Phylogenetic relationships of nine mullet species (Mugilidae) in the Mediterranean Sea

Phylogenetic relationships among four genera and nine species (Mugil cephalus, Mugil soiuy, Liza ramada, Liza aurata, Liza abu, Liza saliens, Liza carinata, Chelon labrosus, Oedalechilus labeo) of the Mediterranean mullets (Mugilidae) were investigated by means of allozyme electrophoresis using a seven-enzyme system (CK*, GAPDH*, G3PDH*, IDHP*, ME*, MDH*, PGM*) comprising eleven putative loci. The highest genetic divergence was 1.299, detected between M. cephalus and L. aurata and the lowest (0.280) was found between L. carinata and L. saliens. The amount of genetic divergence between the genera Chelon and Oedalechilus did not appear to be high (0.285). In a UPGMA tree, all nine species were grouped in two main branchings. In the first branch, C. labrosus and O. labeo clustered as closest taxa and were sister group to L. ramada. The other four Liza species produced two sub-branching in this group; L. carinata branched together with L. saliens, and L. aurata branched together with L. abu. In the second branch the two species of the genus Mugil, M. cephalus and M. soiuy, clustered together and were clearly isolated from the other three genera.     

滇南人工种子繁殖灯台树林木生长状况研究

以不同环境条件下人工灯台树林木50cm处直径、株高、枝下高、分台数、分枝数和冠幅的实测数据为基础,用方差分析、多重比较分析和均值比较等方法研究了灯台树的生长状况。结果表明,灯台树幼林植株长势具有随年均温、最冷月温和相对湿度递增,但随海拔高度递减,呈现良好的长势。     

五种真蝽(Pentatoma Olivier) mtDNA-COII基因序列分析及系统发育关系初探(半翅目:蝽科)

测定并比较分析了真蝽属(Pentatoma)5种昆虫：褐真蝽P．semiannulata、斜纹真蝽P．illuminata、红足真蝽P．rufipes、H本真蝽P．japonica和金绿真蝽P．metallifera以及益蝽亚科2种外群种类(并蝽Pinthaeus humeralis和蠋蝽Arma custos)mtDNA—COII基因部分序列,依据分子数据建立了该5种昆虫的系统发育关系。结果显示,5种真蝽COII基因A T平均含量(73％)高丁弹尾目、缨尾目和直翅目昆虫,低于双翅目、鳞翅目及膜翅目昆虫,而与缨翅目的蓟马和半翅目的突角长蝽Oncopeltus fasciatus非常接近。系统发育结果显示,红足真蝽与日本真蝽亲缘关系最近,形成一个姊妹群,斜纹真蝽与金绿真蝽亲缘关系较近,也形成一个姊妹群,褐真蝽为较早分化的种类。     

杓兰属(兰科)中一个国产种类的新等级(英文)

丽江杓兰大围山变种(Cypripedium lichiangensem var.daweishanense)被提升为种的等级:大围山杓兰(Cypripedium daweishanense)。此种的特征是:中萼片浅黄绿色,上面疏被栗色斑点;花瓣较短,近等长于或略长于唇瓣。而丽江杓兰(Cypripedium lichiangense)的中萼片为紫肝色;花瓣要长得多,大约为唇瓣长的2倍。它们均属于三组(Cypripediumsect.Trigonopedium)。该组共含11种,均为中国特有种。文中提供了一个该组的分种检索表。     

Phylogenetic positions of several amitochondriate protozoa

Several groups of parasitic protozoa, as represented by Giardia, Trichomonas, Entamoeba and Microsporida, were once widely considered to be the most primitive extant eukaryotic group―Archezoa. The main evidence for this is their ‘lacking mitochondria’ and possessing some other primitive features between prokaryotes and eukaryotes, and being basal to all eukaryotes with mitochondria in phylogenies inferred from many molecules. Some authors even proposed that these organisms diverged before the endosymbiotic origin of mitochondria within eukaryotes. This view was once considered to be very significant to the study of origin and evolution of eukaryotic cells (eukaryotes). However, in recent years this has been challenged by accumulating evidence from new studies. Here the sequences of DNA topoisomerase II in G. lamblia, T. vaginalis and E. histolytica were identified first by PCR and sequencing, then combining with the sequence data of the microsporidia Encephalitozoon cunicul and other eukaryotic groups of different evolutionary positions from GenBank, phylogenetic trees were constructed by various methods to investigate the evolutionary positions of these amitochondriate protozoa. Our results showed that since the characteristics of DNA topoisomerase II make it avoid the defect of ‘long-branch attraction’ appearing in the previous phylogenetic analyses, our trees can not only reflect effectively the relationship of different major eukaryotic groups, which is widely accepted, but also reveal phylogenetic positions for these amitochondriate protozoa, which is different from the previous phylogenetic trees. They are not the earliest-branching eukaryotes, but diverged after some mitochondriate organisms such as kinetoplastids and mycetozoan; they are not a united group but occupy different phylogenetic positions. Combining with the recent cytological findings of mitochondria-like organelles in them, we think that though some of them (e.g. diplo-monads, as represented by Giardia) may occupy a very low evolutionary position, generally these organisms are not as extremely primitive as was thought before; they should be poly-phyletic groups diverging after the endosymbiotic origin of mitochondrion to adapt themselves to anaerobic parasitic life.     

Health and wealth: The late-20th century obesity epidemic in the U.S.

Obesity is a rapidly growing public health issue. This paper investigates obesity's relationship to individuals' wealth by analyzing data from a large U.S. longitudinal socio-economic survey. The results show a large negative association between BMI and White female's net worth, a smaller negative association for Black women and White males and no relationship for Black males. Weight changes and dieting also appear associated with wealth changes. Individuals who lose small amounts of weight experience little change in net worth, but those who lose large amounts of weight have a dramatically improved financial position, with Whites showing larger changes than Blacks.     

运用微卫星DNA标记分析我国野生鹌鹑遗传多样性

运用微卫星DNA标记对我国境内分布的两种野生鹌鹁（野生日本鸣鹁、野生普通鹌鹑）和家鹑群体的遗传多样性进行分析。通过计算反映群体变异的多态信息含量（PIC）、固定指数、平均杂合度、基因分化系数等相关指标,结果表明：野生普通鹌鹑群体遗传多样性更为丰富,每个座位平均检测出4．67个等位基因,群体多态信息含量和平均杂合度亦为最高,分别为0．5732和0．6621;家鹁最低,分别为0．5467和0．5933;野生日本鸣鹑介于两者之间;在3个鹌鹑群体中,野生日本鸣鹑与家鹑群体遗传多样性差异程度较小。以标准遗传距离为基础的模糊聚类分析发现：家鹑与野生日本鸣鹑群体模糊等价矩阵系数为0．937,而与野生普通鹌鹑的系数为0．738,这也表明家鹑与野生日本鸣鹁有更近的亲缘关系,进一步从分子水平上证实家鹑起源于野生日本鸣鹁。     

PCR-based RFLP analysis of an intergenic spacer region in cpDNA of some wild wheat species

Wheat is one of the basic food materials for humans and other animals. Continuing studies into breeding new species, which are suitable for agriculture, are based on the contention that the restricting factors are the effects of the nuclear genes. Such focusing of studies on the nuclear genome leads to restriction on the information on organelle DNAs, although cytoplasmic genetic factors are effective on the morphological, physiological and reproductive features of plants. Restriction fragment length polymorphism analysis (RFLP) of chloroplast DNA (cpDNA) has become a powerful tool for studying phylogenetic relationships. In this study, seven wheat species, belonging to Aegilops and Triticum , were studied. An intergenic spacer region of cpDNA was digested by six different restriction endonuclease enzymes, and fragments so obtained were investigated using the agarose gel electrophoresis technique. Discussion on the phylogenetic relationships among Triticum and Aegilops species is based on the resultant data.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 305–310.     

Lipid content and fatty acid composition of target tissues in wild Perca fluviatilis females in relation to hepatic status and gonad maturation

Variation in liver ultra‐structure and composition in relation to energy mobilization was investigated in female perch Perca fluviatilis from the Meuse River between August 2001 and June 2002. In April, just before spawning, the lipo‐somatic index ( I _F) was 0·3%, the gonado‐somatic index ( I _G) was 28% and the total lipid content of the liver was 2·53%. The average areas of lipid droplets and mitochondria were 0·05 and 0·06 μm², respectively. Glycogen supply reached 7·9% of the total area of the hepatocyte. During the sexual resting period, females accumulated energy in perivisceral fat and in the liver to reach 1·6% I _F and 4·85% of liver lipid content in August with lipid droplets average size of 0·09 μm² and glycogen average area of 15%. Liver cells contained a weakly developed rough endoplasmic reticulum (RER) and a great number of small mitochondria (average size 0·02 μm²). The I _G was 0·6% at this time. During the whole annual cycle, the average lipid content of female liver never exceeded 3·9 ± 1·9%. The concentration of docosahexaenoic (DHA), linolenic and linoleic acids increased in mature gonads while linolenic and linoleic acids decreased in the liver during the same period. Fatty acid composition of muscles of perch was characterized by a high content of DHA.     

禽Ⅰ型副粘病毒各种禽源分离株毒力及其相关基因的研究

用测定新城疫病毒(NDV)毒力的经典方法,即鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI),对源于鸡、鸽、鹅、珍珠鸡、孔雀、鹌鹑和画眉鸟等7种禽(鸟)源的共14个禽Ⅰ型副粘病毒(APMV-1)广西分离株,分别测定了毒力。同时对分离株F基因的N一端前段和HN基因的e末端片段进行扩增、测序和分析,并绘制系谱树。结果发现,分离株的MDT在36h～75h之间,除1株鸽源毒株gxp22的ICPI值为0外,其余分离株在1．09～1．95之间;除孔雀源的分离株gxpc52在F基因裂解位点附近的氨基酸序列为^112R-RQ-R-R-F^117之外,其它13株均为^112R-R-Q-K-R-F^117,都符合强毒株的特征。所有分离株与国内参考强毒株F48E8和国外参考强毒株HER／33在HN基因e末端终止密码子的位置相同,也符合强毒株的特征。根据F基因核苷酸序列绘制的系谱树发现,近几年来在广西流行的APMV-1毒株的基因型为Ⅶd亚型;根据HN基因核苷酸序列绘制的系谱树表明,广西各种禽源APMV-1分离株可分为2个群。研究的结果表明,根据F基因裂解位点附近的氨基酸序列和HN蛋白翻译的终止密码子的位置判定APMV-1毒力的结果,都与毒株在临床上的致病情况相符。因此,根据F基因和HN基因序列和结构的特征,均可以判定APMV-1临床分离株的体内致病性。