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EN
The bovine kappa-casein (CASK) gene is known as a potential quantitative trait locus in dairy cattle breeding.However, the molecular basis of the effect of the CASK allele B on different milk properties remains unclear.In this report, a 214 bp fragment of the 5' untranslated region of CASK gene containing 5 potential consensus sequences for different transcription factors was PCR-amplified to find RFLPs.A Dde I RFLP was identified.IN population of 112 Bos taurus (86 cows and 26 bulls of Polish Black and White crossbred Holstein-Friesian) and 7 Bisons bonasus individuals, 7 had no recognition sites for Dd I, 23 were hetrozygous and 89 were cut completly into two fragments.
EN
The bovine kappa-casein (CASK) gene is considered a potential marker for quantitative trait loci (QTL) in dairy cattle.A large amount of research has been performed to explore the nature and variation of the CASK gene and its possible applications in cattle breeding.The purpose of this review is to sum up the knowledge of all known aspects of the CASK gene; molecular structure and function, poltmorphism and allele frequency, methods of genotyping and possibilities of the use of CASK polymorphism in dairy cattle breeding.
EN
In the paper the detection of the SSCP polymorphism within the 5' fragment of bovine beta-lactoglobulin (LGB) gene is described. The 5' fragment of LGB gene (209 bp) was PCR-amplified and then subjected to electrophoresis allowing the detection of SSCP polymorphism. Among 124 animals (50 cows and 74 bulls) six SSCP patterns were identified and named R1, R2, R3, R4, R5 and R6, which occured with the frequency of 0.32, 0.51, 0.09, 0.06, 0.01and 0.01, respectively. The PCR-SSCP method is simple, fast, and relatively inexpensive. The SSCP polymorphism reported in the paper may be useful in looking for the associations between different SSCP patterns and LGB gene expression and milk properties.
EN
The bovine beta-lactoglobulin (LGB) gene is considered a potential quantitative trait locus in dairy cattle breeding. In Black-and-White dairy cattle the LGB gene has two predominant alleles A and B. This can result in three possible genotypes AA, AB and BB. Moreover, within the promoter of the gene several point mutations were found. A herd of one hundred and twenty-four Black-and-White cows were genotyped for two loci: locus LGB (exon IV, alleles A and B) and locus LGB-R (SSCP polymorphism within a fragment of LGB promoter: SSCP patterns R2, R3, R1, R9). In our sample 13 AA, 58 AB and 53 BB LGB cows and 66 R2, 16 R3, 40 R1 and 2 R9 LGB-R cows were identified. A statistical analysis revealed significant associations between LGB, LGB-R genotypes as well as intragenic haplotypes LGB/LGB-R and milk protein content during the first complete lactation. Cows with AA LGB genotype, R3 LGB-R SSCP pattern and AA/R3 haplotypes had the highest protein content. These results support the hypothesis that sequence variation within the promoter of the LGB gene is probably one of the factors responsible for differences in milk protein content.
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vol. 38
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issue 1
51-55
EN
In this report we demonstrate a simple, effective and reliable diagnostic test of BLAD carrier detection based on specific PCR amplification of a 367 bp CD18 gene fragment and RFLP analysis using Taq I restriction enzyme. In a non random population of 220 animals we found 48 BLAD carriers. Within the amplified PCR fragment an unknown intron sequence of 159 bp was identified.
EN
Bovine leukocyte adhesion deficiency (BLAD) is a well characterized lethal autosomal recessive disease that occurs in Holstein cattle.The discovery of this genetic disorder in 1990 by Kehreli et al. was serendipitous and occured in conjunction with studies of the new methods to prevent mastitis in periparturient dairy cows.In this review article we are attempting to summarise the last 6-year research (1990-1995) covering major aspects of BLAD syndrome, its worldwide prevalence with emphasize on current and future development on BLAD research.
EN
A new method facilitating the identification of the two most common alleles (A and B) of the bovine beta-lacoglobulin (LGB) gene is described. The method is based on two steps: PCR amplification of 240 bp fragment of LGB gene followed by the single stranded conformation polymorphism (SSCP) detection. AA, AB and BB genotypes of LGB were identified with this technique. The PCR-SSCP is simple, accurate and relatively inexpensive. Additionally, this method has a potential to detect new variants within the amplified gene fragment.
EN
A total of 306 boars (108 Large White and 198 Landrace) were genotyped for 52 candidate SNPs to determine which of the polymorphisms influence growth rate, meat content and selection index. The effects of SNPs were estimated by a mixed linear model including a random additive polygenic animal effect, fixed effects of SNPs including additive, and pairwise additive-by-additive epistases, year*season of birth, breed and RYR1 genotype. In order to estimate all possible pairwise SNP combinations without overparameterising the model a stochastic approach was adopted. A total of 1 350 replications of the model were generated, each containing five randomly selected SNPs. The final estimates of the fixed effects of the model equaled an average out of the replications. The hypothesis of a nonzero effect of SNP was tested by the Wald test. Among 4 257 estimates calculated, many significant (P<0.01), but mostly minor effects (below 1 phenotypic standard deviation) were recorded. The selected SNPs will be further investigated to determine which may be used in MAS.
EN
DUMPS (Deficiency of Uridine Monophosphate Synthase) is a hereditary recessive disorder in Holstein cattle causing early embryo mortality during its implantation in the uterus. The only way to avoid the economic losses is early detection of DUMPS carriers. Because American Holstein semen has been intensively imported to Poland since 1970, there was a risk that DUMPS could have spread in Polish dairy cattle. In our study, 2209 dairy cattle of the Polish Holstein breed have been screened by the DNA test. The dominant group was young bulls entering the testing program (1171) and proven bulls (781). They represented all sires entering Polish breeding programs between 1999 and 2003. Also, 257 sire dams were included in the screening program. No DUMPS carrier has been found. Our results then indicate that the population of dairy cattle reared in Poland is free from DUMPS. Because of the economical significance of the DUMPS mutation and its recessive mode of inheritance, attention has to be paid to any case of a bull having in his origin any known DUMPS carrier. Such a bull should be tested and if positive eliminated from the active population. Also, young bulls (testing bulls) should be screened for DUMPS if in their progeny a high incidence of embryo mortality is observed and their genealogy cannot exclude their relatedness to any DUMPS carriers.
EN
Nineteen BAC clones were identified by hybridization of the bovine genomic BAC library CHORI-240 with mixed CSN1S1- and CSN3-specific probes. Two of the clones were shown to contain the genes CSN1S1, CSN1S2, CSN2, STATH and CSN3, and five were proved to include the genes CSN2, STATH, CSN1S2 and CSN3. These data showed that the BAC contig was established for the whole casein cluster, including all known five genes.
EN
Milk protein genes expression in cows' mammary epithelial cells is regulated mostly by the action of prolactin mediated through the STAT5A transcription factor. The STAT5A gene is a potential quantitative trait locus (QTL) and genetic marker of production traits in dairy cattle. The sequence of the bovine STAT5A gene was analysed in this study to investigate if mutations in this sequence might be responsible for quantitative variations in milk yield and composition. Ten PCR fragments representing most important functional domains of STAT5A were screened for polymorphism. Using the SSCP method a new SNP (A/G) was found, located in intron 9 at position 9501 (GenBank AJ237937). The frequencies of alleles were estimated in 186 Black-and-White cows (0.52 and 0.48 for A and G, respectively) and in 138 Jersey cows (0.58 and 0.42 for A and G, respectively). For Black-and-White cows with different STAT5A genotypes no significant associations between STAT5A genotypes and milk performance traits were found. Statistically significant differences in the first and second lactations for milk yield, fat and protein content were found in Jersey cows. Cows with the GG genotype showed the highest milk yield, while cows with genotypes AA and AG showed higher protein contents when compared to cows with the GG genotype. Interestingly, cows with genotype AG showed significantly higher protein yields in comparison to cows with the AA genotype. For fat content, cows with genotype AA showed the highest level of this trait in the 1st and 2nd lactation. Further studies are necessary to evaluate an allele substitution effect in the population of sib-families of STAT5A heterozygous bulls.
EN
It is currently debated whether identification of ESR (estrogen receptor) genotypes should be introduced into breeding programs of Large White pigs. The aim of this study was to evaluate the possible relations between ESR/Ava I polymorphism and carcass performance traits in Polish Large White boars. We examined 103 boars originating from one herd in NE Poland. ESR/Ava I genotypes were determined by the PCR-RFLP method. By the use of the Duncan test, we found highly significant differences (P < 0.01) between WW and MW genotypes, as well as significant differences (P < 0.05) between WW and MM genotypes for meatiness. No significant differences were found for daily gain and selection index.
EN
Prolactin plays an important regulatory function in mammary gland development, milk secretion, and expression of milk protein genes. Hence the PRL gene is a potential quantitative trait locus and genetic marker of production traits in dairy cattle. We analysed the sequence of the PRL gene to investigate whether mutations in this sequence might be responsible for quantitative variations in milk yield and composition. Using SSCP and direct sequencing, we detected six single-nucleotide polymorphisms within a 294-bp prolactin gene fragment involving exon 4. All detected mutations were silent with respect to the amino acid sequence of the protein. PCR-RFLP genotyping of SNP 8398 R (RsaI) was used to assess allele frequencies in 186 Black-and-White cows (0.113 and 0.887 for A and G, respectively) and in 138 Jersey cows (0.706 and 0.294 for A and G, respectively). Black-and-White cows with genotype AG showed the highest milk yield, while cows with genotype GG showed the highest fat content.
EN
The molecular basis of BLAD is the D128G mutation of the gene coding for the CD18 subunit of beta?2 integrin. This mutation is lethal, since homozygous (BL/BL) animals die before they reach sexual maturity. In the 1990s, BLAD was the most widespread genetic disease in HF cattle worldwide. The aim of the present study was to determine the frequency of BLAD carriers among 4645 young breeding bulls in Poland in 1995?2006. The frequency of carriers of the mutated allele showed a clear decreasing trend. The highest frequency (7.9%) was recorded while implementing the BLAD control program (1995?1997). Regular monitoring has enabled a great reduction of this threat to the tested population. Today only sporadic cases of BL/TL heterozygotes are reported (ca. 0.8% in 2004?2006).
EN
MilkProtChip is an oligonucleotide microarray based on the arrayed primer extension (APEX) technique, allowing genotyping of single nucleotide polymorphisms (SNPs) in genes of interest for bovine milk protein biosynthesis. APEX consists of a sequencing reaction primed by an oligonucleotide anchored with its 5'end to a glass slide and terminating one nucleotide before the polymorphic site. The extension with one fluorescently labeled dideoxy nucleotide complementary to the template reveals the polymorphism. A total of 75 SNPs were selected among those associated directly or potentially with milk protein content. Among the 75 SNPs, 4 did not produce a positive signal. Most of the remaining SNPs produced a signal for both strands, except for 4 (one strand). In the validation step, 12 Polish Holstein bulls, 1 Polish Red bull, 1 bison (Bison bonasus), 11 Jersey cows and 25 Polish Holstein cows were screened to validate SNPs. Among the 71 selected SNPs ? 26 were found monoallelic, the rest showing at least two genotypes for the entire population under study. All the animals were earlier genotyped for 2?5 SNPs by PCR-RFLP and PCR sequencing and all showed complete concordance with APEX genotyping. APEX reactions showed relatively high signal frequencies: more than 0.9, 0.9?0.8 and below 0.8, for 65, 4 and 2 DNA samples, respectively. The primary application of the MilkProtChip is the simultaneous genotyping of dozens of SNPs to reveal and clarify the genetic background of milk protein biosynthesis. The chip may possibly be used for dairy cattle identification and paternity analysis, evolutionary studies, the evaluation of genetic distances between wild and domestic cattle breeds and the domestication history of bovine species.
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