Fruit structure of Amborella trichopoda (Amborellaceae)

The indehiscent fruitlets of the apparently basalmost extant angiosperm, Amborella trichopoda, have a pericarp that is differentiated into five zones, a thin one‐cell‐layered skin (exocarp), a thick fleshy zone of 25–35 cell layers (outer mesocarp), a thick, large‐celled sclerenchymatous zone (unlignified) of 6–18 cell layers (middle mesocarp), a single cell layer with thin‐walled (silicified?) cells (inner mesocarp), and a 2–4‐cell‐layered, small‐celled sclerenchymatous zone (unlignified) derived from the inner epidermis (endocarp). The border between inner and outer mesocarp is not even but the inner mesocarp forms a network of ridges and pits; the ridges support the vascular bundles, which are situated in the outer mesocarp. In accordance with previous observations by Bailey & Swamy, no ethereal oil cells were observed in the pericarp; however, lysigenous cavities as mentioned by these authors are also lacking; they seem to be an artefact caused by re‐expanding dried fruits. The seed coat is not sclerified. The fruitlets of Amborella differ from externally similar fruits or fruitlets in other basal angiosperms, such as Austrobaileyales or Laurales, in their histology. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 148 , 265–274.     

Analysis of genetic variability of Fusarium oxysporum f. sp. cepae the causal agent of basal rot on onion using RAPD markers

Genetic variability among isolates of Fusarium oxysporum f. sp. cepae was obtained from different onion-growing areas of Tamil Nadu, India. Random amplified polymorphic DNA (RAPD) analysis was carried out using 12 random primers, each of them consisting of 10 base pairs. Four out of the 12 primers were differentiated between some of the tested F. oxysporum f. sp. cepae isolates. Analysis of the genetic coefficient matrix derived from the scores of RAPD profile showed that minimum and maximum per cent similarities among the F. oxysporum f. sp. cepae isolates were in the range of 14–85%. Cluster analysis, using the unweighted pair-group method with arithmetic average, clearly separated the isolates into two clusters (A and B) confirming the genetic diversity among the isolates of F. oxysporum f. sp. cepae from onion.     

Canopy structure of tropical and sub-tropical rain forests in relation to conifer dominance analysed with a portable LIDAR system

Background and Aims

Globally, conifer dominance is restricted to nutient-poor habitats in colder, drier or waterlogged environments, probably due to competition with angiosperms. Analysis of canopy structure is important for understanding the mechanism of plant coexistence in relation to competition for light. Most conifers are shade intolerant, and often have narrow, deep, conical crowns. In this study it is predicted that conifer-admixed forests have less distinct upper canopies and more undulating canopy surfaces than angiosperm-dominated forests.

Methods

By using a ground-based, portable light detection and ranging (LIDAR) system, canopy structure was quantified for old-growth evergreen rainforests with varying dominance of conifers along altitudinal gradients (200–3100 m a.s.l.) on tropical and sub-tropical mountains (Mount Kinabalu, Malaysian Borneo and Yakushima Island, Japan) that have different conifer floras.

Key Results

Conifers dominated at higher elevations on both mountains (Podocarpaceae and Araucariaceae on Kinabalu and Cupressaceae and Pinaceae on Yakushima), but conifer dominance also varied with soil/substrate conditions on Kinabalu. Conifer dominance was associated with the existence of large-diameter conifers. Forests with higher conifer dominance showed a canopy height profile (CHP) more skewed towards the understorey on both Kinabalu and Yakushima. In contrast, angiosperm-dominated forests had a CHP skewed towards upper canopy, except for lowland dipterocarp forests and a sub-alpine scrub dominated by small-leaved Leptospermum recurvum (Myrtaceae) on Kinabalu. Forests with a less dense upper canopy had more undulating outer canopy surfaces. Mixed conifer–angiosperm forests on Yakushima and dipterocarp forests on Kinabalu showed similar canopy structures.

Conclusions

The results generally supported the prediction, suggesting that lower growth of angiosperm trees (except L. recurvum on Kinabalu) in cold and nutrient-poor environments results in a sparser upper canopy, which allows shade-intolerant conifers to co-occur with angiosperm trees either as emergents or as codominants in the open canopy.     

Novel SLC20A2 mutations identified in southern Chinese patients with idiopathic basal ganglia calcification

Idiopathic basal ganglia calcification (IBGC) is a rare neuropsychiatric disorder characterized by bilateral and symmetric cerebral calcifications. Recently, SLC20A2 was identified as a causative gene for familial IBGC, and three mutations were reported in a northern Chinese population. Here, we aimed to explore the mutation spectrum of SLC20A2 in a southern Chinese population. Sanger sequencing was employed to screen mutations within SLC20A2 in two IBGC families and 14 sporadic IBGC cases from a southern Han Chinese population. Four novel mutations (c.82G > A p.D28N, c.185T > C p.L62P, c.1470_1478delGCAGGTCCT p.Q491_L493del and c.935-1G > A) were identified in two families and two sporadic cases, respectively; none were detected in 200 unrelated controls. No mutation was found in the remaining 12 patients. Different mutations may result in varied phenotypes, including brain calcification and clinical manifestations. Our study supports the hypothesis that SLC20A2 is a causative gene of IBGC and expands the mutation spectrum of SLC20A2, which facilitates the understanding of the genotype–phenotype correlation of IBGC.     

卤虫投喂下长吻(鱼危)仔稚鱼消化酶发育和口宽变化的研究

采用酶学和形态学测定方法, 研究在投喂卤虫条件下长吻(鱼危)仔鱼4种主要消化酶: 胃蛋白酶、胰蛋白酶、脂肪酶和淀粉酶的活性变化以及长吻(鱼危)仔鱼口宽、全长变化。实验共进行13d, 实验结果表明: (1)长吻(鱼危)仔鱼全长、口宽的发育与其日龄表现出明显的线性正相关(R_TL²=0.974, R_MW²=0.964)。口宽与全长比值(MW/TL)在仔鱼开口后急剧下降, 并自7日龄开始维持在0.07—0.08, 口宽和全长处于同步发育期并表现出明显的相关性(R²=0.948), 说明7日龄(/h, days post hatching)后口宽和全长处于同步发育期, 标志仔鱼转食的开始。(2)长吻(鱼危)仔鱼初次开口时即可检测出四种消化酶的活性。5—7/h时胰蛋白酶显著高于初孵仔鱼, 与此时仔鱼开始开口摄食的行为相一致。胃蛋白酶、脂肪酶活性在仔鱼孵化后第7天即开口的第3天, 淀粉酶活性在孵化后第6天, 显著高于初次孵化出来的仔鱼。8—13/h时, 胃蛋白酶、胰蛋白酶、脂肪酶和淀粉酶活性均在较高水平平稳的波动, 标志着消化道发育逐渐健全。     

Basal metabolic rate is positively correlated with parental investment in laboratory mice

The assimilation capacity (AC) hypothesis for the evolution of endothermy predicts that the maternal basal metabolic rate (BMR) should be positively correlated with the capacity for parental investment. In this study, we provide a unique test of the AC model based on mice from a long-term selection experiment designed to produce divergent levels of BMR. By constructing experimental families with cross-fostered litters, we were able to control for the effect of the mother as well as the type of pup based on the selected lines. We found that mothers with genetically determined high levels of BMR were characterized by higher parental investment capacity, measured as the offspring growth rate. We also found higher food consumption and heavier visceral organs in the females with high BMR. These findings suggested that the high-BMR females have higher energy acquisition abilities. When the effect of the line type of a foster mother was controlled, the pup line type significantly affected the growth rate only in the first week of life, with young from the high-BMR line type growing more rapidly. Our results support the predictions of the AC model.     

Ezrin蛋白在眼睑基底细胞癌组织中的表达及其意义

目的探讨Ezrin蛋白在眼睑基底细胞癌组织中的表达。方法收集武汉市中心医院和武汉大学人民医院病理科2002—2009年手术切除及活检的眼睑基底细胞癌（basalcellcarcinoma,BCC）标本共20例,另取癌周围组织5例作对照。采用免疫组织化学方法观察各组细胞内Ezrin蛋白表达。利用图像分析系统测定Ezrin蛋白在以上各组中表达的平均光密度和平均阳性面积率。结果眼睑基底细胞癌组织中Ezrin蛋白呈高表达;癌旁组织中Ezrin蛋白呈低表达。图像分析结果显示：眼睑基底细胞癌组织与癌旁组织之间Ezrin蛋白的平均光密度及阳性面积率的差异有显著性意义（P〈0．05）。结论Ezrin蛋白在眼睑基底细胞癌的发生、发展过程中起了重要作用。     

PSCA和Oct-4蛋白在眼睑基底细胞癌组织中的表达及其意义

目的 探讨PSCA和Oct-4蛋白在眼睑基底细胞癌组织中的表达及其意义.方法 收集武汉市中心医院和武汉大学人民医院病理科2002～2009年手术切除及活检的眼睑基底细胞癌（basal cell carcinoma,BCC）标本共20例,另取癌周围组织5例作对照.采用免疫组织化学方法观察各组细胞内PSCA和Oct-4蛋白的表达.利用图像分析系统测定PSCA和Oct-4蛋白在以上各组中表达的平均光密度和平均阳性面积率.结果 （1）PSCA的表达在眼睑基底细胞癌中,PSCA呈高表达,而癌周围组织中PSCA呈低表达.经q 检验,眼睑基底细胞癌组织与癌旁组织之间PSCA的平均光密度及阳性面积率的差异有显著性意义（P〈0.05）.（2）Oct-4的表达眼睑基底细胞癌组织中Oct-4蛋白呈高表达;癌旁组织中Oct-4蛋白呈低表达.图像分析结果显示：眼睑基底细胞癌组织与癌旁组织之间Oct-4蛋白的平均光密度及阳性面积率的差异有显著性意义（P〈0.05）.结论 在眼睑基底细胞癌组织中PSCA和Oct-4蛋白的高表达可能是＂癌干细胞＂,PSCA和Oct-4蛋白也许参与了眼睑基底细胞癌的发生和发展.     

衡阳紫色土丘陵坡地不同恢复阶段土壤基础呼吸及代谢熵的变化

采用空间序列代替时间序列的方法,对衡阳紫色土丘陵坡地不同过程中的不同土层、根际(Rhizosphere,R)与非根际(Non-rhizosphere,S)的土壤基础呼吸(Soil basal respiration,SBR)及代谢熵(Metabolic quotient,qCO2)的变化特征以及它们与土壤理化性质的关系进行研究。结果表明：(1)不同恢复阶段SBR与qCO2存在明显差异,从裸地(Ⅰ)、草本群落(Ⅱ)、灌木群落(Ⅲ)至乔木群落阶段(Ⅳ),SBR显著增强,qCO2显著减小,反映土地质量正在逐渐恢复;(2)不同恢复阶段SBR与qCO2存在垂直变化特征,从0～20cm、20～40cm至40～60cm土层, SBR显著减弱,qCO2显著增加;(3)从Ⅱ→Ⅳ,R与S变化明显,R与S的SBR均显著增强, R/S显著减小,表现出R＞S的特点,R与S的qCO2的逐渐减小, R/S逐渐上升,也表现出R＞S的特点,因此,创造更好的土壤条件有利于该区域植被恢复。