Heritabilities and genetic correlations of fatty acid compositions in longissimus muscle lipid with carcass traits in Japanese Black cattle.

Fatty acid composition and carcass traits of 2,275 Japanese Black steers and heifers were analyzed to estimate the heritabilities and genetic correlations using the REML procedure. Slices of LM at the 6th to 7th rib section were minced and homogenized, and total lipids were extracted for the analysis by a gas chromatograph. Oleic acid accounted for the majority (51.3%), followed by palmitic (26.4%) and stearic (10.8%) acids. Heritabilities of carcass traits were moderate to high, ranging from 0.34 to 0.61, and heritabilities of individual fatty acids varied largely from 0.00 to 0.78. Those of MUFA, SFA, and PUFA were estimated to be 0.68, 0.66, and 0.47, respectively. Predicted breeding values for MUFA in 99 sires ranged from -3.0 to 5.4%. Genetic correlations of fatty acid compositions with carcass traits were generally weak (-0.28 to 0.39). Low but positive genetic correlations were obtained between beef marbling, on which emphasis of selection has been placed, and oleic acid (0.19) or MUFA (0.23). The results indicated the possibility not only for genetic improvement in fat quality traits but also simultaneous improvements with carcass traits by appropriate selection program.

Stearoyl-CoA desaturase mRNA expression during bovine adipocyte differentiation in primary culture derived from Japanese Black and Holstein cattle.

Stearoyl-CoA desaturase (SCD) catalyzes the synthesis of monounsaturated fatty acids (MUFAs). In cattle, the MUFAs are related to softness and flavor of meat. In order to investigate gene expression profile during bovine preadipocyte differentiation, we isolated stromal-vascular cells from perirenal adipose tissues of Japanese Black and Holstein steers. Gene expression level of adipocyte type fatty acid binding protein (FABP4), SCD, sterol regulatory element binding protein 1 (SREBP1) and CCAAT/enhancer binding protein alpha (C/EBP-alpha) were elucidated by real-time PCR assay. The levels of SCD mRNA expression were significantly increased to 10.8 and 6.3-fold in Japanese Black and Holstein, respectively, on day 1 of the culture. The difference in SCD expression between the two breeds may reflect differences in the fat development characteristics of the cattle breeds. Although transcription factors SREBP1 and C/EBP-alpha are supposed to regulate SCD expression, expression levels of the two factors were not completely consistent with that of SCD.

Effect of sire mating patterns on future genetic merit and inbreeding in a closed beef cattle population.

Alternative breeding strategies were simulated based on the population structure of the Tajima strain of Japanese Black cattle. An analysis of the population structure revealed that some sires up to 20 years of age have been used in Tajima. In addition, 95% of newborn calves were the progeny of only 20 sires, and their mating frequencies were significantly skewed. The current average inbreeding coefficient and founder genome equivalents of the strain were estimated to be 0.199 and 2.25, respectively. Average inbreeding coefficient is expected to reach 0.394 within 27 years. Thus, different breeding strategies were assessed for their effect on the level of inbreeding and average genetic merit. We compared strategies that (1) halve the sire service period, (2) double the number of mating sires and (3) lower the skewed sire mating frequency and optimize the frequency for weighted genetic merit and diversity. Reducing the service period yielded a 7.0-12.0% reduction in the rate of inbreeding while maintaining almost the same genetic gain. Increasing the number of sires resulted in a 19.3-21.3% reduction in inbreeding with a corresponding 1.6-8.4% reduction in gain. The rates of inbreeding from the optimized strategies decreased as the weight on genetic diversity increased. However, a strategy that emphasized only genetic gain yielded lower gain than other strategies because the strategy allowed only one sire to mate, resulting in reduced genetic variance and low accuracy of genetic evaluation. In contrast, a strategy with no emphasis on genetic gain when determining mating frequency resulted in reductions of 16.0% and 63.2% in genetic gain and inbreeding, respectively. The strategies examined here are easily applicable and can be expected to reduce immediate loss of genetic diversity.

Genetic analysis of calf market weight and carcass traits in Japanese Black cattle.

Heritabilities of and genetic correlations between additive direct and maternal genetic effects for calf market weight, and additive direct genetic effects for carcass traits, were estimated for Japanese Black cattle by REML procedures under 2-trait animal models. Data were collected from calf and carcass markets in Hyogo and Tottori prefectures and analyzed separately by prefecture. Calf market weight was measured on 42,745 and 23,566 calves in Hyogo and Tottori, respectively. Only the fattening animals with calf market weight were extracted from the carcass database and used for estimation. The carcass traits analyzed were carcass weight, ribeye area, rib thickness, subcutaneous fat thickness, yield estimate, beef marbling score, and 4 meat characters (color, brightness, firmness, and texture). Direct and maternal heritabilities for calf market weight were estimated to be 0.22 and 0.07 in Hyogo, and 0.37 and 0.15 in Tottori, respectively. The estimates of heritabilities for carcass traits were moderate to high in both prefectures. The estimates of direct-maternal genetic correlations for calf market weight were positive (0.17) in Hyogo and negative (-0.63) in Tottori. The direct effect for calf market weight was positively correlated with the direct effect for carcass weight (0.87 and 0.56 in Hyogo and Tottori, respectively) but negatively correlated with the direct effect for beef marbling score (-0.10 in both prefectures). The estimates of genetic correlations between the maternal effect for calf market weight and the direct effects for carcass traits varied from -0.13 to 0.34 in Hyogo and from -0.14 to 0.15 in Tottori. Because direct and maternal genetic effects for early growth traits can be evaluated from calf market weight data in the production system of Japanese Black cattle, this information should be incorporated into selection and mating schemes of the breed.

Evaluation of genetic diversity in Japanese Brown cattle population by pedigree analysis.

The Japanese Brown is the second most common domestic beef breed in Japan. However, nowadays this breed is facing reduction in numbers because of pressure from a profitable domestic breed. This breed is uniformly characterized by its brown coat colour, but is comprised of two isolated sub-breeds, Kumamoto and Kouchi, each possessing a different gene pool. Pedigree analyses were carried out for the two sub-breeds using the pedigree records of animals born from 1970 to 2000. The effective population size has been found to be consistently reducing during the last three decades in both sub-breeds. The current effective sizes were estimated to be 25.5 and 6.0 for the Kumamoto and Kouchi sub-breeds, respectively. The estimate of the effective number of founders (N(ef)) in the Kumamoto sub-breed decreased from 152.1 to 74.4; that of non-founders (N(enf)), from 41.7 to 5.3; and that of founder genome equivalents (N(ge)), from 32.7 to 4.9. The corresponding changes in the Kouchi sub-breed were from 108.2 to 79.4, 16.2 to 4.1, and 14.1 to 3.9. Increasing differences between the two genetic diversity indices in the sub-breeds indicate that the greater part of the reduction of genetic diversity can be attributed to genetic drift that accumulated in the non-founder generations. A comparison with published estimates for several cattle breeds suggests the extremely limited genetic diversity of Japanese Brown. In addition to the avoidance of further reduction of genetic diversity, it will be important to counteract the process of breed decline by establishing a production system to efficiently utilize the unique characteristics of this breed and by developing links between the breed and products with market value.

Prediction of inbreeding in commercial females maintained by rotational mating with partially isolated sire lines.

The solution to the inbreeding problem for livestock breeds in commercial use is often complicated by hierarchical population structure, in which favourable genes are accumulated in the upper level of the hierarchy (breeding population) by artificial selection and the genetic progress achieved is transferred to the lower level through migration of males. When the breeding population is subdivided into several isolated lines, rotational mating with the lines has been shown to be quite an effective system to reduce the short- and long-term inbreeding of commercial females in the lower level. In practice, however, some amount of migration should be allowed among the lines to reduce the rate of inbreeding in each line. In this study, we developed the recurrence equation for the inbreeding coefficient of the commercial females maintained by the rotational mating with partially isolated lines. Numerical computations were carried out to evaluate the effect of the migration on the efficiency of the rotational mating. It was shown that even with a small amount of migration among the lines, the inbreeding of commercial females is substantially inflated. However, when four or five lines are available, the inbreeding coefficient of commercial females can be suppressed to an acceptable level, irrespective of the effective size of line and the migration rate. Application of the mating system to the population of Japanese Black cattle was also examined.

Conservation of genetic diversity in the Japanese Black cattle population by the construction of partially isolated lines.

In the Japanese Black cattle population, five genetically divergent sub-populations have played important roles as suppliers of breeding stocks to the entire breed. We supposed a situation where five lines were constructed from each of the five subpopulations, and applied to this set of lines a management plan to conserve genetic diversity. Assuming that the male migration pattern among the lines followed the island model, we assessed the optimum male migration rate and required male numbers in each line, satisfying the following three conditions simultaneously: (i) the rate of inbreeding in each line was below 0.01 per generation; (ii) at least 97% of the initial genetic diversity was preserved after 10 generations; and (iii) more than 50% of the genes in an initial line were retained in the line after 10 generations. We found that approximately one breeding male should be selected per year and one breeding male should be exchanged among the lines per generation in each line to satisfy these three conditions. Numerical analysis with the migration rates actually observed among the five subpopulations demonstrated that the initial genetic differentiation among the lines was rapidly decayed by an asymmetrical migration pattern. For a successful plan, migration among lines should be strictly managed.

Trace of native cattle in Japanese Holstein assessed by mitochondrial DNA sequence polymorphism.

On the basis of sequence variation in the displacement loop region of mtDNA, 588 Japanese and North American Holstein cows were classified into 5 mitochondrial haplotypes, which were found in Japanese Black cattle. One of the haplotypes (named type 1), which was present at the highest frequency in Japanese Black cattle, was not observed in either European or African cattle. This haplotype is characterized by 2 single-nucleotide polymorphisms. One is called the type B polymorphism, and it refers to a base change from T to C at nucleotide 16042 of the mitochondrial genome (T160042C). The other is called the type I polymorphism, and it refers to the base change as G16093A. The proportion of the Japanese Holstein population with both polymorphisms was 18.3%, whereas none of the North American cows had this genotype. Because the mitochondrial types were inherited maternally, it is clear that a considerable number of Japanese Holstein cows are descended from native Japanese cattle. Polymorphisms B and I accounted for no variance in the estimated breeding value for milk production among cows from the Hyogo herd (582 cows) or the Chiba region herd (758 cows). This result suggests that most autosomal genes of native animals have been successively replaced by those of pure Holstein after grading up of over 15 generations, even though resulting animals have native animal-oriented mitochondrial types and may still have some number of the native autosomal genes.

An association study using AFLP markers and application to a beef cattle breeding population.

Using amplified fragment length polymorphism (AFLP) fingerprinting, selective genotyping was performed to determine if this method was effective for selecting superior breeding stock. Forty-eight cows with extreme genetic merit for beef marbling score (BMS) were selected from a population of Japanese Black cattle (n = 4462), including 25 with the highest for predicted breeding value (PBV) and 23 with the lowest. Sixteen AFLP fragments were selected for further analysis based on fragment frequency differences between the high and low groups. A linear discriminant analysis using these AFLP fragments was applied in order to derive a discriminant function that classified the cows into high and low groups. Seven of the 16 fragments were included in the resulting function and the discriminant scores (general genetic values, GGV) of the 48 cows were calculated using the function. These cows were clearly separated into high and low groups by GGV with a correlation ratio of 0.91 (discriminative error of 2.1%). The same function was then applied to 121 additional cows that were randomly selected from the original population. A significant regression coefficient of GGV on BMS-PBV (R2 = 0.45) was obtained, which indicates that the GGV can be used as a selection criterion for BMS in this population. These results suggest that AFLP fingerprinting can be used for animal breeding without identifying the underlying genes affecting the trait of interest.

Identification of mitochondrial DNA substitutions related to meat quality in Japanese Black cattle.

Complete sequences of mitochondrial (mt) genomes of eight Japanese Black cattle were determined to investigate the relationships between mt deoxyribonucleic acid (DNA) displacement loop (D-loop) types and other mtDNA regions and to identify the variation in the coding region that may influence the economic traits. The survey of mitochondrial sequences in the encoding region revealed 14 substitutions including six antonymous substitutions and one in 16S ribosomal ribonucleic acid (rRNA). Three methods of polymorphic DNA analyses (polymerase chain reaction [PCR]-restriction fragment length polymorphism [RFLP], mismatch PCR-RFLP, PCR-single-strand conformation polymorphism [SSCP]) were performed on these seven candidate substitutions (base pair [bp] 2,232, 12,158, 12,908, 13,310, 14,122, 14,140, and 14,565) for 202 Japanese Black cattle. The substitution of bp 13,310 was observed in all samples, but not in the reference sequence, indicating that this is a minor substitution or a sequencing mistake in the reference sequence. The substitutions at bp 14,122, 14,140, and 14,565 were observed in only a few samples, suggesting that these were also minor substitutions. The substitutions at bp 2,232 (16S rRNA), 12,158, and 12,908 (reduced nicotinamide adenine dinucleotide-ubiquinone oxidoreductase chain-5) were closely related to mitochondrial D-loop types that have previously been related to differences in the carcass traits of Japanese Black cattle. Evaluation of the effects on six carcass traits with mixed model procedures suggests that the bp 2,232 substitution affects longissimus muscle area and beef marbling score. The substitution at bp 2,232 is a strong candidate for the mitochondrial effect on meat quality.

Inbreeding and effective population size of Japanese Black cattle.

The objective of this research was to estimate the amount of inbreeding and effective population size of the Japanese Black breed using pedigree records from bulls and heifers registered between 1985 and 1997. Inbreeding was quantified by three F-statistics: actual inbreeding, inbreeding expected under random mating, and inbreeding due to population subdivision. During the period of 1985 to 1997, the inbreeding expected under random mating increased from 2.3% to 5.0%, whereas the increase of actual inbreeding was more gradual (from 4.7% to 5.4%). The inbreeding due to population subdivision decreased almost linearly and reached 0.5% in 1997, indicating that genetic subdivision of the Japanese Black cattle population has essentially disappeared. The effective size of the breed was estimated from the increasing rate of inbreeding expected under random mating. In the earlier half of this period (1986 to 1990), the breed maintained an effective size of approximately 30. However, after 1991 the effective size sharply decreased and the harmonic mean between 1993 and 1997 was only 17.2. The main cause of this reduction of the effective size was considered to be the intensive use of a few prominent sires. To increase the effective size, an upper limit in the use of AI semen per sire should be imposed.

Highly sensitive urine-based enzyme-linked immunosorbent assay for detection of antibody to Helicobacter pylori.

BACKGROUND: Enzyme-linked immunosorbent assay (ELISA) has been widely used for detection of Helicobacter pylori (H. pylori), but sample collection is often invasive, complicated, and expensive. Urine samples can be obtained noninvasively and are easier and safer to handle than serum samples. A urine-based ELISA, if found to be accurate, would therefore be a useful alternative to serum-based tests for H. pylori. METHODS: An ELISA method was developed for detection of antibodies to H. pylori in urine. Its sensitivity and specificity were compared with those of three commercially available serum-based ELISA kits and the 13C urea breath test (13C-UBT) using samples from 99 healthy volunteers and 20 patients with gastric disorders. RESULTS: With the assumption that 13C-UBT results are 100% accurate, the sensitivity and specificity of the urinary ELISA were 99% and 100%, respectively, and the accuracy (99%) was superior to those of the three serum ELISAs tested. Immunostaining profiles on Western blot analysis using serum samples were almost identical to those obtained using paired urine samples. CONCLUSIONS: These findings suggest that the differences observed among ELISA test results may be due principally to differences between the profiles of antigen coated on plates for the assays, rather than to differences between antibodies in serum and urine. The urine-based ELISA (URINELISA H. pylori) developed in this study is very accurate and would be useful for screening H. pylori infection as an alternative to serum ELISAs.

Split-circulation assist device facilitates heart failure management and increases effects of intra-aortic balloon pumping.

The split-circulation assist device (SCAD) comprises an intra-aortic balloon pump (IABP), percutaneous cardiopulmonary support (PCPS) equipment, and two occlusion balloons that occlude the descending thoracic aorta by alternate inflation. With the SCAD, the failing heart, assisted by IABP, maintains only the upper 25-30% of the entire circulation without any interference by bypass flow from PCPS. An animal experiment indicated that a given rise in cardiac output caused an increase in aortic pressure in the SCAD group about three times greater than that in the control group (an ordinary combination of IABP and PCPS). Thus, by causing greater increases in arterial pressure, the SCAD may make possible detection of subtle increases in cardiac output, and therefore early detection of cardiac recovery. Multiple regression analysis from the pressure and flow data obtained in another experiment indicated that the SCAD facilitated the prediction of cardiac outputs and loads by preventing the bypass flow rate from influencing the aortic pressure. In addition, the SCAD may enhance cardiac assistance by increasing the effects of IABP. Therefore, the SCAD is a useful and potent new circulatory assist device that can facilitate both timely weaning from PCPS and heart failure management.

Effect of mitochondrial DNA variation on carcass traits of Japanese Black cattle.

Japanese Black fattening steers were used to examine relationships between carcass traits and mitochondria displacement loop (D-loop) variations. The D-loop region of Japanese Black cattle was sequenced and revealed 26 mitochondrial haplotypes defined by 25 polymorphic sites. The haplotypes were classified into five mitochondrial types (type 1 to 5) using the unweighted pair-group method with arithmetic means. Carcass weight, longissimus muscle area (LMA), rib thickness, subcutaneous fat thickness, yield estimate, and beef marbling score (BMS) were compared among five mitochondrial types with BLUP procedures. Significant differences between mitochondria types were detected for LMA and BMS. Difference (P < . 05) was observed between mitochondrial types 2 and 4 for LMA. There was a highly significant difference (P < .01) in BMS between types 2 and 4. Difference (P < .05) was also found between types 1 and 4 on BMS. These results suggest that cytoplasmic genetic effects are important sources of variation for carcass traits in Japanese Black cattle.

Rebamipide protects against activation of neutrophils by Helicobacter pylori.

Our objectives were to determine whether rebamipide, a unique antiulcer agent, would inhibit adhesive reactions between neutrophils and endothelial cells as well as the production of active oxygen species from neutrophils elicited by an extract of H. pylori. A water extract of H. pylori that was prepared from biopsy materials obtained from a patient with gastric ulcer increased the surface expression of CD18 on human neutrophils isolated from peripheral blood, the adhesion of neutrophil-endothelial cells, and the production of active oxygen species by neutrophils. Rebamipide, at concentrations of 10(-5) and 10(-6) M, reduced the adherence of neutrophils to endothelial cells as well as the CD18 expression on neutrophils induced by this bacterial extract. Rebamipide also inhibited the production of active oxygen species from neutrophils stimulated by H. pylori extract. These results suggest that rebamipide protects against the gastric mucosal inflammation associated with H. pylori by inhibiting neutrophil function.

Evaluation of OPC-17116 against important pathogens that cause respiratory tract infections.

The antibacterial activity of OPC-17116, a new fluoroquinolone antibacterial agent, against important pathogens that cause respiratory tract infections was evaluated in vitro and in vivo and compared with those of ciprofloxacin, ofloxacin, and norfloxacin. The pharmacokinetic profiles of OPC-17116 were studied in both mice and rats given the drug orally at doses of 50 and 40 mg/kg of body weight, respectively. OPC-17116 showed a high degree of distribution in the lung tissues of both species, with maximum concentrations of 29.6 and 32.0 micrograms/g, respectively. Furthermore, the drug concentrations in lung tissue were about 10 to 15 times greater than the concentrations in plasma. OPC-17116 showed potent antibacterial activity against such pathogens as Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae, and Moraxella catarrhalis. The MICs of this compound for 90% of these organisms except methicillin-resistant S. aureus and P. aeruginosa ranged from < or = 0.006 to 0.78 microgram/ml. The in vitro antibacterial activity of OPC-17116 was reflected by the efficacy of a single oral dose against systemic bacterial infections in mice. OPC-17116 showed a superior effect against gram-positive bacteria, H. influenzae, and M. catarrhalis. In comparison with the other reference compounds, the efficacy of OPC-17116 was less than that of ciprofloxacin against K. pneumoniae and P. aeruginosa. OPC-17116 showed a greater therapeutic effect than the other drugs against experimental acute pneumonia caused by these organisms in mice or rats. This excellent therapeutic effect against respiratory tract infections may be a result of its high level of distribution in lung tissue.

A further study on the left-right asymmetry of the planum temporale.

By means of a rubbed copy method using India ink and an image-analysis system (IBAS 2000), the areas of 106 left-right plana temporalia were compared using fixed brains of both sexes. The left planum was of a larger size than the right planum in two-thirds of the cases. This result was confirmed statistically by the least-squares analysis of variance method (p < 0.01).

Genetic similarity using DNA fingerprinting in cattle to determine relationship coefficient.

The relation between relationship coefficient and genetic similarity was evaluated using DNA fingerprinting in Japanese Black cattle. We proposed a new method for evaluating heterozygous and homozygous minisatellite loci. Genetic similarity by DNA fingerprinting was estimated by two methods--band sharing (BS) and a new evaluation called genetic similarity (GS). Linear regressions of the relationship coefficient (y) on levels of BS (x1) and GS (x2) yielded the equations y = 0.049 + 0.684x1 and y = -0.206 + 1.149x2, with highly significant correlation coefficients of .631 and .813, respectively. It was suggested that DNA fingerprinting could be applied to estimate the relationship coefficient not only in cattle but also in other species.

[Mitral valve surgery using combined superior-transseptal approach to the left atrium].

Although various approaches to the mitral valve surgery have been tried in the past, it still may be difficult to obtain a good surgical field, particularly in cases of small left atrium or reoperation. We performed mitral valve surgery in 6 patients using the combined superior-transseptal approach to the left atrium proposed by Berreklouw. Exposure of the mitral valve was excellent and the operative procedure was simple in all cases. There were no differences in bleeding volume, length of operation or complication of arrhythmia between patients treated with this new approach and a group treated with conventional approach in our institute.

In vitro reactions of isopropyl methanesulfonate with DNA and with 2'-deoxyribonucleosides.

Isopropyl methanesulfonate (IPMS), an SN1 alkylating agent, is a direct-acting mutagen in bacteria. We recently reported that s.c. and topical administration of IPMS to mice resulted in the rapid induction of thymic lymphomas. Thymic lymphoma induction was not observed following administration of the SN2 alkylating agents methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS). We have studied the reactions of IPMS with dAdo, dCyd, dGuo and dThd at pH 6.5 to 7.5 and 37 degrees C for 3 h. IPMS formed the following isopropyl (IP) adducts: 7-IP-Gua (4% yield), O6-IP-Gua (8%), O2-IP-Cyt (1%), O2-IP-dThd (2%), 3-IP-dThd (1%), and O4-IP-dThd (0.4%). Adducts were characterized from UV and mass spectra. IPMS was reacted in vitro with calf thymus DNA (pH 6.5 to 7.5, 37 degrees C, 3 h) and yielded (nmol/mg DNA): 7-IP-Gua (22) O6-IP-dGuo (11), O2-IP-Cyt (9), O2-IP-dThd (2), O4-IP-dThd (2), 3-IP-Ade (0.2) and 3-IP-dThd (0.2). The relatively greater alkylation of exocyclic oxygen atoms in DNA by IPMS compared to values for MMS and EMS reported by others, may play a role in the induction of thymic lymphomas in mice by IPMS and the lack of such activity by MMS and EMS.