Identification of the core motif of the BRCA2 C-terminal RAD51-binding domain by comparing canine and human BRCA2

Mammary tumors are the most common tumors in women and non-spayed female dogs. One of the reasons for mammary tumors is mutations of the tumor suppressor gene, BRCA2. BRCA2 participates in homologous recombination repair by interacting with the RAD51 recombinase. BRCA2 has two RAD51-binding domains, consisting of BRC repeats and the C-terminal RAD51-binding domain, respectively. Although several studies have addressed the function of the C-terminal RAD51-binding domain of human BRCA2, the amino acid sequences required for the RAD51-interaction activity remain unclear. In this study, the C-terminal RAD51-binding domains of canine and human BRCA2 were compared; the canine domain displayed a weaker interaction with RAD51. This difference was attributed to the C-terminal portion of the domain via a comparison between canine and human domains. Furthermore, peptides shorter than those previously reported displayed RAD51-interacting activity, and a core motif of this domain consisting of 25 amino acids was identified. Since a mutation (S3323N) was reported in the core motif of this domain, the effect of this mutation was evaluated. The mutant exhibited similar RAD51-binding activity as that of the wild-type protein, suggesting that the mutation was functionally neutral. These data suggested that the C-terminal portion of the BRCA2 C-terminal RAD51-binding domain influenced its RAD51-interaction activity, and a minimum core motif of 25 amino acids was identified in this domain. These data may help clarify BRCA2 function, as well as the tumorigenic effects of BRCA2 mutation.     

Involvement of thalamic paraventricular nucleus in the anticipatory reaction under food restriction in the rat

To investigate which brain regions are involved in the anticipatory activity in rats restricted feeding for 2 hr, we examined c-Fos expression before and after feeding. Only the thalamic paraventricular nucleus (tPVN) showed c-Fos expression before feeding than after feeding. After the anticipatory locomotor activity rhythm was established, lesioning the tPVN attenuated this rhythm, but not the light-dark entrained rhythm. The anticipatory increase of blood corticosterone levels was not established in long-term tPVN-lesioned rats. These results suggest that the tPVN is involved in the expression of anticipatory reactions under a food-restricted regimen.     

Mapping of QTLs controlling epicotyl length in adzuki bean (Vigna angularis)

Epicotyl length (ECL) of adzuki bean (Vigna angularis) affects the efficiency of mechanized weeding and harvest. The present study investigated the genetic factors controlling ECL. An F₂ population derived from a cross between the breeding line ‘Tokei1121’ (T1121, long epicotyls) and the cultivar ‘Erimo167’ (common epicotyls) was phenotyped for ECL and genotyped using simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP) markers. A molecular linkage map was generated and fifty-two segregating markers, including 27 SSRs and 25 SNPs, were located on seven linkage groups (LGs) at a LOD threshold value of 3.0. Four quantitative trait loci (QTLs) for ECL, with LOD scores of 4.0, 3.4, 4.8 and 6.4, were identified on LGs 2, 4, 7 and 10, respectively; together, these four QTLs accounted for 49.3% of the phenotypic variance. The segregation patterns observed in F₅ residual heterozygous lines at qECL10 revealed that a single recessive gene derived from T1121 contributed to the longer ECL phenotype. Using five insertion and deletion markers, this gene was fine mapped to a ~255 kb region near the end of LG10. These findings will facilitate marker-assisted selection for breeding in the adzuki bean and contribute to an understanding of the mechanisms associated with epicotyl elongation.     

Detection of avian-like rotavirus A VP4 from a calf in Japan

A total of 568 normal feces from calves on a beef farm in Fukui Prefecture, Japan, in 2011–2012 were examined by RT-semi-nested PCR for rotavirus A (RVA) VP4 genes. Through partial sequencing and BLAST analyses of 84 VP4-positive specimens, we identified an avian-like RVA strain, N2342, which shares highest nucleotide identity (80.0%) with known avian-like bovine strain 993/83, in one specimen. Phylogenetic analysis also revealed a close genetic relationship between N2342 and avian RVAs, suggesting bird-to-cattle transmission. We observed frequent contact of wild birds with calves in the farm, suggesting that these birds were the source of the virus.     

UTS2R gene polymorphisms are associated with fatty acid composition in Japanese beef cattle

Fatty acid composition of beef adipose tissue is one of its important traits because a high proportion of monounsaturated fatty acid is related to favorable beef flavor and tenderness. In this study, we searched polymorphisms in full length coding DNA sequence of urotensin 2 recepter and investigated the effects on fatty acid composition (C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, monounsaturated fatty acid, saturated fatty acid). Eight single nucleotide polymorphisms (SNP) were identified by sequence comparison among eight animals, including five Japanese Black and three Holstein cattle. One of these SNP (c.866C>T) was predicted to cause amino acid substitutions (P289L) and the other seven synonymous SNP, including c.267C>T, were presumed to be in linkage disequilibrium. Therefore we selected two SNP (c.267C>T and c.866C>T) for further analysis. We investigated associations between these genotypes and fatty acid composition in three Japanese Black populations (n = 560, 245 and 287) and a Holstein population (n = 202). Tukey‐Kramer's honestly significant difference test revealed that CC genotype in c.267C>T indicated lower C14:0 and higher C18:1 than the other genotypes in Japanese Black cattle and CC genotype in c.866C>T showed lower C16:1 than CT genotype in Holstein cattle (P < 0.05). These results suggested that these genotypes would contribute to production of high‐grade meat as selection markers in beef cattle.     

Immobilization of Boron and Arsenic in Alkaline Coal Fly Ash through an Aging Process with Water and Elucidation of the Immobilization Mechanism

We previously reported that a simple treatment—addition of only small amounts of water to coal fly ash (CFA) to form CFA paste followed by aging for 1–4 weeks—is advantageous for the immobilization of highly soluble B, F, Cr, and As. In this study, we investigated the leachability of Ca, SO₄, B, and As over time from non-aged and aged CFA samples to elucidate a possible immobilization mechanism. For this purpose, two types of CFA samples, one showing effective immobilization of B and As by water addition and aging (sample A) and the other showing less or no immobilization (sample B), were examined. Calcium and SO₄, B, and As in non-aged sample A dissolved immediately after the start of the leaching test, indicating that these elements existed in highly soluble particles. After the rapid dissolution, their concentrations in the leachate gradually increased, possibly due to the dissolution of glassy phases. During the 1-week leaching test, the B and As concentrations in the leachate finally decreased. The addition of only small amounts of water to CFA (Sample A) for aging produce both alkaline and supersaturation conditions for the formation of several types of Ca-bearing secondary minerals such as calcite and ettringite, which are formed under alkaline conditions. Boron and As originally existing as highly soluble particles in CFA are expected to be incorporated into and/or sorbed on these secondary minerals as water-insoluble phases. Compared to non-aged CFA, their leachability from the aged sample A remained lower throughout the entire leaching test. Possibly due to these secondary minerals being formed on the CFA surface, B and As dissolutions associated with glassy phases are also prevented. In contrast, the pH of the leachate from CFA (sample B) at the beginning of the leaching test was acidic and then abruptly became alkaline. This means that water-soluble particles that can produce acidic conditions are also contained in these alkaline CFAs. Dissolution of these substances during aging makes it difficult to generate alkaline conditions in the CFA paste. Consequently, the formation of secondary minerals and the concomitant immobilization of toxic elements are prevented.     

Dietary carbohydrate effects on histological features of ileal mucosa in White Leghorn chicken

White Leghorn chickens were divided into the control, low-carbohydrate (CHO), and CHO-free groups to investigate dietary CHO’s significance on histological features of chicken ileal mucosa. Paraffin sections of distal ileum from each chicken were stained by periodic acid-Schiff reaction and subjected to morphometrical analysis. Most villi in the control group had a fingerlike shape but those of the experimental groups showed irregular shapes. Villus height, crypt depth and the number of mitotic cells per crypt were significantly lower in the CHO-free group than in the control group. The density of goblet cells also showed a significant decreasing trend with a reduction in dietary CHO level. In conclusion, dietary CHO positively affects the proliferation of epithelial cells in the chicken ileum.     

Evaluation of a rapid coliform detection kit from clinical mastitis milk using colloidal gold nanoparticle–based immunochromatographic strips

The accurate identification of mastitis‐causing bacteria assists in effective management by both dairy farmers and veterinarians and can be used to implement the selective use of antimicrobials for treatment. The purpose of this study was to evaluate the ability of our developed anti–ribosomal protein-L7/L12 antibody–coated immunochromatographic strip (ICS) test to detect coliforms in milk by comparing the results with the bacteriological culture method. We investigated the performance of the ICS test as compared with the bacteriological culture method using 308 milk samples from clinical bovine mastitis. First, to determine the optimal ICS test cutoff point for detecting coliform mastitis, we developed a receiver-operating characteristic curve. The result showed that the cutoff point was at 0.5 of our index. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the ICS test were 81.3%, 84.8%, 69.2%, and 91.54%, respectively. As the clinical signs increased in severity, the F-measure, a weighted harmonic mean of the sensitivity and overall PPV performance, increased. Because it is especially important to treat clinical mastitis appropriately in the early stages of detection, the ICS test, which can be used by both dairy farmers and veterinarians on dairy farms, is considered to be a useful tool for detecting coliform mastitis, which often presents with severe signs.