Differential expression of ruminant ZNF496 variants: Association with quantitative trait locus affecting bovine milk concentration and fertility.

A single nucleotide polymorphism in the intergenic region upstream of the ZNF496 gene on Bos taurus chromosome 7 displayed significant population-wide linkage disequilibrium with milk protein percentage in the Israeli Holstein population. The frequency of the allele associated with increased protein concentration was 10%. This single nucleotide polymorphism was located in the promoter region from which a 10-exon transcript of the bovine and the ovine ZNF496 genes are transcribed. The gene architecture was similar to the mouse ortholog Zkscan17. A 5-exon murine antisense transcript was complementary to the 5' untranslated Zkscan17 region that included a sequence domain conserved between mouse and ruminants, suggesting a regulatory function. In the bovine ZNF496 chromosomal region, segregation of a quantitative trait locus (QTL) for milk protein percentage was confirmed in a daughter design sire family. Concordance was not obtained between QTL status of bulls and any of the polymorphisms in the functional elements of ZNF496. This excludes these variations as the causative polymorphism under the assumption of no epigenetic effect for this locus. However, ZNF496 variants were differentially expressed in bovine ovaries, and only the paternal variant was expressed in liver and kidney in a sheep family with polymorphic ZNF496 sequence. Thus, the search for the mutation underlying the minor QTL allele, which is a top economically favorable allele in Israeli Holstein cattle, may be complicated by the presence of an imprinting center in this QTL confidence interval.

Copy number variation of lipocalin family genes for male-specific proteins in tilapia and its association with gender.

Lipocalins are involved in the binding of small molecules like sex steroids. We show here that the previously reported tilapia male-specific protein (MSP) is a lipocalin encoded by a variety of paralogous and homologous genes in different tilapia species. Exon-intron boundaries of MSP genes were typical of the six-exon genomic structure of lipocalins, and the transcripts were capable of encoding 200 amino-acid polypeptides that consisted of a putative signal peptide and a lipocalin domain. Cysteine residues are conserved in positions analogous to those forming the three disulfide bonds characteristic of the ligand pocket. The calculated molecular mass of the secreted MSP (20.4 kDa) was less than half of that observed, suggesting that it is highly glycosylated like its homologue tributyltin-binding protein. Analysis of sequence variations revealed three types of paralogs MSPA, MSPB and MSPC. Expression of both MSPA and MSPB was detected in testis. In haploid Oreochromis niloticus embryos, each of these types consisted of two closely related paralogs, and asymmetry between MSP copy numbers on the maternal (six copies) and the paternal (three copies) chromosomes was observed. Using this polymorphism we mapped MSPA and MSPC to linkage group 12 of an F(2) mapping family derived from a cross between O. niloticus and Oreochromis aureus. Females with high MSP copy number were more frequent by more than twofold than males. Gender-MSPC combinations showed significant deviation from expected Mendelian segregation (P=0.009) suggesting elimination of males with MSPC copies. We discuss different hypotheses to explain this elimination, including possibility for allelic conflict resulted by the hybridization.

Detection of quantitative trait loci affecting twinning rate in Israeli Holsteins by the daughter design.

Twinning rate was analyzed in the Israeli Holstein dairy cattle population by the multiple-trait animal model, and a daughter design genome scan for quantitative trait loci was performed. Each parity was considered a separate trait. Heritabilities of twinning rate were very low, but increased by parity from 0.01 in first parity to 0.03 in fifth parity. All genetic correlations among parities were >0.77, but all environmental correlations were <0.07. Genetic correlations between twinning rate and female fertility (measured as the inverse of the number of inseminations to conception) in the first 3 parities were negative for all 9 parity-by-trait combinations. All environmental correlations were very small, but generally negative. The overall genetic trend since 1985 was positive at 0.02% twinning/yr, whereas the phenotypic trends were positive for parities 3 and 4 and negative for the other parities, but all trends were quite small. A total of 5,221 cows, daughters of 11 sires, were genotyped for 73 markers spanning all 29 autosomes. There were 9 markers with significant effects on twinning rate at P < 0.05, for a false discovery rate of 0.4; thus, about 5 of these probably represent true effects. Significant effects were found on chromosomes 1, 6, 7, 8, 14, 15, and 23. Of these, 3 effects were significant at P < 0.01, for a false discovery rate of 0.24. All 11 families were analyzed by interval mapping of chromosome 7. Only 2 families showed nominally significant effects, but chromosome-wise significance at P < 0.05 was not obtained for either family. Suggestive evidence of quantitative trait loci near the beginning of the chromosome and near position 50 cM were found in both families. Sire 3070 also had a significant effect for female fertility near the beginning of the chromosome. There was also evidence for a third quantitative trait loci at the end of the chromosome for sire 2357.

Detection and analysis of quantitative trait loci affecting production and secondary traits on chromosome 7 in Israeli Holsteins.

A total of 5,459 Israeli Holstein cows, daughters of 11 sires, were genotyped for 29 microsatellites spanning chromosome 7 and analyzed by the daughter design for 9 economic traits: milk, fat, and protein yield, fat and protein percentage, somatic cell score, female fertility, herd life, and milk persistency. Quantitative trait loci at chromosome-wise 0.05 significance were obtained for fat and protein yield, fat percentage, somatic cell score, and female fertility. Peak F-values were obtained at 29 cM for fat and protein yield and fat percentage, at 60 cM for somatic cell score, at 74 cM for herd life, and at 11 cM for female fertility. The 0.95 confidence intervals for quantitative trait loci locations were 20 cM for kilograms of fat, 27 cM for fertility, and 51 cM for somatic cell score. Two loci affecting fertility at opposite ends of the chromosome are apparently segregating in the population. A quantitative trait locus for fertility near the centromere was confirmed by application of the modified granddaughter design to a single family. Estimated frequency of the economically favorable allele in the Israeli Holstein cattle was less than 0.5. Significant genetic gain for fertility seems possible by marker-assisted selection.

Factors affecting incorrect paternity assignment in the Israeli Holstein population.

A total of 6040 Israeli Holstein cows from 181 Kibbutz herds listed as progeny of 11 sires were genotyped for 104 microsatellites. Seventeen markers were deleted due to a frequency of erroneous genotypes >1%, leaving 160,470 valid genotypes. Conflicts between the putative sire and daughter in at least 2 markers and for at least 10% of the markers genotyped per cow were required to reject paternity. Cows that did not meet the requirements for paternity confirmation or rejection were deleted from further analysis. The frequency of rejected paternity was 11.7%. The effects of recorded sire, birth year, geographical region, herd, and inseminator on the frequency of paternity rejection were analyzed with linear and nonlinear models. Only the effects of inseminator and recorded sire were significant in all models tested that included these effects. The main causes of incorrect paternity recording appear to be inseminator recording mistakes, and possibly mistakes with respect to semen labeling at the AI institutes. Incorrect paternity recording due to multiple inseminations by different sires could explain, at most, 20% of the paternity mistakes. Instituting a system of quality control, especially at the level of the inseminator, should reduce paternity errors to no more than 8%, and increase genetic progress by at least 1%.

A complete genome scan of the Israeli Holstein population for quantitative trait loci by a daughter design.

Eleven Israeli Holstein families including 5221 cows were analyzed by a daughter design for eight economic traits: milk, fat and protein production, fat and protein percentage, somatic cell score (SCS), herd-life, and female fertility. The cows were genotyped for 73 microsatellites with maximum spacing between markers of 53 cM. There were 86,304 informative genotypes. Preliminary analysis was by ANOVA of each trait, with the marker effect nested within sire. Significance was determined by controlling the false discovery rate at 0.4, after excluding markers with genome-wide significance for at least a single trait, and traits without any significant effects at this level. Thus, four markers on chromosomes 6 and 14 and female fertility were excluded. There remained 40 significant marker-trait combinations, and it is expected that 24 of these are true effects. To perform interval mapping for the families with significant contrasts, 21 additional markers were genotyped on chromosomes 2, 7, and 27. The bootstrap confidence intervals for gene effect did not include zero for protein percent on chromosome 2 and fat yield, protein yield, and SCS on chromosome 7. Quantitative trait locus heterozygosity was 33%, which is consistent with the hypothesis that only two alleles are segregating with unequal allele frequency.

Population-wide analysis of a QTL affecting milk-fat production in the Israeli Holstein population.

A population-wide linkage disequilibrium on bovine chromosome 14 between microsatellite ILSTS039 and DGAT1, a putative quantitative trait locus affecting milk production traits, was found in the Israeli Holstein population. A total of 394 bulls were genotyped for both DGAT1 and ILSTS039, and 1747 cows were genotyped for ILSTS039. The ILSTS039 allele termed "225," and the DGAT1 K allele (substitution of a lysine residue with alanine), were associated with decreased milk production, and increased fat production and fat and protein percent. The number of 225 ILSTS039 and K DGAT1 alleles per individual were the same for 80% of the bulls genotyped. From the effects associated with cows homozygous for the 225 allele, the effect of the quantitative trait locus appears to be approximately codominant. The substitution effect was 0.16% fat. Genotype probabilities for the quantitative gene were determined for the entire Israeli Holstein milk-recorded population, including 507,725 cows and 1442 bulls, using segregation analysis. Overall frequency of the allele that increased fat percent was 8.9% in cows and 15.5% in bulls. The frequency of this allele decreased from 1981 until 1990, from 15 to 5%, and since has increased to 10%. The effects estimated on the population-wide analyses of both cows and bulls were similar to the effect associated with DGAT1 in the daughters of genotyped bulls. Modified animal model evaluations were computed for the entire population with the effect of this gene included in the model. The correlations between the modified and standard animal model evaluations for all traits were > 0.99.

Analysis of vaginal swabs for paternity testing and marker-assisted selection in cattle.

Blood is the standard source for DNA analysis, but requires venipuncture of cows by veterinarian and tedious and costly DNA extraction. A procedure was developed for sampling of vaginal cells from cows, establishing a cell lysis protocol using robotics, and applying fluorescent analysis of genetic markers. Two insemination technicians collected vaginal cells from 254 elite Israeli Holstein cows located in 152 herds using commercial Catch-All sample collection brushes. Cells were lysed in a 400-microliters solution, and 5 microliters was used as template for polymerase chain reaction (PCR). Sensitivity of the PCR was enhanced using only 1 microliter of lysed cells. Eight markers of the International Society of Animal Genetics paternity panel were amplified in four separate PCR. ILSTS039, a marker for a quantitative trait loci on BTA14, was amplified in a separate reaction. Genotypes from one to nine genetic markers were obtained for 253 out of 254 samples, and 244 cows had genotypes for at least three markers (96%). Cows that did not inherit either paternal allele for at least two loci were considered not to be daughters of the sire listed. Fifteen cows met this criterion, for a paternity misidentification rate of 6.25%. The frequency of allele 225 of ILSTS039, which was associated with increased milk fat content, was 11.1% in the bull-dam population, similar to the 12% found in the cow population in Israel. The use of vaginal cells for genetic analysis is accurate, as demonstrated by replicated analysis and by comparison to individual and population analysis based on DNA derived from blood.

[Correction of tibial varus deformity due to Blount disease using an epi-metaphyseal distraction]. / Korekcja szpotawej deformacji piszczeli na tle choroby Blounta dystrakcja nasadowo-przynasadowa.

The possibility to correct tibial varus deformity due to Blount disease by epi-metaphyseal distraction was presented. The correction was achieved in 2 patients; in one of them leg length discrepancy was eliminated. The method is not invasive, offers continuous rehabilitation and a possibility of equalization of the extremities.

[Early results of leg bone lengthening using epiphysis-metaphysis distraction]. / Wczesne wyniki wydluzenia konczyny dolnej metoda dystrakcji nasadowo-przynasadowej.

The methods and results of elongation of the lower extremity by epiphysis-metaphysis distraction obtained at treatment of 13 children aged from 4 to 15 years, with abbreviation of 30-80 mm have been presented. In 11 children full elongation of the abbreviation of 30-57 mm was obtained. In two children full elongation was not obtained.

[Spinal deformities after laminectomy in children]. / Deformacje kregoslupa po laminektomii u dzieci.

The authors discuss the problem of spinal deformity developing after laminectomy in the light of treated case. Clinical observations and literature survey indicate the necessity of orthopaedic consultation before operations impairing stabilization of the spine. Laminectomy, particularly with disturbance of the stability of articular processes is an indication to spondylodesis, and the presence of kyphosis and absence of posterior spinal elements are the primary indication to anterior spondylodesis.