Mitochondrial DNA analysis on pre-Columbian bone remains of the Herrera peri

Introducción. Los restos óseos arcaicos son fuente privilegiada de información biológica y su caracterización genética permite confirmar o descartar filiaciones propuestas por otras aproximaciones científicas. La historia precolombina de los Andes orientales se divide en tres periodos principales: i) un poblamiento temprano por parte de grupos cazadores-recolectores; ¡i) un periodo intermedio (Herrera) de pueblos con agricultura incipiente, y iii) un periodo tardío de pueblos chibchas, agrícolas y alfareros (agroalfarero). Objetivo. Analizar el ADN mitocondrial de restos óseos del periodo Herrera. Materiales y métodos. Se analizaron 11 individuos pertenecientes al yacimiento arqueológico Madrid 2-41, con una edad aproximada de 2.000 años. Un fragmento (192 pb) del segmento hipervariable I fue amplificado y secuenciado, siguiendo criterios estrictos de autenticidad de ADN arcaico. Las secuencias se compararon con las existentes en bases de datos de Norteamérica y Europa usando herramientas bioinformáticas. Resultados. Todas las secuencias resultaron idénticas y fueron clasificadas como haplogrupo B. Esto puede relacionarse con el tipo de entierro ritual practicado en Madrid 2-41, es decir, probablemente los individuos analizados hagan parte de una familia jerárquicamente importante en la antigua sociedad Herrera. La búsqueda de secuencias homologas en las bases de datos estadounidense y europea no arrojó coincidencias exactas, aunque existe el reporte de un individuo amazónico de -4.000 años de antigüedad (Brasil) cuya secuencia coincide con la hallada en Madrid 2-41. Conclusión. Los individuos del yacimiento arqueológico Madrid 2-41 están estrechamente emparentados entre sí por línea materna y presentan una secuencia aparentemente ausente en poblaciones actuales.Q4Q3Artículo original569-577Introduction. Ancient bone remains constitute an important source of biological information, and their genetic characterization allows the confirmation or rebuttal of human affiliations proposed on the basis of non-molecular approaches. Pre-Columbian history of the Eastern Andes in Colombia has been divided into three main periods: (i) an early colonization by groups of hunter-gatherers, (ii) an intermediate period “Herrera” characterized by primitive agriculture and (iii) a late stage of Chibcha-speaking groups, with agriculture and ceramics (“agroalfarero”). Objective. The mitochondrial DN A on ancient bone remains of the Herrera period were analyzed for comparison with modern and other ancient DNAs. Materials and methods. Mitochondrial DNA was extracted from 11 Herrera individuals [-2,000 years before present (YBP)] found in the Madrid 2-41 archaeological site near Bogotá, Colombia. A 192 bp segment of the hypervariable segment I was amplified and sequenced, following stringent archaic DNA authenticity criteria. The sequences were compared with those in American and European databases using bioinformatics tools. Results. All individuals had identical sequences and were classified as haplogroup B. This identity may be related to the type of ritual burial performed in the site, probably exclusively for members of a hierarchically important family of the ancient Herrera society. The search for homologous sequences in the American and European mtDNA data bases produced no identical coincidences, although a Brazilian Amazonio individual (-4,000 YBP) was recorded with a matching sequence. Conclusion. Individuals buried in the Madrid 2-41 site were maternally closely related and showed a mtDNA sequence that is apparently absent in contemporary populations

Mitochondrial DNA analysis on pre-Columbian bone remains of the Herrera peri

Introducción. Los restos óseos arcaicos son fuente privilegiada de información biológica y su caracterización genética permite confirmar o descartar filiaciones propuestas por otras aproximaciones científicas. La historia precolombina de los Andes orientales se divide en tres periodos principales: i) un poblamiento temprano por parte de grupos cazadores-recolectores; ¡i) un periodo intermedio (Herrera) de pueblos con agricultura incipiente, y iii) un periodo tardío de pueblos chibchas, agrícolas y alfareros (agroalfarero). Objetivo. Analizar el ADN mitocondrial de restos óseos del periodo Herrera. Materiales y métodos. Se analizaron 11 individuos pertenecientes al yacimiento arqueológico Madrid 2-41, con una edad aproximada de 2.000 años. Un fragmento (192 pb) del segmento hipervariable I fue amplificado y secuenciado, siguiendo criterios estrictos de autenticidad de ADN arcaico. Las secuencias se compararon con las existentes en bases de datos de Norteamérica y Europa usando herramientas bioinformáticas. Resultados. Todas las secuencias resultaron idénticas y fueron clasificadas como haplogrupo B. Esto puede relacionarse con el tipo de entierro ritual practicado en Madrid 2-41, es decir, probablemente los individuos analizados hagan parte de una familia jerárquicamente importante en la antigua sociedad Herrera. La búsqueda de secuencias homologas en las bases de datos estadounidense y europea no arrojó coincidencias exactas, aunque existe el reporte de un individuo amazónico de -4.000 años de antigüedad (Brasil) cuya secuencia coincide con la hallada en Madrid 2-41. Conclusión. Los individuos del yacimiento arqueológico Madrid 2-41 están estrechamente emparentados entre sí por línea materna y presentan una secuencia aparentemente ausente en poblaciones actuales.Q4Q3Artículo original569-577Introduction. Ancient bone remains constitute an important source of biological information, and their genetic characterization allows the confirmation or rebuttal of human affiliations proposed on the basis of non-molecular approaches. Pre-Columbian history of the Eastern Andes in Colombia has been divided into three main periods: (i) an early colonization by groups of hunter-gatherers, (ii) an intermediate period “Herrera” characterized by primitive agriculture and (iii) a late stage of Chibcha-speaking groups, with agriculture and ceramics (“agroalfarero”). Objective. The mitochondrial DN A on ancient bone remains of the Herrera period were analyzed for comparison with modern and other ancient DNAs. Materials and methods. Mitochondrial DNA was extracted from 11 Herrera individuals [-2,000 years before present (YBP)] found in the Madrid 2-41 archaeological site near Bogotá, Colombia. A 192 bp segment of the hypervariable segment I was amplified and sequenced, following stringent archaic DNA authenticity criteria. The sequences were compared with those in American and European databases using bioinformatics tools. Results. All individuals had identical sequences and were classified as haplogroup B. This identity may be related to the type of ritual burial performed in the site, probably exclusively for members of a hierarchically important family of the ancient Herrera society. The search for homologous sequences in the American and European mtDNA data bases produced no identical coincidences, although a Brazilian Amazonio individual (-4,000 YBP) was recorded with a matching sequence. Conclusion. Individuals buried in the Madrid 2-41 site were maternally closely related and showed a mtDNA sequence that is apparently absent in contemporary populations

Cultivo de células odontogénicas en soportes de hidrogel PEGDA para uso en regeneración dental

Para lograr la formación de una estructura similar a un diente se estratificaron células de ectodermo oral embrionario (EOE) con células troncales de medula ósea (BMSC) dentro de una matriz de diacrilato de polietilenglicol (PEGDA) que se implantó en el mesenterio ileal de machos adultos de ratas Lewis. Mediante hibridización in situ de bloque completo se evaluó la expresión de tres genes iniciadores putativos de la formación dental (Pitx2, Shh y Wnt10a), estableciendo que en ratas las señales iniciadoras de dentogénesis aparecen entreE12.5 y E13. El tejido ectodérmico embrionario se obtuvo haciendo cruces controlados de hembras a las que se les detectó el estro mediante impedanciometría. En E12.5 las hembras se sacrificaron y se extrajeron los embriones. Se disecó la poción mandibular del primer arco branquial y el ectodermo se separó del mesénquima mediante disociación enzimática con una solución de pancreatina tripsina. Las BMSC se extraje-ron de los huesos largos de las extremidades inferiores de ratas mediante lavado con α-MEM y se cultivaron en cajas de25cm2hasta un segundo pasaje. Las BMSC fueron recombinadas con ectodermo embrionario competente (E12.5 - E13) estratificándolas en un soporte tridimensional de PEGDA, polimerizado con luz ultravioleta (365nm) dentro de un molde piramidal de polipropileno (PP). Los constructos se cultiva-ron entre 48 y 72 horas en α-MEM y posteriormente fueron implantados en el mesenterio ileal de machos adultos (3 a 6meses de edad) por un período de cuatro a seis semanas. Se implantaron 76 constructos (37 experimentales, 27 controles negativos y 12 controles positivos). En la fecha determinada los animales se sacrificaron mediante asfixia con una mezcla de CO2y aire recuperando los constructos que se fijaron en formalina tamponada para luego procesarlos y teñirlos con hematoxilina eosina (HE). La evaluación histológica de los constructos experimentales, positivos y negativos mostró que las BMSC incluidas en el hidrogel sufrieron un proceso de apoptosis conocido como anoikis que impidió su interacción con las células ectodérmicas. En contraste el EOE proliferó durante el período de implantación. A futuro se debe buscarla matriz portadora ideal que permita el confinamiento de los dos grupos celulares y que brinde el soporte estructural necesario para la proliferación de las BMSC facilitando su interacción con las células inductoras de origen ectodérmico.Q3243-254In order to obtain a tooth-like structure, embryonic oral ectoderm cells (EOE) and bone marrow-derived stem cells (BMSC) were stratified within a synthetic hydrogel matrix (PEGDA) and implanted in the ileal mesentery of adult male Lewis rats. Whole-mount in situ hybridization was used to evaluate the expression of Pitx2, Shh and Wnt10a signals indicative of tooth initiation. In rats, expression of the three markers was present in the oral ectoderm starting at embryonic stage E12.5. which was therefore selected for cell harvesting. Embryos were obtained by controlled service of young female Lewis rats in which estrus was detected by impedance reading. At E12.5, pregnant rats were humanely euthanized and embryos were collected. The mandibular segment of the first branchial arch was dissected and the mesenchyme separated from the ectoderm by enzymatic digestion with pancreatin trypsin solution. BMSCs were collected by flushing the marrow of tibiae and femurs of adult Lewis rats with alpha-MEM and cultured in alpha-MEM in 25 cm2 flasks. Second passage BMSC's were recombined with competent oral ectoderm (E12.5-E13) stratifying them within a 3D PEGDA scaffold polymerized by exposure to UV (365 nm) inside a pyramidal polypropylene mold. Constructs were incubated from 24 to 48 hrs in alpha-MEM and then implanted for four to six weeks in the mesentery of adult male (3-6 month old) Lewis rats. 76 constructs were implanted (37 experimental, 27 negative controls and 12 positive controls). Upon maturation, constructs were harvested, fixed in buffered formalin, processed and stained with hematoxylin eosin (HE). Histological evaluation of the experimental and negative constructs showed that BMSCs underwent an apoptotic process due to lack of matrix interactions, known as anoikis, and were thus incapable of interacting with the competent ectoderm. In contrast, embryonic oral ectoderm was able to proliferate during the mesenteric implantation. In conclusion, PEGDA scaffolds are incompatible with BMSCs, therefore it is essential to continue the search for an ideal scaffold that allows proper tissue interactions

Genetic population analysis of 17 Y-chromosomal STRs in three states (Valle del Cauca, Cauca and Narino) from Southwestern Colombia

Q3Q1204-211Seventeen Y-chromosomal (DYS19, DYS389 1/11, DYS390, DYS391, DYS392, DYS393, DYS438, DYS439, DYS437, DYS448, DYS456, DYS458, DYS635, YGATA-H4 and DYS385a/b) short tandem repeat (STR) polymorphic systems were typed in three South West Colombian populations: Valle (short term for Valle del Cauca), Cauca and Nariño. DYS385a/b showed the highest gene diversity in the three populations. A total of 287 different Y-chromosome haplotypes were observed in the 308 males analyzed, and the haplotype diversity among populations was 0.9977. The most frequent haplotype was observed only three times and only nineteen others were observed two times. The highest gene diversity was found in Valle and the lowest in Cauca. Analysis of molecular variance (AMOVA) revealed that variation is mainly within populations (99.1%) in agreement with previous results in European populations. In conclusion, these populations could be pooled together in order to create one “Colombian-Mestizo” database for forensic use

Polimosrfismos de los nenes P53, CYP1A1,CYP1B1,GSTM1,GSTT1 Y GSTP1 en cáncer de seno familiar en una población colombiana.

IP 1222-04-16436En Colombia, el cáncer de senos es la tercera causa de muerte por cáncer después del cáncer gástrico y cuello uterino. En países desarrollados una de cada nueve mujeres desarrolla cáncer de mama a lo largo de su vida y la tercera parte de ellas muere debido a esta neoplasia

A Colombian Caribbean population study of 16 Y-chromosome STR loci

Q1Q1e5-e8Allelic frequencies and haplotypic composition of 305 male unrelated individuals from the Caribbean Colombian states of Atlántico, Bolívar, Cesar, Córdoba, Guajira, Magdalena and Sucre, were determined using 16 Y-chromosome STR loci. Two hundred and ninety three (293) haplotypes were identified, of which 283 were unique and the other 10 were found twice or thrice in the Caribbean population tested. Haplotypic diversity surpassed the values obtained in other populations, ranging from 99.66% in the population of Sucre to 99.99% in the population of Córdoba. We also calculated the overall haplotypic diversity (99.97%) and the discrimination power of these haplotypes (96.1%) in these groups. Analysis of molecular variance (AMOVA) for 10 Colombian and Spanish populations (3139 haplotypes) reveals low differentiation between the Colombian populations of mainly European descent and large distance to Afroamerican populations living in Colombia

Dilemas bioéticos de la genética

La genética y su aliada la ingeniería conforman una tecnociencia de enorme poder transformador del fenómeno de lo viviente en nuestro planeta. La audacia de sus emprendimientos requiere ser acompañada de riguroso discernimiento bioético

Análisis mitocondrial de ADN sugiere una migración Chibcha a Colombia

La caracterización del DNA mitocondrial (mtDNA) permite el estudio de estructuras genéticas y de relaciones filogenéticas en poblaciones humanas, al rastrear linajes liada muy atrás en el tiempo. Analizamos muestras de mtDNA de veinte (20) poblaciones nativas americanas (700 individuos) dispersas por toda Colombia. Las muestras se obtuvieron entre 1989-1993 como parte del programa Expedición Humana y se almacenaron en el Banco Biológico del Instituto de Genética Humana (IGH) de la Pontifica Universidad Javeriana (Bogotá, Colombia). Los haplogrupos se determinaron mediante análisis de RFLPs. El más frecuente fue el haplogrupo A, con 338 individuos (48.3%). El haplogrupo A es también uno de los más frecuentes en Mesoamérica, y nosotros interpretamos nuestro hallazgo como una evidencia en favor de los modelos según los cuales los grupos que hablaban chibcha migraron al norte de Colombia desde Mesoaménca en tiempos prelustoncos. El haplogrupo C se encontró en 199 individuos (28.4%), mientras que los menos frecuentes fueron B v D con 113 y 41 individuos (16 y 6% respectivamente). No se pudieron determinar los haplogrupos de nueve (9) individuos (1.3%) debido a la baja calidad de las muestras de DNA. Aunque todas las poblaciones muestreadas tienen estructuras genéticas que se ajustan en líneas generales a los patrones que se podrían esperar para grupos indígenas contemporáneos de Centro y Suraménca, encontramos que los haplogrupos A y B eran más frecuentes en el norte de Colombia, mientras los haplogrupos C y D eran más frecuentes en el sur y surocddente del país.Q2Artículo original261-278The characterization of mitochondrial DNA (mtDNA) allows the establishment of genetic structures and phylogenetic relationships in human populations, tracing lineages far back in time. We analysed samples of mtDNA from twenty (20) Native American populations (700 individuals) dispersed throughout Colombian territory. Samples were collected during 1989-1993 in the context of the program Expedición Humana (“Human Expedition”) and stored in the Biological Repository of the Institute of Human Genetics (IGH) at the Pontificia Universidad Javeriana (Bogotá, Colombia). Haplogroups were determined by analysis of RFLPs. Most frequent was haplogroup A, with 338 individuals (48.3%). Haplogroup A is also one of the most frequent haplogroups in Mesoamerica, and we interpret our finding as supporting models that propose Chibchan-speaking groups migrated to northern Colombia from Mesoamerica in prehistoric times. Haplogroup C was found in 199 individuals (28.4%), while less frequent were B and D, with 113 and 41 (16% and 6%) individuals, respectively. The haplogroups of nine (9) individuals (1.3%) could not be determined due to the low quality of the samples of DNA. Although all the sampled populations had genetic structures that fit broadly into the patterns that might be expected for contemporary Central and South American indigenous groups, it was found that haplogroups A and B were more frequent in northern Colombia, while haplogroups C and D were more frequent in southern and south-western Colombia

High proportion of BRCA1/2 founder mutations in Hispanic breast/ovarian cancer families from Colombia

Q2Q1225-232In South America, a high proportion of the population is of Hispanic origin with an important representation in Colombia. Since nothing is known about the contribution of BRCA1 and BRCA2 germline mutations to hereditary breast/ovarian cancer in the Hispanic population from Colombia, we conducted the first study of 53 breast/ovarian cancer families from this country. Comprehensive BRCA mutation screening was performed using a range of techniques, including DHPLC, SSCP, and PTT, followed by DNA sequencing analysis. Thirteen deleterious germline mutations (24.5%) were identified in 53 families, comprising eight in BRCA1 and five in BRCA2. The two recurrent BRCA1 mutations, 3450 delCAAG and A1708E, accounted for 100% of all BRCA1 mutations identified in this cohort and the recurrent 3034 delACAA BRCA2 mutation for 40% of all BRCA2 mutations. Haplotype analyses suggested that each of these mutations has arisen from a common ancestor. The prevalence of BRCA1 or BRCA2 mutations was 50% in multiple case breast cancer families, and was 33% for the breast-ovarian cancer families. Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer in Colombia. The spectrum of mutations differed completely to that previously reported in Hispanic families of predominantly Mexican origin from Southern California [1] suggesting that specific genetic risk assessment strategies for the different Hispanic populations in South America and in the United States need to be developed