Effects of Feeding Potato Pulp on Cholesterol Metabolism and Its Association with Cecal Conditions in Rats

To clarify the functional properties of potato pulp (PP), a waste product resulting from extraction of starch from potatoes, we examined the effects of PP on cholesterol metabolism and cecal conditions in rats. Plasma total cholesterol (T-Chol) levels were lower in rats fed a PP-supplemented diet for four weeks than in those fed a control diet. Cecal pH was lowered due to an increase in the levels of cecal total short-chain fatty acids, especially butyrate, in the PP group compared to the control group. Furthermore, animals fed with the PP-supplemented diet showed increased cecal ratios of Lactobacillus and Clostridia and decreased cecal ratios of Bacteroides and Gammaproteobacteria with slightly negative and positive correlations with plasma T-Chol levels, respectively. In conclusion, ingestion of PP for four weeks is likely to improve both cecal conditions and cholesterol metabolism, suggesting that PP has prebiotic effects.     

Evaluation of Si availability in slag fertilizers by an extraction method using a cation exchange resin

A new extraction method for the evaluation of Si availability in slag fertilizers was developed based on findings on the dissolution process of the slags in paddy fields. In the method, the slags were dissolved in water with the addition of a weakly acidic cation exchange resin (H form). The effects of the slag/water ratio, the amount of resin, and temperature on the Si dissolution from the slags were examined in order to determine adequate extraction conditions. The Si dissolution from the slags was enhanced by the addition of the resin. The pH of the extractant was well controlled between 6 and 7 during the extraction. The percentage of the amount of Si extracted by traditional evaluation methods using 0.5 м HCl or an acetate buffer solution to the total amount of Si in the slags was much higher than the Si recovery rate by rice plant (Oryza sativa L. var. Nihonbare) which was measured in our previous study. Moreover, there was no correlation between these values. On the other hand, the percentage of Si extracted by the new method was in the same range as that of the Si recovery rate and a positive correlation was obtained. As a result, Si availability in the slags could be evaluated more precisely by using the method proposed here than by using the traditional methods.     

Starch degradation by alpha-amylase in tobacco leaves during the curing process

Tobacco (Nicotiana tabacum L.) leaf starch is degraded to sugars through curing (42°C/82.3% relative humidity/72 h). Total carbohydrate content remained almost constant, starch content decreased markedly, and soluble sugar content (mostly glucose) increased. α-Amylase and starch phosphorylase activities increased sixfold and threefold, respectively, whereas β-amylase activity was unaltered and isoamylase activity decreased. Increased α-amylase activity was accompanied by increased α-amylase protein levels. Although tobacco has four α-amylase gene members, only NtAMY1 mRNA levels increased. For other starch degradation genes, such as NtBAM1 and NtBMY2 (β-amylase), NtISO1 and NtISO2 (isoamylase) and NtGWD1 and NtGWD3 (glucan water dikinase), the mRNA levels remained unaltered during the first 48 h of curing. NtAMY1 expression was induced by osmotic stress but was unaffected by high temperature and/or injury stresses. Similarly, soluble sugar contents were largely increased by osmotic stress. This suggests that starch is degraded by α-amylase during curing and that α-amylase is coded by NtAMY1, induced by osmotic stress.     

Production of Diabetic Offspring Using Cryopreserved Epididymal Sperm by In Vitro Fertilization and Intrafallopian Insemination Techniques in Transgenic Pigs

Somatic cell nuclear transfer (SCNT) is a useful technique for creating pig strains that model human diseases. However, production of numerous cloned disease model pigs by SCNT for large-scale experiments is impractical due to its complexity and inefficiency. In the present study, we aimed to establish an efficient procedure for proliferating the diabetes model pig carrying the mutant human hepatocyte nuclear factor-1α gene. A founder diabetes transgenic cloned pig was generated by SCNT and treated with insulin to allow for normal growth to maturity, at which point epididymal sperm could be collected for cryopreservation. In vitro fertilization and intrafallopian insemination using the cryopreserved epididymal sperm resulted in diabetes model transgenic offspring. These results suggest that artificial reproductive technology using cryopreserved epididymal sperm could be a practical option for proliferation of genetically modified disease model pigs.     

Application of highly differentiated SNPs between Japanese Black and Holstein to a breed assignment test between Japanese Black and F1 (Japanese Black x Holstein) and Holstein

Two taurine breeds, Japanese Black and Holstein, established from geographically distant origins and selected for different uses, beef and dairy, were extensively genotyped using a genome‐wide single nucleotide polymorphism (SNP) chip with more than 1000 animals of each breed. The genetic structure was examined by principal component analysis, in which the first principal component clearly separated the two breeds and explained more than 15% of the variance. Highly differentiated SNPs were detected throughout the genome, some of which were clustered within small regions on BTA4 (79.2–79.7 Mb, Btau4.0) and BTA26 (22.2–23.6 Mb). A breed assignment test was developed using 18 highly differentiated SNPs to distinguish Japanese Black from F₁ (Japanese Black × Holstein) and Holstein. The error rate that an F₁ or Holstein animal is misjudged as Japanese Black was expected to be < 0.8%, while the error rate that a Japanese Black animal is misjudged as F₁ or Holstein was expected to be < 0.001%. This test provides a reliable and powerful method to detect breed label falsification in retail beef.     

Gentian Kobu-sho-associated virus: a tentative, novel double-stranded RNA virus that is relevant to gentian Kobu-sho syndrome

A virus-like dsRNA of about 23 kbp was detected in gentian plants showing Kobu-sho syndrome including stunting, shortened internodes, and tumors on stems, nodes and roots. Nucleotide sequence analysis has suggested that this dsRNA is related to Pestivirus species but not to any other plant viruses. It was protected from externally added RNase, suggesting that the dsRNA is encapsidated. The dsRNA was co-extracted in a crude homogenate of glutaraldehyde-fixed tissue with the virus-like particles that have been associated previously with Kobu-sho syndrome in gentian (Usugi et al. Jpn J Phytopathol 76:21–24, 2010). The RNA sequence was detected in more than 99 % of Kobu-sho gentian individuals but in less than 20 % of apparently healthy gentian individuals from fields affected with Kobu-sho. Thus, we propose naming the virus Gentian Kobu-sho-associated virus.     

Methanogenic archaeal communities developed in paddy fields in the Kojima Bay polder, estimated by denaturing gradient gel electrophoresis, real-time PCR and sequencing analyses

Methanogenic archaeal communities inhabiting the paddy field soils in the Kojima Bay polder were investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), real-time PCR and sequencing analyses. Soil samples of the plow and subsoil layers were collected in 2006 from four paddy fields that were reclaimed between 1692 and 1954. The DGGE band patterns of the targeted 16S rRNA genes amplified from the extracted DNA from the samples were different from the patterns from the paddy field soils in diluvial and alluvial areas. The numbers of targeted 16S rRNA genes, which were involved with methanogenic archaeal and other archaeal sequences, were approximately 10⁷–10⁸ and 10⁶ g⁻¹ dry soil in the plow and subsoil layers, respectively. Sequences of methanogenic archaeal 16S rRNA genes belonging to Methanocellales (Rice cluster I), Methanosarcinales and Methanobacteriales were obtained from the major DGGE bands. Whereas sequences in Methanomicrobiales, which were predominant methanogens in the diluvial and alluvial paddy fields, were not recovered. Known halophilic and methylotrophic methanogens, which are characteristic of saline and marine environments, were not detected. These results indicate that distinctive methanogenic archaeal communities have developed in the paddy field soils in the Kojima Bay polder.     

Biological nitrification inhibition by Brachiaria humidicola roots varies with soil type and inhibits nitrifying bacteria, but not other major soil microorganisms

The tropical pasture grass Brachiaria humidiola (Rendle) Schweick releases nitrification inhibitory compounds from its roots, a phenomenon termed 'biological nitrification inhibition' (BNI). We investigated the influence of root exudates of B. humidicola on nitrification, major soil microorganisms and plant growth promoting microorganisms using two contrasting soil types, Andosol and Cambisol. The addition of root exudates (containing BNI activity that is expressed in Allylthiourea unit (ATU) was standardized in a bioassay against a synthetic inhibitor of nitrification, allylthiourea, and their function in soil was compared to inhibition caused by the synthetic nitrification inhibitor dicyandiamide. At 30 and 40 ATU g⁻¹soil, root exudates inhibited nitrification by 95% in fresh Cambisol after 60 days. Nitrification was also similarly inhibited in rhizosphere soils of Cambisol where B. humidicola was grown for 6 months. Root exudates did not inhibit other soil microorganisms, including gram-negative bacteria, total cultivable bacteria and fluorescent pseudomonads. Root exudates, when added to pure cultures of Nitrosomonas europaea , inhibited their growth, but did not inhibit the growth of several plant growth promoting microorganisms, Azospirillum lipoferum , Rhizobium leguminosarum and Azotobacter chroococcum. Our results indicate that the nitrification inhibitors released by B. humidicola roots inhibited nitrifying bacteria, but did not negatively affect other major soil microorganisms and the effectiveness of the inhibitory effect varied with soil type.     

Successful blastocyst production by intracytoplasmic injection of sperm after in vitro maturation of follicular oocytes obtained from immature female squirrel monkeys (Saimiri boliviensis)

Advanced reproductive technologies are being applied for the propagation of squirrel monkeys, to ensure their preservation as a genetic resource and the effective use of their gametes in the future. In the present study, oocytes and spermatozoa were collected from live squirrel monkeys, following which piezo intracytoplasmic sperm injection (ICSI) was performed using these gametes. Follicular development was induced by administering equine chorionic gonadotropin (eCG) containing inhibin antiserum to an immature squirrel monkey female. The unilateral ovary was excised after the administration of human chorionic gonadotropin (hCG), to induce ovulation, following which the larger developed follicular oocytes were collected. Follicular oocytes were prepared for ICSI using sperm from the epididymal tail of a unilateral testis extracted from a mature male. The embryos were continuously incubated in CMRL 1066 medium supplemented with 10% (v/v) fetal bovine serum. Embryo culture was performed with cumulus cells. Two experiments of ICSI carried out with three females resulted in 14 mature oocytes from the 49 cumulus-oocyte complexes collected and five embryos, three of which developed into blastocysts. These blastocysts were vitrified, thawed, and transferred to recipient monkeys, but no pregnancies resulted. In conclusion, the present study is the first to successfully produce ICSI-derived blastocysts from MII oocytes obtained by means of hormone administration (a combination of eCG+inhibin antiserum and hCG) and in vitro maturation in immature squirrel monkeys.