Analysis of a polymorphism in the DGAT1 gene in 14 cattle breeds through PCR-SSCP methods

The diacylglycerol O-acyltransferase (DGAT1) is a microsomal enzyme that catalyzes the final step of triglyceride synthesis. Recent work have evidenced a significant association between lysine at amino acid position 232 with elevated milk fat content, while an alanine at this position is associated with lowered milk fat content. The aim of the present work was to develop a simple and inexpensive PCR-SSCP assay in order to discriminate the CG/AA alleles in exon 8 of the DGAT1 gene. In addition, this method was used to analyze the polymorphism of the DGAT1 through PCR-SSCP methods in 14 populations of cattle from Argentine, Bolivia and Uruguay. The PCR primers were designed from GenBank reported sequences. In this study, we found three PCR-SSCP variants, which were denominated from "A" to "C". However, DNA sequencing analysis showed that "A" variant corresponded with the A allele, while both "B" and "C" observed pattern have the motif AA at positions 10,433-10,434 (K allele), being two alternative conformations of the same DNA sequence. Both variants were detected within each breed with the exception of Hereford, and the heterozygosity varied between 0.000 and 0.524. The gene frequency analysis evidenced significant differences among the studied breeds (FST = 0.325, p = 0.000). European Bos taurus breeds, with the exception of Jersey breed, showed the lowest frequency of the K allele, while highest K allele frequencies were harboured by Bos indicus type cattle. In addition, unselected South American Creole cattle breeds and the synthetic Brangus breed had intermediate allele frequencies.Fil: Ripoli, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Centro de Investigaciones en Genética Básica y Aplicada; ArgentinaFil: Corva, Pablo Marcelo. Universidad Nacional de Mar del Plata, Facultad de Ciencias Agrarias, Departamento de Producción Animal, Balcarce; ArgentinaFil: Giovambattista, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Centro de Investigaciones en Genética Básica y Aplicada; Argentin

Análisis de secuencias genómicas sugieren que el gen de la prodinorfina está bajo selección positiva en bovinos

Dynorphin A is an endogenous opioid peptide that is part of the KNDy system in the hypothalamus of mammals. This peptide acts as an inhibitor of the GnRH pulse generation, thus regulating the onset of puberty and reproductive cycles. The PDYN gene encodes the propeptide Prodynorphin, the precursor of Dynorphin A. Despite its physiological relevance, PDYN has not emerged as a candidate gene associated with puberty in genomic association studies conducted in cattle. The present work aimed to search for signatures of selection on the PDYN gene among cattle breeds. To this, the whole genome sequences from 57 samples of ten cattle breeds were used. The samples were grouped based on breed selection history and their productive differences, particularly in terms of sexual precocity. The population structure was analyzed using Principal Component Analyses. To evidence recent selection processes, neutrality tests, such as Tajima’s D and Fu & Li’s F* and D* were performed in defined functional regions of PDYN. The putative promoter of PDYN showed a population structure that is in agreement with the criteria considered to make the groups. In that region, neutrality tests were consistently negative and resulted in statistically significant for the dairy breeds. Also, these breeds exhibited less variability in the haplotype analyses than the others. The results presented here suggest that regulatory regions of PDYN could be under positive selection, particularly in dairy breeds.Dinorfina A es un péptido opioide endógeno que forma parte del sistema KNDy en el hipotálamo de mamíferos. Este péptido actúa como inhibidor de la generación de los pulsos de GnRH, regulando así el inicio de la pubertad y los ciclos reproductivos. El gen PDYN codifica el propéptido Prodinorfina, precursor de Dinorfina A. A pesar de su relevancia fisiológica, PDYN no ha surgido como gen candidato asociado a pubertad en estudios de asociación genómicos en bovinos. El presente trabajo tuvo como objetivo buscar huellas de selección en el gen PDYN entre diferentes razas bovinas. Para alcanzarlo se utilizaron secuencias genómicas de 57 muestras de diez razas bovinas. Las muestras fueron agrupadas considerando la historia de selección y las diferencias productivas entre razas, particularmente en términos de precocidad sexual. La estructura poblacional fue analizada usando análisis de componentes principales. Para evidenciar procesos de selección recientes se realizaron pruebas de neutralidad, tales como D de Tajima y F* y D* de Fu & Li, en diferentes regiones funcionales de PDYN. El promotor putativo de PDYN mostró una estructura poblacional que es consistente con los criterios usados para agrupar las razas. En esa región, las pruebas de neutralidad fueron consistentemente negativas y estadísticamente significativas en las razas lecheras. Además, estas razas también exhibieron menor variabilidad en los análisis de haplotipos que las demás razas. Los resultados presentados aquí sugieren que regiones regulatorias de PDYN estarían bajo selección positiva, particularmente en razas bovinas lecherasFil: Suqueli García, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Castellote, Martín Alfredo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Corva, Pablo Marcelo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentin

Simulation of marker assisted selection strategies in beef cattle

Marker-assisted selection (MAS) has been presented as a promising tool for animal breeding, but its application in beef cattle is still very limited. The technology is still expensive and the way to combine molecular information with more traditional breeding strategies has not been well defined. In order to evaluate MAS strategies, a simulation study was conducted. A beef cattle herd was simulated, in which selection was practiced to improve weaning weight. Three molecular markers with effect on weaning weight explained 40% of the additive variance. Four strategies were compared: mass selection based on phenotypes, marker-assisted selection, selection with animal model (BLUP) and a combined strategy in which the phenotypes were corrected for the effect of the markers and then analyzed with an animal model. Molecular analysis was performed on a limited number of individuals and genotypes of the rest of the population were inferred by segregation analysis. Marker-based selection was the least effective option. Selection based on animal model and the combined strategy performed better than mass selection. Under the simulated conditions, the combined approach showed a slight advantage over the animal model (3% in years 6-8) that would be of little practical relevance. Still, the feasibility of integrating molecular and quantitative genetic information in a single strategy was confirmed. Further research should evaluate options to optimize both the number of markers and of animals to be genotyped

Feed sorting behavior and performance of Argentinian Creole, Braford and crossbred steers during the growing and fattening phases

Local Latin American cattle breeds are considered highly adapted to grazing systems in harsh environments, but their potential in more intensified beef production systems, particularly when compared to imported breeds, is still a matter of debate. Argentinian Creole (CRA), Braford (BRA) and Creole x Braford (CXB) steers were evaluated in the growing (Experiment 1) and fattening phases (Experiment 2). In Experiment 1, 12 animals from each genetic group were allocated after weaning to four pens and fed a total mixed ration for 57 days. In Experiment 2, six 17-month old steers of each genetic group were allocated each to a single pen and fed a high concentrate diet for 55 days. Several traits associated with animal performance, feed intake and feed sorting were recorded. Experiment 1: CRA had lower daily weight gain than the other two groups (P 19 mm, BRA CRA = CXB, P = 0.06). Experiment 2: CRA had lower initial body weight (P 19 mm, BRACRA y CXB, P=0.06). Experimento 2: el peso vivo inicial de CRA fue más bajo que en BRA y CXB (P<0.01) y la diferencia con BRA también fue significativa al final del experimento (P<0.01). CRA tuvo menor espesor de grasa dorsal (P<0.01). El área inicial y final del ojo de bife fue similar entre grupos en ambos experimentos. La clasificación de las partículas en alimento fue similar entre grupos (P≥0.21). Todos los resultados sugieren que CRA tuvo un desempeño productivo inferior a BRA y CXB en ambos experimentos.Instituto de Investigación Animal del Chaco SemiáridoFil: Della Rosa, María Milagros. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Corva, Pablo Marcelo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Departamento de Producción Animal; ArgentinaFil: Royo, Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Zimerman, María. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Bottegal, Diego Nicolas. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Nasca, Jose Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; Argentin

Delayed type hypersensitivity induced by intradermal inoculation of a Neospora caninum tachyzoite antigen in previously exposed cattle

The aim of this study was to evaluate delayed type hypersensitivity (DTH) induced by the intradermal inoculation of a Neospora caninum tachyzoite soluble lysate in cattle previously exposed with the protozoa. Four experimental groups were selected according to the prior exposure to N. caninum antigen. All cows were intradermally injected with a N. caninum tachyzoite soluble lysate and skinfold thickness growth at the inoculation sites was measured at 0, 24, 48, 72 and 96 h post inoculation (hpi). Additionally, specific antibodies and IFN-γ production were assessed. Cows experimentally infected with live N. caninum tachyzoites and cows naturally exposed to N. caninum developed skin reactions compatible with DTH between 24 and 96 hpi (p  0.05). Furthermore, serological status of the animals was not modified due to the intradermal inoculation. The highest IFN-γ production was observed at 15 days after intradermal inoculation (p < 0.05). Therefore, these results suggest that cattle previously exposed to N. caninum develop a reaction compatible with DTH which could be useful as in vivo cell mediated immunity parameter for assessed bovine neosporosis.EEA BalcarceFil: Fiorani, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas;, ArgentinaFil: Armendano, Joaquín Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Hecker, Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Araoz, Virginia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Leunda, María Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Pereyra, Susana Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Corva, Pablo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Odeon, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Moore, Prando Dadin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentin

Einfluss von drei Einzelnucleotidpolymorphismen im CAPN1 Gen auf die Zartheit von Rindfleisch

Meat tenderness is an important trait in beef cattle production, as consumers consider tenderness the most important attribute of beef palatability. There is ample evidence that post mortem proteolysis of myofibrillar proteins is responsible for the decline in shear force uring storage. The bovine micromolar calcium-activated neutral protease CAPN1) gene encodes the large subunit of μ-calpain, which is thought to be one of the most important enzymes involved in post mortem tenderization (KOOHMARAIE 1996). Three single-nucleotide polymorphisms (SNPs) on the CAPN1 gene (316, 530 and 4 751 markers)have been associated with tenderness in different cattle breeds (PAGE et al. 2002, PAGE et al. 2004, WHITE et al. 2005). A more recent study confirmed that markers 316 and 4 751 had an effect on beef tenderness (VAN EENENNAAM et al. 2007). The objective of this research was to determine the existence of polymorphisms and to assess the effect of the reported SNP in the bovine CAPN1 gene on tenderness from a sample of Angus and Brangus steers fattened on pasture.Fil: Soria, Liliana A.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Corva, Pablo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Sica, Andrea Branda. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Schor, Alejandro. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal. Cátedra de Bovinos de Carne; ArgentinaFil: Melucci, Lilia Magdalena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Villarreal, Edgardo L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Mezzadra, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Cantet, Rodolfo Juan Carlos. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Miquel, Maria Cristina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin

Association between five candidate genes and milk yield in the Saavedreña creole cattle breed

Utilizando PCR-RFLP y AS-PCR se caracterizaron los polimorfismos de los genes candidatos aS1-caseína, k-caseína, b-lactoglobulina, prolactina y hormona de crecimiento en 146 muestras de sangre de vacas Criolla Saavedreña de la Estación Experimental de Saavedra (Bolivia) seleccionadas para producción lechera estudiando la asociación de dichos genes con la producción de leche en vacas de primera lactancia. El único locus que evidenció diferencias significativas en producción de leche entre los tres posibles genotipos fue CASk, siendo el genotipo AA el que se encontró asociado con una mayor producción de leche (F= 5,75; p= 0,004). Este genotipo produjo 20 p.100 (150 litros) más que los genotipos BB y AB.Using PCR-RFLP and AS-PCR the candidate genes aS1-casein, k-casein, b-Lactoglobulin, prolactin and growth hormone were characterized in 146 Saavedreño Creole cows belonging to the Saavedra Experimental Station (Bolivia) and the association between these genes and milk yield in first lactation cows was analyzed. Only k-casein locus exhibit significant differences between milk yield of its different genotypes, being the genotype AA the most productive (F= 5.75; p= 0.004). This genotype produced 20 percent (150 l) more than BB and AB genotypes.Fil: Ripoli, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Corva, Pablo Marcelo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Antonini, Alicia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: de Luca, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Rojas, F.. Centro de Investigación Agrícola Tropical (ciat); BoliviaFil: Dulout, Fernando Noel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Giovambattista, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

Effects of cytoplasmic inheritance on preweaning traits of Hereford cattle

The influence of cytoplasmic inheritance on birth and weaning weight was evaluated in an experimental Hereford herd. Data on 1,720 records for birth and weaning weights from calves born between 1963 and 2002 were studied. Variance components were estimated using MTDFREML procedures and an animal model was fitted for each trait. Direct and maternal additive effects and permanent environment and maternal lineage effects were treated as random, while year and month of birth, age of dam and sex of the calf were treated as fixed. Identification of maternal lineages was based on pedigree information. The contribution to phenotypic variance of cytoplasmic lineages defined by pedigree information was negligible for both traits. Mitochondrial genotypes of cows present in the herd in 2002 were analyzed by single strand conformation polymorphism (SSCP) analysis. Only five different genotypes were identified among 23 maternal lineages. All the animals with records were assigned to maternal genotypes based on pedigree information. The statistical analysis was repeated, removing maternal lineage from the model and including mitochondrial genotype as a fixed effect. No evidence of genotype effects was detected. These results suggest a negligible effect of the mitochondrial genome on the preweaning traits of this Hereford herd.Facultad de Ciencias Veterinaria

Association between five candidate genes and milk yield in the Saavedreña creole cattle breed

Utilizando PCR-RFLP y AS-PCR se caracterizaron los polimorfismos de los genes candidatos aS1-caseína, k-caseína, b-lactoglobulina, prolactina y hormona de crecimiento en 146 muestras de sangre de vacas Criolla Saavedreña de la Estación Experimental de Saavedra (Bolivia) seleccionadas para producción lechera estudiando la asociación de dichos genes con la producción de leche en vacas de primera lactancia. El único locus que evidenció diferencias significativas en producción de leche entre los tres posibles genotipos fue CASk, siendo el genotipo AA el que se encontró asociado con una mayor producción de leche (F= 5,75; p= 0,004). Este genotipo produjo 20 p.100 (150 litros) más que los genotipos BB y AB.Using PCR-RFLP and AS-PCR the candidate genes aS1-casein, k-casein, b-Lactoglobulin, prolactin and growth hormone were characterized in 146 Saavedreño Creole cows belonging to the Saavedra Experimental Station (Bolivia) and the association between these genes and milk yield in first lactation cows was analyzed. Only k-casein locus exhibit significant differences between milk yield of its different genotypes, being the genotype AA the most productive (F= 5.75; p= 0.004). This genotype produced 20 percent (150 l) more than BB and AB genotypes.Instituto de Genética Veterinari

Association between five candidate genes and milk yield in the Saavedreña creole cattle breed

Utilizando PCR-RFLP y AS-PCR se caracterizaron los polimorfismos de los genes candidatos aS1-caseína, k-caseína, b-lactoglobulina, prolactina y hormona de crecimiento en 146 muestras de sangre de vacas Criolla Saavedreña de la Estación Experimental de Saavedra (Bolivia) seleccionadas para producción lechera estudiando la asociación de dichos genes con la producción de leche en vacas de primera lactancia. El único locus que evidenció diferencias significativas en producción de leche entre los tres posibles genotipos fue CASk, siendo el genotipo AA el que se encontró asociado con una mayor producción de leche (F= 5,75; p= 0,004). Este genotipo produjo 20 p.100 (150 litros) más que los genotipos BB y AB.Using PCR-RFLP and AS-PCR the candidate genes aS1-casein, k-casein, b-Lactoglobulin, prolactin and growth hormone were characterized in 146 Saavedreño Creole cows belonging to the Saavedra Experimental Station (Bolivia) and the association between these genes and milk yield in first lactation cows was analyzed. Only k-casein locus exhibit significant differences between milk yield of its different genotypes, being the genotype AA the most productive (F= 5.75; p= 0.004). This genotype produced 20 percent (150 l) more than BB and AB genotypes.Instituto de Genética Veterinari