Diversity and effective population size of four horse breeds from micro satellite DNA markers in South-Central Mexico

This study assesses genetic diversity and population structure of Quarter Horse, Azteca, Thoroughbred and Creole horses, frequently used for horse dancing competitions in traditional regional festivities. Since most animals in the studied area are used as breeders, the results support the improvement of management strategies, including periodical assessment of these populations to ensure acceptable population sizes and breed integrity, and documenting genetic flow and reproductive management.The South-Central region of Mexico has experienced a sizeable introduction of purebred horses for recreational aims. A study was designed to assess effective population sizes and genetic diversity and to verify the genetic integrity of four horse breeds. Using a 12-microsatellite panel, Quarter Horse, Azteca, Thoroughbred and Creole (CRL) horses were sampled and analysed for diversity and genetic structure. Genetic diversity parameters showed high numbers of heterozygous horses but small effective population sizes in all breeds. Population structure results suggested some degree of admixture of CRL with the other reference breeds. The highly informative microsatellite panel allowed the verification of diversity in introduced horse populations and the confirmation of small effective population sizes, which suggests a risk for future breed integrity

Secuenciación y análisis del genoma mitocondrial de subespecies de venado cola blanca Odocoileus virginianus

Tesis. (Maestro en Ciencias en Biotecnología Genómica). Instituto Politécnico Nacional, Centro de Biotecnología Genómica. 2012. 1 archivo PDF, (86 páginas), tesis.ipn.m

Loci asociados con enfermedades genéticas y calidad de carne en bovinos Charolais mexicanos

Allelic and genotypic frequencies of eight markers previously associated to genetic disorders and meat quality and located in the calpain (CAPN1-4751 and CAPN1-316) , calpastatin (CAST-T1), thyroglobulin (TG5), myostatin (MSTN, Q204X), argininosuccinate synthase (ASS), monophosphate synthase (UMPS) and myophosphorylase (PYGM) genes, were determined from 493 registered Charolais animals sampled from two herds located at Sonora (n= 157) and three at Nuevo León (n= 336), Mexico. No carriers of mutated alleles of ASS and UMPS genes were found, but carriers of the MSTN Q204X allele were identified at frequencies of 1 % in Sonora populations and 8.6 to 14.4 % in Nuevo Leon. In addition, carriers of PYGM marker were identified at frequencies of 6.49 and 1% in a herd from Sonora and other from Nuevo León, respectively. Analysis of gene differentiation among herds and with four loci showed that there are highly significant differences within Northwest populations (P<0.0001) and between them and the Northeast (P<0.001), differentiation is mainly explained by the loci CAPN-316 and TG5. According to the obtained results, the periodic monitoring of the PYGM marker gene and of the allele Q204X the MSTN gene is propose; also it is important to implement strategies to confirm the usefulness of those markers associated with quality and productivity as a tool to complement breeding programs.Se determinaron las frecuencias alélicas y genotípicas de ocho marcadores localizados en los genes calpaína (CAPN, 4751 y 316), calpastatina  (CASTT1) y tiroglobulina (TG5), asociados a calidad de carne, y en los genes, miostatina (MSTN, Q204X), arginino succinato sintasa (ASS), monofosfato sintasa (UMPS) y miofosforilasa (PYGM), asociados a enfermedades genéticas de ganado bovino. Se muestrearon 493 animales Charolais de registro de dos hatos ubicados en Sonora (n=157) y tres en Nuevo León (n=336). No se encontraron portadores de los alelos T-ASS y T-UMPS, pero sí portadores del alelo Q204X del gen MSTN en frecuencias de ≤ 1 % en las poblaciones de Sonora y de 8.6 a 14.4 % en las de Nuevo León. Además, se identificaron portadores del marcador del gen PYGM, en frecuencias del 6.5 y de 1.0 % para un hato de Sonora y otro de Nuevo León, respectivamente. El análisis de diferenciación génica pareado entre las poblaciones y con los cuatro loci mostró que hay diferencias altamente significativas dentro de poblaciones del noroeste (P<0.0001) y entre éstas y las del noreste (P<0.001), la cual es explicada principalmente por los loci CAPN-316 y TG5. De acuerdo a los resultados obtenidos se recomienda el monitoreo del marcador del gen PYGM y del alelo Q204X del gen MSTN, así como también implementar estrategias para confirmar la utilidad de los marcadores asociados a calidad y productividad como herramienta para complementar los programas de mejoramiento genético

Frecuencia de SNP en genes candidatos para crecimiento y su efecto en caracteres de peso vivo en ganado para carne de Tamaulipas

El objetivo del estudio fue analizar las frecuencias alélicas de 28 Polimorfismos de un solo nucleótido (SNP) localizados en genes candidatos para crecimiento en bovinos, así como determinar su efecto sobre rasgos de peso vivo en hatos de las razas Charolais y Simmental. Se tomaron muestras de pelo de 313 animales provenientes de cinco hatos ubicados en cuatro municipios de Tamaulipas y se genotipificaron con la tecnología de Sequenom Mass Array.Todos los marcadores resultaron ser polimórficos en las poblaciones evaluadas y sus frecuencias alélicas fueron significativamente diferentes entre razas (P<0.05). El análisis de asociación determinó que en los animales de la raza Charolais, el marcador PRL+2723 tiene un efecto significativo (P=0.0350) sobre el peso al nacimiento y el marcador localizado en el gen GHR (GHR-6.1), sobre peso al destete (P=0.0226). El GHR-6.1 también se asoció con el peso al año en los animales de la raza Simmental.  El marcador LEP-3100 (P=0.0249) también tuvo un efecto significativo sobre el peso al destete en los animales Simmental.El panel probado es polimórfico en las dos razas evaluadas y tres de los marcadores tuvieron efecto significativo en los parámetros de peso vivo evaluados, por lo que tienen el potencial de validarse y usarse como una herramienta adicional en la selección y mejoramiento genético del ganado de carne en Tamaulipas

Novel single nucleotide polymorphisms in candidate genes for growth in tilapia ( Oreochromis niloticus )

ABSTRACT The objective of the present work was to identify and validate single nucleotide variations located in candidate genes to growth traits in tilapia (Oreochromis niloticus). Two transitions were identified in the promoter region of the growth hormone gene (GH); eight nucleotide changes were identified in introns and promoter region of the IGF-I gene; and a transition (T/C) was identified in the Myogenin gene (MyoG). The highest genotypic frequency (0.8) for GHpA1 and MyoG was found in the GG and TT homozygous individuals, while the highest frequency (0.9) for GHpB1 was observed in the CT heterozygous fish. There was no genotypic frequency in the CC homozygous tilapia for the GHpB1 and MyoG markers. Based on their allelic frequencies, validation as novel single nucleotide polymorphisms (SNP) of those variations located at O. niloticus GH and MyoG genes was possible. These new markers will allow their association with growth traits in tilapia to be exploited in order to determine their potential use as assisted-selection markers

Diversity and effective population size of four horse breeds from micro satellite DNA markers in South-Central Mexico

This study assesses genetic diversity and population structure of Quarter Horse, Azteca, Thoroughbred and Creole horses, frequently used for horse dancing competitions in traditional regional festivities. Since most animals in the studied area are used as breeders, the results support the improvement of management strategies, including periodical assessment of these populations to ensure acceptable population sizes and breed integrity, and documenting genetic flow and reproductive management.The South-Central region of Mexico has experienced a sizeable introduction of purebred horses for recreational aims. A study was designed to assess effective population sizes and genetic diversity and to verify the genetic integrity of four horse breeds. Using a 12-microsatellite panel, Quarter Horse, Azteca, Thoroughbred and Creole (CRL) horses were sampled and analysed for diversity and genetic structure. Genetic diversity parameters showed high numbers of heterozygous horses but small effective population sizes in all breeds. Population structure results suggested some degree of admixture of CRL with the other reference breeds. The highly informative microsatellite panel allowed the verification of diversity in introduced horse populations and the confirmation of small effective population sizes, which suggests a risk for future breed integrity