Presence and release of calcitonin gene-related peptide in rat stomach

Immunoreactive (IR)-calcitonin gene-related peptide (CGRP) was identified throughout the entire stomach of rats, being most highly concentrated in the pyloric region, and the concentrations in muscular layers being higher than those in mucosal layers. In addition, IR-CGRP was also present in the venous effluent from isolated perfused rat stomach, and its release was stimulated by dibutyryl cyclic AMP or theophylline but not by glucagon. Gel chromatography as well as HPLC of both tissue extracts and gastric perfusate showed three identical major peaks of IR-CGRP, one of which coeluted with synthetic CGRP. These results suggest that CGRP in the stomach plays a role in the regulation of gastric function.     

The sre gene (ORF469) encodes a site-specific recombinase responsible for integration of the R4 phage genome.

The sre gene (ORF469) of the R4 phage encodes a protein similar to the resolvase-DNA invertase family proteins. Insertional gene disruption of sre prevented a lysogen from entering the lytic cycle, implying that Sre protein is a site-specific recombinase needed for excision of the R4 prophage genome (M. Matsuura, T. Noguchi, T. Aida, M. Asayama, H. Takahashi, and M. Shirai, J. Gen. Appl. Microbiol. 41:53-61, 1995). To determine whether this sre gene is also necessary for the integration reaction, we studied its function by integration plasmid analysis. When deletions, frameshifts, and site-directed mutations that caused an amino acid substitution of Ser-17 for Ala were introduced into the sre structural gene, transformation efficiency of Streptomyces parvulus 2297 with these plasmid DNAs was severely reduced. However, an adenine insertion just before the possible initiation codon of the sre gene did not significantly decrease the efficiency. These data suggest that the Sre protein is a site-specific recombinase responsible for integration of the R4 phage genome.     

Responses of non-spiking giant interneurons to substrate tilt in the crayfish, with special reference to multisensory control in the compensatory eyestalk movement system

In the brain of the intact crayfish, three pairs of non-spiking giant interneurons (G1, G2, G3; NGIs) scarcely responded to substrate tilt about the longitudinal axis of the body either in the dark or in the presence of an overhead light. However, when the statolith was removed, these NGIs responded with depolarizing and hyperpolarizing potentials respectively to upward movements of the ipsilateral legs (2nd–5th pereiopods) and upward movements of the contralateral legs produced by substrate tilt. The relationships between the polarity of the potential and the direction of movement in the contralateral legs were opposite to those in the ipsilateral legs. The amplitude of the responses was proportional to the frequency (0.5-0.05 Hz) and amplitude of tilting. When the legs were moved unilaterally, the NGIs responded with depolarizing and hyperpolarizing potentials to upward movements of the ipsilateral legs and to upward movements of the contralateral legs, respectively. When the legs were moved bilaterally in the same direction by upward or downward movement of the substrate, the NGIs scarcely responded to the leg movements. A hypothetical model is presented to account for the pathways of sensory inputs to the NGIs and the role of NGIs in compensatory oculomotor system.     

Analysis of the Epitopes Recognized by Mouse Monoclonal Antibodies Directed to Yersinia enterocolitica Heat-Shock Protein 60

To determine amino acid sequences of the epitopes recognized by monoclonal antibodies (mAbs) 3C8 and 5C3 directed against Yersinia enterocolitica heat-shock protein (HSP60), a dot blot analysis was perfomed using synthesized peptides of Y. enterocolitica HSP60 such as peptides p316-342, p327-359, p340-366, p316-326, p316-321, p319-323, and p321-326 which represent positions of amino acids in Y. enterocolitica HSP60. The dot blot analysis revealed that 5C3 mAb reacted with p316-342, p316-326 and p321-326, and 3C8 mAb p316-342 and p316-326. These results indicate that the epitopes recognized by the mAbs were associated with eleven amino acids, Asp Leu Gly Gln Ala Lys Arg Val Val Ile Asn, of p316-326. The sequence homology between p316-326 of Y. enterocolitica HSP60 and the rest of the HSP60 family suggests that the five amino acids of Lys, Arg, Val, Ile and Asn, which are highly conserved in the HSP60 family, might be related with the epitope recognized by 3C8. In contrast, it was also demonstrated that three amino acids of Leu, Gly and Val, which are not well conserved in the HSP60 family, might be related to the epitope recognized by 5C3.     

Metabolism and Translocation of Gibberellins in the Seedlings of Pharbitis nil (II). Photoperiodic Effects on Metabolism and Translocation of Gibberellins Applied to Cotyledons

We investigated the metabolism and translocation of two gibberellins(GAs), [³H]GA₂₀ and [³H]GA₁, which were applied at low concentrationto the cotyledons of Pharbitis nil (cv. Violet). Seedlings weregrown under three different photoperiodic conditions: continuouslight (CL-CL), continous light followed by short day conditions(CL-DT) and long day conditions followed by short day conditions(DT-DT). Translocation of the applied [³H]GAs from cotyledonsto hypocotyls was promoted by DT for all GAs examined. Whilethe conversion of the translocated [³H]GA₁ to [³H]GA₈ and itsconjugates was rapid in hypocotyl, the conversion of translocated[³H]GA₂₀ to [³H]GA₂₉ was slow. Radioactivity in epicotyls wasdetected much more rapidly on application of [³H]GA₂₀ than of[³H]GA₁, [³H]GA₈ and [³H]GA₂₉ and their conjugates. The conversionof [³H]GA₂₀ to [³H]GA₁ in the epicotyl was more rapid underCL-CL conditions. This result in consistent with the higherlevel of endogenous GA₁ existing in epicotyls under CL-DT thanDT-DT conditions. However, when [³H]GA₁ was applied to the cotyledon,only small amounts of [³H]GA₈ and its conjugates were detectedin the epicotyl regardless of the photoperiodic conditions.This result may suggest that the translocation and metabolismof [³H]GA₂₀ from cotyledons to epicotyl was faster under CL-CLthan DT-DT conditions and may correlate with the increased epicotylelongation of GA₂₀ treated plants under CL-DT than DT-DT conditions. (Received June 28, 1995; Accepted November 2, 1995)     

Two new loci for hybrid sterility in cultivated rice (Oryza sativa L.)

Female gamete abortion in Indica-Japonica crosses of rice was earlier identified to be due to an allelic interaction at the S-5 locus on chromosome 6. Recently, in other crosses of rice, similar allelic interactions were found at loci designated as S-7 and S-8, located on chromosomes 7 and 6 respectively. All of them are independent of each other. At the S-5 locus, Indica and Japonica rice have S-5 ⁱ and S-5 ^j alleles respectively and Javanicas, such as Ketan Nangka, have a neutral allele S-5 ⁿ .The S-5 ⁱ /S-5 ^j genotype is semi-sterile due to partial abortion of female gametes carrying S-5 ^j , but both the S-5 ⁿ /S-5 ⁱ and S-5 ⁿ /S-5 ^j genotypes are fertile. The S-5 ⁿ allele is thus a wide-compatibility gene (WCG), and parents homozygous for this allele are called wide-compatible varieties (WCV). Such parents when crossed with Indica or Japonica varieties do not show F₁ hybrid sterility. Wide-compatible parents have been used to overcome sterility barriers in crosses between Indica and Japonica rice. However, a Javanica variety, Ketan Nangka (WCV), showed typical hybrid sterility when crossed to the Indian varieties N22 and Jaya. Further, Dular, another WCV from India, showed typical hybrid sterility when crossed to an IRRI line, IR2061-628-1-6-4-3(IR2061-628). By genetic analyses using isozyme markers, a new locus causing hybrid sterility in crosses between Ketan Nangka and the Indicas was located near isozyme loci Est-1 and Mal-1 on chromosome 4, and was designated as S-9. Another new locus for hybrid sterility in the crosses between Dular and the IR2061-628 was identified and was found linked to four isozyme loci, Sdh-1, Pox-2, Acp-1 and Acp-2, on chromosome 12. It was designated as S-15. On the basis of allelic interactions causing female-gamete abortion, two alleles were found at S-9, S-9 ^kn in Ketan Nangka and S-9 ⁱ in N22 and Jaya. In the heterozygote, S-9 ^kn /S-9 ⁱ , which was semisterile, female gametes carrying S-9 ^kn were aborted. The hybrid of Dular and IR2061-628, with a genetic constitution of S-15 ^Du /S-15 ⁱ , was semi-sterile and the female gametes carrying S-15 ^Du were aborted. A Japonica tester variety, Akihikari, and an Indica variety, IR36, were found to have neutral alleles, S-9 nand S-15 n, at these loci, in addition to S-7 nand at S-7. The accumulation of three neutral alleles into a breeding line should help solve the hybrid sterility problem in wide crosses of rice.     

Effect of β-alanyl-L-histidinato zinc on differentiation of osteoblastic MC3T3-El cells: Increases in alkaline phosphatase activity and protein concentration

The effect of -alany-L-histidinato zinc (AHZ) on bone cell function was investigated in osteoblastic MC3T3-E1 cells. Cells were cultured for 3 days at 37°C in a CO₂ incubator in plastic dishes containing -modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus AHZ (10^–7–10^–5 M) or other reagents, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10^–7–10^–5 M) produced a remarkable increase of alkaline phosphatase activity and protein concentration in osteoblastic cells. Thus increases were seen with the prolonged cultivation (12–21 days). With the culture of 1, 3 and 12 days, the effect of AHZ (10^–6 M) to increase alkaline phosphatase activity and protein concentration was more intensive than the effect of zinc sulfate, (10^–6 M). The AHZ effects were completely abolished by the presence of cycloheximide (10^–6 M), indicating that AHZ stimulates protein synthesis in the cells. The present study suggests that AHZ has a stimulatory effect on cell differentiation, and that this effect is partly involved on protein synthesis in osteoblastic cells.     

Tumor Necrosis Factor-α (TNF-α), Interferon-γ, and Interleukin-6 but Not TNF-β Induce Differentiation of Neuroblastoma Cells: The Role of Nitric Oxide

Abstract: Tumor necrosis factor-a (TNF-α), interferon-γ (IFN-7), and interleukin-6 (IL-6), but not TNF-β, can induce the in vitro differentiation of the neuroblastoma cell line N103 in a dose-dependent manner. Differentiation of N103 was accompanied by the arrest of cell growth and neurite formation. The induction of neuroblastoma cell differentiation by TNF-α and IFN-γ can be specifically inhibited by a nitric oxide (NO) synthase inhibitor, l -N^G-monomethylarginine. In contrast, the differentiation of N103 cells by IL-6 was not affected by l -N^G-monomethylarginine. These results indicate that TNF-α and IFN-γ, but not IL-6, induce the differentiation of neuroblastoma cells via NO. This is confirmed by the finding that the culture super- natants of N103 cells induced by TNF-α and IFN-γ, but not that by IL-6, contained high levels of NO₂⁻, the production of which was inhibited by l - N ^G-monomethylarginine. Furthermore, the differentiation of N103 cells can be induced directly in a dose-dependent manner by the addition of nitroprusside, a generator of NO, into the culture medium. These data therefore indicate that NO may be an important mediator in the induction of neuronal cell differentiation by certain cytokines such as TNF-α and IFN-γ and that neuronal cells, in addition to the macrophagelike brain cells, can be induced by immunological stimuli to produce large quantities of NO.     

A Serine Protease in Soybean Seeds That Acts Specifically on the Native {alpha} Subunit of {beta}-Conglycinin

A proteolytic activity directed against the