冲绳海槽北部全新世沟鞭藻孢囊组合及其古环境意义

通过B-3GC柱状样84个样品的分析,获得了冲绳海槽北部全新世高分辨率沟鞭藻孢囊记录。B-3GC柱状样中沟鞭藻孢囊化石丰富,包含14属28种孢囊。其中的Spiniferitesspp.和Operculodiniumcentrocarpum是沟鞭藻孢囊组合的优势组分,此外最常见的种类是Protoperidinium孢囊。通过与浮游有孔虫氧同位素指标对比,可以确定全新世Spiniferitesspp.和Operculodiniumcentrocarpum的含量变化主要与表层海水温度变化相关,Spiniferitesspp.是较暖水的标志,Operculodiniumcentrocarpum则指示了偏凉的海水。根据这一指标推测冲绳海槽北部早全新世的表层海水温度偏低,约6500aB.P.后由于黑潮及其分支(主要是对马暖流)的影响增强,导致海水温度升高。但在3700—2300aB.P.期间因黑潮及其分支强度有所减弱而引起该区域表层海水温度降低。孢囊组合中异养型沟鞭藻Protope-ridinium孢囊含量随时间逐渐降低,这一趋势可以作为海平面上升引起冲绳海槽北部陆源物质输入减少的有力证据。黑潮及其分支影响的加强造成约6000—3700aB.P.和约2300aB.P.以后两个时期冲绳海槽北部表层海水相对贫营养低生产力。     

Development and characteristics of microsatellite markers in Pinus merkusii

Pinus merkusii is an important industrial species that is distributed only in Southeast Asia. We isolated 10 microsatellite markers from this species using a dual‐suppression‐polymerase chain reaction technique. Of these markers, five loci were codominant and polymorphic. The number of alleles per locus ranged from three to six and the expected heterozygosity ranged from 0.389 to 0.728. These microsatellite markers will be available for analysis on population genetics and mating patterns.     

Female-biased sex ratio in a wild bruchid seed-predator, Kytorhinus sharpianus. I. Larval competition and other factors

Abstract.

• 1 A wild bruchid seed-predator, Kytorhinus sharpianus, has a complex life cycle consisting of bi- and trivoltinism on a wild leguminous plant, Sophola flavescens. Observations of adults showed significant female-biased sex ratios (from 1:2 to 1:6) for nine generations over 4 years.
• 2 To investigate the potential effects of larval competition on the sex ratio, we altered the number of hatched eggs per seed and counted emergent males and females under laboratory conditions. Although only one adult could emerge per seed, the ratio of the females that emerged increased with the number of hatched eggs per seed. However, the sex ratio was not significantly different from 1:1 in the case of one hatched egg per seed.
• 3 We dissected seeds bearing two hatched eggs at regular intervals, and classified the surviving and the dead larvae according to their developmental stage. Over time, one larva within each seed always survived, while the other larva died from the second to fourth instar before the seed resource became exhausted.
• 4 In order to study the effects of the difference in the stages of two larvae in a seed on the emergence sex ratio, we manipulated intervals between the first and second ovipositions in the laboratory. As the difference in developmental stages of the two larvae increased, the closer to 1:1 the emergence sex ratio became.
• 5 Field observations, however, showed that about 60% of infested seeds were bored by only one K.sharpianus larva. This suggests that female dominance in larval competition within a seed may be relatively unimportant in causing the female-biased sex ratio in the field.

     

Indispensability of Iron for the Growth of Cultured Chick Cells

In order to clarify the role of iron in the growth promoting effect of transferrin (Tf), the effects of the following substances were examined in cultured chick skeletal myogenic cells: transition metal ions (Fe²⁺, Fe³⁺, Cr³⁺, Cu²⁺, Mn²⁺, Co²⁺, Cd²⁺, Zn²⁺ and Ni²⁺), Tf complexes with these metals and metal-free apoTf.
The cells did not grow well when incubated in a culture medium composed of Eagle's minimum essential medium and horse serum. But they grew well in the presence of Fe²⁺ or Fe³⁺ (10–100 μM) or iron-bound Tf (10–500 nM) in the medium. None of the transition metal ions other than iron was effective. Neither apoTf nor Tf complexes with these metals showed the growth promoting effect. The generality of the requirement of iron for cell growth was ascertained in the primary culture of other types of chick embryonic cells: fibroblasts, cardiac myocytes, retinal pigment cells and spinal nerve cells.
The results show that iron is one of the indispensable substances for cell growth and suggest that Tf protein plays a role in facilitating the transport of iron into the cells.     

Translation of RNA from Eggs During Post-Diapause Development of Bombyx mori

Eggs of Bombyx mori are aroused from diapause by long-term chilling and develop when transferred to 25°C. During the first 20 hr of post-diapause development, the polysome content and the presumed rate of protein synthesis increase about 3-fold, while the ribosome content and the total RNA content increase only 1.1-fold. In this study, total RNAs were extracted from chilled eggs (termed 0 hr of development), and post-diapause eggs at 10 and 20 hr of development. The RNAs were purified further by high pressure liquid chromatography to remove RNA-like oligonucleotides. On translation in a protein-synthesizing system derived from wheat germ with a subsaturating amount of RNA, no difference was found in the relative amounts of translatable mRNA activity at 10 and 20 hr of development from that at 0 hr. Moreover, the translation products of the different RNA preparations in a rabbit reticulocyte lysate system appeared very similar when separated by gel electrophoresis and located by fluorography. These facts suggest that protein synthesis in early post-diapause development is controlled at a translational level.     

A stress‐inducible sulphotransferase sulphonates salicylic acid and confers pathogen resistance in Arabidopsis

Sulphonation of small molecules by cytosolic sulphotransferases in mammals is an important process in which endogenous molecules are modified for inactivation/activation of their biological effects. Plants possess large numbers of sulphotransferase genes, but their biological functions are largely unknown. Here, we present a functional analysis of the Arabidopsis sulphotransferase AtSOT12 (At2g03760). AtSOT12 gene expression is strongly induced by salt, and osmotic stress and hormone treatments. The T‐DNA knock‐out mutant sot12 exhibited hypersensitivity to NaCl and ABA in seed germination, and to salicylic acid (SA) in seedling growth. In vitro enzyme activity assay revealed that AtSOT12 sulphonates SA, and endogenous SA levels suggested that sulphonation of SA positively regulates SA production. Upon challenging with the pathogen Pseudomonas syringae, sot12 mutant and AtSOT12 over‐expressing lines accumulate less and more SA, respectively, when compared with wild type. Consistent with the changes in SA levels, the sot12 mutant was more susceptible, while AtSOT12 over‐expressing plants are more resistant to pathogen infection. Moreover, pathogen‐induced PR gene expression in systemic leaves was significantly enhanced in AtSOT12 over‐expressing plants. The role of sulphonation of SA in SA production, mobile signalling and acquired systemic resistance is discussed.     

Metabolism of Pyrimidines in Protoplasts from Cultured Catharanthus roseus Cells

The metabolism of [2-¹⁴C]thymine, [2-¹⁴C]thymidine, [2-¹⁴C]uraciland [¹⁴C]uridine was investigated in protoplasts obtained fromsuspension cultures of Catharanthus roseus. Most of the exogenouslysupplied thymine, thymidine and uracil was degraded, and salvageof these pyrimidines accounted for 5–36 per cent of thetotal amount of ¹⁴C-labelled precursors which was metabolized.However, more than 80 per cent of the labelled uridine was utilizedfor the biosynthesis of nucleotides and nucleic acids, and therest was degraded. In contrast to the results from protoplastsof sugar cane cells in suspension culture, the data indicatethat protoplasts possess a pathway for the degradation of pyrimidines,and that the overall metabolism of these pyrimidines in protoplastsis very similar to the metabolism in the intact cells. Catharanthus roseus, madagascar periwinkle, protoplasts, pyrimidine metabolism     

小鼠α1,2岩藻糖基转移酶基因的克隆及表达

本文报告小鼠GDP岩藻糖:β半乳糖苷α1,2-岩藻糖基转移酶(α1,2-fucosyltansferase,α1,2- FT)基因的克隆,并进行功能鉴定。利用RT-PCR方法克隆小鼠α1,2-岩藻糖基转移酶基因编码区 MFUT-Ⅱ,测序后将其插入表达载体pcDNA3．1的多克隆位点,构建表达载体pcDNA3．1-MFUT-Ⅱ; 采用磷酸钙法将其转染于COS-7细胞进行表达,通过对底物特异性比较研究酶的性质;应用 Northern印迹杂交法研究基因在小鼠组织中的表达情况;应用southern印迹杂交法分析基因存在状态。结果证实MFUT-Ⅱ为小鼠α1,2-岩藻糖基转移酶基因家族的新成员,含有一个完整的开放读码框,可编码347个氨基酸．其估计分子质量为39 kDa,和小鼠H及Secl基因具有序列同源性,分别与人类Se基因(79．0％)、大鼠Rat FTB(89％)基因、兔Rabbit FT-Ⅲ基因(77％)具有较高的序列同源性。用MFUT-Ⅱ基因转染的COS-7细胞具有α1,2-FT活性,MFUT-Ⅱ可在多种组织中产生 3．5kb大小的mRNA转录产物。基因Southern印迹杂交分析结果显示:基因MFUT-Ⅱ仅为一个拷贝。这些结果证明MFUT-Ⅱ为小鼠的Se基因。     

Vespidae (Hymenoptera) of Vietnam 3: Synoptic key to Vietnamese species of the polistine genus Ropalidia, with notes on taxonomy and distribution

Nineteen species of the paper wasp genus Ropalidia are recorded from Vietnam, of which three are new records for Vietnam. A key to all of the species, distribution records and taxonomic remarks are given. New synonymies proposed are: Ropalidia bicolorata parvula van der Vecht, 1962, under R. bicolorata van der Vecht, 1962; R. hongkongensis juncta van der Vecht, 1941, under R. hongkongensis (de Saussure, 1854); Icaria jucunda Cameron, 1898, and R. marginata sundaica van der Vecht, 1941, under R. marginata (Lepeletier, 1836); R. rufocollaris atrata van der Vecht, 1941, under R. rufocollaris (Cameron, 1900); and R. stigma rufa van der Vecht, 1941 and R. stigma nigrolineata van der Vecht, 1962, under R. stigma (Smith, 1858).