Genetic and phenotypic characterization of a Japanese wild-derived DOB/Oda rat strain

Wild-derived rat strains can provide novel genome resources that are not available in standard laboratory strains. Genetic backgrounds of wild-derived strains can facilitate effective genetic linkage analyses and often modulate the expression of mutant phenotypes. Here we describe the development and characterization of a new inbred rat strain, DOB/Oda, from wild rats (Rattus norvegicus) captured in Shitara, Aichi, Japan. Phenotype analysis of 109 parameters revealed that the DOB/Oda rats had small body weight, preference for darkness, and high locomotor activity compared with the rat strains in the National BioResource Project for the Rat (NBRP-Rat) database. Genome analysis with 357 SSLP markers identified DOB/Oda-specific alleles in 70 markers. The percentage of SSLP markers that showed polymorphism between the DOB/Oda strain and any of 132 laboratory strains from NBRP-Rat varied from 89 to 95 %. The polymorphic rate (average of the values of the percentage) for the DOB/Oda strain was 91.6 %, much higher than the rates for available wild-derived strains such as the Brown Norway rat. A phylogenic tree constructed with DOB/Oda and all the strains in NBRP-Rat showed that the DOB/Oda strain localized within the wild rat groups, apparently separate from the laboratory strains. Together, these findings indicated that the DOB/Oda rat has a unique genome that is not available in the laboratory strains. Therefore, the new DOB/Oda strain will provide an important genome resource that will be useful for designing genetic experiments and for the discovery of genes that modulate mutant phenotypes.     

An NAD(P)H Model Reaction: Reduction of α-Keto Esters by the Hantzsch Ester Accelerated by Zinc Complex in the Reformatsky Mixture

Aiming to get useful steroidal alkaloids by tissue culture of Solanum laciniatum Ait., indefinitely growing callus tissue was prepared from the mother plant. Some nutritional requirements for the growth of the callus tissue were studied. By examining steroidal compounds in callus culture, cholesterol, stigmasterol, β-sitosterol, lanosterol, squalene, diosgenin and a new steroidal alkaloid were found to be formed in the callus culture. The new steroidal alkaloid was found to be solasodine derivative containing rhamnose and other unidentified sugars.     

Purification and Properties of an S-PI(Pepstatin Ac)-insensitive Carboxyl Proteinase from a Xanthomonas sp. Bacterium

A S-PI(Pepstatin Ac)-insensitive carboxyl proteinase was found in culture filtrate of a Xanthomonas sp. bacterium. The carboxyl proteinase was highly purified and about 100 mg of the enzyme was obtained from 601 of culture filtrate, with a recovery of 25%. The optimum condition for the action of the purified enzyme toward casein was approx. pH 2.7 and its activity was not inhibited by any of such carboxyl proteinase inhibitors as Pepstatin, S-PI, and DAN but EPNP inhibited it. Such behavior of the enzyme against inhibitors resembles that of Pseudomonas sp. carboxyl proteinase, the first found from a bacterium. Some differences were observed, however, in their properties such as optimum pH, isoelectric point, and amino acid composition.     

Availability of Energy in Alcohols,Aldehydes and Ketones by Growing Chicks

Biological availability of 23 alcohols, 16 aldehydes and 2 ketones was compared by the mini-test with chicks. Chicks can utilize methanol and ethanol, but not the alcohols of carbon chain from 3 to 9. Lauryl and myristyl alcohols were well utilized but those of higher carbon chain than 14 were not, mainly due to low digestibility. Glycerol and D-sorbitol were well utilized but not 4 other poly alcohols tested. Aldehydes and ketones with free carbonyl group showed low availability or even toxicity, but their derivatives with masked group showed no detrimental effect. Acetaldehyde, acetal and aldehydes of carbon chain longer than 9 were partially utilized.     

Availability of Energy in Ester and Ether Derivatives of Glycols by Growing Chicks

Biological availability of 33 esters, 17 ethers and 2 acetals of ethanediol, 1,2-propanediol, 1,3-butanediol and 1,4-butanediol was compared by mini-test with chicks. Chicks can utilize esters of ethanediol, 1,2-propanediol and 1,3-butanediol with acetic acid and fatty acids of carbon chain length from 5 to 12 with more improved palatability than that of free acids, while availability of esters of these glycols with propionic and butyric acids was low. Esters of 1,4-butanediol and ether derivatives of these glycols was not available, except ethyl ether of di-ethanediol which was partially available. Acetacetal of ethanediol was partially available but n-butyracetal was not.     

Studies on the Polyuronide of Oh-gyo-tye (The Achine of Ficus awkeotsang MAKINO)

A polyuronide, main component of the water extract of achine of Ficus awkeotsang MAKINO (on-gyo-tye), was purified by ion-exchange chromatography on DEAE-cellulose. The polyuronide (Fraction IB) is homogeneous electrophoretically and consists mainly of galacturonic acid. Optical rotation of Fraction IB is and content of methoxyl group is trace. In periodate oxidation of Fraction IB, molar ratio of galacturonic acid residue and periodate consumption was 1, and formic acid formation was very small. Periodate oxidation product of Fraction IB was oxidized further with bromine and the resulted substance was hydrolyzed. In the hydrolyzate, presence of large amount of tartaric and glyoxylic acids and small amount of tartronic acid were detected by paper chromatography. Reduced viscosity of aquous solution of Fraction IB increased with decreasing of the concentration of Fraction IB solution. From these results, it was deduced that Fraction IB has a linear structure of 1→4 linkage of d-galacturonic acid, probably α-linkage.     

Total Synthesis of Nodakenetin and Marmesin

Nodakenetin and marmesin were synthesized from β-resorcylaldehyde through 2-(α-hy-droxyisopropyl)-6-hydroxycoumaran.     

Streptomyces Pepsin Inhibitor-Insensitive Carboxyl Proteinase from Lentinus edodes

A Streptomyces-pepsin inhibitor (S-PI or Pepstatin Ac), and DAN-insensitive carboxyl proteinase was found in a still culture filtrate of Lentinus edodes. The new carboxyl proteinase was purified, and about 9 mg purified enzyme was obtained from 19 liters of culture filtrate, with 11% recovery. The enzyme showed a single band on polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were 40,000 and pH 4.2, respectively. The enzyme did not contain histidine and was composed of 387 amino acid residues. The enzyme was most active between pH 2.7 ~ 2.9, and stable over a pH of 3.2 ~ 5.2 for 3 hr at 37°C. The enzyme was not inhibited by S-PI or synthetic pepsin inhibitors such as DAN and EPNP. The physicochemical and enzymological properties were very similar to those of Scytalidium lignicolum carboxyl proteinase A, which was reported to be an S-PI-, and DAN-insensitive carboxyl proteinase.     

Bio-functional pickles that reduce blood pressure of rats

Addition of γ-aminobutyric acid (GABA) and angiotensin converting enzyme (ACE)-inhibitory peptides to the pickles was studied in order to develop a new type of pickles that reduce blood pressure. Based on the outcome of these studies, a new type of fermentation bed composed of rice bran and white miso has been successfully developed. The advantage of such pickles is that they not only contain both GABA and ACE-inhibitory peptides, but also that their taste and flavor are excellent, with colors close to the original ones. The new type of pickles could temporarily reduce blood pressure in two types of rats, spontaneously hypertensive rats and NaCl-sensitive model rats. Thus, the newly developed pickles appear to be beneficial for pickle business.