ISOLATION AND CHARACTERIZATION OF A PRESPORE SPECIFIC STRUCTURE OF THE CELLULAR SLIME MOLD, DICTYOSTELIUM DISCOIDEUM

A method was described for isolation of the prespore specific vacuole (PSV) from slugs of the cellular slime mold, D. discoideum . A cellular component, which was fractionated in accordance with immunohistochemical staining using heteroplastic antispore serum, was found to consist of only the PSV. It was thus concluded that the PSV is identical with the cytoplasmic granule which has been shown by the antiserum to be specifically present in the prespore cell, and hence that the PSV is the only structure which contains the prespore specific substance (antigenic mucopolysaccharide). The isolated PSV contained polysaccharide equivalent to 14% of its protein content, and antigenic mucopolysaccharide constitutes about 60% of the total polysaccharide.     

PERIODIC CHANGES IN THE CONTENT OF PROTEIN-BOUND SULFHYDRYL GROUPS AND TENSION AT THE SURFACE OF STARFISH OOCYTES IN CORRELATION WITH THE MEIOTIC DIVISION CYCLE*

The sulfhydryl content of protein and the tension at the surface were measured for starfish oocytes from the first meiotic division to the cleavage stage. A cyclic change in both the protein-SH and the tension at the surface was found to accompany the division cycle, including the first and second meiotic divisions. It is concluded that the unequal meiotic divisions share the same character with the equal divisions of cleavage, with respect to changes both in the protein-SH and the tension at the surface.     

基于matR基因序列分析的山茶科系统关系

通过线粒体matR基因序列分析探讨了山茶科的分类学范围和系统演化关系。结果显示,传统山茶科的两个核心——山茶亚科（Theoideae或Camellioideae）和厚皮香亚科（Ternstroemioideae）不构成姐妹群关系,山茶亚科是一个支持率很高的单系类群,厚皮香亚科没有形成单系;山茶亚科下可区分出3个明显的分支,基部的分支由紫茎属（Stewartia）和舟柄茶属（Hartia）组成,木荷属（Schima）、美洲荷属（Franklirda）和美国大头茶属（Gordonia）构成第2个分支,该分支与由山茶属（Camellia）、核果茶属（Pyrenaria）、多瓣核果茶属（Parapyrenaria）、石笔木属（Tutcheria）、大头荣属（Polyspora）和圆籽荷属（Aptersperma）组成的第3个分支互为姐妹群。研究结果很好地支持了Prince和Parks等学者提出的的狭义山茶科（仅含山茶亚科）和狭义大头茶属的概念以及科下3个族（紫茎族Stewartieae、大头茶族Gordonieae和山茶族Theeae）的划分。但本研究更为清晰地揭示了科下3个族间的系统关系,即紫茎族是最基部的分支,山茶族与大头茶族间有更近的亲缘关系。同时,本文认为,厚皮香（亚）科是否为单系类群值得进一步研究。     

Revision of the Euthalia phemius complex (Lepidoptera: Nymphalidae) based on morphology and molecular analyses

Adults of the Euthalia phemius complex, which is composed of three South‐East Asian nymphalid species, Euthalia phemius, Euthalia ipona, and Euthalia euphemia, were genetically analysed by examining mitochondrial and nuclear genes. The E. phemius complex was also examined morphologically, with particular emphasis on wing markings and male genitalia. No significant differences amongst the three species in the complex were detected with respect to either genetic distance or genital morphology. We therefore conclude that the three currently recognized Euthalia species belong to a single species. Accordingly, E. ipona is synonymized with E. phemius. Euthalia euphemia is treated as a subspecies of E. phemius. Type specimens of all taxa and a synonymic list for the E. phemius complex are also given. In addition, we briefly discuss the evolution and biogeography of the species complex. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 304–327.     

Ommochrome Deficiency in an Albino Strain of a Terrestrial Isopod,Armadillidium vulgare

In order to clarify the cause of ommochrome deficiency in an albino strain of the terrestrial isopod, Armadillidium vulgare, levels of xanthom-matin, 3-hydroxykynurenine, 3-hydroxyanthranilic acid and tryptophan in whole body extracts of the albino and the wild type individuals were determined together with enzyme activities of kynurenine-3-hydroxylase, kynureninase and tryptophan-2,3-dioxygenase. Xanthommatin could not be detected in the albinos. The levels of 3-hydroxykynurenine and 3-hydroxyanthranilic acid were determined by high-performance liquid chro-matography (HPLC) with electrochemical detection and were markedly low in the albinos compared with the wild type individuals. In contrast to those, the tryptophan levels determined by HPLC with fluorescence detection did not differ significantly between the two phenotypes. In the albino A. vulgare, kynurenine-3-hydroxylase activity was lower and kynureninase activity was higher than in the wild type, although the differences were not statistically significant. Tryptophan-2,3-dioxygenase activity in the albinos was less than 10% that in the wild type. Thus, ommochrome deficiency in the albino A. vulgare is considered to be caused by the extremely low activity of tryptophan-2,3-dioxygenase.     

Isolation and characterization of microsatellite DNA markers from mangrove crab,Scylla paramamosain

The first five variable microsatellite DNA loci for mangrove crab, Scylla paramanosain, were developed. Allelic variation and other characteristics at these loci were examined in this species captured at the Urado Bay, Japan. The number of alleles per locus ranged from 24 to 44. The expected heterozygosity across loci ranged from 0.900 to 0.999 and probability of identity (P_I) ranged from 2.8 × 10^?3 to 1.7 × 10^?2. Therefore, these microsatellite markers could be useful for estimating effect of stock enhancement release and population genetic structure of mangrove crab.     

Quantitative aspects of heterogeneity in soil organic matter dynamics in a cool-temperate Japanese beech forest: a radiocarbon-based approach

Soil is the largest carbon reservoir in terrestrial ecosystems; it stores twice as much carbon as the atmosphere. It is well documented that global warming can lead to accelerated microbial decomposition of soil organic carbon (SOC) and enhance the release of CO₂ from the soil to the atmosphere; however, the magnitude and timing of this effect remain highly uncertain due to a lack of quantitative data concerning the heterogeneity of SOC biodegradability. Therefore, we sought to identify SOC pools with respect to their specific mean residence times (MRTs), to use those SOC pools to partition soil respiration sources, and to estimate the potential response of the pools to warming. We collected surface soil and litter samples from a cool-temperate deciduous forest in Japan, chemically separated the samples into SOC fractions, estimated their MRTs based on radiocarbon (¹⁴C) isotope measurements, and used the data to construct a model representing the soil as a complex of six SOC pools with different MRT ranges. We estimate that a minor, fast-cycling SOC pool with an MRT of less than 10 years (corresponding to the O horizon and recognizable plant leaf fragments in the A1 horizon) is responsible for 73% of annual heterotrophic respiration and 44% of total soil respiration. However, the predicted response of these pools to warming demonstrates that the rate of SOC loss from the fast-cycling SOC pool diminishes quickly (within several decades) because of limited substrate availability. In contrast, warming will continue to accelerate SOC loss from slow-cycling pools with MRTs of 20–200 years over the next century. Although using a ¹⁴C-based approach has drawbacks, these estimates provide quantitative insights into the potential importance of slow-cycling SOC dynamics for the prediction of positive feedback to climate change.     

Different phylogeographic patterns in two Japanese Silpha species (Coleoptera: Silphidae) affected by climatic gradients and topography

To reveal differences in phylogeographic patterns of flightless insect species occurring in different regions of Japan, we studied the phylogeography and demographic history of Silpha beetles occurring in cool-temperate habitats of two major islands, Honshu and Hokkaido, using sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. Honshu has a more mountainous topography, and cool-temperate habitats occur discontinuously, whereas Hokkaido, located to the north of Honshu, has more continuous cool-temperate habitats. A species endemic to Honshu, S. longicornis occurs on Honshu, whereas S. perforata occurs on Hokkaido and the East Asian continent. Our results indicate that the ancestors of S. longicornis colonized Honshu via a south-west route c . 0.7 Mya and the species has highly divergent populations in isolated mountainous areas of Honshu, whereas S. perforata colonized Hokkaido via a northern route less than 90 000 years ago and has less divergent geographic populations. During the last glacial period, S. perforata was probably restricted to refugia in southern Hokkaido and later expanded into northern Hokkaido, whereas S. longicornis populations existed in many isolated refugia, probably because of the complex topography of Honshu. Thus, our study demonstrates that, even between closely related species, interactions among biology, latitudinal climatic gradients and topography can produce different phylogeographic patterns.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 452–467.