Associations between two novel rSNPs in 5'-flanking region of the bovine casein gene cluster and milk performance traits.

Ten evolutionary conservative sequences with high identity level to homological sequences in other mammal species were revealed in 5'-flanking region of casein's genes cluster. Five novel SNPs located inside of the evolutionary conservative regions were identified. The binding sites were revealed to be present in one allelic variant of four detected SNPs. So these SNPs were considered as rSNPs. Significant differences of allelic frequencies were revealed between beef cow's group and dairy cow's group in two rSNPs (NCE4, NCE7, p<0.001). Different alleles of those two rSNPs were shown to be associated with some milk performance traits in Black-and-White Holstein dairy cows. Significant difference of protein percentage has been found between cows with G/G and A/A genotypes (P<0.05) and A/G and A/A genotypes (P<0.05) for NCE4 polymorphism. The groups of animals with genotypes G/G and A/G for NCE7 polymorphism were significantly different in milk yield at the first lactation (kg) (P<0.01), milk fat yield (kg) (P<0.05) and milk protein yield (kg) (P<0.01). For the last trait the difference was significant also between cows with genotypes G/G and A/A for rSNP NCE7 (P<0.05).

[Expression profiling of candidate genes for abdominal fat mass in domestic chicken Gallus gallus].

The quantitative traits of mass and percentage of abdominal fat in chicken and various types of obesity in mammals are homologous and functionally similar. Therefore, the genes involved in obesity development in humans and laboratory rodents as well as those responsible for pig lard thickness could be involved in abdominal fat deposition in broilers. Expression of candidate genes FABP1, FABP2, FABP3, HMGA1, MC4R, PPARG, PPARGC1A, POMC and PTPN1 was studied in fat, liver, colon, muscle, hypophysis, and brain in chicken (broilers) using real-time PCR. Significant difference in the HMGA1 gene expression in the liver of broiler chicken with high (3.5 +/- 0.18%) and low (1.9 +/- 0.56%) abdominal fat concentration has been revealed. The expression of this gene was been shown to correlate with the amount (0.7, P < or = 0.01) and mass (0.7, P < or = 0.01) of abdominal fat. The PPARG gene expression in liver in the same chicken subsets was also significantly different. Correlation coefficients of the gene expression with the abdominal fat amount and mass were respectively 0.55 (P < or = 0.05) and 0.57 (P < or = 0.01). Based on these results, we suggest that the HMGA1 and PPARG genes are involved in abdominal fat deposition. The search for single nucleotide polymorphisms (SNPs) in the HMGA and PPARG regulatory regions could facilitate identifying genetic markers for broiler breeding according to the mass and percentage of abdominal fat.

[Investigation of pseudoautosomal and bordering regions in avian Z and W chromosomes with the use of large insert genomic BAC clones].

To study pseudoautosomal and bordering regions in the avian Z and W chromosomes, we used seven BAC clones from genomic libraries as DNA probes of fragments of different gametologs of the ATP5A1 gene located close to the proximal border of the pseudoautosomal region (PAR) of sex chromosomes of domestic chicken and Japanese quail. Localization of BAC clones TAM31-b100C09, TAM31-b99N01, TAM31-b27P16, and TAM31-b95L18 in the short arm of Z chromosomes of domestic chicken and Japanese quail (region Zp23-p22) and localization of the BAC clones CHORI-261-CH46G16, CHORI-261-CH33F10, and CHORI-261-CH64F22 on W chromosomes of these species and in the short arm of Z chromosomes (region Zp23-p22) were determined by fluorescence in situ hybridization with the use of W-specific probes. The difference in the localization of the BAC clones on the Z and W chromosomes is probably explained by divergence of the nucleotide sequences of different sex chromosomes located beyond the pseudoautosomal region.

[Design of a system for genotyping of Gallus gallus based on the rSNP (regulatory single nucleotide polymorphism) alleles affecting the egg shell thickness].

PCR amplification of the six fragments of regulatory and coding regions of chicken ChEST985k21 gene (accession no. CR523443), substantially affecting the egg shell thickness quantitative trait, was carried out. Sequencing of these fragments in six chickens from a native Polish breed, Green-legged Partridgenous, with different manifestation of the trait of interest enabled identification of six single nucleotide polymorphism (SNP) sites within the ChEST985k21 sequence. Five of these sites were located in the regulatory region, and one site, in the coding region. For all SNPs identified, the existence of transcription factor binding sites, present in only one allelic variant, was demonstrated. This finding enables considering these sites as regulatory single nucleotide polymorphisms, rSNP. The effect of rSNP discovered on the chicken egg shell thickness was tested using PCR amplification with allele-specific primers. In the groups of chicken of Rhode Island Red breed with thick (389.9 +/- 13.09 microm) and thin (315.7 +/- 21.38 microm) egg shells statistically significant differences in the allele frequencies of the ST2_1, ST3_1, ST3_2, and ST3_3 polymorphic loci. In the same groups of birds, statistically significant differences in the shell thickness were observed in the rSNP allele genotypic classes ST2_1, ST3_1, ST3-2, ST3_3, and ST6_1. Based on these data, it was concluded that rSNPs influenced manifestation of the quantitative trait examined, and the genotyping system for marker assisted selection was constructed.