Associations of polymorphisms in the Pit-1 gene with growth and carcass traits in Angus beef cattle.

The Pit-1 gene was studied as a candidate for genetic markers of growth and carcass traits. Angus beef cattle that were divergently selected for high- or low-blood serum IGF-I concentration were used in this study. The single-strand conformation polymorphism method was used to identify polymorphism in the Pit-1 gene including regions from intron 2 to exon 6. Two polymorphisms, Pit1I3H (HinfI) and Pit1I3NL (NlaIII), were detected in intron 3 of the Pit-1 gene. One polymorphism, Pit1I4N (BstNI), was found in intron 4, and a single nucleotide polymorphism, Pit1I5, was found in intron 5. The previously reported polymorphism in exon 6, Pit1E6H (HinfI), was also studied in 416 Angus beef cattle. Associations of the polymorphisms with growth traits, carcass traits, and IGF-I concentration were analyzed using a general linear model procedure. No significant associations were observed between these polymorphisms and growth and carcass traits.

Association of a genetic marker with blood serum insulin-like growth factor-I concentration and growth traits in Angus cattle.

The objective of this research was to evaluate a biallelic genetic marker identified in the first promoter region of the bovine IGF-I gene. The point mutation was identified as a T-to-C transition by sequencing the polymorphic fragments. A PCR-RFLP procedure was developed for determining the marker genotypes. Marker genotypes were determined for 760 Angus calves from divergent lines that were created by selection for high or low serum IGF-I concentration (allele A: 63.9%, B: 36.1%). Data were analyzed using the multiple-trait derivative-free restricted maximum likelihood computer programs with animal models. The full animal model included fixed effects of marker genotype, birth year, season of birth, sex, age of dam, and selection line; random effects of animal, maternal genetic, and maternal permanent environmental effects; and a covariate for age of calf. Traits analyzed included blood serum IGF-I concentrations on d 28, 42, and 56 of the postweaning test, mean IGF-I concentration, birth weight, weaning weight, on-test weight, off-test weight, off-test hip height, postweaning gain, and weight gain during the 20-d period immediately after weaning. Results from the analysis across selection lines showed a significant association of the BB genotype with higher weight gain during the first 20 d after weaning and a slight dominance effect of the marker on postweaning gain. Analysis within the low IGF-I line also showed a significant association of the BB genotype with higher weight gain during the first 20 d after weaning and with on-test weight, although analysis within the high IGF-I line did not show any significant association. The associated effects of the marker need to be verified in other cattle populations.

Association of single nucleotide polymorphisms in the growth hormone and growth hormone receptor genes with blood serum insulin-like growth factor I concentration and growth traits in Angus cattle.

This study was conducted to identify polymorphisms in the promoter and coding regions of the bovine growth hormone and growth hormone receptor genes and to study association of polymorphisms identified in these genes with growth traits and serum insulin-like growth factor-I (IGF-I) concentration. The denaturing gradient gel electrophoresis method and sequencing were utilized to identify three new single nucleotide polymorphisms in the promoter region of the growth hormone gene in Angus cattle. Polymerase chain reaction-based restriction fragment length polymorphism procedures were developed for rapid determination of the single nucleotide polymorphism genotypes in the growth hormone and the growth hormone receptor genes among Angus calves from lines divergently selected for high or low blood serum IGF-I concentration. The IGF-I concentration and growth traits were analyzed using animal models. The single nucleotide polymorphism in the promoter region of the growth hormone receptor gene was associated with serum IGF-I concentration on d 42 of the postweaning test and with mean IGF-I concentration. The associated effects of the markers need to be verified in other populations.

Response to divergent selection for insulin-like growth factor-I concentration and correlated responses in growth traits in Angus cattle.

A divergent selection experiment for serum IGF-I concentration was established in 1989 at the Eastern Agricultural Research Station located in Belle Valley, Ohio. One hundred spring-calving (50 high line and 50 low line) and 100 fall-calving (50 high line and 50 low line) cows with unknown IGF-I concentrations were randomly assigned to the 2 divergent selection lines. Results of this study included 2,507 calves from the 1989 through 2005 calf crops. (Co)variance components were estimated for direct and maternal additive genetic effects using an animal model and multiple-trait, derivative-free, REML (MTDFREML) computer programs. Estimated breeding values were also obtained and regressed on years to estimate direct and correlated responses to divergent selection for serum IGF-I concentration. Estimates of direct heritability for growth traits from a single trait model were moderate and ranged from 0.33 ± 0.06 for birth weight to 0.42 ± 0.06 for preweaning BW gain. Heritability estimates for direct effects were 0.44 ± 0.07, 0.43 ± 0.07, 0.35 ± 0.06, and 0.48 ± 0.07 for IGF-I concentration at d 28, 42, and 56 of the 140-d postweaning period, and for mean IGF-I concentration, respectively. Maternal heritability and the proportion of phenotypic variance due to permanent environment effect of dam were ≤0.25 for growth traits and IGF-I concentrations. Cattle in the high line had significantly (P < 0.001) greater direct effects of mean IGF-I concentration than those in low line (high line: 66.92 ± 4.40 ng/mL vs. low line: -40.82 ± 5.18 ng/mL) in 2005. Direct responses per year for mean IGF were 5.18 ng/mL in the high line and -3.76 ng/mL in the low line. The regression of direct effects of preweaning BW gain on year were not significantly different from zero in either the high or low line. However, genetic trends were negative and significant for birth weight and postweaning BW gain in the high line and were positive and significant in the low line. Results demonstrated that divergent selection for serum IGF-I concentration in beef cattle will change the genetic potential for IGF-I concentration and that selection for lesser IGF-I concentration will result in increased birth weights and postweaning BW gains.

Detection of nucleotide variations in the D-loop region of bovine mitochondrial DNA using polymerase chain reaction-based methodologies.

Allele-specific polymerase chain reaction (ASPCR) and single-strand conformation polymorphism (SSCP) were used to characterize 16 Holstein maternal lines. ASPCR was used to detect polymorphic nucleotides at eight different positions in the displacement loop (D-loop) of bovine mitochondrial DNA (mtDNA): 16022, 16057, 16074, 16231, 16247, 106, 169 and 363. ASPCR analysis of the maternal lines showed variations at nucleotide positions 106, 169, and 363 of the mtDNA. Within-line variation was observed in five maternal lines for nucleotide 363. SSCP analysis of the mtDNA D-loop region revealed variations that classified the maternal lines into six different genotypes. Based upon the variations observed by ASPCR and SSCP analysis, the animals representing the 16 maternal lines could be assigned to 10 different genotypic groups. These procedures provide a rapid, simple, non-radioactive, and reliable method of detecting polymorphism in the D-loop region of bovine mtDNA.

Bovine lymphocyte antigens: serological relationships with erythrocyte and spermatozoan antigens.

Bovine lymphocytotoxicity tests with 20 unabsorbed bovine blood group sera revealed extensive reactivity which in the majority of cases had no indication of blood group relationship. Six of these sera were absorbed with selected lymphocytes to produce eleven antisera of reduced specificity. Again, most of the sera had reaction patterns which could not be related to the hemolytic patterns of any known blood group antibodies. However, five comparisons involving unabsorbed antisera and two comparisons involving absorbed antisera provided statistical evidence of similarities between their lymphocytotoxic reaction patterns and the hemolytic reaction patterns of certain blood group antibodies. Several of the sera appeared to contain related cytotoxic specificities, and three such absorbed sera may have contained an anti-J specificity. All six examined monospecific isoimmune blood group antisera contained lymphocytic reactivities not related to their hemolytic specificities. Two normal sera containing naturally occurring anti-J had no cytotoxic activity. Anti-semen sera likewise were devoid of lymphocytotoxic activity.

Removal of blood group determinants from bovine erythrocyte membranes. 2. Degradation of ghosts by butanol and pyridine.

Ghosts produced from erythrocytes collected from six different cattle were degraded with butanol and pyridine. Of a total of 38 different antigenic determinants available for investigation among the six cows, F, V, J and L were the only specificities detected in the subfractions resulting from either method of degradation. After butanol degradation V, J and L antigens were found in the soluble protein fraction, while F was found in the insoluble protein. Pyridine digestion resulted in all four determinants being detected in the sialoprotein layer, while J was found in the lipoprotein as well. All antigens were relatively weak, being detected in inhibition strengths of 10.0 to 1.25 mg/ml.

Production of foetally stimulated lymphocytotoxic antibodies by multiparous cows.

Serum samples were collected monthly from second gestation cows and examined for the presence of lymphocytotoxic antibodies. Of 25 cows studied 16 (64%) raised antibodies during or immediately after second gestation. Ten of these cows (40%) raised antibodies during gestation, some as early as 5 months before parturition. Reactors which had had first-gestation reactivity responded earlier, but had peak antibody titers no higher than cows without observable first gestation reactions. Cows with antibodies of similar specificity in the first two gestations responded earlier than those with different antibody specificities. Regardless of the time of first antibody detrection, peak titers were usually achieved during the first month postpartum. Antibody persistence increased with parity. Among cows of all ages sampled at random times, there was a linear relationship of serum reactivity to cow age.

Amylase genetic variation of serum in Holstein cattle.

Three amylase phenotypes, AmIB, AmIC, and AmIBC, were detected by electrophoresis of blood serum from 329 Holstein cattle. These phenotypes appear to be controlled by two alleles AmIB and AmIC at the amylase I locus (AmI). Frequencies were .518 and .482 for alleles B and C. The numbers of phenotypes corresponded closely to expectations of Hardy-Weinberg equilibrium. No evidence of linkage between the AmI locus and other genetic marker loci of blood and milk was detected.

Production of foetally stimulated lymphocytotoxic antibodies by primiparous cows.

Serum samples from groups of heifers at different pregnancy-related stages (preconception, month of pregnancy, and postpartum) were examined for the presence of lymphocytotoxic antibodies. Only a few weak and transitory antibodies were observed before or during the first pregnancy. These did not appear to be foetally stimulated. Strong or medium strength antibodies were detected in first or second month postpartum samples from 8 of 27 heifers (30%). The reactive sera were in every case reactive with the offspring of the cows from which the respective sera were collected.

Stimulation of maternal anti-lymphocyte antibodies by first gestation bovine fetuses.

Serum samples were taken from first-calf dairy heifers, twice weekly, for a period of 4 weeks, starting 2 weeks before the estimated date of parturition and continuing for 2 weeks post partum. Samples from each heifer were incubated with lymphocytes from the respective calf when possible, and from a 36-cow donow panel, in the presence of complement. Of the 31 heifers tested, 11 (35%) raised detectable lymphocytotoxic antibodies against fetal antigens; 3 had detectable, but weak, antibody titres as early as 10 days before parturition while the others had stronger antibody reactivity which was detectable 4--12 days post partum. The titres of these post-partum antibodies peaked 4--7 days after they were first detected. Sephadex G-200 fractionation of the sample taken at 2 weeks post partum showed that 11 responding cows had antilymphocytic activity in the IgG fraction while 8 also had IgM antibody activity.

Serological relationships among antigens of the BoLA and the bovine M blood group systems.

Alloimmunizations with either lymphocytes or red cells from donor cows positive for BoLA w16 and blood group M' antigens into recipients negative for these antigens produced antisera reactive in the cytotoxic test with w16-positive lymphocytes and in the haemolytic test with M'-positive erythrocytes. Similarly, alloimmunizations of blood group M1-negative recipients with either lymphocytes or red cells from donor cows possessing the M1 blood group factor produced antisera specifically reactive with lymphocytes and erythrocytes from M1-positive cattle. Absorptions with either lymphocytes or erythrocytes from individual animals of the same M antigenic type as the donor removed all haemolytic and cytotoxic reactivity. The results indicate that blood group M' and BoLA w16 share a similar antigenic structure. Likewise, blood group M1 has an antigenically similar counterpart which is also part of the BoLA system.

Dermal abscesses with Staphylococcus aureus, cytomegalovirus and acid-fast bacilli in a patient with acquired immunodeficiency syndrome (AIDS).

A 34-year-old man with acquired immunodeficiency syndrome presented with multiple skin lesions clinically suggestive of molluscum contagiosum. Three skin biopsy specimens were obtained which showed dermal abscesses containing multiple gram-positive cocci admixed with granular necrotic dermal material. In 2, there were cytomegalic inclusions present in macrophages and endothelial cells within the granulation tissue; immunohistochemistry was positive for cytomegalovirus (CMV) antigens. One biopsy specimen also contained a few acid-fast bacilli associated with mononuclear inflammatory cells. Cultures from the lesions grew Staphylococcus aureus and the lesions resolved when the patient was administered a course of systemic cephalosporin. Although lesions with multiple infectious agents have been reported in immunosuppressed patients, this is the first case describing the association of 3 organisms in a single skin biopsy specimen.

Characteristics of frozen colostrum thawed in a microwave oven.

Use of a microwave oven to thaw frozen colostrum was evaluated. Colostrum was collected from nine cows, four of which were immunized to produce specific colostral antibodies. Colostrum from each cow was frozen, subsequently thawed, and pooled. One-liter aliquots of the pooled colostrum were frozen and assigned randomly to three thawing treatments. Colostrum was thawed using one of three regimens: 10 min in a microwave oven at full power (650 W), 17 min in a microwave oven at half power (325 W), and 25 min in 45 degrees C water. Colostrum thawed in the microwave oven was slightly coagulated and had lower volume and total protein content than colostrum thawed in water. Casein and pH were not different among treatments. Both concentration and total content of immunoglobulin A were higher in the control than in microwave treatments. Neither amount nor concentration of immunoglobulin G and immunoglobulin M were different among treatments. Immunological activity, measured by a hemolytic test, was lower for microwave treatments than the control but did not differ between microwave treatments. Frozen colostrum thawed in a microwave oven should provide a reasonable source of colostrum when fresh high quality colostrum is not available.

Association of bovine lymphocyte antigens with milk fat percentage differences.

A group of 246 Holstein artificial insemination bulls was examined for associations of bovine lymphocyte antigens with differences in transmitting ability for milk and fat yield and fat percent. The mean fat percentage associated with the w10 allele was .15% greater than the mean for four other alleles. No differences in phenotypic or allelic effects were detected for milk or fat yield.

Removal of blood group determinants from bovine erythrocyte membranes. 3. Action of proteolytic enzymes on intact cells.

Bovine erythrocyte treatment with chymotrypsin, trypsin, pronase, papain, or ficin eliminated or weakened the reactivity of 18 of the 47 blood group factors which were examined. Thirteen of the affected factors were from the B system, and one each was from the C, FV, L, M, and R'S' systems. Variation attributable to pheno-group (allele) or genotype influences was observed in the effects upon six of the factors. Ficin-treated V/V, but not F/V or F/F, cells were rapidly lysed by normal rabbit serum (complement control). Absorptions with pronase-treated V positive cells indicated that essentially all V antigenicity was removed. However, immunizations with pronase-treated V positive cells elicited V antibody production in one of two recipient cows. The numbers of antigens removed by different enzymes did not appear to be closely related to the amount of protein removed.