Equine coat color is an important phenotypic trait, predominantly within the context of correct animal identification. Due to the increased import of horses to Poland during the last years, uncommon coat colors seem to occur more often. In this study, we have analyzed the genotypes of cold-blooded horses representing four breeds (Polish Cold-blooded Horse, Belgian Draft Horse, Percheron Horse and Ardennes Horse) for genes determining basic coat colors (MC1R and ASIP) as well as silver and cream dilutions (PMEL17 and MATP). We have also compared the results of our molecular study with the coat color of each horse listed in the breeding documents. Uneven distribution of genotypes between the investigated groups was observed. Moreover, we have identified several mistakes in coat color descriptions of horses, which justifies the necessity for genetic testing, particularly in case of coat colors difficult to categorize “by eye”. We also suggest to extend the list of horse coat colors recognized by the Polish Horse Breeders Association.
Fat content of carcass is an important multigenic trait in pig breeding. There are reports indicating several chromosomes, e.g. 1, 2, 4, 5, 6, 7, 12, 13, 14 and 18 which possibly harbour QTLs for fatness traits. Among QTL candidate genes there are leptin (LEP) and its receptor (Lepr), both playing essential role in food intake and energy balance. Moreover, expression level and polymorphism of the adipocyte specific transcription factors, such as CREB (cAMP response element binding protein) or C/EBP (CCAAT/enhancer-binding protein) may also cause phenotypic variation of the fatness traits. Some of the candidate QTLs, as Lep, Lepr, C/EBP and additionally H-FABP (fatty acid binding protein gene) and RYR1, are localized on chromosome 6. It is foreseen that searching for polymorphisms of the chosen genes may reveal association between a genotype and phenotypic variation of selected fatness traits. However, the studies are complex and require analysis of numerous genes.Cited are 71 references.
In the present study we show FISH localization of 4 porcine BAC clones harbouring potential candidate genes for fatness traits: DGAT1 (SSC4p15), PPARA (SSC5pl5), ADIPOR1 (SSC10p13) and CREB (SSC15q24). Until now the CREB and ADIPOR1 genes are considered to be monomorphic, DGAT1 is highly polymorphic, while for the PPARA gene only 1 SNP was identified. Assignment of the studied genes in relation to QTL chromosome regions for meat quality in pig chromosomes SSC4, SSC5, SSC10 and SSC15 is discussed.
α-Lactalbumin (α-LA) is one of the most abundant milk whey proteins among different mammalian species including domestic horse. The aim of this study was to screen for polymorphism in the 5’-flanking region of the equine α-LA (LALBA) gene and to assess the potential relationship of particular genotypes with LALBA gene expression variability (measured at the mRNA and protein levels) and with basic milk composition traits. Initial screening for LALBA gene 5’-flanking variants was conducted using direct sequencing of DNA derived from 96 horses representing 12 breeds (Polish Primitive Horse, Polish Coldblood Horse, Polish Warmblood Horse, Silesian, Hucul, Fiording, Haflinger, Shetland Pony, Welsh Pony, Arabian, Thoroughbred and Percheron). Association analysis of detected polymorphisms, gene expression and milk composition traits was carried out for 74 horses (Polish Primitive Horse, Polish Coldblood Horse and Polish Warmblood Horse breeds). Altogether 4 single nucleotide polymorphisms (SNPs) (c.−165G>C, c.−222A>G, c.−357C>A and c.−928C>T) were found in the LALBA gene 5’-flanking region (NC_009149.3 GenBank sequence, gene coordinates on ECA6: 67372475–67375877). Although bioinformatic prediction suggested that 3 of them may alter the consensus sequences for transcription factors, no significant associations between genotypes and LALBA gene expression were recorded. However, a significant relationship (P < 0.05) was noticed for c.−928C>T SNP genotypes and basic milk composition (fat and protein contents) of Polish Primitive Horse mares. Additionally, in our study the significant impact of horse breed and lactation period on LALBA gene expression and basic milk composition traits was revealed.