Tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis]

The tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis (Trematoda: Echinostomatidae) was observed by scanning electron microscopy. Three-day (juvenile) and 16-day (adult) worms were harvested from rats (Sprague-Dawley) experimentally fed the metacercariae from the laboratory-infected fresh water snail, Hippeutis cantori. The worms were fixed with 2.5% glutaraldehyde, processed routinely, and observed by an ISI Korea DS-130 scanning electron microscope. The 3-day old juvenile worms were elongated and ventrally curved, with their ventral sucker near the anterior two-fifths of the body. The head crown was bearing 37-38 collar spines arranged in a zigzag pattern. The lips of the oral and ventral suckers had 8 and 5 type II sensory papillae respectively, and between the spines, a few type III papillae were observed. Tongue or spade-shape spines were distributed anteriorly to the ventral sucker, whereas peg-like spines were distributed posteriorly and became sparse toward the posterior body. The spines of the dorsal surface were similar to those of the ventral surface. The 16-day old adults were leaf-like, and their oral and ventral suckers were located very closely. Aspinous head crown, oral and ventral suckers had type II and type III sensory papillae, and numerous type I papillae were distributed on the tegument anterior to the ventral sucker. Scale-like spines, with broad base and round tip, were distributed densely on the tegument anterior to the ventral sucker but they became sparse posteriorly. At the dorsal surface, spines were observed at times only at the anterior body. The results showed that the tegument of E. cinetorchis is similar to that of other echinostomes, but differs in the number and arrangement of collar spines, shape and distribution of tegumenal spines, and type and distribution of sensory papillae.     

Changes in the Levels of Chlorophyll and Light-Harvesting Chlorophyll a/b Protein of PS II in Rice Leaves Aged under Different Irradiances from Full Expansion through Senescence

Effects of irradiance on changes in the amounts of chlorophyll(Chl) and light-harvesting chlorophyll a/b protein of PS II(LHCII) were examined in senescing leaves of rice (Oryza sativaL.). Results of treatments at two irradiances (100% and 20%natural sunlight) were examined after the full expansion ofthe 13th leaf throughout the course of senescence. With 20%sunlight, the Chl content decreased only a little during leafsenescence, while with 100% sunlight it decreased appreciably.Similarly, the amount of LHCII protein during treatment with20% sunlight remained almost constant. However, the ratio ofChl a/b during the shade treatment decreased significantly andthe rate of decrease was greater than during the full-sunlighttreatment. The ratio of Chl a/b for Chl a and b bound to LHCIIwas about 1.2, irrespective of leaf age or irradiance treatment.When the amounts of Chl bound to LHCII were calculated fromthe total leaf content of Chl and the ratio of Chl a/b, assuminga ratio of Chl a/b bound to LHCII of 1.2, they were well correlatedwith the amounts of LHCII protein. Changes in the amounts of LHCII synthesized during the two irradiancetreatments were examined using an ¹⁵ tracer. Incorporation of¹⁵N into LHCII declined dramatically during both treatmentsfrom full expansion through senescence, suggesting that therewas little synthesis of LHCII protein during that time. In addition,the amount of LHCII synthesized during senescence was lowerduring the shade treatment than during the 100% sunlight treatment.These results indicate that the absence of an apparent changein levels of LHCII with shade treatment during senescence wascaused by the very low rate of turnover of LHCII protein. (Received June 17, 1992; Accepted September 28, 1992)     

Alteration of mitochondrial genomes containing atpA genes in the sexual progeny of cybrids between Raphanus sativus cms line and Brassica napus cv. Westar

Summary We have investigated the fate of the mitochondrial genomes of cybrids derived from donor-recipient protoplast fusion between X-irradiated Raphanus sativus (cms line) and iodoacetamide-treated Brassica napus cv. Westar. Two out of ten fusion products were male-sterile with the diploid chromosome number of B. napus. The mitochondrial (mt) genomes of the cybrids and their progeny were further analyzed by DNA-DNA hybridizaion using the pea mitochondrial ATPase subunit gene (atpA) as a probe. One cybrid, 18-3, had a 3.0 kb fragment characteristic of B. napus and a 2.0 kb non-parental fragment when the BamHI-digested DNA was hybridized with the probe. In the first-backcrossed progeny of this cybrid, the hybridization pattern was not stably inherited. A 4.0 kb radish fragment, not detectable in the cybrid, appeared in one of the BC₁ generation siblings, and the 2.0 kb non-parental fragment was lost in another. The hybridization patterns in BC₁ progeny siblings of cybrid 12-9 were also varied. The alteration of mtDNA in the cybrid progeny continued to the BC₂ generation. There was no clear evidence of a heteroplasmic state or of sub-stoichiometric molecules in the mt genome of cybrid 18-3. A possible cause of the observed alteration in the mt genome is discussed.     

Production of recombinant human glucagon in the form of a fusion protein in Escherichia coli; recovery of glucagon by sequence-specific digestion

Summary Recombinant human glucagon was succesfully produced with a high level of expression in Escherichia coli as a fusion protein with human interferon . The synthetic gene was designed to release glucagon, which does not contain glutamic acid residues, from fusion protein with the Staphylococcus aureus strain V8 protease that specifically cleaves the peptide bond on the carboxyl side of the glutamic acid residue. The resulting glucagon was purified to homogeneity by a combination of C₁₈ reverse-phase HPLC and ion-exchange HPLC. The yield of intact glucagon obtained from 11 of culture was approximately 12 mg. The structure of recombinant human glucagon was confirmed by HPLC and amino acid composition/sequence analyses. Offprint requests to: J. Ishizaki     

Microbial asymmetric hydrolysis of N-acetyl-1-methyl-3-phenylpropylamine to optically active 1-methyl-3-phenylpropylamine

Summary The asymmetric hydrolysis of N-acetyl-1-methyl-3-phenypropylamine (MPAc) by microorganisms was investigated. Various bacteria belonging to the genera Bacillus, Agrobacterium, Corynebacterium, Arthrobacter, Brevibacterium, Cellulomonas, Acinetobacter, Nocardia and Rhodococcus showed this hydrolysing activity and yielded (S)-1-methyl-3-phenylpropylamine (MPPA). Using washed cells of N. erythropolis IAM 1440, 15.1 mg/ml of (S)-MPPA was formed, with a 38.8% conversion yield and high stereoselectivity (97.9% enantiomeric excess), in an organic solvent-water diphase system. The same (S)-amine and (S)-1-phenylethylamine were also produced in good yields from the valeryl and isovaleryl derivatives of MPPA, and N-acetyl-1-phenylethylamine, respectively.     

Agrobacterium-mediated transformation and regeneration of kiwi fruit

Summary Genetically transformed kiwi fruit (Actinidia deliciosa) plants were obtained from hypocotyl and stem segments co-cultured with Agrobacterium tumefaciens strain EHA101 harboring a binary vector, pLAN411 or pLAN421, which contained the neomycin phosphotransferase II (nptII) gene and the -glucuronidase (GUS) gene. After co-culturing with the A. tumefaciens, the hypocotyl or stem segments were cultured on a selection medium containing 25g/ml kanamycin and 500g/ml Claforan. After one month in culture, shoots had regenerated from the cuttings. Green shoots were analyzed for NPTII activity and GUS activity. Eighty-five percent of the green shoots examined expressed the nptII and GUS genes. GUS histochemical assays revealed strong GUS expression in guard cells, mesophyll cells, and trichomes.     

Suppression of the degradation of recombinant human apolipoprotein E by a protease inhibitor obtained from fetal bovine serum in serum-free culture

The recombinant human apolipoprotein E (Apo-E) produced by Chinese hamster ovary cells (CHO-322 cells) in serum free culture was degraded to 24K and 23K fragments that contained N-terminal amino acid. The degradation site of Apo-E to 24K fragment was between Arg180 and Leu181 and the C-terminal amino acid of 23K fragment was Gly169. In fetal bovine serum (FBS)-containing culture, the degradation was inhibited. However, in calf serum (CS) the inhibitory activity was not detected. Thus, we attempted the purification of the factor with this inhibitory activity from FBS. A protease inhibitor was purified to give a single peak from FBS by ammonium sulfate precipitation and combination of several column chromatographies. When this FBS-derived protease inhibitor (FBS-d-PI) was added to serum-free culture of CHO-322 cells, degradation of recombinant Apo-E to the 24K and 23K fragments was dose-dependently suppressed and accumulation of intact Apo-E in culture supernatant was observed. FBS-d-PI was found to be a glycoprotein with relative molecular size of 75K daltons under reducing condition, and 85K daltons under nonreducing condition by SDS-PAGE. A complex of FBS-d-PI and a cellular protease was also detected in culture supernatant by western blot analysis using mouse monoclonal antibodies against FBS-d-PI.     

稻瘟菌诱导的水稻几丁酶、β-1.3-葡聚糖酶活性及分布

稻瘟菌(Pyricularia oryzae C.)孢子感染或菌丝培养液处理后,水稻的几丁酶和β-1,3-葡聚糖酶活力被分别诱导提高6～9倍和3～5倍。用亲和层析初步纯化的几丁酶在体外能降解稻瘟菌细胞壁和抑制它的孢子萌发。这两个酶在细胞间隙和细胞内都有分布。     

Developmental interactions between the army wormLeucania separata [Lep.: Noctuidae] and its parasiteApanteles ruficrus [Hym.: Braconidae]

The developmental interactions between the gregarious endoparasitoidApanteles ruficrus Hal. and the army worm,Leucania separata Walker were investigated. The parasitoid preferred young host larvae and developed in 9.5 days irrespective of host age at the time of parasitization. The growth of parasitized host larvae were depressed. The net maximum weight of the host larva was positively correlated with the number of parasitoid eggs laid when the 2nd instar was parasitized. And when parasitizing in 2nd instar, the weight of parasitoid was negatively correlated with the number of eggs laid. The parasitoid has an ability to regulate the size of the host and the parasitoid itself according to the number of eggs laid when the host larva is very small.