MIXED MODEL APPROACHES FOR ESTIMATING GENETIC VARIANCES AND COVARIANCES

The limitations of methods for analysis of variance(ANOVA)in estimating genetic variances are discussed. Among the three methods(maximum likelihood ML, restricted maximum likelihood REML, and minimum norm quadratic unbiased estimation MINQUE)for mixed linear models, MINQUE method is presented with formulae for estimating variance components and covariances components and for predicting genetic effects. Several genetic models, which cannot be appropriately analyzed by ANOVA methods, are introduced in forms of mixed linear models. Genetic models with independent random effects can be analyzed by MINQUE(1)method whieh is a MINQUE method with all prior values setting 1. MINQUE(1)method can give unbiased estimation for variance components and covariance components, and linear unbiased prediction (LUP) for genetic effects. There are more complicate genetic models for plant seeds which involve correlated random effects. MINQUE(0/1)method, which is a MINQUE method with all prior covariances setting 0 and all prior variances setting 1, is suitable for estimating variance and covariance components in these models. Mixed model approaches have advantage over ANOVA methods for the capacity of analyzing unbalanced data and complicated models. Some problems about estimation and hypothesis test by MINQUE method are discussed.     

Inhibitors of Urokinase and Thrombin in Cultured Neural Cells

Recent studies have suggested important roles for certain proteases and protease inhibitors in the growth and development of the CNS. In the present studies, inhibitors of urokinase or thrombin in cultured neural cells and serum-free medium from the cells were identified by screening for components that formed sodium dodecyl sulfate-stable complexes with 125I-urokinase or 125I-thrombin. Rinsed glioblastoma possessed two components that complexed 125I-urokinase. One was type 1 plasminogen activator inhibitor (PAI-1), because the 125I-urokinase-containing complexes were immunoprecipitated with anti-PAI-1 antibodies. The other component formed complexes with 125I-urokinase that were not recognized by antibodies to PAI-1 or protease nexin-1 (PN-1). Its identity is unknown. In addition to these cell-bound components, the glioblastoma cells also secreted two inhibitors that formed complexes with 125I-urokinase; one was PAI-1, and the other was PN-1. The secreted PN-1 also formed complexes with 125I-thrombin. It was the only thrombin inhibitor detected in these studies. Human neuroblastoma cells did not contain components that formed detectable complexes with either 125I-urokinase or 125I-thrombin. However, human neuroblastoma cells did contain very low levels of PN-1 mRNA and PN-1 protein. Added PN-1 bound to the surface of both glioblastoma and neuroblastoma cells. This interaction accelerated the inhibition of thrombin by PN-1 and blocked the ability of PN-1 to form complexes with 125I-urokinase. Thus, cell-bound PN-1 was a specific thrombin inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)     

大鼠侧脑室注射精氨酸加压素对针刺镇痛的影响

以钾离子透入法引起大鼠甩尾反应为指标,测定动物的痛阈。由侧脑室注射精氮酸加压素(AVP)后,大鼠痛阈升高33.6％～68.5％,针刺镇痛效应明显加强,痛阈提高202.4％～302.7％。脑室注射抗精氨酸加压素血清,动物痛阈虽无明显变化,但针刺镇痛效应明显削弱,痛阈仅增加41.6％～71.0％。注射抗β-内啡肽血清和抗强啡肽A血清并不阻断AVP增强针刺镇痛效应。本工作的结果提示,脑内AVP参与针刺镇痛,这种作用与脑内内源性β-内啡肽和强啡肽的关系不甚密切。     

Induction of an organ-specific autoimmune disease, lymphocytic hypophysitis, in hamsters by recombinant rubella virus glycoprotein and prevention of disease by neonatal thymectomy.

Glycosylated, membrane-associated E1 (58-kDa) and E2 (47- to 49-kDa) rubella virus proteins and unglycosylated nucleoprotein C (33 kDa), from separately expressed vaccinia virus recombinants, were injected into golden Syrian hamsters. Rubella virus E1 and E2 glycoproteins consistently induced an organ-specific autoimmune disease, autoimmune lymphocytic hypophysitis, which was evidenced by the induction of autoantibodies against pituitary cells and by lymphocytic infiltration of the pituitary. Neonatal thymectomy prevented the disease. In contrast, rubella virus nucleoprotein C did not induce either autoantibodies against pituitary cells or lymphocytic infiltration of the pituitary. This finding raises the possibility that virus-specific protein itself can induce an organ-specific autoimmune disease in certain circumstances.     

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.