Natural hybridization between two Japanese medaka species (<Emphasis Type="Italic">Oryzias latipes</Emphasis> and <Emphasis Type="Italic">Oryzias sakaizumii</Emphasis>) observed in the Yura River basin,Kyoto, Japan

To determine the actual state of hybridization between two Japanese medaka species (Oryzias latipes and Oryzias sakaizumii) in their natural environment, we used nuclear DNA markers at 10 loci to analyze 215 individuals from eight wild populations in the middle reaches of the Yura River basin in Japan, where the two species are sympatric. Despite large genetic differentiation between the two species, reproductive isolation between them could not be confirmed. We also discussed the formation of the current distribution patterns of the two species and their hybridization zone in the Yura River basin.     

The ter mutation first causes primordial germ cell deficiency in ter/ter mouse embryos at 8 days of gestation

The ter (teratoma) mutation causes primordial germ cell (PGC) deficiency in ter/ter embryos at 9.5–12.5 days of post-coitum (dpc) in mouse strains 129/Sv- ter and LTXBJ- ter . To study the effects of the ter mutation on the PGC development more precisely, we examined the PGC number and distribution in 7.5–12.5 dpc embryo of ter congenic C57BL/6J- ter strain using their complete serial sections. The ter genotypes of embryos were identified by the polymerase chain reaction (PCR) polymorphisms of the microsatellite DNA of the Grl -1 locus mapped near the ter locus. Results showed that: (i) the PGC number in ter/ter embryos was similar to those of + / ter and + / + embryos at 7.5 dpc, and did not increase at 8.0–12.5 dpc, although those of normal littermates did usually; (ii) the PGC migration to genital ridges was never affected in all embryos; and (iii) the ter genotype difference in the PGC numbers was not recognized between + / ter and + / + embryos. We concluded that the ter mutation does not affect the PGC appearance around 7.5 dpc, but first causes PGC deficiency around 8.0 dpc at the beginning of their migration and proliferation, suggesting that the normal function of the ter gene may be essential for the proliferation or survival mechanisms of PGC.     

Mapping of cyclosporin A binding sites in cyclophilin A by using synthetic peptides

In order to map cyclosporin A (CsA) binding sites of cyclophilin (CyP), we synthesized the complete set of overlapping 157 octapeptides corresponding to human CyP A using the multi-pin peptide synthesis system. The pin-coupled synthetic octapeptides were examined in terms of binding ability to CsA by a modification of the enzyme-linked immunosorbent assay. Significant binding of CsA was detected with 35 synthetic N alpha-acetylated octapeptides possessing the N-terminal amino acids corresponding to the residues in positions 24-26, 42-44, 69-73, 75, 76, 89-91, 102, 116, 124-131, 144-151 and 152 in human CyP A, respectively. Other eight octapeptides showed moderate CsA binding activity. The distinct binding of octapeptides covering the C-terminal region of the CyP A was particularly significant. These data are to be compared with the information provided by X-ray and NMR studies on the CsA binding sites and furnish thus a test of the reported method. The present study also gave added insight into the CsA interaction sites of CyP.     

Juvenile development of a flathead,Suggrundus meerdervoortii (Scorpaeniformes: Platycephalidae)

Juvenile development ofSuggrundus meerdervoortii was described, based on twelve specimens (12.9–43.8 mm SL) collected from off Yamagata Prefecture, Japan Sea. Two exterior openings in the lateral line scales were completed at ca. 35 mm SL, with the interopercular flap and iris lappet being visible at ca. 44 mm SL, these all being useful taxonomic characters. In juveniles and additional young and adult specimens (ca. 70–191 mm SL), the proportions of head length, snout length, orbital diameter, caudal peduncle depth and caudal fin length decreased with growth; interorbital width decreased rapidly until ca. 70 mm SL, but more or less stabilised thereafter (70–191 mm SL).     

Comprehensive analysis of the Co-structures of dipeptidyl peptidase IV and its inhibitor

Background

We comprehensively analyzed X-ray cocrystal structures of dipeptidyl peptidase IV (DPP-4) and its inhibitor to clarify whether DPP-4 alters its general or partial structure according to the inhibitor used and whether DPP-4 has a common rule for inhibitor binding.

Results

All the main and side chains in the inhibitor binding area were minimally altered, except for a few side chains, despite binding to inhibitors of various shapes. Some residues (Arg125, Glu205, Glu206, Tyr662 and Asn710) in the area had binding modes to fix a specific atom of inhibitor to a particular spatial position in DPP-4. We found two specific water molecules that were common to 92 DPP-4 structures. The two water molecules were close to many inhibitors, and seemed to play two roles: maintaining the orientation of the Glu205 and Glu206 side chains through a network via the water molecules, and arranging the inhibitor appropriately at the S2 subsite.

Conclusions

Our study based on high-quality resources may provide a necessary minimum consensus to help in the discovery of a novel DPP-4 inhibitor that is commercially useful.

     

Roles of aldo-keto reductases 1B10 and 1C3 and ATP-binding cassette transporter in docetaxel tolerance

Docetaxel (DTX) is widely used for treatment of inveterate lung and prostate cancers, but its continuous administration elicits the hyposensitivity. Here, we established the DTX-resistant variants of human lung cancer A549 and androgen-independent prostate cancer Du145 cells and found that the resistance development provoked aberrant up-regulations of aldo-keto reductase (AKR) 1B10 and AKR1C3 in A549 and Du145 cells, respectively. In addition, the sensitivity to the DTX toxicity was significantly decreased and increased by overexpression and knockdown of the two AKR isoforms, respectively. Furthermore, the resistant cells exhibited a decreased level of reactive 4-hydroxy-2-nonenal formed during DTX treatment, and the decrease was alleviated by adding the AKR inhibitors, inferring that the two AKRs confer the chemoresistance through elevating the antioxidant properties. The development of DTX resistance was also associated with enhanced expression of an ATP-binding cassette (ABC) transporter ABCB1 among the ABC transporter isoforms. The combined treatment with inhibitors of the two AKRs and ABCB1 additively sensitized the resistant cells to DTX. Intriguingly, the AKR1B10 inhibitor also suppressed the lung cancer cross-resistance against cisplatin. The results suggest that combined treatment with AKRs (1B10 and 1C3) and ABCB1 inhibitors exerts overcoming effect against the cancer resistance to DTX and cisplatin, and can be used as the adjuvant therapy.     

Presence of the Novel Pituitary Protein „7B2” in Bovine Chromaffin Granules: Possible Co-Release of 7B2 and Catecholamine as Induced by Nicotine

We observed the presence of the novel pituitary protein "7B2" and its release in the bovine adrenal medulla. The 7B2 concentration (mean +/- SEM) in extracts of the bovine adrenal medulla was 952 +/- 155 pg/mg tissue (n = 6). 7B2 was distributed in the chromaffin granule fraction prepared from the bovine adrenal medulla and was released by high K+ and/or nicotine from cultured cells of the bovine adrenal medulla. Co-release of 7B2 with catecholamine induced by nicotine from the cultured bovine chromaffin cells was also observed. In an analysis of the bovine adrenal medulla chromaffin granule fraction on gel permeation chromatography, there was a major peak with an apparent molecular weight of 45,000, whereas a major peak with an apparent molecular weight of 20,000 was found in that on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. On reverse-phase HPLC, a major peak with a retention time of 35 min was observed in the bovine chromaffin granule fraction and in the bovine anterior pituitary extract. These findings indicate that 7B2 is a secretory protein in the bovine adrenal medulla. The possibility that 7B2 might be released with catecholamine, possibly in response to stress, warrants investigation.     

Lipopolysaccharides of Group F,a new group of vibrios

The sugar composition of the O-antigenic lipopolysaccharides isolated from Group F vibrios was analysed. 2-Keto-3-deoxy-octonate was totally absent from the lipopolysaccharides. As common component sugars, glucose, galactose, L-glycero-D-mannoheptose, and glucosamine were present. The Group F vibrios examined were found to be divided into two groups, designated tentatively as groups I and II, on the basis of the pattern of the sugar composition of their lipopolysaccharides. As additional sugar components, mannosamine, quinovosamine and two unidentified amino sugars, F1 and F2, were present in group I, while rhamnose, galactosamine, an unidentified amino sugar, F3, and a relatively high content of D-glycero-D-mannoheptose were found in group II.     

Molecular cloning and sequencing of cDNA encoding urinary stone protein, which is identical to osteopontin.

We have sequenced a cDNA of urinary stone protein. cDNA sequences show complete homology between urinary stone protein and human osteopontin (bone sialoprotein) (nucleotides 265-886 and 1183-1424). Osteopontin is a recently discovered bone matrix protein which has been implicated in mediating mineral formation within bone extracellular matrix. This result shows that osteopontin is presumably involved in stone formation as stone matrix.     

Effect of certain growth factors on proliferation in serum-free collagen gel culture of vaginal epithelial cells from prepuberal mice exposed neonatally to diethylstilbestrol

Neonatal treatment with diethylstilbestrol (DES) induces ovary-independent vaginal epithelial changes in mice. The response of vaginal epithelial cells from intact prepuberal BALB/cCrgl mice treated neonatally with 2 micrograms of DES for 5 days to growth-stimulatory and -inhibitory factors was studied using a serum-free collagen gel culture system that sustains the growth of normal vaginal epithelial cells. Cells from control and DES-exposed mice at 21 days of age showed about a 5-fold increase in number during 10 days in a serum-free medium supplemented with transferrin, bovine serum albumin fraction V, insulin, and epidermal growth factor. Epidermal growth factor and insulin stimulated dose-related proliferation of vaginal epithelial cells from both control and DES-exposed mice; however, cells from DES-exposed mice showed a reduced growth response to epidermal growth factor and an increased growth response to insulin, compared with control cells. Insulin-like growth factor I (1-100 ng/ml) tested in the absence of insulin failed to stimulate cell growth. Transforming growth factor-beta (0.05-5 ng/ml) consistently inhibited cell growth in a dose-dependent manner.