Reactions of photosystems I and II in spinach chloroplast fragments treated with ethylene glycol

Photochemical reactions of chloroplast fragments isolated fromspinach leaves were measured in the presence of ethylene glycolor were measured after washing with an ethylene glycol-containingmedium. 2,6-Dichlorophenolindophenol (DPIP) photoreduction,oxygen evolution and oxygen uptake (a photosystem I reaction)were investigated in ethylene glycol-treated chloroplast fragments.By washing with ethylene glycol, oxygen evolution was stronglyinhibited, but oxygen uptake was not much affected by ethyleneglycol washing. Chloroplast fragments in 50% ethylene glycolmaintained a high rate of DPIP photoreduction (85% of the controlactivity in an ethylene glycol-less medium). In 67% ethyleneglycol, DPIP photoreduction mediated by photosystem II was eliminatedand only a small rapid reduction mediated by photosystem I wasobserved. Chloroplast fragments inhibited by ethylene glycolphotoreduced DPIP in the presence of p-aminophenol added asan artificial electron donor to photosystem II. The restoredactivity of DPIP photoreduction was inhibited by 3-(3',4'- dichlorophenyl)-1,1-dimethylurea. (Received September 8, 1970; )     

INHIBITORY EFFECT OF GROWTH RETARDANTS ON THE INDUCTION OF FLOWERING IN WINTER WHEAT

1. Growth retardants, CCC, Amo-1618, Phosfon-D and B-995, appliedduring seed vernalization inhibited the ear development of winterwheat. CCC applied during green plant vernalization inhibitedflowering,but it had no appreciable effect on the final stemlength. Theinhibition by CCC was reversed by foliar applicationof gibberellin.On the other hand, CCC applied after the vernalizationperiodaffected the final stem length but not flowering.
2. Theamount of endogenous gibberellin-like substance(s) was greaterin the vernalized plant than in the non-vernalized plant. Nogibberellin-like substance was detected in the CCC-treated plant.
3. Endogenous gibberellin-like substance(s), whose biosynthesisis inhibited by some growth retardants, may play a part in thevernalization process in winter wheat.

¹Present address: National Institute of Agricultural Sciences,Nishigahara, Kitaku, Tokyo     

Micromere Differentiation in the Sea Urchin Embryo: Two-Dimensional Gel Electrophoretic Analysis of Newly Synthesized Proteins

A method for large-scale culture of isolated blastomeres of sea urchin embryos in spinner flasks was developed. Micromeres and meso-, macromeres isolated from sea urchin embryos at the 16-cell stage were cultured by this method and the patterns of protein synthesis by their descendants were examined by two-dimensional gel electrophoresis of [³⁵S] methionine-labeled proteins. Six distinct proteins with molecular weights of 140–kDa, 105–kDa, 43–kDa, 32–kDa, and 28–kDa (two components) were specifically synthesized by differentiating micromeres. Quantitative analysis of the two-dimensional gel patterns demonstrated that all these proteins, except the 32–kDa protein, appeared at the time of ingression of primary mesenchyme cells (PMC's) in vivo , several hours earlier than the onset of spicule formation. The synthesis of 32–kDa protein was paralleled to active spicule formation and the uptake of Ca²⁺. Cell-free translation products directed by poly (A)⁺ RNAs isolated from descendant cells of micromeres and meso-, macromeres were compared by two-dimensional gel electrophoresis. Several spots specific to the micromere lineage were detected. However, none of them comigrated with the proteins synthesized specifically by the cultured micromeres. The results suggest that the expression of these proteins specific to differentiating micromeres may involve post-translational modification.     

GENERAL PATTERN, 35SO4-INCORPORATION AND INTRACELLULAR LOCALIZATION OF GLYCANS IN DEVELOPING SEA URCHIN (ANTHOCIDARIS) EMBRYOS

Glycosaminoglycan (GAG) prepared from sea urchin embryos ( Anthocidaris crassispina ) at various stages with or without pulse ³⁵SO₄-labelling was separated into various fractions by chromatography on DEAE-cellulose with a linear NaCl concentration gradient: fraction "P" (nonacidic) and fractions "A" through "F" (of increasing acidities). The ³⁵SO₄-radioactivity was negligible in "P" and "A", largest in "B" and "C", and decreased in the other fractions three alphabetical order. During development (hatched blastulae to gastrulae) the glycans in fractions "P" and "A" decreased in amount, whereas those in "E" and "F" increased. "E" contained heparin-like (AMPS-1) and dermatanpolysulfate-like (AMPS-2) GAG in addition to a sulfated fucogalactan-like (E₁) glycan. Another sulfated fucogalactan-like (F₁) glycan was found in "F". A sulfated polysialic acid-like (S₁) glycan was found in "C". An EDTA-extract of gastrulae gave AMPS-2, E₁ and F₁. The mitochondria-rich fraction gave AMPS-1, whereas the yolk granule-rich fraction gave S₁. Most of the other still unidentified components in "B", "C", and "D" appeared to be derived from glycoproteins and were mainly located in the crude yolk-mitochondrial and cytosol fractions.     

Analysis of Cellular Mosaicism in a Transgenic Mouse by Histological In Situ Hybridization

One of the transgenic mice carrying a chicken δ-crystallin gene was found to be mosaic with regard to the distribution of the exogenous gene. Taking advantage of the exogenous DNA sequences as a cell lineage marker detectable by histological in situ hybridization technique, we studied cellular mosaicism in mouse 7–5. This mouse carried the exogenous gene in 20–40% of its cells, probably reflecting chromosomal integration of the exogenous DNA which occurred in a blastomere of around the 4-cell stage. The cells carrying the gene contributed to virtually any kind of tissue and their distribution varied from one tissue to another. For instance, in the neural retina, gene-positive cells formed columns several cells wide, indicating that migration of the cells derived from the founder cells is mainly along the radial axis. However, in other tissues we examined, clusters of the marked cells were less obvious, indicating the occurrence of extensive cell mixing during histogenesis. Thus, mosaic analysis of cell lineage in mouse ontogeny appears meaningful in early developmental stages or when clonal outgrowth takes place in a tissue.     

SYNCHRONOUS MASS-CULTURE OF CHLORELLA

A new culture apparatus was constructed to obtain large quantitiesof synchronized cells of Chlorella ellipsoidea. Two flat culturechambers made of lucid acrylate resin (each 20 liters in capacity)were placed in a water thermostat together with a bank of 17daylight fluorescent lamps, and the culture was run by the methodstarting from a homogeneous population of D_s-cells accordingto TAMIYA et al. It was demonstrated that with this apparatusone can obtain as much as 200–400 mg (dry weight) eachof algal material at 8 or 9 different stages in one cell cycle.Completely synchronized cell cycles could be repeated as manyas 10 times in one series of experiment, indicating that theapparatus can produce 2–4g (dry weight) each of algalcells of different developmental stages. (Received April 2, 1964; )     

Origin of the disjunct distribution of flower colour polymorphism within Limonium wrightii (Plumbaginaceae) in the Ryukyu Archipelago

The sea lavender, Limonium wrightii , has six morphs of flower colour variation. The geographical distribution of flower colour morphs is disjunct; the distribution of the pink flower morph is divided into two subregions, and that of the yellow flower morph intervenes between them. The present study aimed to examine the origin of this apparent distribution pattern of flower colour in L. wrightii . Two main hypotheses (i.e. past dispersal events and phenotypic changes by natural selection and/or stochastic processes) have been proposed to account for the origin of leapfrog distribution patterns. To determine which hypothesis was applicable, we conducted a molecular phylogenetic analysis using sequence variation in chloroplast DNA (three regions of intergenic spacers, trnG - trnfM , trnV - trnM , and psbA-trnH ). We sequenced 58 accessions of L. wrightii frin 28 islands in the Ryukyu Archipelago and the Izu-Ogasawara Islands, located south of the Japanese mainland, and 12 accessions of four congeneric species. Within L. wrightii , we obtained four lineages of ten haplotypes. These lineages and haplotypes did not correlate with the different flower colours. These results indicate that the formation processes of populations are complex. The haplotypes of the pink flower morph did not show a sister relationship between the two disjunct subregions, indicating that the disjunct populations of the pink flower morphs are unlikely to share the pink flower colour as a result of common ancestry. We conclude that the observed leapfrog distribution pattern is caused by natural selection and/or stochastic processes.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 709–717.     

A systematic revision of Potentilla lineata and allied species (Rosaceae) in the Himalaya and adjacent regions

IKEDA, H. & OHBA, H., 1993. A systematic revision of Potentilla lineata and allied species (Rosaceae) in the Himalaya and adjacent regions . Potentilla lineata and allied species (Rosaceae) in the Himalaya and adjacent regions are revised. Potentilla festiva Soják, P. josephiana H. Ikeda & H. Ohba, P. lineata Trev., P. fallens Card, and P. polyphylla Wall, ex Lehm. are recognized. Potentilla josephiana is a new name for P.fulgens Wall, ex Hook. var. intermedia Hook. f. Four varieties are recognized in P. polyphylla: var. polyphylla; var. himalaka H. Ikeda & H. Ohba, var. nov.; var. interrupta (Yü & Li) H. Ikeda & H. Ohba, stat. & comb, nov.; and var. barbata Lehm. A polyploid series is found in this group. Four putative hybrids between the species are also recognized.