PHYLOGENOMICS AND SECONDARY PLASTIDS: A LOOK BACK AND A LOOK AHEAD1

Despite their importance to evolution, ecology, and cell biology, eukaryotes that acquired plastids through secondary endosymbiosis remain poorly studied from a genomic standpoint. Chromalveolata, a eukaryotic supergroup proposed to have descended from a heterotrophic eukaryote that acquired a red algal plastid by secondary endosymbiosis, includes four major lineages (alveolates, cryptophytes, haptophytes, and heterokonts). The chromalveolates exhibit remarkable diversity of cellular organization, and the available data suggest that they exhibit equal diversity in their genome organization. One of the most obvious differences in cellular organization is the retention of a highly reduced red algal nucleus in cryptophytes (also known as cryptomonads), but there are other major differences among chromalveolate lineages, including the loss of photosynthesis in multiple lineages. Although the hypothesis of chromalveolate monophyly is appealing, there is limited support for the hypothesis from nuclear genes, and questions have even been raised about the monophyly of chromalveolate plastids. Evidence for the chromalveolate hypothesis from large‐scale nuclear data sets is reviewed, and alternative hypotheses are described. The potential for integrating information from chromalveolate genomics into functional genomics is described, emphasizing both the methodological challenges and the opportunities for future phylogenomic analyses of these groups.     

PRODUCTIVITY AND COMPOSITION OF A BALDCYPRESS-WATER TUPELO SITE AND A BOTTOMLAND HARDWOOD SITE IN A LOUISIANA SWAMP

The productivity and composition of two study sites in a southern Louisiana freshwater swamp were studied from October 1973 to November 1974. Net productivity was determined from measurements of litter-fall, stem growth of woody species, and harvest samples of annual herbaceous understory. Annual stem growth was calculated from biomass estimates on two different dates. The annual increase in stem biomass was 800 g dry wt/m² for a bottomland hardwood site (BLH) and 500 g dry wt/m² for a baldcypress-water tupelo site (CT). Litter-fall was 574 g dry wt/m²/yr for BLH and 620 g dry wt/m²/yr for CT. Harvest samples within the two plots yielded 200 g dry wt/m² and 20 g dry wt/m² for BLH and CT, respectively. Minimum net primary production was calculated as the sum of the three: 1574 g dry wt/m²/ yr for BLH and 1140 g dry wt/m²/yr for CT. Maximum estimates of herbaceous production and insect consumption were made by using values from the literature. Estimated total net primary productivity was 1733 g dry wt/m²/yr for BLH and 1516 g dry wt/m²/yr for CT. Tree composition was determined by the point-centered quarter method. Relative frequency, relative density, absolute density, relative dominance, and importance value (IV) were calculated for the tree species along each transect. In the bottomland hardwood area many woody species exist with Acer rubrum var. drummondii (IV = 23.9) and Nyssa aquatica (IV = 18.4) the most dominant. In the baldcypress-water tupelo area, fewer woody species exist and Taxodium distichum (IV = 39.2) and N. aquatica (IV = 37.6) dominated. Comparison of productivity data from several southeastern swamps indicate that flowing water regimes tend to result in the highest swamp forest productivity.     

曲霉及其有性型散囊菌的新分类群和新记录种

在收集和分离我国曲霉工作中,发现一个国内新纪录和三个新分类群:1.埃及曲霉,国内新记录。2.合阳曲霉新种,与爪甲曲霉相近,但颜色和具刺不育菌丝有所不同。3.温特曲霉烟色变种,与原变种的主要区别在于颜色为蓝灰色并具异常膨大的梗基。4.瘤突散囊菌新种,其子囊孢子的纹饰独特,凸面具粗疏瘤状突起。     

DIFFICULTIES AND A WAY OUT: A BAYESIAN APPROACH FOR SENSORY DIFFERENCE AND PREFERENCE TESTS

There are some theoretical difficulties in the philosophy and methodology of sensory difference and preference tests. The difficulties lie in the assumption that the subjects have the same response ability, which is in conflict with psychological ideas about the processes of perception and decision. A Bayesian approach may overcome these difficulties by treating the parameter of proportion as a random variable. This paper presents a Bayesian approach for analysis of data from such sensory tests.     

国产铁青树科植物的订正与补充报导以及有关该科的分类和区系等若干问题的初步探讨

本文除对中国铁青树科植物作一订正与补充报导外,还对该科起源、分类、区系等若干问题作一初步的探讨。作者根据该科具多类型的特征,如形态、解剖等既有原始性状,又有略进化的特点,特别是少数种木质部导管有梯状穿孔以及古植物孢粉和化石分别出现于晚白垩纪或早第三纪等资料,认为该科可能起源于白垩纪,起源中心可能接近于古地中海西部的南美洲东北部热带古陆地区,而亚洲南部热带古陆地区是分化中心之一,同时怍者在研究该目各科及邻近目、科的分类、解剖及孢粉形态后提出:另立铁青树目的主张是合理的,该目可能起源于从木兰目中已灭绝的原始类群向蔷薇目进化过程中派生的一个分枝上衍生出的一个目,在这分枝的早期还先后分化出山龙眼目、卫矛目、鼠李目等,这几个目均具多类型、即既具有原始性状、又具有稍进化的过渡性的特征,另外在这分枝的中、后期,还衍生出进化类型的檀香目及蛇菰目,此外作者研究了赤苍藤属分类及花粉特征后,认为该属仍是铁青树科的范畴,不应另立为赤苍藤科,但该属又与铁青树科已知的三亚科性状有明显区别,因此建议在该科下另立一新亚科——赤苍藤亚科。     

正四面体晶格的计数、分布及其应用

本文引入正四面体晶格（简称D晶格）、D格点、D格点简并度等新概念,对正四面体晶格的计数及分布规律进行了系统地研究,从归纳法和组合数学两条途径均得出了正四面体的顶点、棱上、面上、体内及总的D格点数的一般公式,而且得到了其D格点简并度的表达式;归纳总结出了D格点碱基组分表及分布规律．解释了经验方程〔1〕;计算了人的46条染色体DNA分子的简并度,探讨了不同生物种类DNA的排序花样．     

几种不同条件下竹红菌甲素的光谱特性

本文报道了不同浓度竹红菌甲素的吸收光谱.甲素在不同比例的二甲基亚砜与HEPES溶液中的荧光光谱,试验了甲素与几种生物物质的结合,说明脂溶性的甲素能与类脂很好的结合,甲素光照后对红细胞膜的损伤大于白蛋白和色氨酸,说明生物膜是甲素光敏作用较好的靶.     

LYSOSOMAL PHOSPHOLIPASES A1 AND A2 OF NORMAL AND BACILLUS CALMETTE GUERIN-INDUCED ALVEOLAR MACROPHAGES

A single intravenous injection of 0.1 mg of heat-killed Bacillus Calmette Guérin (BCG) in 0.1 ml of Bayol F produced an accumulation of activated alveolar macrophages (BCG induced). Cells were collected 3.5–4.0 wk after injection. Phospholipases A and three lysosomal marker enzymes (acid phosphatase, β-glucuronidase, and lysozyme) were measured in homogenates, and the distribution of the phospholipases A and lysosomal, mitochondrial, and microsomal marker enzymes were examined after sucrose gradient centrifugation of a postnuclear (1,000 g) supernatant. Homogenates of normal and BCG-induced macrophages contained phospholipases A₁ and A₂ which had optimal activity at pH 4.0 in the presence of 2.0 mM ethylenediaminetetraacetate (EDTA). These activities were inhibited 50–70% by 2.0 mM CaCl₂. Homogenates of BCG-induced macrophages had specific activities of β-glucuronidase, acid phosphatase, and lysozyme, which were increased 1.5- to 3.0-fold over the controls, whether expressed as activity per mg protein or activity per 10⁷ cells. The specific activities of the phospholipases A, on the other hand, were consistently lower than those of the control. Distribution of the phospholipases A and the lysosomal marker enzymes after sucrose gradient centrifugation suggested that the phospholipases A active at pH 4.0 in the presence of EDTA are of lysosomal origin since: (a) BCG treatment caused a selective increase in the density of particles which contained both the phospholipases A and three lysosomal marker enzymes; and (b) since the density of mitochondria and microsomes were not affected by BCG treatment. The increase in the density of lysosomes seen here may be related to previously described morphologic changes of BCG-induced alveolar macrophages.     

中国叶螨科一新属新种暨叶螨科分亚科、分族检索表(蜱螨目)

叶螨科(Tetranychidae Donnadieu,1875)迄今分为2亚科6族78属,其中苔螨亚科(Bryobiinae Berlese,1913)32属,叶螨亚科(Tetranychinae Berlese,1913)33属。作者在鉴定江西叶螨标本时,发现一新属、新种。其形态特征均不同于上述6族,故建立一新族——华苔螨族(Sinobryobiini trib.nov.),置于苔螨亚科中。同时,该新族只有2对肛毛,须肢跗节有小型的端感器,又与原有的亚科特征不符,因而有必要对叶螨科分亚科和分族的鉴别特征进行订正,本文以检索表的简明形式予以发表。长度单位均为μm。 华苔螨族Sinobryobiini新族