Morphological and Biochemical Studies on the Cerebral Cortex from Reeler Mutant Mice: Development of Cortical Layers and Metabolic Mapping by the Deoxyglucose Method

Abstract: Cerebral cortex from reeler mutant mice was examined morphologically and biochemically. The sequential process of postnatal cell migration in the cerebral cortex of reeler (rl/rl) was examined morphologically. The dense cellular cortical plate lies below the molecular layer near the cerebral surface just after birth in normal mice while in reeler most of the cells are concentrated in the center of the cortex. In the cortex of adult reeler, the broad laminar structure of the neurons could be seen to form inverted positions in the cortical layers. The total wet weight, and the concentration of DNA and RNA in the pallium cerebri from reeler did not differ significantly from those in the control. As to the protein profiles of the pallium cerebri detected by SDS- polyacrylamide gel electrophoresis, no significant differences were observed. Activities of CNPase (2',3'-cyclic nucleotide 3'-phosphohydrolase), which is a myelin enzyme of CNS, and choline acetyltransferase were at the same level in both the reeler and the control. Therefore, reeler mutation does not appear to affect the genetically determined cell numbers, number of cholinergic fibers, and myelination. By autoradiographic observation of the cerebral cortex after intraperitoneal injection of [¹⁴C]2-deoxyglucose, it was revealed that 2-deoxyglucose was incorporated intensively into the fourth layer (granular layer) of the cerebrum from the control. In reeler it was also incorporated into the granular layer but in a more widespread distribution. We conclude that terminals to the granular layer make metabolically active synapse, perhaps even in a manner inverted from normal.     

Changes in spatial distribution pattern during the larval stage of the fall webworm,Hyphantria cunea drury (Lepidoptera: Arctiidae)

Summary The changes in spatial distribution pattern during larval stage of the fall webworm,Hyphantria cunea were quantitatively investigated in the field experimental populations. The female adult deposits eggs as a cluster and the hatchlings make a compact colonial-web. In this period, the all-or-none type mortality which is characteristic in gregarious insect species was occasionary recognized before spinning a compact colonial-web. Once making a compact colonial-web, the larvae feed the leaves in the colonial-web up to about 5th instar. In this period, the movement of larvae occurred due to the local food shortage in a colonial-web and the expansion of colonial-web. As the larvae developed, the colonial-web was separated into several small groups. These larvae began to disperse about 5th instar. In this period, the local food shortage seems to be an important trigger for the larval dispersal. The mean concentration of larvae on leaves abruptly decreased, and finally the larvae became solitary at the 6th or 7th instars. The dispersal process in later larval stage is not necessarily due to the complete food shortage. The dispersal prior to the occurrence of food shortage may be a safety mechanism to protect the larvae from the food shortage.     

Semisynthesis and properties of some insulin analogs

The trypsin-catalyzed coupling of bovine (Boc)₂-desoctapeptide (B23-B30)-insulin with synthetic octapeptides, H-Gly-X₂-X₃-X₄-Thr-Pro-Lys(Boc)-Thr-OH (X₂ = Phe or Ala, X₃ = Phe or Ala, X₄ = Tyr or Ala), followed by deprotection and purification produced the [Ala^B24, Thr^B30]-, [Ala^B25, Thr^B30]-, and [Ala^B26, Thr^B30]-analogs of bovine insulin in yields of 32, 35, and 32%, respectively. The biological activity of these analogs decreased in the order, normal insulin ([Thr^B30]-bovine insulin) = Ala^B26-insulin > Ala^B25-insulin > Ala^B24-insulin, as assayed for receptor binding and some other biological effects, in contrast with the corresponding Leu-analogs of human insulin, in which the activity decreased in the order, normal insulin > Leu^B24-insulin > Leu^B25-insulin. The affinity to insulin antibodies greatly diminished in both Ala^B24-insulin and Leu^B24-insulin but not in the B25-substituted analogs. The CD spectra of the Leu- and the Ala-analogs were compared with those of normal insulins to show that no apparent correlation seems to exist between the decrease in biological activity and the conformational changes observed in solution. The effects of organic solvents on the peptide-bond equilibrium and on the stability of trypsin are also discussed.     

Thermodynamics of equilibria of hemoglobins M Milwaukee-I and Saskatoon and isolated chains of hemoglobin a with carbon monoxide

The thermodynamic parameters of the CO-equilibria of isolated chains of hemoglobin A and of two α-chains in hemoglobins M Milwaukee-I and Saskatoon at 25°, pH 7.0 were determined. The parameters for the binding of the first CO molecule to the hemoglobins M were ΔH′=?17 and ?18 kcal/mole heme and ΔS′=?30 and ?29 e.u. for hemoglobins M Milwaukee-I and Saskatoon, respectively. In contrast to this the characteristics of the second step of the binding were ΔH′=+5.9^· and +4.3 kcal/mole and ΔS′=+51 and +49 e.u. These values for the second step were also significantly different from those of the isolated α-chain (ΔH′=?15 kcal/mole and ΔS′=?11 e.u.).     

Genetic polymorphisms of blood proteins in the troops of Japanese macaques,Macaca fuscata: IV. Erythrocyte esterase polymorphism inMacaca fuscata

Genetic variation at the locus controlling A₁ band of erythrocyte esterase was found in the Japanese macaque,Macaca fuscata. Existence of four alleles,Es-A ₁ ¹ ,Es-A ₁ ² ,Es-A ₁ ³ , andEs-A ₁ ⁴ , controlling the mobility of the band and codominance relation between them were postulated. A majority of the troops examined were monomorphic inEs-A ₁ 1-1 phenotype, and the variant phenotypes were observed to occur only in Yugawara-Ihama, Arashiyama, and Koshima areas.     

Plantago asiatica mosaic virus: An emerging plant virus causing necrosis in lilies and a new model RNA virus for molecular research

Taxonomy Plantago asiatica mosaic virus belongs to the genus Potexvirus in the family Alphaflexiviridae of the order Tymovirales.Virion and genome propertiesPlantago asiatica mosaic virus (PlAMV) has flexuous virions of approximately 490–530 nm in length and 10–15 nm in width. The genome of PlAMV consists of a single‐stranded, positive‐sense RNA of approximately 6.13 kb. It contains five open reading frames (ORFs 1–5), encoding a putative viral polymerase (RdRp), movement proteins (triple gene block proteins, TGBp1‐3), and coat protein (CP), respectively.Host rangePlAMV has an exceptionally wide host range and has been isolated from various wild plants, including Plantago asiatica, Nandina domestica, Rehmannia glutinosa, and other weed plants. Experimentally PlAMV can infect many plant species including Nicotiana benthamiana and Arabidopsis thaliana. It also infects ornamental lilies and frequently causes severe necrotic symptoms. However, host range varies depending on isolates, which show significant biological diversity within the species.Genome diversityPlAMV can be separated into five clades based on phylogenetic analyses; nucleotide identities are significantly low between isolates in the different clades.TransmissionPlAMV is not reported to be transmitted by biological vectors. Virions of PlAMV are quite stable and it can be transmitted efficiently by mechanical contact.Disease symptomsPlAMV causes red‐rusted systemic necrosis in ornamental lilies, but it shows much weaker, if any, symptoms in wild plants such as P. asiatica.ControlControl of the disease caused by PlAMV is based mainly on rapid diagnosis and elimination of the infected bulbs or plants.     

Sustained expression in mammalian cells with DNA complexed with chitosan nanoparticles

This work investigates the preparation and in vitro efficiency of chitosan gene transfection systems. Chitosan was used to prepare nanoparticles with a size range of 40-200 nm as determined using photon correlation spectroscopy (PCS) and 40-80 nm as determined using transmission electron microscopy (TEM). The ability of particles to complex DNA was investigated using gel retardation. Plasmid DNA pGL3-Control encoding firefly luciferase and pCH110 encoding beta-galactosidase were used as reporter genes. For transfection 293 human embryonal kidney cells and Chinese hamster ovary (CHO-K1) cells were used. The expression of luciferase was assayed and expressed as relative light units per milligram of protein (RLU/mg protein). Results showed that these chitosan particles have potential as vectors for the transfer of DNA into mammalian cells. Cellular transfection by the chitosan-pGL3-Control particles showed a sustained expression of the luciferase gene for about 10 days. Commercial transfection reagents, SuperFect and Lipofectin were also used. In contrast to chitosan particles, the duration of expression for both SuperFect and Lipofectin was only about 2 days. Agarose gel electrophoresis and displacement experiments using polyaspartic acid indicated a probable multiple interaction between DNA and chitosan whilst the interaction between DNA and the polyamidoamine dendrimer appears to be only ionic interaction. No toxic effect on the mammalian cells was seen with chitosan. SuperFect and Lipofectin however, were observed to engender marked cytotoxicity. Poly-D,L-lactide (PLA) nanoparticles (40-80 nm) and poly-L-lactide (PLLA) lamellae (2-6 microm) were also used to load DNA by an adsorption procedure, but these failed to give good expression data.     

生物转化生产D-塔格糖的食品级菌种选育及L-阿拉伯糖异构酶的克隆表达

L-阿拉伯糖异构酶(L-arabinose isomerase,L-AI)是一种可以催化D-半乳糖为D-塔格糖的胞内异构化酶。随着塔格糖在食品工业中越来越广泛的应用,能够将半乳糖转化为塔格糖的食品级微生物以及食品级来源的L-AI受到更大的关注。文中从各种酸奶制品、泡菜及其他一些食品中采集不同的样品,筛选出1株具有L-AI酶活的食品级菌株,经过生理生化鉴定以及16S rDNA序列测定,确定该菌株为戊糖片球菌,命名为Pediococcus pentosaceus PC-5。以该菌基因组为模板,克隆L-AI基因,并在大肠杆菌BL21成功地异源表达。表达产物经粗提取后,在40℃下加入Mn2+,使D-半乳糖转化为D-塔格糖的转化率为33%。