Studies in the Mitosis of Euglena I. On the Chromosome Cycle of Euglena viridis Ehrbg.

The chromosome cycle in the vegetative division of Euglena viridis was investigated. The seeming chromatin granules in the interphase nucleus are in reality thread structures, paired and very loosely twisted. Each component of the paired threads is called a chromatid, and consists of a fine thread of even thickness, the chromonema.
In the prophase, linear contraction and thickening of the chromatids occurs by means of the spiralization of them. In the later prophase, the coiled chromonema splits into two finer strands which show the plectonemic spiral. At the metaphase, the chromosomes are arranged in the form of an equatorial ring, encircling the median portion of the elongated endosome. Nearly all of the chromosomes have a submedian or a sub-terminal and a few of them have a terminal kinetochore. In the early anaphase, separation of the sister chromosomes takes place beginning at the kinetochore. The spindle fibres in the metaphase and anaphase were not observed. The two stranded spiral in the chromosomes is separated into distinct components by the uncoiling in the later telophase, and they are transformed, in the interphase nucleus, into the paired chromatids.     

蓝藻Trichodes mium thiebautii细胞外多糖的抗癌活性

蓝藻T .Thiebautii细胞外多糖经DEAE -sephacel纯化 ,醋酸纤维膜电泳鉴定具均一性后进行了抗腹水癌Sar coma-1 80活性 (体内 )和直接阻碍癌细胞活性 (体外 )的研究 ,显示出具有一定的抗癌活性和直接阻碍癌细胞活性。     

短吻贫齿龙(双孔亚纲:海龙目):头后骨骼及系统关系研究(英文)

短吻贫齿龙是根据一保存较完整的头骨和下颌标本建立的;标本采自贵州关岭地区三叠系法郎组灰岩。对其头后骨骼进行了详细描述。短吻贫齿龙在肩带的乌喙骨和间锁骨及腰带的肠骨显示了与众不同的特征,例如:紧靠肩臼后方乌喙骨有一明显的凹,间锁骨后半部比前部要窄很多,及肠骨背突末端加宽等。头骨进一步细修表明,其中一些部位需要进行重新记述。依据头后骨骼和头骨中的新信息,对短吻贫齿龙的特征作了修订。系统关系分析表明,贫齿龙是个askeptosaurid,其下颌宽大于长的反关节突和肱骨缩小的三角-胸大肌嵴表明它与产自瑞士和意大利的Askeptosaurus关系最近。     

Distributional Change of Membrane-associated Calcium in Sea Urchin Eggs during Fertilization

The "source and sink" for the intracellular calcium released during fertilization were examined in sea urchin eggs, Hemicentrotus pulcherrimus , with chlortetracycline as a fluorescent chelate probe. In order to distinguish the differential distribution of membrane-associated calcium in various compartments in cytoplasm, eggs were stratified by centrifugation before or after fertilization. Only the layer containing mainly mitochondria exhibited the chlortetracycline-fluorescence in unfertilized eggs. After fertilization, a new fluorescent band emerged in the membrane-rich clear layer of stratified eggs. Chlortetracycline-fluorescence in the clear layer was gradually redistributed surrounding the prophase nucleus and then incorporated into the mitotic apparatus. From these observations, we postulate that the major source(s) of released free calcium ions at fertilization is in the mitochondira layer and membranes in the clear layer are newly activated as the calcium sequestering system after fertilization.     

Consequences of forest fragmentation in an understory plant community: extensive range expansion of native dwarf bamboo

Understory bamboo species are important and influential components of temperate forests in at least several parts of the world. Here we report a study testing the effect of forest fragmentation on the dynamics of the dwarf bamboo Sasa chartacea and on forest herb communities in the Tokachi plain of Hokkaido, Japan. We studied 16 forest fragments of different sizes and small plots established in these fragments to examine the relationship between the abundance of S. chartacea, landscape and environmental conditions, and forest herb communities. Sasa chartacea was more abundant near forest edges and in smaller fragments, suggesting that the species has expanded its local range and increased its abundance in response to forest fragmentation. Edge‐related changes in light and soil moisture might have facilitated this range expansion. The species richness of forest herbs was strongly negatively related to the density of S. chartacea. Because much larger variation in species richness was explained by S. chartacea density than distance to the nearest forest edge, the expansion of S. chartacea has likely excluded other understory species by competition. In addition, the density of S. chartacea significantly explained variation in the species composition of forest herbs across plots. Taken together, our results emphasize the key roles of dwarf bamboos in changing plant communities following forest fragmentation.     

Discovery of an oak gall wasp (Hymenoptera: Cynipidae) inducing galls on deciduous oak trees in India

We report for the first time the occurrence of an oak gall wasp Andricus mukaigawae (Mukaigawa) (Hymenoptera: Cynipidae) on the deciduous oak Quercus griffithii Hook. F & Thomson ex Miq. in India. Andricus mukaigawae is the only cynipid species that has been observed to induce galls on deciduous oak species in India to date. In addition, this is the first record of a gall wasp species with a distribution extending all the way from the eastern Palearctic region to the Indian subcontinent, suggesting the existence of a close relationship between cynipid faunas on deciduous oak trees in the two regions.     

Clusiidae (Diptera) from log emergence traps in the Yambaru, a subtropical forest of Japan

Five species of Clusiidae (Diptera), Craspedochaeta biseta (Hendel), hendeli a plumosa (Sasakawa), Heteromeringia sexramifera Sueyoshi, Phylloclusia yambarensis sp. n., and Sobarocephala uncinata Sueyoshi, were collected from log emergence traps installed in a subtropical forest of Japan from February 2006 to February 2008. Craspedochaeta biseta (Hendel) was newly recorded in Japan. Wood debris was gathered from 1–22 year old secondary stands managed by the improvement cutting of natural forest (ICNF) and unmanaged stands, and categorized by stage of decay and size, and then enveloped in fine net bags (emergence trap). In total, 84 clusiid adults were obtained. Most were reared from wood debris in an advanced stage of decay and from 2 year old or older managed and unmanaged forest stands, although P. yambarensis was reared from wood debris in an early stage of decay and from 1 year old forests after cuttings. Log emergence traps effectively sample clusiids, taking both sexes in approximately equal numbers. Specimens collected by this trap may resolve the difficulty in identifying male and female specimens of several clusiid species that show sexual dimorphism.