildlife Refuge in Costa Rica. Individuals were captured from different gaps using nets. Blood samples were taken to determine chemical parameters of blood and hematocrit, as well as morphological values and body conditions. In addition, samples of feces and ectoparasites were collected. The hematocrit CI 95.0% was [14.7091, 18.7356] and no significant difference were found between sexes. The 95% CI for blood chemistry parameters were: AST (U/L) [87.6214, 148.929], CK (U/L) [1439.2, 2487.08], AU (umol/L) [68.22, 90.43 ], GLU (mmol/L) [4.26, 5.47], PHOS [0.46, 0.61], Ca (mmol/L) [1.99, 2.15], PT (g/L) [22.16, 24.44], K (mmol/L ) [3.31, 3.83], and Na (mmol/L) [127.92, 130.93]. A total of 21 fecal samples was obtained, of which 10 were positive for parasites (23.8% Strongyloides, 14.3% Ascaridia, 9.5% Coccidia, and 9.5% Pentastomid). A leech from the Rhynchobdellidae family was the only ectoparasite found (Placobdella sp.). None of the individuals were ill or had abscesses in relation to their morphological attributes. Based on the results, the handling used does not represent a risk for this reptile population O objetivo deste trabalho é determinar os parâmetros sanguíneos e a presença de parasitas em uma população selvagem de tortugas deslizantes (Trachemys scripta emolli) durante a estação seca de 2013 no Refúgio de Vida Selvagem Caño Negro, Costa Rica. Usando redes, os indivíduos foram capturados de diferentes tocas. Foram coletadas amostras de sangue para determinar os parâmetros químicos e o hematócrito, assim como dos valores morfológicos e das condições corporais. Além disso, foram coletadas amostras de fezes e ectoparasitas. O IC do hematócrito de 95% foi [14 7091, 18 7356] e não foram encontradas diferenças significativas entre os sexos. O IC de 95% nos parâmetros de química do sangue foram: AST (U/L) [87 6214, 148 929], CK (U/L) [1439.2, 2487.08], AU (umol/L) [68.22, 90.43 ], GLU (mmol/L) [4.26, 5.47], PHOS [0.46, 0.61], Ca (mmol/L) [1.99, 2.15], PT (g/L) [22.16, 24.44], K (mmol/L ) [3.31, 3.83] e Na (mmol/L) [127.92, 130.93]. Havia também 21 amostras de fezes, das quais 10 eram positivas para parasitas (23.8% de estrongiloidose, 14.3% de ascarídea, 9.5% de coccídea e 9.5% de pentastomida). Uma sanguessuga da família Rhynchobdellida foi o único ectoparasita encontrado (Placobdella sp.). Nenhum dos indivíduos estava doente ou teve abscessos em relação aos seus atributos morfológicos. De acordo com os resultados, o manejo empregado não representa um risco para essa população de répteis Instituto Costarricense de Electricidad, Costa Rica Universidad Nacional, Costa Rica Escuela de Medicina Veterinaria

Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the admixture of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods here we infer the sub-populations involved in admixture for over 6,500 Latin Americans and evaluate the impact of sub-continental ancestry on the physical appearance of these individuals. We find that pre-Columbian Native genetic structure is mirrored in Latin Americans and that sources of non-Native ancestry, and admixture timings, match documented migratory flows. We also detect South/East Mediterranean ancestry across Latin America, probably stemming from the clandestine colonial migration of Christian converts of non-European origin (Conversos). Furthermore, we find that Central Andean ancestry impacts on variation of facial features in Latin Americans, particularly nose morphology, possibly relating to environmental adaptation during the evolution of Native Americans.

The development of new strategies to renew and repair neuronal networks using neural plasticity induced by stem cell graft could enable new therapies to cure diseases that were considered lethal until now. In adequate microenvironment a neuronal progenitor must receive molecular signal of a specific cellular context to determine fate, differentiation, and location. TRPV1, a nonselective calcium channel, is expressed in neurogenic regions of the brain like the subgranular zone of the hippocampal dentate gyrus and the telencephalic subventricular zone, being valuable for neural differentiation and neural plasticity. Current data show that TRPV1 is involved in several neuronal functions as cytoskeleton dynamics, cell migration, survival, and regeneration of injured neurons, incorporating several stimuli in neurogenesis and network integration. The function of TRPV1 in the brain is under intensive investigation, due to multiple places where it has been detected and its sensitivity for different chemical and physical agonists, and a new role of TRPV1 in brain function is now emerging as a molecular tool for survival and control of neural stem cells.

In this chapter the history of Caribbean human population migratory movements are discussed. In the first part a macro perspective which considers large migrations was taken into account and in the second part a micro perspective focusing on a small population derived from East-Indian workers who settled in the Atlantic coast of Costa Rica. We argue that the human migratory history of the Caribbean is evident in the genetic makeup of this group of Indo-Costa Ricans, which was analyzed typing mtDNA and Y-chromosomal markers.

The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call First American. However, speakers of Eskimog-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.

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The mtDNA variation of 321 individuals from 17 Native American populations was examined by high-resolution restriction endonuclease analysis. All mtDNAs were amplified from a variety of sources by using PCR. The mtDNA of a subset of 38 of these individuals was also analyzed by D-loop sequencing. The resulting data were combined with previous mtDNA data from five other Native American tribes, as well as with data from a variety of Asian populations, and were used to deduce the phylogenetic relationships between mtDNAs and to estimate sequence divergences. This analysis revealed the presence of four haplotype groups (haplogroups A, B, C, and D) in the Amerind, but only one haplogroup (A) in the Na-Dene, and confirmed the independent origins of the Amerinds and the Na-Dene. Further, each haplogroup appeared to have been founded by a single mtDNA haplotype, a result which is consistent with a hypothesized founder effect. Most of the variation within haplogroups was tribal specific, that is, it occurred as tribal private polymorphisms. These observations suggest that the process of tribalization began early in the history of the Amerinds, with relatively little intertribal genetic exchange occurring subsequently. The sequencing of 341 nucleotides in the mtDNA D-loop revealed that the D-loop sequence variation correlated strongly with the four haplogroups defined by restriction analysis, and it indicated that the D-loop variation, like the haplotype variation, arose predominantly after the migration of the ancestral Amerinds across the Bering land bridge.

Artículo científico -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1988 Sparteine sulfate (50 mg) was administered to 170 Cuna Amerindians, 142 of whom were unrelated, and the drug and its dehydrometabolites were determined in the 0- to 12-hour urine samples. The log10 of the metabolic ratio was unimodally, but not normally, distributed and showed the following values: mean 0.21 ± 0.26, median 0.24, limits 0.73 and 0.76, skewness 1.00, and kurtosis 4.95. On the basis of these results, it can be concluded that there are no deficient metabolizers in the Cuna sample population studied. However, the similarity of the skewness found between the Cuna sample population studied and the extensive Canadian white group, as well as an inflection point at 6.3 U in the former's probit plot, suggests the existence of at least two subgroups congregating within the same single mode in the frequency distribution curve. The use of the inflection point is discussed thoroughly, concluding that although it does not allow exclusion of the existence of genotypically different subgroups, the limitations of the data do not permit its use to determine the number of heterozygotes and thus the existence of polymorphism. The possibility of an isozyme variant, consistent with the general genetic structure of Amerindians, as suggested by the coexistence of two subgroups within the unimodal curve, is entertained. (CLIN PHARmAcoL THER 1988;43:456-65.) Universidad de Costa Rica. Instituto de Investigaciones en Salud. Universidad de Panamá Universidad de Toronto UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA)

We sequenced the genomes of a ∼7,000-year-old farmer from Germany and eight ∼8,000-year-old hunter-gatherers from Luxembourg and Sweden. We analysed these and other ancient genomes1,2,3,4 with 2,345 contemporary humans to show that most present-day Europeans derive from at least three highly differentiated populations: west European hunter-gatherers, who contributed ancestry to all Europeans but not to Near Easterners; ancient north Eurasians related to Upper Palaeolithic Siberians3, who contributed to both Europeans and Near Easterners; and early European farmers, who were mainly of Near Eastern origin but also harboured west European hunter-gatherer related ancestry. We model these populations’ deep relationships and show that early European farmers had ∼44% ancestry from a ‘basal Eurasian’ population that split before the diversification of other non-African lineages., Instituto Multidisciplinario de Biología Celular

artículo (arbitrado). Universidad de Costa Rica, Centro de Investigación en Biología Celular y Molecular, 2012 Estimates of mutation rates for the noncoding hypervariable Region I (HVR-I) of mitochondrial DNA (mtDNA) vary widely, depending on whether they are inferred from phylogenies (assuming that molecular evolution is clock-like) or directly from pedigrees. All pedigree-based studies so far were conducted on populations of European origin. In this paper we analyzed 19 deep-rooting pedigrees in a population of mixed origin in Costa Rica. We calculated two estimates of the HVRI mutation rate, one considering all apparent mutations, and one disregarding changes at sites known to be mutational hot spots and eliminating genealogy branches which might be suspected to include errors, or unrecognized adoptions along the female lines. At the end of this procedure, we still observed a mutation rate equal to 1.24 × 10−6, per site per year, i.e., at least three-fold as high as estimates derived from phylogenies. Our results confirm that mutation rates observed in pedigrees are much higher than estimated assuming a neutral model of long-term HVRI evolution. We argue that, until the cause of these discrepancies will be fully understood, both lower estimates (i.e., those derived from phylogenetic comparisons) and higher, direct estimates such as those obtained in this study, should be considered when modeling evolutionary and demographic processes. Universidad de Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)

Objective To determine if individuals who carry mitochondrial markers which have been previously shown to affect longevity also have differential lifetime reproductive success (LRS). Methods We extracted the mtDNA from living subjects residing in Atenas, Costa Rica. Since mtDNA does not recombine, and its probability of mutation is low, we assume that all maternal ancestors of the living subjects have the same mtDNA. We reconstructed the maternal genealogy of the living subjects, so that we have information on the LRS and longevity of the maternal ancestors of the living subjects. We compared the LRS of women who carried the 5178A marker in haplogroup D (associated with decreased longevity) and who carried the 150T polymorphism (associated with increased longevity) with the LRS of controls born in the same half century time period from 1750 to 1939. Results We found that the LRS of neither group of women with a longevity-associated polymorphism (LAP) differed from the LRS of controls, even if these women differed significantly from the controls in their longevity. Conclusions Although LAPS significantly affect longevity, such differential longevity does not result in differential lifetime reproductive success. From an evolutionary perspective, these longevity-associated polymorphisms do not affect the carriers' Darwinian fitness. Am. J. Hum. Biol., 2011. © 2010 Wiley-Liss, Inc.

artículo (arbitrado) -- Universidad de Costa Rica, Centro de investigaciones en Biología Celular y Molecular, 2008. Este documento es privado debido a limitaciones de derechos de autor. Previous work compared frequency of longevity-associated polymorphisms (LAPS) in long-lived individuals and in controls from the general population (primarily in Europe and Japan), suggesting the polymorphisms are responsible for unusual longevity. However, individuals from the general population are not the control group for long-lived subjects because both were born in different periods. We report results of a project which collected mtDNA from living subjects in Costa Rica, and traced back their maternal genealogy. Since mtDNA does not recombine and its probability of mutation is low, we can assume that the maternal ancestors had the same mtDNA of their descendants. We compared the longevity of individuals with LAPS with the longevity of controls born in the same time period. We did not confirm previous associations for several markers, but found that the 5178A mutation in haplogroup D is associated with decreased longevity, whereas the 150T mutation is associated with increased longevity. These associations however, are not significant for all time periods under study. While our data confirm that mtDNA make up affects longevity, they also indicate that the time period in which a person was born had a much greater impact on longevity than presence or absence of a marker. Supported by a grant from the National Institutes of Aging (1-R03-AG022616-01) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)