Location of nuclear antigen(s) recognized by DSB389 MAb, a monoclonal antibody against desmin, observed by confocal laser scanning fluorescence microscopy

The location of antigen(s) of DSB389 MAb, a monoclonal antibody which was raised against an intermediate filament protein, desmin, was investigated in HeLa S3 cells by indirect immuno-electron microscopy and by confocal laser scanning fluorescence microscopy. At interphase, the antigen(s) locates mainly in the intra-nuclear space adjacent to chromatin and sometimes near the nuclear periphery. At mitosis, they locate at the periphery of the chromosomes -first at each chromosome, then around the mass of chromosomes. The antigen(s) are thought to be a component of one type of nuclear matrix which is present outside both chromatin and chromosomes and which has some structural role(s) in organizing them in the nucleus or in the nuclear region.     

Occurrence and induction of spermidine-N1-acetyltransferase in Escherichia coli

Spermidine acetylase activity was detected in extracts prepared from $\text{Escherichia coli}$ and there was a marked increase in activity over the early period of growth. This increase reached a maximum 3 h after inoculation and was followed by an increase in ornithine decarboxylase activity. The acetylase was also able to use spermine as a substrate, but not putrescine. With spermidine and acetyl-CoA as substrate, the product formed was exclusively N¹-acetyl-spermidine. This is the first evidence for the occurrence in bacteria of spermidine-N¹-acetyltransferase, an enzyme which has previously been described in mammalian cells. These results suggest that acetylation of spermidine may be involved in the growth of $\text{Escherichia coli}$ and in the regulation of its polyamine content.     

Chemical modification of pig liver initiation factor eIF-2 with N-ethylmaleimide. Amino acid sequences around the N-ethylmaleimide-reactive sulfhydryl groups and the effect of GDP on the modification

The activity of eukaryotic initiation factor eIF-2 as to the formation of the ternary complex, eIF-2 GTP Met-tRNA(f), is inhibited by N-ethylmaleimide. Our preparation of pig liver eIF-2 contained alpha and gamma subunits and was inhibited by more than 90% by N-ethylmaleimide. Using our eIF-2, we determined the sequences around the N-ethylmaleimide-reactive sulfhydryl groups, studied the effect of GDP on the sulfhydryl modification and that of NEM on the [3H]GDP binding, and examined the protective effect of GTP against the inhibition of ternary complex formation by N-ethylmaleimide. Both subunits of native eIF-2 contained [14C]N-ethylmaleimide-reactive sulfhydryl groups. One N-ethylmaleimide-reactive sulfhydryl group was in the alpha subunit and 4 were in the gamma subunit. The sequence of the peptide of the alpha subunit was determined to be: Ala-Gly-Leu-Asn-Cys-Ser-Thr-Glu-Thr-Met-Pro-Ile. Two of the four [14C]N-ethylmaleimide-reactive sulfhydryl groups in the gamma subunit were highly reactive, their sequences being: Ile-Val-Leu-Thr-Asn-Pro-Val-Cys-Thr-Glu-Val-Gly-Glu-Lys (gamma 1); Ser-Cys-Gly-Ser-Ser-Thr-Pro-Asp-Glu-Phe-Pro-Thr-Asp-Ile-Pro-Gly-Thr-Lys (gamma 3a). Peptide gamma 3a contained the consensus sequence element (AspXaaXaaGly) of GTP-binding proteins. With preincubation of eIF-2 with GDP, the incorporation of [14C]N-ethylmaleimide into the gamma subunit was reduced to 40% of the control level, but the 14C-incorporation into the alpha subunit did not change.(ABSTRACT TRUNCATED AT 250 WORDS)     

Higher susceptibility to osmolality of the medaka (Oryzias latipes) mutants in orthologue genes of mammalian skin transglutaminases

Transglutaminase (TG) is an essential enzyme to catalyze cross-linking reactions of epidermal proteins. Recently, we biochemically characterized human skin TG orthologues for medaka (Oryzias latipes), a model fish. By genome editing, gene-modified fishes for the two orthologues were obtained, both of which lack the ordinal enzymes. These fish appeared to exhibit higher susceptibility to osmolality at the period of larvae.     

Length-weight relationships of six Nemacheilid fish species (Teleostei: Cypriniformes) from different rivers of Manipur,India

The length-weight relationships (LWRs) of six Nemacheilid species (Schistura chindwinica, S. fasciata, S. khugae, S. minuta, S. reticulata and S. rubrimaculata) have been analyzed. Fish samples were collected on quarterly basis from March 2018 to February 2019. Sampling was performed using cast nets (mesh size 5–10 mm; about 50 sq m area covered each time and water depth was 4 ft approx.), and electrofishing (Ultrasonic Inverter Electro Fisher, 24 volts, 4 m) in the day time. The total length (TL) of individual fish was measured to 0.1 cm with a digital caliper and body weights (BW) were measured to 0.001 g with digital electronic balances. The parameters for the LWR equations were calculated, and the respective statistics such as the 95% confidence interval for parameters “a” and “b” are provided as well as the coefficient of correlation. For five species a new maximum total length has been documented.     

Patterns of genetic diversity of mitochondrial DNA within captive populations of the endangered itasenpara bitterling: implications for a reintroduction program

In this study, the level of genetic diversity of captive populations of the itasenpara bitterling (Acheilognathus longipinnis) was assessed to obtain information useful for successful captive breeding and reintroduction; this analysis was performed using mitochondrial DNA (mtDNA) sequence data. Comparison of the captive and wild populations showed low levels of genetic diversity within the captive population and significant genetic differentiation among the captive populations and also between the wild and captive populations, suggesting at chance effect during the founding process for the captive population and a subsequent genetic drift. Therefore, for successful reintroduction, it is important that the reintroduced population reflects all the genetic diversity available from the captive populations, and that releasing a large number of individuals that consist of all captive populations.     

Inducible transgenic expression in the short‐lived fish Nothobranchius furzeri

This study demonstrates inducible transgenic expression in the exceptionally short‐lived turquoise killifish Nothobranchius furzeri, which is a useful vertebrate model for ageing research. Transgenic N. furzeri bearing a green fluorescent protein (Gfp) containing construct under the control of a heat shock protein 70 promoter were generated, heat shock‐induced and reversible Gfp expression was demonstrated and germline transmission of the transgene to the F1 and F2 generations was achieved. The availability of this inducible transgenic expression system will make the study of ageing‐related antagonistically pleiotropic genes possible using this unique vertebrate model organism.     

A Simple Determination Method for Herbicides,NIP and CNP in Soil Using Single Ion Monitoring Mass Spectrometry

A purified extracellular endo β-1,3-xylanase (EC 3.2.1.32) from an isolated strain, Aspergillus terreus A-07, was found to hydrolyze 1,3-xylosyl linkages only. When rhodymenan (β-1,4 and β-1.3-linked xylan) was hydrolyzed by β-1,3-xylanase (EF-6), four β-1,4-linked xylooligosaccharide fractions were produced. The main product was β-1,4-xylotriose, with trace amounts of other β-1,4-linked xylooligosaccharides. Successive degradation by β-l,4-xylosidase of the β,4-xylooligosaccharides that were produced from hydrolysis of β-1,3-xylanase on rhodymenan yielded only xylose as the final product.

We compared the action pattern of this enzyme with that of an extracellular endo β-l,4-xylanase (EC 3.2.1.8) of Streptomyces. From a mixture of products of β-1,4-xylanase hydrolysis on rhodymenan, an isomeric xylotriose was isolated by charcoal chromatography after treating with β-1.4-xylosidase. The structure of this isomeric xylotriose was elucidated by methylation analysis and its susceptibility to β-1,4-xylanase, β-1,3-xylanase, and β-1,4-xylosidase. The obtained isomeric xylotriose was identified as 3-O-β-xylopyranosyl-4-O-β-D-xylopyranosyl-D-xylose (X1→3X1→4X). It has a melting point of 224~225°C and ${\left[\alpha \right]}_{\text{D}}^{20}$(c = 1, H₂O)= —46°.