Experimentation with Animals: A Key Aspect of the 3Rs. The Genetic Quality

The genetic quality of laboratory animals is essential for reproducibility of scientific research. Working with animals of certifiedgenetic quality is still a pending issue in Argentina due to the lack of routine genetic controls, of information on the genetic background of animals and of proper training. Apart from being concerned with having their results published and getting funding for research, scientists should know the genetic origin of laboratory animals. Consequently, they should perform genetic controls to verifywhether animal integrity has been compromised by accidental genetic contamination or genetic drift. The aim of this work was toevaluate the genetic purity of the inbred C57BL/6J mouse strain from three animal facilities belonging to the Buenos Aires UniversitySchool of Medicine network by analyzing a panel of microsatellite markers. Female mice tail samples (3-5 mm) were taken and genomic DNA was obtained by organic extraction. The genetic profile of each animal was determined by PCR-fragment analysis, usingmicrosatellites D1Mit155, D2Mit493, D3Mit49, D13Mit13, D6Mit8 and D12Mit12, located on six different autosomal chromosomesand selected from the Mouse Genome Informatics database (www.informatics.jax.org/searches). The results obtained provided keydata on the genetic quality of the three inbred animal colonies studied. They also served as an example for other laboratory animalfacilities in Argentina and as a starting point to modify the conditions and management of laboratory animal colonies. We determinedthe genetic purity of the inbred C57BL/6J mouse strain in all animal facilities evaluated. All six loci analyzed were homozygous,certifying their isogenicity and phenotypic uniformity. These results are promising for animal facilities mainly performing biomedical research. They also show a positive evolution in handling animal colonies and use of the 3Rs, and researcher commitment withanimal science, since they promote the supply of genetically quality-controlled animals. The positive impact of these results shouldencourage other researchers using this inbred strain to perform periodic genetic monitoring, thereby consolidating the supply ofquality-controlled mice. This pioneering study carried out in IGEVET (CONICET- UNLP) should consolidate the genetic monitoring ofinbred strains throughout the country.Fil: Lizarraga, Maria Alfonsina. 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: Posik, Diego Manuel. 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: Zappa, María Eugenia. 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: Castillo, Nadia Sabiela. 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

Genetic characterization of Argentine and Bolivian Creole cattle breeds assessed through microsatellites

In the present report, the polymorphisms from 9 microsatellites were used to assess genetic diversity and relationships in 4 Creole cattle breeds from Argentina and Bolivia, 4 European taurine breeds, and 2 American zebu populations. The Creole populations display a relatively high level of genetic variation as estimated by allelic diversity and heterozygosity, whereas the British breeds displayed reduced levels of genetic diversity. The analysis of molecular variance indicated that 7.8% of variance can be explained by differences among taurine and zebu breeds. Consistent with these results, the first principal component (PC), which comprised the 40% of the total variance, clearly distinguishes these 2 groups. In addition, all constructed phylogenetic trees cluster together Nelore and Brahman breeds with robust bootstrap values. Only 1% of variance was due to difference between American Creole and European taurine cattle. Although this secondary split was supported by the classical genetic distance and the second PC (15%), the topology of trees is not particularly robust. The presence of zebu-specific alleles in Creole cattle allowed estimating a moderate degree of zebu admixture. When these data were compared with mitochondrial and Y chromosomal studies, a clearl pattern of male-mediated introgression was revealed. The results presented here contribute to the understanding of origin and history of the American Creole cattle.Instituto de Genética Veterinari

Species identification of a suspected bone found in blood sausage

The case of an identification for a small bone found in a blood sausage is described. The similitude with a rodent bone leads the consumer to demand the government organism responsible of food quality control. Bone and blood sausage DNA analysis was performed in order to determinate the origin species and the possibility of food contamination and/or adulteration. DNA sequence analysis confirmed the pig origin of both samples with an identity higher than 98%.Fil: Posik, Diego Manuel. 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. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Bustamante, Ana Victoria. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Sanidad Animal y Medicina Preventiva. Laboratorio de Inmunoquímica y Biotecnología; ArgentinaFil: Lyall, V. 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: Peral Garcia, Pilar. 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: Padola, Nora Lía. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Sanidad Animal y Medicina Preventiva. Laboratorio de Inmunoquímica y Biotecnología; 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

Genetic diversity of BoLA-DRB3 in South American Zebu cattle populations

Background: Bovine leukocyte antigens (BoLAs) are used extensively as markers of disease and immunological traits in cattle. However, until now, characterization of BoLA gene polymorphisms in Zebu breeds using high resolution typing methods has been poor. Here, we used a polymerase chain reaction sequence-based typing (PCR-SBT) method to sequence exon 2 of the BoLA class II DRB3 gene from 421 cattle (116 Bolivian Nellore, 110 Bolivian Gir, and 195 Peruvian Nellore-Brahman). Data from 1416 Taurine and Zebu samples were also included in the analysis. Results: We identified 46 previously reported alleles and no novel variants. Of note, 1/3 of the alleles were detected only in Zebu cattle. Comparison of the degree of genetic variability at the population and sequence levels with genetic distance in the three above mentioned breeds and nine previously reported breeds revealed that Zebu breeds had a gene diversity score higher than 0.86, a nucleotide diversity score higher than 0.06, and a mean number of pairwise differences greater than 16, being similar to those estimated for other cattle breeds. A neutrality test revealed that only Nellore-Brahman cattle showed the even gene frequency distribution expected under a balanced selection scenario. The FST index and the exact G test showed significant differences across all cattle populations (FST =0.057; p < 0.001). Neighbor-joining trees and principal component analysis identified two major clusters: one comprising mainly European Taurine breeds and a second comprising Zebu breeds. This is consistent with the historical and geographical origin of these breeds. Some of these differences may be explained by variation of amino acid motifs at antigen-binding sites. Conclusions: The results presented herein show that the historical divergence between Taurine and Zebu cattle breeds is a result of origin, selection, and adaptation events, which would explain the observed differences in BoLA-DRB3 gene diversity between the two major bovine types. This allelic information will be important for investigating the relationship between the major histocompatibility complex and disease, and contribute to an ongoing effort to catalog bovine MHC allele frequencies according to breed and location.Instituto de Genética Veterinari

Inferencia del origen del bovino Criollo Cubano a través del análisis de patri- y matrilinajes

Antes de descubrimiento, no existían bovinos en América. Los primeros, fueron introducidos en la Antillas Mayores (La Española, Puerto Rico, Jamaica y Cuba), y desde allí trasladados al resto de Latinoamérica. Actualmente, existen en Cuba alrededor de 1300 bovinos Criollos, concentrados principalmente en la región oriental. Con el objetivo de analizar el origen materno de esta raza y detectar eventos contemporáneos de flujo génico por vía paterna, se analizó un fragmento de 240 pb del D-loop mitocondrial (mtADN) y 5 microsatélites del cromosoma Y (BTY), en 36 hembras y 21 machos respectivamente. La diversidad genética se estimó mediante el número de haplotipos, el número de sitios polimórficos, el número de diferencias nucleotídicas entre pares de secuencias y el índice de diversidad nucleotídica, mientras que el análisis filogenético se realizó utilizando el método de median joining network. Dicho análisis permitió detectar 15 haplotipos mitocondriales (10 del haplogrupo europeo T3, 3 del africano T1, 1 del cercano oriente T2 y 1 ambiguo T1-T3) y 3 haplotipos en el BTY, ambos del haplogrupo cebuíno Y3. En el mtADN se detectaron 23 sitios polimórficos con una diversidad nucleotídica de 0,014 y 3,36 diferencias medias entre pares de secuencias. En conclusión, la población de bovinos Criollos Cubanos presentó una composición haplotípica mitocondrial comparable a la de otras razas criollas y mediterráneas, hecho que concuerda con su origen histórico. El BTY evidenció altos niveles de introgresion paterna de genes del zebú.Cattle was absent from America before the discovery. Initially, bovine were brought to Greater Antilles (La Española, Puerto Rico, Jamaica and Cuba islands), and in the course of a few years, they were taken from Caribbean islands to the rest of Latin America. Nowadays, Cuban Creole cattle population is about 1300 heads, mainly located in the eastern region of the island. With the aim of analyzing the maternal origin of Cuban Creole cattle and detect possible contemporaneous, male mediated, gene flow, a 240 pb fragment of mitochondrial D-loop (mtDNA) and five microsatellites of Y chromosome (BTY) were studied in 36 dams and 21 sires, respectively. Genetic diversity was evaluated through number of haplotypes, mean number of pairwise differences and nucleotide diversity. The phylogenetic analysis was performed using a median joining. A total of 15 mtDNA haplotypes were detected in the studied population (10 from the European haplogroup T3, 3 from the African T1, 1 from the Nearern East T2, and 1 ambiguous T1-T3). The number of polymorphic sites, the mean nucleotide diversity, and the mean number of pairwise differences were 23, 0.014 and 3.36, respectively. Two patrilinages were detected, both belonging to the Y3 Zebu haplogroup. In conclusion, Cuban Creole cattle population had a mtDNA haplotypic composition similar to the observed in Creole and Mediterranean breeds, what is in concordance with its historical origin. Y chromosome analysis evidenced a male mediated process of zebu introgression.Fil: Liron, Juan Pedro. 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: Acosta, A.. Centro Nacional de Sanidad Agropecuaria. Laboratorio de Genética Molecular; CubaFil: Rogberg Muñoz, Andres. 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: Uffo, O.. Centro Nacional de Sanidad Agropecuaria. Laboratorio de Genética Molecular; CubaFil: Posik, Diego Manuel. 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: Garcia, J.. Ministerio de la Agricultura. Dirección Nacional de Genética; CubaFil: Peral Garcia, Pilar. 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

BioSmalltalk: a pure object system and library for bioinformatics

We have developed BioSmalltalk, a new environment system for pure object-oriented bioinformatics programming. Adaptive end-user programming systems tend to become more important for discovering biological knowledge, as is demonstrated by the emergence of open-source programming toolkits for bioinformatics in the past years. Our software is intended to bridge the gap between bioscientists and rapid software prototyping while preserving the possibility of scaling to whole-system biology applications. BioSmalltalk performs better in terms of execution time and memory usage than Biopython and BioPerl for some classical situations.Availability: BioSmalltalk is cross-platform and freely available (MIT license) through the Google Project Hosting at http://code.google.com/p/biosmalltalk Supplementary information: Supplementary data are available at Bioinformatics online.Instituto de Genética Veterinari

Gene frequencies of BoLA-DRB3 alleles estimated through sequence-based typing (PCR-SBT) in a Holstein population of La Pampa province

El objetivo del presente estudio consistió en estimar las frecuencias alélicas del exón 2 del gen de Clase II del Sistema Principal de Histocompatibilidad BoLA-DRB3 en una población de ganado Holstein de la provincia de La Pampa. Los polimorfismos presentes en el exón 2 del gen BoLA-DRB3 se identificaron mediante la técnica de secuenciación directa (PCR-SBT). Los resultados obtenidos permitieron detectar un total de 21 alelos con un rango de frecuencia de 0,014 a 0,222. Esto resultó en una heterocigosidad esperada de 0,91. Estos resultados se compararon con los reportados para ganado Holstein de Japón, evidenciando que con la excepción del alelo BoLA-DRB3*1201, ambas poblaciones presentaron los mismo alelos mayoritarios (BoLA-DRB3*1101, *1501 y *0101). Este resultado sería consecuencia del alto nivel de homogeneidad exhibido por esta raza, debido al uso de la misma genética a nivel global.The objective of this study was to estimate allele frequencies of the BoLA-DRB3 exon 2 in a Holstein population from La Pampa province. The exon 2 polymorphisms were genotyped by sequence-based typing method (PCR-SBT). In the studied herd, a total of 21 variants were detected, ranging from 0.014 to 0.222. This resulted in an expected heterozygocity of 0.91. Obtained data were compared with those reported for Japanese Holstein population, showing that with the exception of BoLA-DRB3*1201 allele, both populations shared the same major variants (BoLA-DRB3*1101, *1501 and *0101). This result could be consequence of the high level of homogeneity present in Holstein breed, due to the use of same genetic on the whole world.Fil: Baltian, Laura Rosana. Universidad Nacional de La Pampa. Facultad de Ciencias Veterinarias; ArgentinaFil: 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: Takeshima, S. N.. Riken. Viral Infectious Diseases Unit; JapónFil: Aida, Y.. Riken. Viral Infectious Diseases Unit; JapónFil: 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

Ausencia de la translocación 1/29 en bovinos Aberdeen Angus

Las translocaciones robertsonianas son las translocaciones más frecuentes en el ganado bovino. La primera translocación robertsoniana descripta en el Ganado bovino fue la 1/29. Al igual que otras fusiones céntricas esta alteración reduce la fertilidad de los animales portadores, ya que se originan gametas genéticamente desbalanceadas, provocando un aumento de la mortalidad embrionaria temprana. Se evaluó la incidencia de la translocación 1/29 en 89 bovinos Aberdeen Angus (38 hembras y 51 machos) pertenecientes a 4 establecimientos de la Provincia de Buenos Aires. Se obtuvieron muestras de sangre heparinizadas, las que se cultivaron para su posterior análisis citogenético. El análisis citogenética reveló la ausencia de esta translocación en todos los animales estudiados. En el caso de los machos la morfología del cromosoma Y fue de tipo submetacéntrico. Los resultados obtenidos concuerdan con los reportados para razas carniceras británicas. Por otra parte, los animales estudiados no mostraron una disminución de la fertilidad, lo cual podría estar asociado con la ausencia de la translocación 1/29. Una ampliación de estos estudios sería necesaria para acceder a un mayor conocimiento del estado de esta alteración en esta raza.Robertsonian translocations are the most frequent chromosomal aberrations in cattle. The first robertsonian translocation described was the 1/29 translocation. Like other centric fusions, this abnormality reduces fertility as a consequence of genetic excess or deficiency in the germ cells, increasing early embryonic mortality. The incidence of 1/29 translocationin in 89 Aberdeen Angus cattle (38 dams and 51 sires) belonging to 4 farms of the Buenos Aires Province was analyzed, as well as the Y chromosome morphology. Heparinized blood samples were obtained and cultured for cytogenetic analysis. The results obtained showed the absence of the 1/29 translocation in all the animals studied. In all the bulls analyzed Y chromosome morphology was submetacentric. The results obtained in the present work are in concordance with previously results reported for the British beef breeds, like Aberdeen Angus. On the other hand the animals studied did not show fertility reduction, then this could be associated with the absence of the 1/29 translocation. Further studies are needed to assess the entire breed.Facultad de Ciencias Veterinaria

Computational prediction of nsSNPs effects on protein function and structure, a prioritization approach for further in vitro studies applied to bovine GSTP1

The development of high-throughput technologies in the last decade produced an exponential increase in the amount of biological data available. The case of redox biology and apoptosis is not an exception, and nowadays there is a need to integrate information from multiple “omics” studies. Therefore, validation of proposed discoveries is essential. However, the study in biological systems of the effect of the massive amounts of sequence variation data generated with next-generation sequencing (NGS) technologies can be a very difficult and expensive process. In this context, the present study aimed to demonstrate the advantages of a computational methodology to systematically analyze the structural and functional effects of protein variants, in order to prioritize further studies. This approach stands out for its easy implementation, low costs and low time consumed. First, the possible impact of mutations on protein structure and function was tested by a combination of tools based on evolutionary and structural information. Next, homology modeling was performed to predict and compare the 3D protein structures of unresolved amino acid sequences obtained from genomic resequencing. This analysis applied to the bovine GSTP1 allowed to determine that some of amino acid substitutions may generate important changes in protein structure and function. Moreover, the haplotype analysis highlighted three structure variants worthwhile studying through in vitro or in vivo experiments.Fil: Falomir Lockhart, Agustin Horacio. 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: Villegas Castagnasso, Egle Etel. 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; ArgentinaFil: Rogberg Muñoz, Andres. 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 de Buenos Aires, Facultad de Agronomía, Departamento de Producción Animal; Argentin

Determinación de los motivos aminoacídicos presentes en los sitios de unión a los antígenos de los alelos del gen BoLA-DRB3 en una población Holstein de La Pampa y su asociación con mastitis

La intensidad de la respuesta inmune es regulada por los motivos aminoacídicos en los sitios de reconocimiento a antígenos (SRA) presentes en los bolsillos de las moléculas presentadoras del Complejo Principal de Histocompatibilidad. El objetivo del presente trabajo fue estudiar la asociación entre dichos motivos y la resistencia/susceptibilidad a mastitis medida a través del conteo de células somáticas (CCS) en leche de ganado Holstein de la provincia de La Pampa. La población se dividió en: 1) grupo caso con alto CCS y presencia de mastitis (≥ 250.000 cel/ml, susceptible) y 2) grupo control con bajo CCS (< 250.000 cel/ml, resistente). De una muestra de 128 animales, se tipificaron 40 para el segundo exón del gen BoLA-BRB3 mediante la técnica de secuenciación directa; 20 vacas correspondientes a cada grupo. Se detectaron 24 alelos en la población analizada. Se calcularon las frecuencias génicas de los motivos aminoacídicos de los cinco bolsillos (1, 4, 6, 7 y 9) del SRA en los dos grupos de animales. Se utilizó el test Odds Ratio (OR) de Woolf-Haldane para estudiar la asociación. No se hallaron diferencias significativas entre los motivos aminoacídicos de los bolsillos 1, 4, 7 y 9 entre los grupos con alto y bajo CCS. Sin embargo, el motivo T11Y30 del bolsillo 6 (presente en los alelos BoLA-DRB3*0601, *0901 y *4401) evidenció un valor significativo de OR = 0,11 (p= 0,03). Esto sugiere una asociación entre dicho motivo con un menor riesgo a desarrollar mastitis. El rol del motivo aminoacídico T11Y30 en la respuesta inmune de los animales que lo poseen deberá ser validado en poblaciones independientes.The intensity of the immune response is regulated by amino acid motifs in antigen recognition sites (ARS) present in the pockets of Major Histocompatibility Complex molecules. The objective of this work was to study the association between these motifs and resistance/ susceptibility to mastitis measured by somatic cell counts (SCC) in milk from Holstein cattle from the province of La Pampa. The population was divided into: 1) case group with high SCC and presence of mastitis (≥ 250,000 cells/ml susceptibility) and 2) control group under SCC (&lt; 250,000 cells/ml resistant). From a sample of 128 animals, 40 were genotyped for the second exon of BoLA-BRB3 gene by direct sequencing technique, 20 cows for each group. A total of 24 alleles were detected in the analyzed population. Gene frequencies of amino acid motifs of the five pockets (1, 4, 6, 7 and 9) from ARS in the two groups of animals were calculated. Test Odds Ratio (OR) Woolf-Haldane was used to study the association. No significant differences between amino acid motifs of pockets 1, 4, 7 and 9 between groups with high and low SCC were found. However, the T 11 Y 30 motif in pocket 6 (found in BoLA-DRB3 * 0601, * 0901 and * 4401 alleles) showed a significant OR value = 0.11 (p = 0.03). This suggests an association between this motif with a lower risk of developing mastitis. The role of amino acid motif T 11Y 30 in animal immune response should be validated in independent populations.Instituto de Genética Veterinari