Conformational change in hamster scrapie prion protein (PrP27-30) associated with proteinase K resistance and prion infectivity

The scrapie prion protein (PrP27-30) is a crucial component of the prion and is responsible for its transmissibility. Structural information on this protein is limited because it is insoluble and shows aggregated properties. In this study, PrP27-30 was effectively dispersed using sonication under the weak alkaline condition. Subsequently, the small PrP27-30 aggregates were subjected to different pH, heat, and denaturing conditions. The loss of proteinase K (PK) resistance of PrP27-30 and prion infectivity were monitored along with spectroscopic changes. Prion inactivation could not be achieved by the loss of PK resistance alone; a significant loss of the PrP27-30 amyloid structure, which was represented by a decrease in thioflavin T fluorescence, was required for the loss of transmissibility.     

Changes in the Expression Patterns of the Genes Involved in the Segregation and Function of Inner Cell Mass and Trophectoderm Lineages During Porcine Preimplantation Development

In mouse embryos, segregation of the inner cell mass (ICM) and trophectoderm (TE) lineages is regulated by genes, such as OCT-4, CDX2 and TEAD4. However, the molecular mechanisms that regulate the segregation of the ICM and TE lineages in porcine embryos remain unknown. To obtain insights regarding the segregation of the ICM and TE lineages in porcine embryos, we examined the mRNA expression patterns of candidate genes, OCT-4, CDX2, TEAD4, GATA3, NANOG, FGF4, FGFR1-IIIc and FGFR2-IIIc, in blastocyst and elongated stage embryos. In blastocyst embryos, the expression levels of OCT-4, FGF4 and FGFR1-IIIc were significantly higher in the ICM than in the TE, while the CDX2, TEAD4 and GATA3 levels did not differ between the ICM and TE. The expression ratio of CDX2 to OCT-4 (CDX2/OCT-4) also did not differ between the ICM and TE at the blastocyst stage. In elongated embryos, OCT-4, NANOG, FGF4 and FGFR1-IIIc were abundantly expressed in the embryo disc (ED; ICM lineage), but their expression levels were very low in the TE. In contrast, the CDX2, TEAD4 and GATA3 levels were significantly higher in the TE than in the ED. In addition, the CDX2/OCT-4 ratio was markedly higher in the TE than in the ED. We demonstrated that differences in the expression levels of OCT-4, CDX2, TEAD4, GATA3, NANOG, FGF4, FGFR1-IIIc and FGFR2-IIIc genes between ICM and TE lineages cells become more clear during development from porcine blastocyst to elongated embryos, which indicates the possibility that in porcine embryos, functions of ICM and TE lineage cells depend on these gene expressions proceed as transition from blastocyst to elongated stage.     

Effect of lodging on the level of mycotoxins in wheat,barley, and rice infected with the <Emphasis Type="Italic">Fusarium graminearum</Emphasis> species complex

Lodging is one possible risk factor that leads to increased cereal mycotoxin contamination, but few reports have been published on the subject. We examined the effects of lodging on the level of deoxynivalenol (DON) and nivalenol (NIV) contamination in wheat, barley, and rice infected with the Fusarium graminearum species complex. Case-control and intervention studies were applied to test the hypothesis that lodging increases the level of mycotoxin contamination. A total of 66 grain samples were collected from each field in 12 Japanese prefectures from 2002 to 2006. Each sample set consisted of grains from lodged and nonlodged plants. The concentration of DON + NIV in lodged plants was significantly higher than in nonlodged plants. All samples of wheat and barley were contaminated with DON and NIV; however, most of the lodged rice samples were contaminated only with NIV. In intervention trials to investigate the effects of lodging duration, a small area of wheat inoculated with the pathogen was completely lodged by trampling. Even with 5 days of lodging, the levels of DON + NIV in wheat grain at harvest increased by 27–51% compared to nonlodged control plots. For rice, half of each plot area was completely lodged by trampling 20 days before harvest. The level of NIV in lodged rice grain was significantly higher than that in nonlodged rice at optimum and delayed harvests, because lodging significantly increased the level of Fusarium mycotoxins in the three crops. Thus, practices (e.g., rational use of fertilizers) to avoid lodging should reduce the risk of mycotoxin contamination. This is the first epidemiological study on the effect of lodging on mycotoxin production by the F. graminearum species complex in wheat, barley, and rice.     

Biology of the prolactin family in bovine placenta. II. Bovine prolactin-related proteins: Their expression, structure and proposed roles

The placenta produces various peptides and steroid hormones that regulate placental function and fetal growth. Prolactin‐related proteins are peptides that are produced by the placenta and belong to the growth hormone/prolactin family, and have structural similarity to prolactin and placental lactogen. Although several prolactin‐related protein genes have been detected in bovine placenta, their expression profiles and functions are not clear. The main difficulties in examining their biological function is the similarity between their genes and the lack of information about their proteins. Recently, molecular biology methods have been used to detect some new bovine prolactin‐related proteins, and elucidate their biological functions. This review focuses on the structures, expression profiles and conceivable functions of prolactin‐related proteins in bovine placenta. With respect to their expression profiles, bovine prolactin‐related proteins fall into four groups: (i) those expressed around the implantation period; (ii) those that reach peak expression in the middle of gestation; (iii) those that increase with the progress of gestation, reaching a peak in late gestation; and (iv) those that reach a plateau in early gestation and are maintained at that level throughout gestation. Data indicate that bovine prolactin‐related proteins have different biological roles in different periods of gestation. In situ monitoring suggests that bovine prolactin‐related protein‐I has a role in the attachment of trophoblast cells to endometrium during the early implantation period.     

Effects of photoperiod on the secretion of growth hormone in female goats

The aim of the present study was to clarify the effect of photoperiod on the secretion of growth hormone (GH) in goats. Adult female goats were kept at 20°C with an 8‐h or 16‐h photoperiod, and secretory patterns of GH for 4 h (12.00 to 16.00 hours) were compared. In addition, the goats were kept under a 16‐h photoperiod and orally administered saline (controls) or melatonin, and the effects of melatonin on the secretion of GH were examined. GH was secreted in a pulsatile manner. There were no significant differences in pulse frequency between the 8‐ and 16‐h photoperiods; however, GH pulse amplitude tended to be greater in the group with the 16‐h photoperiod (P = 0.1), and mean GH concentrations were significantly greater in the 16‐h photoperiod (P < 0.05). The GH‐releasing response to GH‐releasing hormone (GHRH) was also significantly greater for the 16‐h photoperiod (P < 0.05). There were no significant differences in GH pulse frequency between the saline‐ and melatonin‐treated groups. However, GH pulse amplitude and mean GH concentrations were significantly greater in the saline‐treated group (P < 0.05). The present results show that a long photoperiod enhances the secretion of GH, and melatonin modifies GH secretion in female goats.     

Strength properties of glued laminated timber made from edge-glued laminae I: strength properties of edge-glued karamatsu (Larix kaempferi) laminae

The object of this study was to investigate the strength properties of edge-glued laminae and to propose a suitable grading method based on the lamina modulus of elasticity (MOE). Edge-glued laminae composed of lumber with similar MOEs (uniform laminae) and edge-glued laminae produced by randomly gluing lumber independent of MOE (random laminae) were made from karamatsu (Larix kaempferi) lumber having the same thickness and length, but various widths. For both the uniform and random laminae, there was a strong correlation between MOE values measured using the longitudinal vibration technique, the static bending test, and a grading machine. The average values of bending, tensile, and compressive strengths of the uniform laminae were similar to those of the random laminae. On the other hand, the average strength of laminae without end joints was significantly higher than that of finger-jointed laminae for both uniform and random laminae. Finger-joints and knots played a significant role in the failure of specimens, but the edge-gluing and the difference in MOE within an edge-glued lamina did not appear to affect the strength properties. The bending, tensile, and compressive strengths of edge-glued laminae were strongly correlated to the lamina MOE.     

Kazusa Marker DataBase: a database for genomics,genetics, and molecular breeding in plants

In order to provide useful genomic information for agronomical plants, we have established a database, the Kazusa Marker DataBase (http://marker.kazusa.or.jp). This database includes information on DNA markers, e.g., SSR and SNP markers, genetic linkage maps, and physical maps, that were developed at the Kazusa DNA Research Institute. Keyword searches for the markers, sequence data used for marker development, and experimental conditions are also available through this database. Currently, 10 plant species have been targeted: tomato (Solanum lycopersicum), pepper (Capsicum annuum), strawberry (Fragaria × ananassa), radish (Raphanus sativus), Lotus japonicus, soybean (Glycine max), peanut (Arachis hypogaea), red clover (Trifolium pratense), white clover (Trifolium repens), and eucalyptus (Eucalyptus camaldulensis). In addition, the number of plant species registered in this database will be increased as our research progresses. The Kazusa Marker DataBase will be a useful tool for both basic and applied sciences, such as genomics, genetics, and molecular breeding in crops.     

Foliar disease resistant and productive mutants from the introgression lines of peanut (Arachis hypogaea)

With an objective of developing the induced mutants for superior productivity and resistance to foliar diseases in peanut, two introgression lines (IL-3 and IL-4) derived from ABK genomes of peanut were subjected to gamma and sodium azide mutagenesis. Evaluation of M₁, M₂ and M₃ generations could identify foliar disease resistant and productive mutants. Large-scale evaluation of M₄ mutants during the rainy season of 2017 confirmed the superiority of 12 mutants over the respective parents and the best check (GPBD 4). The selected mutants were resistant to leaf spots (early and late) and rust diseases, and significantly more productive than the parents and GPBD 4. ddRAD-Sequencing of these mutants identified the single nucleotide polymorphisms (SNPs) when compared to their parents. The genes harbouring these structural mutations were also identified. However, no copy number variations (CNVs) were observed between the mutants and the parents. The selected mutants carried resistant-type alleles at the marker loci linked to foliar disease resistance. These promising mutants (M₈) are currently under initial trials of variety development for commercial release.