ANALYSIS OF HELICOVERPA ARMIGERA SINGLE NUCLEOPOLYHEDROVIRUS IMMEDIATE EARLY 1 (IE‐1) GENE*

Abstract A 6.12 kb Xbal‐H fragment of the Helicoverpa armigem single nucleopolyhedrovirus (HaSNPV) gemone was cloned and the complete sequence of this fragment was sequenced by random sequencing method. Sequence comparison and analysis revealed an ORF13 which was homologous to ie‐1 of Auiographa California nucleopolyhedrovirus (AcMNPV). The homologous encoding gene is ie‐1. The total length of the encoding region of HaSNPV gene was 1986 bp and was predicted to encode 661 amino acid protein(IE‐1) with molecular weight of 76.5 kD. The alingment of putative HaSNPV IE‐1 amino acid sequence with those of other 9 reported baculoviruses IE‐Is showed that the HaSNPV IE‐1 was most closely related to Helicoverpa zea nucleopolyhedrovirus (HzNPV) IE‐1, with 97% amino acid identidy. But it showed a low degree of sequence similarity to those of AcMNPV, Bombyx mori nucleopolyhedrovirus (BmNPV), Choristoneura fumiferana nucleopolyhedrovirus (CfMNPV), Lymantria dispar nucleopolyhedrovirus (LdMNPV), Orgyia pseudotsugata nucleopolyhedrovirus (OpMNPV), Spodoptera exigua nucleopolyhedrovirus (SeMNPV), Plutella xylostella granulovirus(PxGV) and Xestia c‐nigrum granulovirus (XcGV), with 23%, 23%, 23%, 25%, 23%, 14%, 27% and 7% amino acid identity, respectively. A phylogenetic tree of ten baculoviruses IE‐1 was also given.     

Maleylacetate reductase of Pseudomonas sp. strain B13: dechlorination of chloromaleylacetates,metabolites in the degradation of chloroaromatic compounds

The maleylacetate reductase of 3-chlorobenzoate-grown cells of Pseudomonas sp. strain B13 has been purified 50-fold. The enzyme converted 2-chloromaleylacetate to 3-oxoadipate with temporary occurrence of maleylacetate; 1 mol of chloride was eliminated during the conversion of 1 mol of 2-chloro- and 2,3-dichloromaleylacetate; 2 mol of NADH were consumed per mol of 2-chloro- and 2,3-dichloromaleylacetate while only 1 mol was necessary to catalyze the conversion of maleylacetate or 2-methylmaleylacetate. The maleylacetate reductase failed to use fumarylacetate as a substrate. The role of the enzyme in the chloroaromatics degradation is discussed.     

广东格氏线虫中国品系（C85011）的研究

本文首次报道采自我国广东省海陵岛的格氏线虫Steinernema glaseri(steiner,1929)中国品系(CB5011)。经研究(C85041)与国外的格氏线虫(NC513,KG)品系可以杂交并产生正常后代,但与国外品系有以下区别:交合刺顶端腹面具槽形凹陷,而非钩状;在试管斜面培养(C85011),它的三龄感染期幼虫除分散爬满管壁外,还在培养基斜面的顶端结成立体团块,而国外的品系不结成立体团块;(C85011)的酯酶凝胶电泳酶带与国外格氏线虫的主要酶带位置相同,但当加样量增加到40微升以上,(C85011)除具三条主带外,还比国外的格氏线虫多3—4条弱带。     

Nutritional Study of Three Strains of Naegleria gruberi*

Naegleria gruberi strains cloned from amebas isolated from a Vero cell culture (“TS”), a sewer drainage ditch (“PD”), and an established laboratory line (“S”) were morphologically identical except for differences in size and flagellate transforming ability. Cultivation on a Trypticase-yeast extract-glucose medium (“TYG”) fortified with autoclaved E. coli resulted in increased cell size of 2 strains. Differences also were noted in growth rates and optimal growth temperatures. The autoclaved E. coli in TYG medium was replaceable with serum only for strains TS and PD. A basal salts medium + autoclaved E. coli supported growth of all 3 strains, but the basal salts medium + serum would not support growth of any of the strains.     

Differential Effect of Phosphate Starvation on the Rates of Cell Division and Plastid Replication in Euglena*

SYNOPSIS. The effects of phosphate starvation on the synthetic and division rates of Euglena gracilis strain Z are described. Phosphate starvation inhibits rates of the following processes, in the order: RNA synthesis > DNA synthesis > cell division > chlorophyll synthesis and plastid replication. As a consequence of the differential effect of phosphate starvation on the synthetic and division rates the average gross chemical composition of the cells is subject to continuous change.     

Infectivity and Recovery of Tetrahymena pyriformis Strain S from Adult Female Cockroaches (Periplaneta americana)*

Hemocoelomic injection of 5,800–8,000 cells of Tetrahymena pyriformis strain S per female cockroach resulted in lethargy of the insects within 24 hr and death within 72 hr. Ciliates could be recovered 24–48 hr after injection of these amounts of ciliates. Inoculation of smaller numbers of cells resulted in no apparent ill effects to the insects and ciliates could not be recovered. After recovery from cockroaches and reestablishment in axenic culture, the ciliates were rounded and contained large numbers of lipid droplets which decreased on continued cultivation. The ciliates underwent a sequence of morphologic alterations involving a decrease in length and width to form ovoid cells, an approach to the pyriform shapes (but smaller than normal size), an elongation to an abnormal length/width ratio, and then, after 6 days in culture, a return to the normal shape with usual dimensions.     

Transport of maltose by Pseudomonas fluorescens W

The system for uptake of maltose in Pseudomonas fluorescens W was inducible. Using a mutant strain unable to hydrolyze maltose, it was shown that maltose was taken up unaltered against a concentration gradient. Uptake of ¹⁴C maltose was only significantly inhibited by nonradioactive maltose or maltotriose. These were the only sugars that could displace accumulated radioactive maltose in the strain unable to hydrolyze maltose. Uptake exhibited saturation kinetics and was inhibited by energy poisons, indicating that this system was one of active transport. Sulfhydryl-binding reagents reversibly inhibited maltose uptake. No transport ability was lost when cells were subjected to osmotic shock. Using the protein-binding dye 7-diazonium-1,3-naphthalene disulfonate a protein or proteins located in or external to the cell membrane was implicated in maltose transport. The hydrolysis of p-nitrophenyl--D-glucoside (PNPG) was used as an indirect measure of transport ability since penetration of PNPG, not its hydrolysis, was the rate-limiting step.Abbreviations PNPG paranitrophenyl--D-glucoside - NDS 7-diazonium-1,3-naphthalene disulfonic acid - PMB p-hydroxymercuribenzoate - MBS p-chloromercuriphenylsulfonic acid - PCMB p-chloromercuribenzoate - CCCP carbonyl cyanide m-chlorophenylhydrazone - DNP 2,4-dinitrophenol - HOQNO 2-heptyl-4-hydroxyquinoline-N-oxide     

Heterotrophic (Dark) CO2 Fixation by Euglena gracilis. Possible regulation by tricarboxylic acid cycle intermediates

SYNOPSIS. Heterotrophic (dark) CO₂ fixation by Euglena gracilis strain Z varies with phase of batch culture and mode of nutrition. Dark CO₂ fixation increased transiently during the growth of cells under photoautotrophic (CO₂, light) and heterotrophic (glucose, dark) conditions. Cells grown heterotrophically with acetate or ethanol had no transient increase in fixation. The addition of acetate to a heterotrophically growing culture during the period of increasing dark CO₂ fixation resulted in rapid elimination of this fixation. The results suggest that dark CO₂ fixation in Euglena functions in anaplerotic feeding of the tricarboxylic acid cycle, drained by biosyntheses during growth. Induction of the glyoxylate cycle by acetate may provide an alternate source of tricarboxylic cycle intermediates, obviating the requirement for dark CO₂ fixation as a source of the intermediates.     

Activities of Glucose-6-phosphate, 6-phosphogluconate,and Isocitrate Dehydrogenases from Leishmania donovani Cultivated at 25 and 37 C*

SYNOPSIS. The activities of glucose-6-phosphate dehydrogenase (G-6-PD) (EC No. 1.1.1.49), 6-phosphogluconate dehydrogenase (PGD) (EC No. 1.1.1.44), and isocitrate dehydrogenase (ICD) (EC No. 1.1.1.42) from promastigotes of Leishmania donovani strain 3S grown at 25 C in modified Tobie's (mT) medium and from promastigotes of the 37 C-adapted substrain of this strain cultivated in the mT at 37 C were assayed at 25 and 37 C. At 25 C ICD from both the strain and the substrain had the highest, and PGD, the lowest activity; the activity of G-6-PD was intermediate, but much closer to that of ICD. Irrespective of the temperature of the assay, the activities of G-6-PD and ICD from the 37 C substrain were significantly higher than those of these enzymes from the parental strain; however, the activity of PGD from the 25 C strain was slightly higher than that of this dehydrogenase from the 37 C-adapted stock. No significant activity losses of G-6-PD and ICD from either the strain or the substrain were noted after incubation of the extracts in the presence of 0.25 M sucrose at 37 C for 2 hr. PGD was unstable in such extracts, but it could be rendered stable by the addition of 4 mM 6-phosphogluconate. G-6-PD was the least and ICD the most dependent on Mg²⁺ ions. In the 15–25 C range, the Q₁₀ values of the enzymes from the 25 C strain were 2.83, 2.5, and 2.63 for G-6-PD, PGD, and ICD, respectively. These values for the respective enzymes in the 25–35 C range were 2.06, 1.67, and 1.62. The Q₁₀ values of the enzymes from the 37 C substrain in the 15–25 C range were 2.06 for G-6-PD, 3.25 for PGD, and 2.77 for ICD; in the 25–35 C range, the corresponding values were 1.67, 1.46, and 1.83. Cultivation of the 37 C substrain at 25 C was accompanied by a drop in G-6-PD and ICD activities.