Growth allocation between height and stem diameter in nonsuppressed reproducing Abies mariesii trees

To understand the growth patterns with respect to competition and leaf‐mass increase in reproducing trees, growth allocation between height and stem diameter was examined for nonsuppressed reproducing Abies mariesii trees in a subalpine forest in northern Honshu, Japan. The growth allocation was analyzed by dividing the relative growth rate of the stem volume into the relative contributions of height and stem‐diameter growth. During a 9‐yr period, height growth and seed‐cone production showed obvious annual variation, while stem‐diameter growth recorded moderate variation. For two of three years of seed‐cone production during the 9‐yr period, trees with larger seed‐cone production were associated with less height growth in the following year of seed‐cone production; however, there was no trend of height growth in the year of seed‐cone production. In the following year of mast seeding, trees with larger stem‐volume growth were associated with less height growth. This trend was also shown for the relationship between the cumulative stem‐volume growth during the 9‐yr period and growth allocation to height, suggesting that trees with a larger biomass increase depress the allocation of photosynthate to competition with a large expenditure for reproduction. In contrast to this, trees with a smaller biomass increase might allocate photosynthate to competition with surrounding trees. The results of this study suggest that an increase in reproductive organs during life history and annual variation in reproduction are closely associated with the growth patterns of the stem in A. mariesii trees.     

The evolution of social behaviour in sentinel crabs (Macrophthalmus): implications from molecular phylogeny

Crabs of the genus Macrophthalmus are known to exhibit highly developed and diverse social behaviour, such as allocleaning, fighting and waving display behaviour, the first being observed widely throughout the genus. Fighting behaviour between males has been classified previously into grasping fighting and claw‐extending fighting, and male waving display into four patterns, the vertical non‐forward‐pointing type, vertical forward‐pointing type, lateral non‐forward‐pointing type and lateral forward‐pointing type, on the basis of interspecific behaviour comparisons. To understand the evolutionary pathways of these social behavioural activities, 978‐bp nucleotide sequences from mitochondrial 16S rRNA genes of 21 species, including two outgroup taxa, were analysed and a molecular phylogeny was reconstructed. The resultant tree demonstrated striking inconsistencies with the relationships inferred from morphological features. Species with similar habitat conditions showed similar morphological features, although they were not phylogenetically close relatives. Phylogenetic analysis of allocleaning behaviour suggested that it evolved once in the early history of the lineage. The analysis of fighting behaviour demonstrated that species with claw‐extending fighting, being a more complex behaviour than grasping fighting, are found in the most ancestral part of the phylogeny. The analysis also revealed that claw‐extending fighting has evolved secondarily on two occasions, suggesting that fighting behaviour is not characterized by sufficient phylogenetic components. The superimposition of a waving pattern on to the phylogeny indicated that the lateral non‐forward‐pointing type has evolved from the vertical non‐forward‐pointing type, the lateral forward‐pointing type having evolved from the vertical forward‐pointing type. This scenario also appeared reasonable with respect to the behavioural trends of cheliped movements in waving. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 88 , 45–59.     

Isolation and characterization of microsatellite loci in the threatened brook lamprey Lethenteron sp. N

A microsatellite‐enriched genomic library was obtained for the threatened brook lamprey, Lethenteron sp. N, and from it 16 dinucleotide markers were successfully isolated and characterized. These markers were found to have between 1 and 6 alleles with heterozygosity ranging from zero to 0.79. Cross‐species amplification was successful, with eight loci amplifying products in the counterpart cryptic species, Lethenteron sp. S, as well as 15 loci in Lethenteron japonicum. One out of 10 primer pairs previously reported also amplified products in all the three species.     

粳稻品种幼苗耐冷性比较研究

利用人工模拟低温胁迫的方法,研究了３个日本粳稻品种日本晴、金南风和福光以及２个台湾粳稻品种台竹１５７、加南２０的苗期耐冷性,并以当地推广高产籼稻品种特三矮２号作对照。从对株高、主茎叶片数、地上部干物重、死苗率等形态性状的调查和叶绿素含量、电解质外渗率等生理性状测定的结果显示,日本晴、金南风、福光和台竹１５７苗期的耐冷性较强,加南２０的耐冷性较弱,但比特三矮２号的耐冷性略强。这为防止早稻烂秧死苗而开     

Organelle DNA Synthesis in the Quiescent centre of Arabidopsis thaliana (Col.)

The behaviour of cell nuclei and organelle nucleoids (organellenuclei) was studied in the root apical meristem of 3-d-old seedlingsof Arabidopsis thaliana (Col.). Samples were embedded in Technovit7100 resin, cut into thin sections and stained with 4'-6-diamidino-2-phenylindole(DAPI) for observation of DNA. DNA synthesis in cell nucleiand organelle nucleoids was investigated using the incorporationof [³H] thymidine or 5-bromo-2'-deoxyuridine (BrdU). Incorporated[³H] thymidine and BrdU were detected by microautoradiographyor immunofiuorescence microscopy, respectively. Central cellsand cells just above the central cells of the quiescent centre(QC) showed an extremely low activity of DNA synthesis. However,DNA synthesis occurred in at least one organelle nucleoid ofall cells in the QC within 24 h. This suggests the cells inthe QC are quiescent with regard to nuclear DNA synthesis, butnot with regard to the organelle nucleoids. Key words: Arabidopsis thaliana, quiescent centre, root apical meristem, mitochondrial nucleoid (nuclei), plastid nucleoid (nuclei)     

Studies on the metabolism of a sulfur-oxidizing bacterium V. Comparative studies on sulfur and sulfite oxidizing systems of Thiobacillus thiooxidans

Properties of the oxidation systems of sulfur and sulfite ofa sulfur oxidizing bacterium, Thiobacillus thiooxidans, arecompared by using various inhibitors. Oxidation of sulfur isinhibited by a low concentration of monoiodoacetic acid, NEMand pCMB. Inhibition by pCMB is diminished by the addition ofan equivalent amount of cysteine to that of added pCMB. Althoughinhibition by pCMB is also observed in the oxidation of sulfite,it is not diminished by the addition of excess cysteine andthe extent of inhibition is lower than that in the oxidationof sulfur. Metal chelating agents, such as DDC, 8-hydroxyquinoline, salicylaldoximeand neocuproine have inhibitory effects on the oxidation ofsulfur but do not affect the oxidation of sulfite. Carbon monoxide inhibits the oxidation of sulfur photo-irreversiblyand the oxidation of sulfite photo-reversibly. Alcohols and organic acids, inhibit the oxidation of both sulfurand sulfite. The cell-free extract prepared by sonic disruptionof cells can oxidize sulfite, but not sulfur. The sulfur oxidizingextract can be, however, prepared by disruption under a nitrogenatmosphere. Both the soluble and participate fractions are requiredfor the oxidation of sulfur, while sulfite oxidation is catalyzedby the participate fraction alone. ¹Partly supported by a grant from the Ministry of Education.     

Biochemical and egg size evolution of freshwater fishes in the Rhinogobius brunneus complex (Pisces, Gobiidae) in Okinawa, Japan

Many colour morphs have been recognized in the Rhinogobius brunneus complex. A recent electrophoretic study has revealed that some of the colour morphs are well differentiated from each other genetically. In Okinawa, egg-size and life-history variation has been found in addition to the colour variation in this species complex. To clarify the nature of this life-history variation, gobies of a fluviatile morph with large eggs as well as three other amphidromous morphs with small eggs, inhabiting a single stream sympatrically in Okinawa, were analysed by electrophoresis and the females were also used for comparison of egg and clutch sizes. Electrophoretic data for 34 loci showed that each morph was separated by a fixed-allele difference for at least one locus, indicating that the four morphs which occurred sympatrically are reproductively isolated from each other. However, Nei's genetic distance between the fluviatile morph and one of the amphidromous morphs was much smaller (0.026) than distances among amphidromous gobies (0.323-0.480). Egg size of the former was by far the largest among the four. These results imply that speciation of the fluviatile morph accompanied by the egg-size increase has been completed rapidly without considerable genetic differentiation.     

Comparative Analysis of Melanins and Melanosomes Produced by Various Coat Color Mutants

Pigmentation in the skin, hair, and eyes of animals is influenced by a number of genes that modulate the activity of melanocytes, the intervention of enzymatic controls at different stages of the melanogenic process, and the physico-chemical properties of the final pigment. The results of combined phenotypic, ultrastructural, biochemical, and chemical analyses of hairs of a variety of defined genotypes on a common genetic background performed in this study are consistent with the view that pigmentation of dark to black hairs results from the incorporation of eumelanin pigments whereas that of yellow hairs results from the incorporation of eu- and pheomelanins. It is also clear that relatively minor differences in melanin content can have dramatic effects on visible hair color. A good correlation was found for expression of (and enzyme activities associated with) TRP1 and TRP2 with eumelanin synthesis and eumelanosome production.