Cloning and nucleotide sequencing of the antitumor antibiotic C-1027 apoprotein gene.

The apoprotein gene for a chromoprotein antitumor antibiotic, C-1027, was cloned from the producer strain, Streptomyces globisporus C-1027, and sequenced. The process verified that; (1) the sequence included the entire structural gene directing a precursor of the apoprotein (pre-apoprotein having Met1---Ala33 leader peptide ahead of the apoprotein) and flanking regions, (2) the amino acid sequence of the apoprotein deduced from the base sequence perfectly matched the one based on protein analysis, (3) 3rd letters of the codons were 88% G or C, while the 1st plus the 2nd letters were 63% G or C, (4) the structural gene had 57% homology with that of macromomycin apoprotein (mcmA) while the flanking regions had little homology with the corresponding ones of mcmA, except some homology at the -10th and -35th promoter regions, and (5) the gene was transcribed as a monocistronic mRNA in an early growth phase, independent of chromophore production.     

Administration of retinoic acid to pregnant mice increases the number of fetal mouse glomeruli

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and CKD is a serious global health problem. Low glomerular number is one of the risk factors for CKD; therefore, the glomerular number is associated with the risk of CKD. Increasing the glomerular number above normal levels may reduce the risk of CKD. It has been reported that, in vitro, the addition of retinoic acid (RA) to the culture medium increases the glomerular number. However, there is no report of an increase in glomerular number above normal levels with the addition of RA in vivo. In this study, RA (20 mg/kg) was administered intraperitoneally to pregnant mice once at embryonic day (E) 10.5, E12.5, E14.5, or E16.5. The fetuses were harvested at E18.5 and fetal mouse kidneys were evaluated. Fetal kidney volume and weight were significantly increased in the E16.5 group compared to the control group. The total glomerular number in the E16.5 group was also approximately 1.46 times higher than that in the control group. In summary, we established a method to increase the glomerular number in the fetal kidney by administration of RA to pregnant mice at E16.5. These results will facilitate the investigation of whether CKD risk is reduced when the glomerular number increases above normal.     

Measuring fig foraging frequency of the Yakushima macaque by using automatic cameras

An automatic camera system was employed to reveal the fig foraging frequency of primary seed dispersers on Yakushima Island, southern Japan. Seven automatic cameras were settled on sample branches of Ficus superba (Miq.) Miq. var. japonica Miq. to record animals foraging for figs. Figs on sample branches were counted at approximately 3 day intervals. The cameras took 168 photographs including 155 pictures of Yakushima macaques and two of birds, indicating that most of the figs at the inner parts of the crowns were eaten by the macaques. There was a linear relationship between the number of macaques foraging for figs on sample branches and the number of figs that dis-appeared within each period, suggesting that the automatic camera system was useful for estimating fig loss as a result of the foraging activity of the macaques on a branch basis.     

Effects of carrageenan on immune responses. Studies on the macrophage dependency of various antigens after treatment with carrageenan.

Carrageenan, a sulfated polygalactose having macrophage toxic properties, elicited a marked suppression of IgM response to T cell-dependent antigens such as sheep red blood cells (SRBC), dinitrophenylated bovine serum gamma-globulin (DNP-BGG), and trinitrophenylated concanavalin A (TNP-Con A). In contrast, carrageenan did not inhibit antibody responses to such T cell-independent antigens as trinitrophenylated DEAE-dextran (TNP-DEAE-dextran), trinitrophenylated polyvinyl pyrrolidone(TNP-PVP), and trinitrophenylated Ficoll (TNP-Ficoll). Compared to total spleen cells, spleen cells from which macrophages had been removed by adhesion to plastic Petri dishes had less effect on the production of antibody against T cell-dependent antigens, but no change or a rather stimulated effect was observed in in vitro antibiody synthesis against T cell-independent antigens. These results strongly suggest that macrophages are involved in antibody responses to T cell-dependent antigens but not in those to T cell-independent antigens. However, the antibody response to trinitrophenylated lipopolysaccharide (TNP-LPS), a T cell-independent antigen, was inhibited by carrageenan treatment, suggesting that the response is macrophage dependent. Moreover, antibody response to higher doses of dinitrophenylated phytohemagglutinin (DNP-PHA), a T cell-dependent antigen, was shown to be macrophage independent by carrageenan treatment, although the antibody response to low doses of the antigen was macrophage dependent. Considering all these results, carrageenan treatment seems to be a very useful method to determine whether immune response to various antigens are macrophage dependent or not.     

A highly sensitive method for detection of 32P incorporation into acid-soluble compounds and its application to evaluate ATP-forming ability of Bacillus megaterium QM B1551 spores at the very early stage of germination

A method for specific removal of [32P]orthophosphate (Pi) as phosphomolybdate-triethylamine complex was slightly modified by repeating the Pi precipitation procedures in the presence of unlabeled Pi, which resulted in a complete removal of 32Pi (greater than 99.98%). Using this modified method, we determined 32P incorporation into acid-soluble compounds in order to evaluate the ATP-forming ability of Bacillus megaterium spores at the very early stage of germination. Addition of fructose as a substrate started the 32P incorporation later than a few min after triggering germination. This delay of a few min was well coincident with the onset of 3-phosphoglycerate (3PGA) breakdown, indicating that fructose metabolism and the accompanying aerobic ATP formation were initiated only after fructose phosphorylation by the ATP derived from anaerobic breakdown of endogenous 3PGA. In contrast, addition of glucose started incorporation of 32P into acid-soluble compounds immediately after germination. In the latter case, NADH generated by glucose oxidation to gluconate (catalyzed by glucose dehydrogenase) might serve as an initial ATP source without depending on 3PGA breakdown and glucose metabolism via the Embden-Meyerhof pathway.     

New voyages to explore the natural product galaxy

Journal of Industrial Microbiology & Biotechnology - Natural products are a large family of diverse and complex chemical molecules that have roles in both primary and secondary metabolism, and...