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Reproduction rate, and litter size in particular, is one of the most economically important aspects of pig production. Progress in researching the porcine genome has enabled polymorphic loci controlling reproduction characteristics in animals to be identified. An example of a gene affecting reproduction is the prolactin receptor (PRLR) gene, which has been mapped to chromosome 16 in pigs. The mechanism through which the PRLR gene affects litter size is not yet known, nor is it known whether the PRLR polymorphism itself causes differences in litter size or whether this polymorphism is a marker for the closely linked major gene for litter size.
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The aim of this study was to examine the relationship between genotype two SNPs located in the promoter region of CYP19 gene and milk production traits. The study included 181 Jersey cows. The genotypes were identified by the PCRRFLP method. The frequencies of the most common alleles were as follows: A – 0.98 (CYP19/PvuII) and A – 0.94 (CYP19/Cfr13I). The results showed that there were no statistically significant associations between the individual genotypes of both SNPs and milk traits; however, the animals with heterozygous genotypes achieved the lowest milk yield and the highest protein and fat content in milk.
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Celem prowadzonych badań było oszacowanie ewentualnych zależności pomiędzy genotypami TG/PsuI a wybranymi cechami użytkowości mlecznej (wydajność mleka, białka, i tłuszczu oraz zawartość białka i tłuszczu). Badaniami objęto 180 krów rasy jersey. Genotypy poszczególnych osobników oznaczano za pomocą metody PCR-RFLP. Frekwencja genotypów i alleli była następująca: CC – 053, CT – 0,44, CC – 0,03 oraz C – 0,75 i T – 0,25. Wprowadzonych badaniach nie wykazano statystycznie istotnych zależności pomiędzy genotypami TG a analizowanymi cechami, jednakże zaobserwowano tendencje do utrzymywania się powiązania genotypów z analizowanymi cechami użytkowości mlecznej.
The aim of this study was to estimate the relations between the CRH-A145G polymorphism and milk production traits (yields of milk, protein, and fat, as well as protein and fat content) in 176 Jersey cows. The genotype and allele frequencies were estimated and they were as follows: AG – 0.31; GG – 0.69; A – 0.16; G – 0.84. Statistical analysis revealed that studied polymorphism significantly affected the fat yield, fat content (P≤0.05) and protein content in milk (P≤0.05). The results indicate that selection for the CRH-A145G AG animals might contribute to increase the value of these traits in Jersey cattle. However, further studies are necessary to verify the results of our study.
The synthesis of estrogens from androgens is catalyzed by an enzyme complex called aromatase, and therefore has a unique potential to influence the physiological balance between the sex steroid hormones. This enzyme complex consists of two components: aromatase cytochrome P450 and NADPH-cytochrome P450 reductase. Aromatase is conserved amongst all vertebrates and mammals in particular. It is a member of the cytochrome P450 super-family of enzymes. Within this, aromatase cytochrome P450 is presently the sole member of family 19, and is encoded by the gene known as CYP19 which contains a number of tissue-specific promoters that direct aromatase expression in different tissues via alternative splicing. A number of tissues in mammals have the capacity to express aromatase. These include the ovaries and testes, the placenta, adipose tissue, osteoblasts of bone, vasculature smooth muscle, and numerous sites in the brain.
STATs (signal transducers and activators of transcription) are latent transcription factors present in the cytoplasm of the majority of animal cells. They are activated by tyrosine phosphorylation and then translocated to the nucleus where they induce transcription of target genes. The STAT5A factor mediates the actions of cytokines and peptide hormones, including prolactin and growth hormone. STAT5A, previously known as MGF (mammary gland factor), is the most important transcription factor mediating the action of ligands on the expression of genes responsible for production traits in cattle.
The aim of the study was to investigate associations between SLC27A1 genotypes and estimated breeding value of milk production traits (milk, fat and protein yield, kg; fat and protein content, %) in the Polish Holstein-Friesian cows’ herd. Three single nucleotide polymorphisms were genotyped,the g.14996C>G. in the exon 3, g.14791C>T in exon 4 and g.14589A>G in exon 5 of SLC27A1 gene.The genotype and allele frequencies for each polymorphism and the SLC27A1 haplotype frequencies were estimated in the examined herd. Significant relations between the SLC27A1 g.14791C>T SNP and breeding value for protein content were found. The results indicate that selection for the SLC27A1-CC individuals might contribute to increased protein content of milk in Polish Holstein-Friesian cows. Further studies are needed to confirm these results.
The aim of the study was to investigate how leptin R4C single nucleotide polymorphism (SNP) in the leptin gene affects the somatic cell count (SCC) in milk as well as milk production traits such as daily milk yield, fat content, protein content, lactose content, and dry matter content in milk. A total of 162 Polish Holstein- -Friesian (Red-White strain) cows were used in this study. The genotype and allele frequencies were as follows: CC - 0.26, CT - 0.56, TT - 0.18, C - 0.54, T - 0.46. Statistical analysis revealed that the studied polymorphism significantly affected the daily milk yield (P ≤ 0.05). The results indicate that selection of R4C TT animals might contribute to increased milk yield in Holstein-Friesian cattle.
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