A pair of rosette glands in the embryo and zoeal larva of an estuarine crab Sesarma haematocheir, and classification of the tegumental glands in the embryos of other crabs

A pair of rosette glands (one of the tegumental glands in crustaceans) is present at the root of the dorsal spine of the thorax in mature embryos of the estuarine crab Sesarma haematocheir. Each rosette gland is spherical, 45-50 microm in diameter. This gland consists of three types of cells: 18-20 secretory cells, one central cell, and one canal cell. The secretory cells are further classified into two types on the basis of the morphology of secretory granules. There are 17-19 a cells, and only one b cell per rosette gland. An a cell contains spherical secretory granules of 2-3 microm in diameter. The granules are filled with highly electron-dense materials near the nucleus but have lower electron-density near the central cell. The secretory granules contained in the b cell have an irregular shape and are 1-1.5 microm in diameter. The density of the materials in the granules is uniform throughout the cytoplasm. The secretory granules contained in both the a and b cells are produced by the rough endoplasmic reticulum. Materials in the granules are exocytotically discharged into the secretory apparatus inside the secretory cell, sent to the extracellular channels in the central cell, and secreted through the canal cell. The rosette gland can be distinguished from the epidermal cells 2 weeks after egg-laying and the gland matures just before hatching. Materials produced by this gland are secreted after hatching and secretion continues through five stages of zoeal larvae. These rosette glands were never found in the megalopal larva. Rosette glands are found in the embryos of Sesarma spp. and Uca spp. In other crabs, tegumental glands are also found at the same position as in the embryo of S. haematocheir, but the fine structure of their glands is largely different from that of the rosette gland. On the basis of the morphology of secretory cells (a-g cell types), the tegumental glands of a variety of crab embryos can be classified into four types, including rosette glands (type I-IV). The function of these tegumental glands is not yet known, but different types of the gland seem to reflect the phylogeny of the crabs rather than differences of habitat.     

Morphological and anatomical effects of abscisic acid (ABA) and fluridone (FLU) on the growth of rice mesocotyls

It has been reported that abscisic acid (ABA) promotes the growth ofrice mesocotyls. We investigated the effects of ABA and fluridone (FLU), aninhibitor of ABA biosynthesis, on the morphological and anatomicalcharacteristics of the mesocotyl of dark-grown rice seedlings. By 5 days aftersowing (DAS), the mesocotyl of control seedlings had reached their a maximumlength of 50.0 mm. In ABA treated seedlings, the mesocotylcontinued growing until 12 DAS, reaching a length of 152.6 mm.Mesocotyls treated with FLU elongated until 4DAS attaining a final length ofonly 10.5 mm. The data indicated that the greater length ofmesocotyls in seedlings treated with ABA was mainly due to their longer growingperiod. An anatomical study showed that the cell division activity of themesocotyl localised near the coleoptilar node and that ABA prolonged the celldivision activity of the meristem. The results suggested that ABA regulates thegrowth of rice mesocotyls by controlling the activity of the meristem localisednear the coleoptilar node.     

Mineral composition and accumulation of silicon in tissues of blueberry (Vaccinum corymbosus cv. Bluecrop) cuttings

Research was carried out with the objective of investigating the mineral composition and Si accumulation in tissues of young cuttings of blueberry (Vaccinum corymbosus L. cv. Bluecrop). Blueberry cuttings were irrigated every day for 1 hour (140 ml per pot) with river water containing 0.66 to 1.0 mol m^–3 SiO₂, and after 7 months of growth their mineral composition and silicon distribution were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mean contents of N, K, Mg, Cu and Zn in young leaves were the same as those in old ones. On the other hand, the mean contents of P, Ca, Si, Fe and Mn in old leaves were higher than those in young leaves. Although Si is not known to be an essential element for growth of blueberries, it was the element that accumulated the most in leaves, with a mean content of 32.0 and 60.0 mg g^–1 dry weight in young and old leaves, respectively. The mean Si content in young leaves was 3.1, 56.7, 4.8, 4.9 and 85 times higher than the mean contents of N, P, K, Ca and Mg, respectively, and was 5.4, 60.0, 8.8, 6.8 and 100 times higher than in old leaves. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis of dry ash samples showed that Si accumulated in many parts of the leaves, forming phytoliths in the upper epidermis, including some parts of the palisade mesophyll, in the lower epidermis around the stomata, including guard cells, and in some parts of the spongy mesophyll, and in the veins. There were also silica bodies of unknown origin on the upper epidermis.     

基于涡度协方差法和生理生态法对落叶松林CO2通量的初步研究

 该文利用涡度协方差法和生理生态学方法（不同分量的累积和）获得的通量观测数据,对老山落叶松(Larix gmelinii)林(45°20′N, 127°34 ′E)的碳收支进行了分析。通过对每0.5 h所测数据进行的分析表明,能量平衡达到75％,说明涡度协方差法适应于本站的研究。较阴天气情况 下,林分光照利用效率显著高于晴朗天气,可能归因于阴天较多的散射光。以单位土地面积计算发现,通过涡度协方差法计算的落叶松林生态 系统的总初级生产力在20～50 μmol•m^-2•s^-1之间,远高于冠层叶片的总光合速率9.8～23.4μmol•m^-2•s^-1 (平均值16.2μmol•m^-2•s^-1 ),而 当综合考虑冠层光合和林下植物光合作用时,两种方法测定结果吻合性较好,说明林下植物对落叶松林碳平衡有重要影响。在估计森林生态系 统呼吸方面,以有风夜晚净生态系统交换量（NEE）来代表生态系统呼吸总量（3～9μmol•m^-2•s^-1）低估了生态系统呼吸总量,粗略估计较生 理生态学方法（不同呼吸分量的累积和）低估了50%左右（14.2μmol•m^-2•s^-1）。结果发现两种方法在估计森林碳平衡方面存在一定的差异, 呼吸量的估计差异应是今后研究的重点。     

Increased mRNA Levels of Sphingosine Kinases and S1P Lyase and Reduced Levels of S1P Were Observed in Hepatocellular Carcinoma in Association with Poorer Differentiation and Earlier Recurrence

Although sphingosine 1-phosphate (S1P) has been reported to play an important role in cancer pathophysiology, little is known about S1P and hepatocellular carcinoma (HCC). To clarify the relationship between S1P and HCC, 77 patients with HCC who underwent surgical treatment were consecutively enrolled in this study. In addition, S1P and its metabolites were quantitated by LC-MS/MS. The mRNA levels of sphingosine kinases (SKs), which phosphorylate sphingosine to generate S1P, were increased in HCC tissues compared with adjacent non-HCC tissues. Higher mRNA levels of SKs in HCC were associated with poorer differentiation and microvascular invasion, whereas a higher level of SK2 mRNA was a risk factor for intra- and extra-hepatic recurrence. S1P levels, however, were unexpectedly reduced in HCC compared with non-HCC tissues, and increased mRNA levels of S1P lyase (SPL), which degrades S1P, were observed in HCC compared with non-HCC tissues. Higher SPL mRNA levels in HCC were associated with poorer differentiation. Finally, in HCC cell lines, inhibition of the expression of SKs or SPL by siRNA led to reduced proliferation, invasion and migration, whereas overexpression of SKs or SPL enhanced proliferation. In conclusion, increased SK and SPL mRNA expression along with reduced S1P levels were more commonly observed in HCC tissues compared with adjacent non-HCC tissues and were associated with poor differentiation and early recurrence. SPL as well as SKs may be therapeutic targets for HCC treatment.     

Scaling-up technique for net ecosystem productivity of deciduous broadleaved forests in Japan using MODIS data

We attempted to obtain carbon sequestration maps of deciduous forests in Japan using detectable parameters from the Moderate Resolution Imaging Spectrometer (MODIS) sensor and to determine how the spatial pattern of carbon sequestration differs within the same forest ecosystem type. For this investigation, we firstly parameterized the MODIS algorithm at one flux tower site, Takayama, for the years 2002–2003. The MODIS algorithm could link flux-based net ecosystem productivity (NEP) with simple functions controlled by a thermal infrared band and a vegetation index. Second, the performance of the MODIS algorithm was validated through comparisons with the flux-based NEP at another flux tower site, Hitsujigaoka. The MODIS-based NEP at Hitsujigaoka was also within an accuracy of a flux-based NEP with R ² of 0.879 and root mean square error of 1.64 gC m⁻² day⁻¹, regardless of canopy structure and age. The MODIS algorithm was noteworthy for its general applicability in different locations. Finally, we used the MODIS algorithm for the same forest ecosystem type in Japan for regional extrapolation of NEP. The MODIS-based NEP of deciduous forests in Japan showed great variance with 347 ± 288 gC m⁻² year⁻¹ in 2002, according to the stand structure and climatic condition of the year. Studies for quantification of ecosystem carbon balance need to consider variance, frequency and spatial distributions of NEP. Satellite remote sensing demonstrated the potential for the large-scale mapping of NEP.     

Microsite variation in light availability and photosynthesis in a cool-temperate deciduous broadleaf forest in central Japan

An empirical light simulation model was applied to estimate stand scale photosynthesis in a deciduous broadleaved forest in central Japan. Based on diurnal courses of photosynthetically active photon flux density (PPFD), we characterized the components of incoming light within the forest canopy, and found that the instantaneous relative PPFD (PPFD under the canopy relative to that above the canopy) under diffuse light condition was a reliable estimator of the intensity and duration of PPFD. We calculated the daily photosynthesis (A_day) for each PPFD class using photosynthesis–light response curves. Model simulated A_day were corroborated with the estimates obtained from the nearby CO₂ flux tower. The result demonstrated the potential of the light simulation model. The light use efficiency of two dominant species, Betula ermanii as overstory and Sasa senanensis as understory species, were then evaluated. At the forest understory, PPFD under 50 mol m^–2 s^–1 contributed to 77% of the sunshine duration on a completely clear day. Therefore, a higher apparent quantum yield for S. senanensis enhanced the utilization of low PPFD for photosynthesis. On the other hand, at the upper forest canopies, B. ermanii with a higher light-saturated photosynthetic rate used high PPFD efficiently. Consequently, potential of daily net photosynthesis for both B. ermanii and S. senanensis was high under each light condition. Such interspecific difference in the patterns of light utilization was suggested as one of factors allowing coexistence of the two species in the study forest.     

Autotaxin–lysophosphatidic acid–LPA3 signaling at the embryo‐epithelial boundary controls decidualization pathways

During pregnancy, up‐regulation of heparin‐binding (HB‐) EGF and cyclooxygenase‐2 (COX‐2) in the uterine epithelium contributes to decidualization, a series of uterine morphological changes required for placental formation and fetal development. Here, we report a key role for the lipid mediator lysophosphatidic acid (LPA) in decidualization, acting through its G‐protein‐coupled receptor LPA₃ in the uterine epithelium. Knockout of Lpar3 or inhibition of the LPA‐producing enzyme autotaxin (ATX) in pregnant mice leads to HB‐EGF and COX‐2 down‐regulation near embryos and attenuates decidual reactions. Conversely, selective pharmacological activation of LPA₃ induces decidualization via up‐regulation of HB‐EGF and COX‐2. ATX and its substrate lysophosphatidylcholine can be detected in the uterine epithelium and in pre‐implantation‐stage embryos, respectively. Our results indicate that ATX–LPA–LPA₃ signaling at the embryo‐epithelial boundary induces decidualization via the canonical HB‐EGF and COX‐2 pathways.     

Entrainment of a semilunar rhythm by a simulated moonlight cycle in the terrestrial crab,Sesarma haematocheir

Summary Sesarma haematocheir is a species of terrestrial crabs inhabiting hillsides and paddy fields near the sea. Females show a semilunar rhythm of zoea-release coinciding with days of spring tides and in addition with the time of high water occurring at the nearby seacoast about dusk. Nature of environmental stimuli or zeitgebers that induce the semilunar rhythm of zoea-release was examined experimentally. In case that a population of males and females was kept under the condition of a 24-h light-dark cycle (LD 14:10) only, females showed a free-running semilunar rhythm of egg-laying and zoea-release synchronized from field conditions. On the other hand, a semilunar rhythm of egg-laying and zoea-release was entrained by the combination of the 24-h LD and a simulated 24.8-hr moonlight cycle of which the phase was shifted in relation to the natural lunar cycle. This result suggests that the 24.8-h moonlight cycle acts as a zeitgeber of a semilunar rhythm. The 12.4-h tidal cycle parallels with the 24.8-h moonlight cycle in the field. On the basis of the perception of a distinct phase relationship between the 24-h LD and the 24.8-h moonlight cycle, it is considered that crabs substitute the 24.8-h moonlight cycle for the 12.4-h cycle of tides as a zeitgeber to synchronize the phase of the semilunar rhythm with a tidal situation.     

Phylogenetic analysis of paraneopteran orders (Insecta: Neoptera) based on forewing base structure, with comments on monophyly of Auchenorrhyncha (Hemiptera)

Phylogenetic relationships among three paraneopteran clades (Psocodea, Hemiptera and Thysanoptera) were analysed based on the morphology of forewing base structure. Monophyly of Paraneoptera was supported by nine autapomorphies, monophyly of Condylognatha (= Thysanoptera + Hemiptera) by two autapo‐ morphies, monophyly of Thysanoptera by five autapomorphies and monophyly of Hemiptera by one autapomorphy. Thus, (Psocodea + (Thysanoptera + Hemiptera)) were proposed to be the phylogenetic relationships within Paraneoptera. A homoplastic similarity of the third axillary sclerite was observed between Thysanoptera and Heteroptera, and a possible evolutionary factor providing this homoplasy was discussed. The present analysis also suggested a monophyletic Auchenorrhyncha, and reduction of the proximal median plate was considered as an autapomorphy of this clade.