Cattle temperament is a complex trait, and molecular studies aimed at defining this trait are scarce. We used an interaction networks approach to identify new genes (interacting genes) and to estimate their effects and those of 19 dopamine- and serotonin-related genes on the temperament traits of Charolais cattle. The genes proopiomelanocortin (POMC), neuropeptide Y (NPY), solute carrier family 18, member 2 (SLC18A2) and FBJ murine osteosarcoma viral oncogene homologue (FOSFBJ) were identified as new candidates. Their potential to be associated with temperament was estimated according to their reported biological activities, which included interactions with neural activity, receptor function, targeting or synthesis of neurotransmitters and association with behaviour. Pen score (PS) and exit velocity (EV) measures were determined from 412 Charolais cows to calculate their temperament score (TS). Based on the TS, calm (n = 55; TS, 1.09 ± 0.33) and temperamental (n = 58; TS, 2.27 ± 0.639) cows were selected and genotyped using a 248 single-nucleotide variation (SNV) panel. Of the 248 variations in the panel, only 151 were confirmed to be polymorphic (single-nucleotide polymorphisms; SNPs) in the tested population. Single-marker association analyses between genotypes and temperament measures (EV, PS and/or TS) indicated significant associations of six SNPs from four candidate genes. The markers rs109576799 and rs43696138, located in the DRD3 and HTR2A genes, respectively, were significantly associated with both EV and TS traits. Four markers, rs110365063 and rs137756569 from the POMC gene and rs110365063 and rs135155082 located in SLC18A2 and DRD2, respectively, were associated with PS. The variant rs110365063 located in bovine SLC18A2 causes a change in the amino acid sequence from Ala to Thr. Further studies are needed to confirm the association of genetic profile with cattle temperament; however, our study represents important progress in understanding the regulation of cattle temperament by different genes with divergent functions.

The objective of this study was to perform a genomewide association study (GWAS) for growth traits in Charolais beef cattle and to identify SNP markers and genes associated with these traits. Our study included 855 animals genotyped using 76,883 SNP from the GeneSeek Genomic Profiler Bovine HD panel. The examined phenotypic data included birth, weaning, and yearling weights as well as pre- and postweaning ADG. After quality control, 68,337 SNP and 823 animals were retained in the analysis. The association analysis was performed using the principal components method via the egscore function of the GenABEL version 1.8-0 package in the R environment. Eighteen SNP located in 13 BTA were associated with growth traits ( < 5 × 10). The most important genes in these genomic regions were (), (), (), (), and ( [angiotensinase C]), due to their relationships with perinatal and postnatal survival, bone growth, cell adhesion, regulation of adipogenesis, and appetite. In conclusion, this study is the first to describe a GWAS conducted in beef cattle in Mexico and represents a basis for further and future research. This study detected new QTL associated with growth traits and identified 5 positional and functional candidate genes that are potentially involved in variations of the analyzed traits. Future analyses of these regions could help to identify useful markers for marker-assisted selection and will contribute to the knowledge of the genetic basis of growth in cattle and be a foundation for genomic predictions in Mexican Charolais cattle.

Analysis of cultured catfish from six farms in Tamaulipas, Mexico was achieved using a combination of microsatellite PCR analysis and semiautomatic fluoresce-based detection, in order to provide a first assessment of the genetic variability on cultured catfish in Mexico. Five microsatellites showed extensive polymorphism with allele numbers ranging from 10 and 20. Overall observed heterozygosity at each locus ranged between 0.76 and 0.91 and the average polymorphic information content (PIC) for the five loci was 0.811, indicating that these loci can be used for studies of paternity identification, linkage and population genetics. On the basis of the F ST values (F ST = 0.03829; p = 0.00000) it appears that there was a small amount of genetic differentiation between the channel catfish stocks. The high intrapopulation allelic diversity was the most remarkable parameter.

Background: Channel catfish are one of the most important aquaculture species raised for food purposes in Mexico. Two temporal samples were obtained from the largest channel catfish breeding hatchery in Mexico to identify changes in genetic diversity and inbreeding that are promoted by traditional hatchery management. Results: The genetic parameter analysis of 11 microsatellite loci showed no significant change in genetic diversity (p > 0.05). However, a significant heterozygosis deficiency was detected (p < 0.001), and genetic structure analysis indicated moderate differentiation between the temporally divided populations (FST = 0.08). A moderate level of inbreeding and a slight increase of the inbreeding coefficient from 0.23 to 0.27 were the result of traditional hatchery practices. To achieve an effective population size, the temporal approach resulted in a limited number of breeders to maintain genetic variability. Conclusions: Although no significant change in genetic diversity parameters was found, the heterozygote deficiency and low effective number of breeders suggest that there is a risk for increased inbreeding. Thus, we propose the need for controlled reproductive management and the establishment of genetic programs in hatcheries. Molecular tools can provide valuable information to facilitate the achievement of these goals.

Native strains of Trichoderma isolated from sorghum and common bean crop soils were investigated to assess their biocontrol potential over the phytopathogenic fungus Macrophomina phaseolina, isolated from diseased plants. The Trichoderma strains were characterized with a polyphasic approach, which combined the analysis of their morphological characteristics, enzymatic activity, macro- and microculture test results, rDNA restriction patterns (AFLP), ITS1-5.8S-ITS2 rDNA sequences, and protein profiles. The integration of these data sets can be used to select new isolates as biological control agents against native fungal phytopathogens. In general, we observed a positive correlation between the secretion of beta-1,3-glucanase and N-acetylhexosaminidase, and the biocontrol capacities of all the Trichoderma isolates. Strains with the best hyperparasitic behavior against M. phaseolina isolated from diseased bean and sorghum were Trichoderma sp. (TCBG-2) and Trichoderma koningiopsis (TCBG-8), respectively.