A radiation hybrid framework map of bovine chromosome 13

In this paper we present a 5000-rad radiation hybrid framework map of bovine chromosome 13 (BTA13) containing 13 loci, including five conserved genes and eight polymorphic microsatellites. All framework markers are ordered with odds greater than 1000:1. Furthermore, we present a comprehensive map of BTA13 integrating 11 genes and 16 microsatellites. The proposed order is in general agreement with the recently published medium-density linkage maps. A model of five blocks of genes with conserved order between human, mouse and cattle is presente

A radiation hybrid framework map of bovine chromosome 13

In this paper we present a 5000-rad radiation hybrid framework map of bovine chromosome 13 (BTA13) containing 13 loci, including five conserved genes and eight polymorphic microsatellites. All framework markers are ordered with odds greater than 1000:1. Furthermore, we present a comprehensive map of BTA13 integrating 11 genes and 16 microsatellites. The proposed order is in general agreement with the recently published medium-density linkage maps. A model of five blocks of genes with conserved order between human, mouse and cattle is presented

10592_2006_9221_8_4-web 1009..1

Abstract Thirteen nuclear-encoded dinucleotide microsatellites were characterized from a genomic DNA library of greater amberjack, Seriola dumerili. The microsatellites include 12 perfect-repeat motifs and one imperfect-repeat motif. The number of alleles at the 13 microsatellites among a sample of 29 fish ranged from 3 to 25; gene diversity (expected heterozygosity) ranged from 0.296 to 0.948, while observed heterozygosity ranged from 0.276 to 0.897. Following Bonferroni correction, genotypes at all 13 microsatellites fit expectations of Hardy-Weinberg equilibrium. One pairwise comparison of microsatellites deviated significantly from expectations of genotypic equilibrium, suggesting that these two microsatellites may be linked. Greater amberjack support commercial and recreational fisheries along both the Atlantic and Gulf coasts of the U.S. and represent a species with potential for worldwide aquaculture. The microsatellites developed will be useful for conservation and population genetic studies of 'wild' and domesticated populations of greater amberjack

Molecular crosstalk between a chemical and a biological stressor and consequences on disease manifestation in rainbow trout

The aim of the present study was to examine the molecular and organism reaction of rainbow trout, Oncorhynchus mykiss, to the combined impact of two environmental stressors. The two stressors were the myxozoan parasite, Tetracapsuloides bryosalmonae, which is the etiological agent of proliferative kidney disease (PKD) and a natural stressor to salmonid populations, and 17b-estradiol (E2) as prototype of estrogen-active chemical stressors in the aquatic environment. Both stressors, the parasite and estrogenic contaminants, co-exist in Swiss rivers and are discussed as factors contributing to the decline of Swiss brown trout populations over the last decades. Using a microarray approach contrasting parasite-infected and non-infected rainbow trout at low or high estrogen levels, it was observed that molecular response patterns under joint exposure differed from those to the single stressors. More specifically, three major response patterns were present: (i) Gene expression responses to one stressor are weakened by the presence of the second stressor; (ii) Gene expression responses to one stressor are enhanced by the presence of the second stressor; (iii) Gene expression responses at joint treatment are dominated by one of the two stressors. Organism-level responses to concurrent E2 and parasite treatment – assessed through measuring parasite loads in the fish host and cumulative moralities of trout - were dominated by the pathogen, with no modulating influence of E2. The findings reveal function- and level-specific responses of rainbow trout to stressor combinations, which are only partly predictable from the response to the single stressors

Rainbow trout resistance to bacterial cold-water disease is moderately heritable and is not adversely correlated with growth

Chantier qualité GAInternational audienceThe objectives of this study were to estimate the heritabilities for and genetic correlations among resistance to bacterial cold-water disease and growth traits in a population of rainbow trout (Oncorhynchus mykiss). Bacterial cold-water disease, a chronic disease of rainbow trout, is caused by Flavobacterium psychrophilum. This bacterium also causes acute losses in young fish, known as rainbow trout fry syndrome. Selective breeding for increased disease resistance is a promising strategy that has not been widely used in aquaculture. At the same time, improving growth performance is critical for efficient production. At the National Center for Cool and Cold Water Aquaculture, reducing the negative impact of diseases on rainbow trout culture and improving growth performance are primary objectives. In 2005, when fish averaged 2.4 g, 71 full-sib families were challenged with F. psychrophilum and evaluated for 21 d. Overall survival was 29.3% and family rates of survival varied from 1.5 to 72.5%. Heritability of postchallenge survival, an indicator of disease resistance, was estimated to be 0.35 ± 0.09. Body weights at 9 and 12 mo posthatch and growth rate from 9 to 12 mo were evaluated on siblings of the fish in the disease challenge study. Growth traits were moderately heritable, from 0.32 for growth rate to 0.61 for 12-mo BW. Genetic and phenotypic correlations between growth traits and resistance to bacterial cold-water disease were not different from zero. These results suggest that genetic improvement can be made simultaneously for growth and bacterial cold-water disease resistance in rainbow trout by using selective breeding

Candidate SNPs for carcass and meat traits in Nelore animals and in their crosses with Bos taurus

The objective of this work was to evaluate the effects of single-nucleotide polymorphisms (SNPs) in the genes IGF1 (AF_017143.1: g. 198C>T), MSTN (AF_320998.1:g. 433C>A), MYOD1 (NC_007313:g. 1274A>G) and MYF5 (NC_007303:g.1911A>G) on carcass and meat traits in Nelore (Bos indicus) and Nelore x B. taurus. A total of 300 animals were genotyped and phenotyped for rib eye area (REA), backfat thickness (BT), intramuscular fat (IF), shear force (SF) and myofibrillar fragmentation index (MFI). The effects of allele substitution for each SNP were estimated by regression of the evaluated phenotypes on the number of copies of a particular allele using the general linear model. The polymorphism at IGF1 was non-informative in Nelore animals. In crossbred animals, the IGF1 C allele was associated with greater REA. However, this relation was not significant after Bonferroni correction for multiple testing. The A allele of the MSTN polymorphism was absent in Nelore cattle and was only found in two crossbred animals. The polymorphisms of MYOD1 and MYF5 were little informative in Nelore animals with G allele frequency of 0.097 and A allele frequency of 0.031, respectively. These markers show no association with the analyzed traits in the total sample of evaluated animals