Accuracy of imputation of single nucleotide polymorphism marker genotypes from low‐density panels in Japanese Black cattle

Using target and reference fattened steer populations, the performance of genotype imputation using lower‐density marker panels in Japanese Black cattle was evaluated. Population imputation was performed using BEAGLE software. Genotype information for approximately 40 000 single nucleotide polymorphism (SNP) markers by Illumina BovineSNP50 BeadChip was available, and imputation accuracy was assessed based on the average concordance rates of the genotypes, varying equally spaced SNP densities, and the number of individuals in the reference population. Two additional statistics were also calculated as indicators of imputation performance. The concordance rates tended to be lower for SNPs with greater minor allele frequencies, or those located near the ends of the chromosomes. Longer autosomes yielded greater imputation accuracies than shorter ones. When SNPs were selected based on linkage disequilibrium information, relative imputation accuracy was slightly improved. When 3000 and 10 000 equally spaced SNPs were used, the imputation accuracies were greater than 90% and approximately 97%, respectively. These results indicate that combining genotyping using a lower‐density SNP chip with genotype imputation based on a population of individuals genotyped using a higher‐density SNP chip is a cost‐effective and valid approach for genomic prediction.     

Enhancement of antigen-specific immunoglobulin G production in mice by co-administration of L-cystine and L-theanine

Supplementation with both cystine and glutamic acid increases the synthesis of glutathione (GSH), which has a marked effect on immune cell function, as compared with supplementation with either amino acid alone in human macrophages in vitro. As dietary glutamic acid is metabolized during intestinal transport, oral administration of L-theanine (gamma-glutamylethylamide), which is metabolized to glutamic acid mainly in the liver, may act as a glutamic acid donor in vivo. The present study was performed to investigate the effects of oral administration of L-cystine and/or L-theanine on GSH levels and immune responses. Co-administration of L-cystine (200 mg/kg) and L-theanine (80 mg/kg) for 11 days before immunization significantly increased the levels of total GSH in the liver 6 hr after immunization as compared with the levels in control mice. To examine the effects of administration of L-cystine and/or L-theanine on the balance of T helper (Th) 1/Th2 cell responses, the serum ratios of the Th1 cytokine, interferon (IFN)-gamma, and the Th2 cytokine, interleukin IL-10, were investigated. At 24 hr after immunization, co-administration significantly increased the IL-10/IFN-gamma ratio compared with the ratios of the control and single-administration mice. Furthermore, co-administration before primary immunization significantly enhanced serum antigen-specific IgG levels. Taken together, these findings suggest that co-administration of L-cystine and L-theanine enhances antigen-specific IgG production partly through augmentation of GSH levels and Th2-mediated responses.     

Effect of the timing of first cleavage on in vitro developmental potential of nuclear-transferred bovine oocytes receiving cumulus and fibroblast cells

The aim of the present study was to examine whether cumulus and fibroblast cell nuclear-transferred oocytes, which have high and low potential to develop into normal calves, respectively, are different in terms of in their patterns of timing of first cleavage and in their relationships between timing of first cleavage and in vitro developmental potential. The timing of first cleavage was similar in both types of nuclear-transferred and in vitro fertilized oocytes. More than 86% of the oocytes cleaved within 24 h after activation or in vitro fertilization; these oocytes contributed to more than 98% of the total number of blastocysts in all three groups. The potential of oocytes that cleaved at different intervals to develop into blastocysts differed among the groups. The developmental potential of the cumulus cell nuclear-transferred oocytes and in vitro fertilized oocytes decreased with the increase in time required for cleavage. Fibroblast cell nuclear-transferred oocytes that cleaved at 20 h, an intermediate cleaving time, had higher potential to develop into blastocysts. The results of the present study suggest that the type of donor nucleus used for nuclear transfer affects the timing of first cleavage.     

Inhibitory effect of 2,4-dibromophenol and 2,4,6-tribromophenol on larval survival and metamorphosis of the sea urchin <Emphasis Type="Italic">Strongylocentrotus nudus</Emphasis>

ABSTRACT:   As a possible factor leading to the low recruitment level of sea urchins in kelp forests, the inhibitory effect of 2,4-dibromophenol (DBP) and 2,4,6-tribromophenol (TBP) released from the large perennial brown algae Ecklonia kurome and Eisenia bicyclis on survival and metamorphosis of eight-armed larvae of the sea urchin Strongylocentrotus nudus was examined. The percentage of larvae that underwent metamorphosis in filtered sea water after 1 h exposure to one-half dilution of saturated dibromomethane solution (∼60 ppm) as a chemical inducer reached approximately 100% after 1 h, while that in filtered sea water containing 1 ppm TBP was reduced to 73%. This was further reduced to less than 40% in the presence of 10 and 20 ppm TBP after 2 h. In filtered sea water containing 1 and 10 ppm DBP, the proportion of metamorphosed larvae was reduced markedly to 43 and 5% after 2 h, respectively. All larvae exposed to 50 ppm TBP and to 20 and 50 ppm DBP died after 1 h. These findings suggest that DBP is more toxic than TBP for sea urchin larvae, strongly inhibiting their metamorphosis.     

Relative parasitic fitness of isolates of Pyricularia oryzae Cav. with different sensitivities to fungicides

The relative parasitic fitness of isolates of Pyricularia oryzae with different sensitivities to isoprothiolane (di-isopropyl 1,3-dithiolan-2-ylidenemalonate) and IBP (S-benzyl O, O-di-isopropyl phosphorothioate) was studied in the absence of fungicides. Four field isolates (S-1,S-2,MR-1 and MR-2) and two in-vitro mutants (Rvt-1 and Rvt-2) were used for disease epidemics. S-l and S-2 were wild types; MR-1 and MR-2 were sensitive to isoprothiolane and moderately resistant to IBP, and Rvt-1 and Rvt-2 were resistant to both fungicides. Twelve epidemics were made by inoculating rice seedlings with mixed conidial suspensions of two isolates or mutants. The value of relative parasitic fitness (W = 0-1.0) was calculated for each isolate and epidemic. S-l and S-2 were stronger (W = 1.0) than MR-2, Rvt-1 and Rvt-2; but weaker (W = 0.75, 0.73, respectively) than MR-1. MR-1 was strongest among all isolates and mutants used. MR-2 was slightly weaker (W = 0.9-1.0) than S-l and S-2, but stronger than Rvt-1 and Rvt-2. Rvt-1 and Rvt-2 had smaller values of W, ranging from 0.25-0.58, in the epidemics with each field isolate. These results suggest that the proportions of in-vitro mutants do not increase unless intensive selection pressure is given, and would be expected to decrease rapidly after the selection pressure is removed. Isolates moderately resistant to IBP, such as MR-1 and MR-2, however, had high values of W, suggesting that they would increase or would not decrease rapidly in the absence of selection pressure. These results may well explain why isolates highly resistant to isoprothiolane and IBP have seldom been found, and why a large number of isolates moderately resistant to IBP but sensitive to isoprothiolane have been observed in the field.     

Identification of novel inhibitors of calling and in vitro [14C]acetate incorporation by pheromone glands of Plodia interpunctella

Some octopamine agonists were found to suppress in vitro biosynthesis of the calling pheromone of the Indian meal moth, Plodia interpunctella. Isolated pheromone-gland preparations incorporated sodium [14C]acetate at a linear rate for 3 h when incubated with the pheromone biosynthesis activating neuropeptide (PBAN). This incorporation was dependent on the dose of PBAN (up to 0.5 microM). Thin-layer chromatography of a pheromone-gland extract revealed quantitative incorporation of radioactivity into a product exhibiting the same mobility as (Z,E)-9,12-tetradecadienyl acetate, the main component of the calling pheromone of P interpunctella. Twenty-seven octopamine agonists were initially screened using a calling behaviour bioassay of female P interpunctella. Four derivatives with activity in the nanomolar range were identified which were, in order of decreasing pheromonostatic activity: 2-(2,6-diethylphenylimino)thiazolidine > 2-(2,6-diethylphenylimino)oxazolidine > 2-(2,6-dimethylphenylimino)thiazolidine > 2-(2-ethylphenylimino)oxazolidine. These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis. The results of the present study indicate that these derivatives could provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.     

Quantities and types of ceramides and their relationships to physical properties of the horn covering the claws of clinically normal cows and cows with subclinical laminitis

Quantities and types of ceramides and their relationships to physical properties of the horn covering the claws of clinically normal cows and cows with subclinical laminitis were investigated. Total ceramide content of the horn covering the sole and wall from cows with subclinical laminitis was 872.2 +/- 146.6 microg/g and 528.6 +/- 61.3 microg/g, respectively, and was significantly (P < 0.01, 0.05) lower than that from clinically normal cows. The mean moisture content in the claws from cows with subclinical laminitis (43.5% +/- 4.3%) was significantly (P < 0.05) higher than that in the claws from clinically normal cows. The hardness of claws from cows with subclinical laminitis (35.2 +/- 3.5) was significantly (P < 0.05) less than that of claws from clinically normal cows. Significant correlations between ceramides and moisture content (P < 0.001) and between ceramide and hardness (P < 0.001) were found in clinically normal cows and cows with subclinical laminitis. Our results indicate that decreases in ceramide contents may be related to changes in physical properties of the horn covering the claw in cows with subclinical laminitis.     

Inhibition of juvenile hormone biosynthesis and methyl farnesoate epoxidase activity by 1,5-disubstituted imidazoles in the cockroach,Diploptera punctata

Seventeen substituted imidazoles were tested as inhibitors of juvenile hormone (JH) III synthesis by cockroach corpora allata in an in-vitro radio-chemical assay. Most of these 1,5-disubstituted imidazoles were highly potent, with IC₅₀ values of less than 100nM. The compounds differed in their ability to cause an accumulation of the precursor methyl farnesoate in the glands. Four of the imidazoles were tested by topical application to previtellogenic adult females, and all caused a significant inhibition of JH synthesis and an accumulation of intraglandular methyl farnesoate for at least three days after treatment. Methyl farnesoate epoxidase activity of homogenates of corpora allata was inhibited by the compounds TH -14 and TH -27. This P450-dependent epoxidase activity was inhibited at less than 10 nM. The results show that the 1,5-disubstituted imidazoles are powerful inhibitors of the last step of juvenile synthesis in this cockroach.     

Increase in oxidized proteins in Theileria sergenti-infected erythrocyte membrane

As a part of the elucidation of the pathogenesis of anemia in Theileria sergenti infection, oxidized-erythrocyte membrane proteins (OEMPs) collected from T. sergenti-infected calves were examined. The amount of OEMPs were seen to increase with the progress of the anemia and showed a maximum value around the crisis period of the infection. The increase of OEMPs coincided with band Nos. 1, 2, 2.1, 3, 4.1, 5, 6, and 7. The majority of them was located at the Triton X-100 un-extractive phase, and was confirmed as cytoskeletal proteins. This evidence indicates the enhancement of erythrocytic oxidation, and suggests that it might be one of the aggravating factors of anemia in T. sergenti infection.