biparous:A Novel bHLH Gene Expressed in Neuronal and Glial Precursors inDrosophila

Genetic studies have uncovered many genes that are involved in the first steps of neuronal development inDrosophila.Less is known about the intermediate steps during which individual precursor cells follow either the neuronal pathway or the glial pathway. We report the identification of a novel bHLH gene,biparous,expressed in neuronal and glial precursors inDrosophila.Unlike most bHLH genes,biparousexpression continues to the final stages of neurogenesis in the embryo. Expression ofbiparousis not observed in end stage postmitotic neurons and precedes the expression ofrepo,a gene activated in later stages of glial differentiation. The bHLH domain is sufficiently different from previously described bHLH domains to imply a novel function.     

Biochemical systematics of Japanese fireflies of the subfamily Luciolinae and their flash communication systems

Japanese fireflies of the subfamily Luciolinae are biochemically analyzed using 13 allozymes, and the phylogenetic relationships obtained from this analysis are compared with their flash communication systems. As a result, the Japanese Luciolinae can be divided into three groups.Hotaria parvula andH. tsushimana together withLuciola yayeyamana andL. kuroiwae from the first group, and they use the same communication system.L. lateralis, Curtos okinawana, andC. costipennis make up the second group, and their communication systems are also the same.L. cruciata makes up the last one, and its communication system is different from the other fireflies of Luciolinae. Therefore, their taxonomical arrangement and communication systems are not congruent. However, the genetic similarity deduced by allozymic analysis of the members of the Japanese Luciolinae is highly consistent with their flash communication systems.     

Urocystis tranzscheliana,a newly recorded smut fungus onPrimula sieboldii from Japan

A smut fungus onPrimula sieboldii was newly found in Japan and identified asUrocystis tranzscheliana by comparative morphology. This species causes systemic infection ofP. sieboldii and produces sori in its ovaries.Contribution No. 121, Laboratories of Plant Pathology and Mycology, Institute of Agriculture and Forestry, University of Tsukuba.     

Efficiency of serum copper/zinc ratio for differential diagnosis of patients with and without lung cancer

We examined serum copper (Cu), serum zinc (Zn), and the serum copper/zinc ratio (Cu/Zn) in 162 patients. All of them were seen to have an abnormal shadow in the chest X-ray films, that is, 109 patients with lung cancer (LC) and 53 patients with no lung cancer (NLC). The mean Cu and Cu/Zn in LC patients were significantly higher than those in NLC patients (p<0.05). In LC patients, Cu and Cu/Zn were higher and Zn was lower in advanced tumors than early ones. There was a significantly clear relation between Cu or Cu/Zn and the tumor (T) stages. When the relative risk (RR) of LC was estimated, it was seen that the higher Cu and Cu/Zn became, the higher RR became. Furthermore, we showed the sensitivity of the receiver operator characteristic of the test (ROC) curve for Cu, Cu/Zn, and carcinoembryonic antigen (CEA) to diagnose LC, as explained in a paragraph of methods.The determinations of Cu, Zn, and Cu/Zn are simple and inexpensive. They also appear to have a great diagnostic value in determining the local invasion of LC and as a screening test in the high-risk patients for LC.     

Effects of the Degree of Polymerization on the Binding of Xyloglucans to Cellulose

Xyloglucan oligosaccharides were isolated with various degreesof polymerization (DP) and reduced with tritiated sodium borohydride.The ³H-oligosaccharides were tested for their ability to bindto amorphous and microcrystalline celluloses and to cellulosefilter paper. The time course of binding indicated that theradiolabeled oligosaccharides continued to be bound for at least1 h after heating at 120°C. The binding probably requiredthe organization of the oligosaccharides and celluloses by gradualannealing after heating. Although neither pentasaccharide (glucose:xylose, 3 : 2), heptasaccharide (glucose: xylose, 4 : 3) andnonasaccharide (glucose : xylose : galactose : fucose, 4 : 3: 1 : 1) failed to bind to the celluloses, binding occurredwith oligosaccharides with DP equivalent to more than four consecutive1,4-ß-glucosyl residues. The extent of binding tothe celluloses increased gradually from octasaccharide (glucose:xylose, 5 : 3) to hendecosanosaccharide (glucose/xylose, 12: 9), with the increase in the DP of 1,4-ß-glucosylresidues. The binding of reduced cello-dextrins to celluloserequired at least 4 consecutive 1,4-ß-glucosyl residues.The extent of binding of cellopentitol or cellohexitol to cellulosewas similar to that of hendecosanosaccharide, showing lowerbinding for xyloglucan oligosaccharides in spite of longer chainsof 1,4-ß-glucosyl residues. These findings suggestthat the mode of binding to cellulose of xyloglucan oligosaccharidesis different from that of cello-oligosaccharides. (Received February 18, 1994; Accepted June 1, 1994)     

Cloning, nucleotide sequence and expression of a hemolysin gene of Clostridium septicum

Abstract A genomic library of Clostridium septicum NCTC547 strain was made in Escherichia coli by means of λgt10. The DNA insert of a hemolysin-positive (Hly⁺) λ-clone was transferred into pUC19. The resulting plasmid, pCS21, confers a Hly⁺ phenotype on E. coli . Crude lysates of E. coli (pCS21) possessed a strong lytic activity on human erythrocytes and also a lethal effect on mice, characteristic of an α toxin. Nucleotide sequence analysis revealed that the insert DNA (5.2 kb) in pCS21 included at least one open reading frame of 1380 bp. The coding frame for hemolysin was predicted to be 1329 bp in size and to encode a protein of 49.8 kDa. It coincided with the molecular mass (48 kDa) of the α toxin secreted by C. septicum . Taken together, the data indicated that plasmid pCS21 indeed encoded an α toxin gene of C. septicum .     

W-heterochromatin of chicken; its unusual DNA components,late replication,and chromatin structure

About 65% of DNA in the chicken W chromosome has been shown to consist ofXhoI andEcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kbXhoI and the 1.2-kbEcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescencein situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed alongXhoI andEcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the β-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of theHaeIII-digested MSB-1 nuclei yielded a chromatin fraction in whichXhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for theXhoI family sequence were present in this fraction.     

Cytotoxicity Induced by Monoclonal Antibody to α-Fetoprotein Coadministered with Spleen Cells of Nude Mice

This paper describes an attempt to effectively induce antibody-dependent cell-mediated cytotoxicity (ADCC) in nude mice. A monoclonal antibody against α-fetoprotein, 80G, coadministered with spleen cells from other nude mice bearing HuH-7N (xenograft of human hepatoma cell line, HuH-7) significantly suppressed the growth of HuH-7N as compared to treatment with 80G alone. 80G with spleen cells from normal nude mice also had some suppressive effect. In contrast, no effect was observed with each spleen cells alone as well as 80G alone. These results suggest that further supply of effector cells could enhance ADCC activity in nude mice.     

Effect of coexisting cells on the NGF-inducing neurite growth from PC12h-R

Possible roles of coexisting cells in inducing neurite growth from a nerve cell were studied. Nerve growth factor (NGF)-inducing neurite growth from PC12h-R (a cell line derived from cultured nerve cells) was investigated at various cell densities. At the cell density 10²10⁴ cells/ml neurites appeared even without NGF. In contrast, no neurite appeared without NGF in single cell culture. The neurite growth observed in plural cell culture without NGF was only partially inhibited by antibody to NGF receptor (Ab-NGFR). However, the effect of the used medium alone was mostly inhibited by Ab-NGFR. These results suggest that the neurite inducing potency of coexisting cells is via different sites than the NGF receptor.Abbreviations Ab-IgG-FITC anti-mouse-IgG labeled with fluorescein isothiocyanate - Ab-NF monoclonal antibody to neurofilament 160 kD - Ab-NGFR monoclonal antibody to NGF receptor - BDNF brain-derived neurotrophic factor - D-medium medium for differentiation culture - DMEM Dulbecco's modified Eagle's medium - M-medium medium for multiplication culture - NGF nerve growth factor - NGFR NGF receptor - NT-3 neurotrophin-3 - PC12 pheochromocytoma cell line - PC12h-R subclone of PC12 - Sup-D supernatant of D-medium