ABSTRACT
Chickens (Gallus gallus domesticus) from the Americas have long been recognized as descendants of European chickens, transported by early Europeans since the fifteenth century. However, in recent years, a possible pre-Columbian introduction of chickens to South America by Polynesian seafarers has also been suggested. Here, we characterize the mitochondrial control region genetic diversity of modern chicken populations from South America and compare this to a worldwide dataset in order to investigate the potential maternal genetic origin of modern-day chicken populations in South America. The genetic analysis of newly generated chicken mitochondrial control region sequences from South America showed that the majority of chickens from the continent belong to mitochondrial haplogroup E. The rest belongs to haplogroups A, B and C, albeit at very low levels. Haplogroup D, a ubiquitous mitochondrial lineage in Island Southeast Asia and on Pacific Islands is not observed in continental South America. Modern-day mainland South American chickens are, therefore, closely allied with European and Asian chickens. Furthermore, we find high levels of genetic contributions from South Asian chickens to those in Europe and South America. Our findings demonstrate that modern-day genetic diversity of mainland South American chickens appear to have clear European and Asian contributions, and less so from Island Southeast Asia and the Pacific Islands. Furthermore, there is also some indication that South Asia has more genetic contribution to European chickens than any other Asian chicken populations.
ABSTRACT
BACKGROUND: American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. METHODOLOGY/PRINCIPAL FINDINGS: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. CONCLUSIONS/SIGNIFICANCE: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.
Subject(s)
Cattle/genetics , Genetic Variation , Animals , Breeding , Microsatellite RepeatsABSTRACT
Colombia has one of the most genetically diverse creole cattle populations, with eight creole breeds and two improved creole (Colombian) breeds. A high demand for meat and milk has led to the inevitable selection of highly productive cattle and the introduction of foreign breeds. Unfortunately, these breeds are often ill-suited for tropical conditions. These factors threaten the size of the creole livestock population, which is considered part of Colombia's national heritage. Objective: to estimate the allelic frequencies of the Kappa-Casein gene (CNS3) in Colombian creole cattle breeds (GCC). Methods: a total of 354 blood samples were taken from 30 animals of each of the following breeds: Blanco Orejinegro (BON), Caqueteño (CQT), Casanareño (CAS), Horned Costeño (Costeño con Cuernos, CCC), Chino Santandereano (ChS), Hartón del Valle (HV), Romosinuano (ROM), and Sanmartinero (SM), each representing the 8 established ''criollo'' (creole) breeds; the Lucerna (LUC) and Velasquez (VEL) representing the two Colombian improved breeds; and Brahman and Holstein as control breeds. DNA was extracted by a salting-out procedure and a 453 bp fragment on chromosome 6 was amplified by PCR. CSN3 alleles were identified using single strand conformation polymorphism (SSCP) and their sequence compared with those of the Genebank for Bos taurus and Bos indicus. Results: higher frequencies for allele variants of CSN3 A (0.39) and B (0.41) were found relative to the frequencies of I (0.038), G (0.095), A1 (0.025), E (0.006), and N (0.006). The allele of interest (CSN3 B) had a high frequency in the CCC (0.81), ROMO (0.66), CQT (0.55), ChS (0.48), and VEL (0.43) breeds. Conclusions: these findings suggest that Colombian creole breeds harbor a high genetic diversity which enriches its gene pool and warrants future conservation efforts to protect its integrity.
Colombia es uno de los países más diversos en recursos genéticos criollos. Posee ochos razas de ganado criollo (GCC) y dos razas de criollo mejorado o razas colombianas. La creciente demanda de alimentos ha generado una forzosa selección de individuos altamente productivos e introducción de razas foráneas (Holstein y Brahman) poco adaptadas a condiciones tropicales, lo que ha puesto en riesgo el tamaño efectivo del ganado criollo, considerado patrimonio nacional. Objetivo: estimar la frecuencia alélica del gen (CNS3) de la Kappa-Caseína en el (GCC). Métodos: se usaron 354 muestras de sangre de ocho razas bovinas criollas (30 individuos por raza): Blanco Orejinegro (BON), Caqueteño (CQT), Casanareño (CAS), Costeño con Cuernos (CCC), Chino Santandereano (ChS), Hartón del Valle (HV), Romosinuano (ROMO) y Sanmartinero (SM), dos colombianas Lucerna (LUC) y Velásquez (VEL) y dos controles Brahman y Holstein. Con el fin de estimar la frecuencia de los alelos k-caseína (k-CN) se amplificó un fragmento de 453 pb para k-CN (cromosoma 6). Los alelos se identificaron mediante la técnica PCR-SSCP. Resultados: se encontró mayor frecuencia para las variantes de k-CN A (0.39) y B (0.41), en comparación a I (0.038), G (0.095), A1 (0.025), E (0.006) y N (0.006). El alelo de interés k-CN B presentó alta frecuencia en las razas CCC (0.81), ROMO (0.66), CQT (0.55), ChS (0.48), y VEL (0.43). Conclusiones: la alta frecuencia del alelo de interés del gen k-CN ratifica al GCC como alternativa viable en esquemas sostenibles de producción de leche de mejor calidad y corrobora la necesidad de evaluación y caracterización de recursos zoogenético, como primer paso para su conservación.
A Colômbia é um dos países mais diversificado em recursos genéticos crioulos, tem oito bovinos da raça nativa e duas raças melhoradas ou raças crioulo colombiano (GCC). A alta demanda por alimentos tem levado a uma seleção forçada das pessoas altamente produtivas e/ou introdução de raças estrangeiras mal adaptados às condições tropicais, que têm prejudicado o tamanho efetivo de animais considerados património crioulo. Objetivo: estimar a frequência do alelo do gene Kappa-Caseína (CNS3) na (GCC). Métodos: foram utilizados 354 amostras de sangue de oito raças nativas (30 indivíduos por raça): Blanco Orejinegro (BON), Caqueteño (CQT), Casanareño (CAS), Costeño con Cuernos (CCC), Chino Santandereano (ChS), Hartón del Valle (HV), Romosinuano (ROM) e Sanmartinero (SM), dois Colombianas Lucerna (LUC) e Velásquez (VEL) e dois controles (Brahman and Holstein). Para estimar a freqüência de alelos de κ-caseína (CSN3), amplificaram um fragmento de 453 pb para CSN3. Os alelos foram identificados por PCR-SSCP. Resultados: encontramos uma maior freqüência de variantes do CSN3 A (0.39) e B (0.41), comparado com I (0.038), G (0.095), A1 (0.025), E (0.006) e N (0.006). O alelo de interesse CSN3 B apresentou alta freqüência em raças CCC (0.81), ROMO (0.66), CQT (0.55), CHS (0.48) e VEL (0.43). Conclusões: estes resultados sugerem que o CCG é um recurso genético, que abriga uma grande diversidade genética e apoia a necessidade de avaliação e caracterização dos recursos genéticos animais como um primeiro passo para a conservação.
ABSTRACT
The Hartón del Valle(HV)cattleisa Criollo breed of Spanish descent that has adapted to the conditionsof the Cauca valley (Colombia). This breed is currently listed as “vulnerable” because its population has dramatically declined in the last two years. Prompted by the uncertain future of this breed and its importance as a potential resource of valuable genes. Objective: this study addressed the diversity, genetic structure and ancestry of HV cattle using mitochondrial DNA (mtDNA). Methods: a 350-bp fragment was amplified and sequenced from 72 HV animals in 9 separate farms and from animals of Brahman and Holstein breeds. To analyze the breed's ancestry, the sequences were compared with 560 sequences available in the GenBank, representing 50 Bos taurus and Bos indicus breeds. Results: in accordance with the Spanish origin of the HV breed, there was a high representation of European mtDNA (91.7%) and a low representation of African (5.5%) and Middle Eastern mtDNA (2.7%). The average haplotype diversity was 0.65 ± 0.05. The farm with the oldest ancestry was the only population in which three mitochondrial lineages were observed; unfortunately, it was recently depopulated. Proximity was observed between HV and two Columbian breeds, the Romosinuano and Costeño con Cuernos. A comparative analysis with the sequences deposited in the GenBank from numerous breeds revealed the presence of 37 haplotypes, seven of which were unique to HV. Conclusions: the following Iberian breeds were found to be most closely related to HV: Tudanca, Rubia Gallega, Negra Serrana, Murciana, Pajuna, Avileña, Garvonesa and Mertolenga. Phylogenetic analysis confirmed the Iberian ancestry and some African influence on this Latin American Criollo breed.
El Hartón del Valle (HV),es una raza adaptada a las condiciones del Valle del Cauca(Colombia) que está catalogada como “vulnerable” y cuya población ha descendido drásticamente en los últimos dos años. Objetivo: debido al futuro incierto y a la importancia como recurso potencial en la seguridad alimentaria regional se abordó el estudio de la diversidad, la estructura genética y la ancestría del HV, mediante ADN mitocondrial (ADNmt). Métodos: se amplificó y secuenció un fragmento de 350 pb en 72 animales HV, provenientes de nueve poblaciones y de controles de las razas Brahman y Holstein. Para analizar la ancestría las secuencias fueron comparadas con 560 secuencias de 50 razas Bos taurus y Bos indicus, depositadas en el GenBank. Resultados: de acuerdo con su origen español, se encontró una marcada influencia del ADNmt europeo (91.7%) y baja participación de taurinos de origen africano (5.5%) y del cercano Oriente (2.7%). La diversidad haplotípica promedio fue 0.65 ± 0.05. El hato más antiguo fue el único que mostró los tres linajes mitocondriales, sin embargo, este ha sido liquidado recientemente. Se observó proximidad entre el HV con las razas colombianas Romosinuano y Costeño con Cuernos. La comparación con las secuencias depositadas en el GenBank con diferentes razas reveló la presencia de 37 haplotipos, de los cuales siete fueron únicos en el HV. Conclusiones: las razas ibéricas más cercanas al HV fueron: Tudanca, Rubia Gallega, Negra Serrana, Murciana, Pajuna, Avileña, Garvonesa y Mertolenga. El árbol filogenético confirmó la ancestralidad ibérica y la influencia africana en las razas criollas de América Latina.
O Hartón del Valle (HV) é uma raça adaptada às condições da região pertencente ao departamento do Valle del Cauca (Colombia). A raça está catalogada como vulnerável já que sua população tem sido reduzida drasticamente nos últimos dois anos. Objetivo: devido a incerteza no futuro da raça e a sua importancia como recurso potencial na segurança alimentaria regional, abordou-se o estudo da diversidade, a estrutura genética e a ancestralidade do gado HV, utilizando DNA mitocondrial (mtDNA). Métodos: para isto, se amplificou e sequenciou um fragmento de 350 pares de bases em 72 animais provenientes de nove populações e também de controles das raças Brahman e Holandesa. Para analizar a ancestralidade das sequências, estas foram comparadas com outras 560 de 50 raças Bos taurus y Bos indicus depositadas no genebank. Resultados: de acordo com sua origem espanhola, foi encontrada uma marcada influência do DNA mitocondrial europeu (91.7%), e baixa participação de taurinos de origem africana (5.5%) e do Oriente Próximo (2.7%). A média da diversidade haplotípica foi de 0.65 ± 0.05. A população de gado HV mais antiga foi a única que apresentou as três linhagens mitocondriais encontradas; embora, esta população foi terminada recentemente. Observou-se também proximidade do gado HV com as raças colombianas da região Caribe, Romosinuano e Costeño con Cuernos. A comparação com as sequências depositadas no genebank com diferentes raças revelou a presença de 37 haplotipos, dos quais sete foram únicos no HV. Conclusões: as raças ibéricas mais aproximadas do HV foram: Tudanca, Rubia Gallega, Negra Serrana, Murciana, Pajuna, Avileña Garvonesa e Mertolenga. A árvore filogenética confirmou sua ancestralidade ibérica e a influência africana nas raças crioulas da América Latina.