Graph-Theoretical Analysis of Cleavage Pattern: Graph Developmental System and Its Application to Cleavage Pattern of Ascidian Egg

The skeletal structure of the embryo is represented by the graph. In the graph, the cells and the connectivities between the cells are reduced to the nodes and edges, respectively. Along cleavage history, the series of graphs is obtained. In this paper I propose a new graph developmental system(GDS) which develops the series of graphs. And I represent and analyze the cleavage pattern of the ascidian egg by GDS. In order to represent it by GDS, at first, the connectivities between the cells are labeled according to the developments of the connectivities at the next time step, and next the cells are labeled. But there are two ways of labeling the cells, then two types of GDS are defined: (1) to label according to the pattern of the connectivities of their descendant cells after two time steps (G-GDS), (2) to label according to the cell fates (C-GDS). The C-GDS of the ascidian egg produces 16 cleavage patterns at 64-cell stage non-deterministically. If some labels are distinguished at 16-cell stage, the C-GDS becomes deterministic at 64-cell stage.
GDS will be useful to simulate morphogenesis by the computer graphics.     

PHYSIOLOGICAL ACTIVITIES OF HELMINTHOSPOROL AND HELMINTHOSPORIC ACID: II. EFFECTS ON EXCISED PLANT PARTS

Effects of H-ol and H-acid were observed using excised partsof several plant species. Both H-ol and H-acid were active inelongation of oat coleoptile and mesocotyl, expansion of Raphanusleaf disk, but were inactive in elongation of wheat coleoptileand of green stem of pea. They gave also negative results inthe standard Avena curvature test and in the split pea test.In expansion of lettuce cotyledon, H-ol was inactive while H-acidwas active. In excised plant parts, as in intact plants, theactivity of H-ol and H-acid resembles rather gibberellins thanauxins and cytokinins. (Received August 20, 1966; )     

K-Casein Suppresses Melanogenesis in Cultured Pigment Cells

The effects of bovine milk proteins on melanogenesis in B16 cells were examined. Both whey protein isolate and casein exhibited depigmenting properties. Among the major protein components of milk—including β-lactoglobulin, α-lactalbumin, α-, β-, and k-casein—only K-casein exhibited the depigmenting effect. However, the carboxyl terminal peptide of K-casein, glycomacropeptide, did not show this activity. Also, K-casein promoted the proliferation of the cells and inhibited the activity of tyrosinase in the cells. These results indicate that K-casein acts as a melanogenesis-suppressing modulator.     

Enhanced Melanogenesis Induced by Tyrosinase Gene-Transfer Increases Boron-Uptake and Killing Effect of Boron Neutron Capture Therapy for Amelanotic Melanoma

Specific and powerful cancer killing effect for melanoma by boron neutron capture therapy (BNCT) using DOPA analogue, ¹⁰B-p-boronophenylalanine (¹⁰B-BPA), has been established, but amelanotic melanoma is insufficiently responsive to ¹⁰B-BPA BNCT in comparison with actively melanin-producing melanoma. Although the accumulation mechanism of ¹⁰B-BPA within melanoma was not established, we have recently obtained findings suggesting that melanin monomers, key intermediates for melanin polymer formation, play a critical role in ¹⁰B-BPA accumulation. In addition, there are some kinds of human amelanotic melanomas, such as MEL2A, in which expression of tyrosinase is repressed or lacking though tyrosinase-related protein (TRP)-l and TRP-2 are well expressed. Thus, by using a similarly tyrosinase-lacking mouse amelanotic melanoma cell line, A1059, we constructed TA1059 cells by transfecting human tyrosinase-cDNA into these cells. TA1059 cells acquired higher DOPA-oxidase and DOPAchrome tautomerase activity as well as eumelanin content at even higher levels than those of B16F10 cells. TA1059 cells showed about 2.5 times higher ^p-boronophenylalanine (BPA) uptake than A1059 cells in culture. In animal experiments, by using these cell lines, tumor growth of TA1059 was significantly suppressed by ¹⁰B-BPA BNCT as compared with A1059. These findings indicate that the induction of active melanin biosynthesis by melanogenic gene-transfer effectively improves the treatment of amelanotic melanoma by BNCT.     

INFLUENCE OF INORGANIC NITROGENOUS COMPOUNDS ON TOBACCO SEED GERMINATION INDUCED BY GIBBERELLIN A3, KINETIN AND AMMONIUM SALTS OF ORGANIC ACIDS

1. Investigations were made on the influence of inorganic nitrogenouscompounds upon the the germination of tobacco seeds (Nicotianatabacum L. var. virginica (AGDH.) COM. "Bright Yellow") inducedby GA₃, kinetin and ammonium salts of organic acids. Potassiumnitrate, ammonium chloride, ammonium sulfate and ammonium nitrategreatly increase the germination of the seeds induced by theabove reagents, while these inorganic salts, given alone, arealmost ineffective in causing germination.
2. Kinetin was shownto induce germination of tobacco seeds inthe dark. The discrepancywith the results of previous investigationsin this respectwas discussed.
3. It was inferred that nitrogenous metabolismis involved in theprocess of dark-germination of tobacco seedsas induced by theabove-stated stimulating factors and promotedby inorganic nitrogenoussubstances.

(Received July 17, 1961; )     

Establishment of the Embryo-derived Stem (ES) Cell Lines from Mouse Blastocysts: Effects of the Feeder Cell Layer.

The ES ceii lines are embryo-derived stem cell lines directly isolated from the inner cell mass of mouse blastocysts using feeder cell layer. We have established a number of ES cell lines from 129 or C57BL/6 strain mice by using the feeder layer of the STO cells (from ATCC) or the primary embryonic fibroblasts, which was obtained by trypsinizing the 16-day-old BALB/c mouse fetus. The ES cell lines established on the STO feeder layer showed differentiation into various tissues in solid tumors when injected into syngenic mice. Karyotype was, however, nearly tetraploid. The ES cell lines established on the primary fibroblasts exhibited differentiation into larger variety of tissues in solid tumors. Karyotype was almost diploid and majority of the cells kept normal set of chromosomes in G-banding. We conclude that the primary fibroblasts are better feeder layer than the STO cells for establishment and maintenance of the ES cell lines.     

Descriptions of two new species of Vietomartyria Hashimoto & Mey (Lepidoptera, Micropterigidae) from South China, with reference to autapomorphies of the genus

Two new species of micropterigids, Vietomartyria nankunshana Hirowatari & Hashimoto sp. nov. and V. nanlingana Hirowatari & Jinbo sp. nov., are described from Nankunshan and Nanling (Guangdong, China), respectively. The genus Vietomartyria Hashimoto & Mey, 2000, which was originally established as a monotypic genus, is redefined based on the following autapomorphies shared by the three species: (i) the long basal stalk of each flagellomere; (ii) the many (>100) minute serrate projections near the gonopore of aedeagus; and (iii) the gonopore situated dorsally near the apex.