留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

2006年  第27卷  第5期

显示方式:
论文
The Y chromosome and mtDNA from 32 male samples of Bo people were typed. The results showed that the Bo people originated from the south of China possessing the dominant patrilineal and matrilineal haplotypes that are prevalent in the southern East Asian populations. The multidimensional scaling analysis on the Bo people's hapoltypes, combined with published Y chromosome and mtDNA data from East Asian populations, demonstrated that the Bo people are genetically closer to the southern populations than to the northern. This indicates that the Bo people are descendants of a southern China origin population, which is consistent with archeological evidence. The genetic dissection of the Bo people sheds new light on the origin and dispersion of the prehistoric "cliff coffin" culture.
Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (MⅡ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to explore the relationship between oocyte maturation and GDF-9 gene expression. Preantral follicles of 10-day old mice were isolated from the ovaries and were cultured for 12 days. Oocytes from day 2 (D2), D4, D6, D8, D10, D12 cultured in vitro were named the in vitro group and oocytes of day 12 (D12), D14, D16, D18, D20, D22 grown in vivo were named the in vivo group. Follicle survival, antrum formation and maturation rate were 89.5%, 51.8% and 56.6% respectively in follicles cultured in vitro. After RT-PCR and agarose gel electrophoresis, relative mRNA abundance of GDF-9 was measured in each group of oocytes. At day 8-12, the GDF-9 gene expression level of oocytes in vitro was significantly lower than that in vivo (P<0.05). We conclude that MⅡ oocytes can be obtained from in vitro culture of preantral follicles. The GDF-9 gene expression of oocytes varies at different growth stages in vivo. The low expression of GDF-9 in oocytes cultured in vitro may be the cause of their low developmental capacity.
Suppression subtractive hybridization (SSH) libraries were constructed in blastula stage and tail bud stage embryos in the orange-spotted grouper (Epinephelus coioides). The subtraction efficiency of the two subtractive cDNA libraries indicated by α-tubulin cDNA was approximately 28 and 27 folds, respectively. One hundred and ninety two and 960 PCR positive clones were respectively selected to perform dot blot tests; 15 and 131 dot blot positive clones were obtained from SSH plasmid libraries in the blastula and tail bud stage embryos. Sequence analysis and database searches showed that there were 11 known genes and four unknown cDNA fragments in the sequenced 15 dot blot positive clones for the blastula embryos and 123 known genes and eight unknown cDNA fragments in the sequenced 131 dot blot positive clones for the tail bud embryos. RT-PCR analysis revealed the state of partially differential expression and tissue distribution of 12 cDNA fragments. Further functional studies on the differentially expressed genes screened in this study will provide more information on the molecule regulation mechanisms of embryo development, early sex determination and gonad differentiation in groupers.
Many studies have indicated that there are geographic or even microgeographic variations in songs of a single bird species. We investigated whether it is possible for song variations to exist in one species within a single habitat. From March to June in 2005, the songs of Brownish-flanked Bush-Warblers within one habitat of 85 ha in Xiaoheshan Forest Park in Hangzhou, Zhejiang Province were recorded using a SHARP-CE-15l recorder (frequency response 30-l4 000 Hz) and super uni-directional electric condenser microphone (frequency response 40-14 000 Hz). The song phrase patterns and sonogram structures were compared, and the time domain, frequency domain and short-time energy have been analyzed using a computer sound spectrum analysis system. The results showed that Brownish-flanked Bush-Warblers sing six different songs within this small habitat. Those songs significantly varied in tone, structure and other acoustic features, which may imply breeding competition in Brownish-flanked Bush-Warblers.
Mollusks, arthropods and chordates which were visible to the naked eye were observed and collected in Dongbei and Shuijiang caves of Libo county five times between February and July from 2002 to 2005. Four hundred and forty samples from Dongbei Cave were classified into three phyla, five classes, 10 orders, 20 families and 39 species or groups of species. Four hundred and ninety-eight samples from Shuijiang Cave were classified into three phyla, six classes, 11 orders, 20 families and 25 species or groups of species. Six animal communities were identified in the light belt of the two caves according to their species types and numbers of individuals in the light belt of two cave. The communities which have the highest values of species richness community diversity, maximum diversity, evenness, dominance and community similarity are respectively: B (4.1059), H (2.4716), B (3.3322), E (0.9042), C (0.3442) and A-C (0.5251). The community diversity and correlation of environmental factors were also studied. The temperature, humidity, content of CO 2 and N 2, content of organic matter and some inorganic salts in soil were analyzed by Pearson correlation. The results showed that the content of organic matter in soil is positively related to species number, species richness and maximum community diversity, with correlations of 0.885, 0.909, 0.868 respectively (two-tailed significance test, P≤0.05), and significantly positively related to diversity, with the coefficient of 0.611, (two-tailed significance test, P≤0.1). This suggests that the content of organic matter in soil is one of the important elements influencing the community variation of cave animals. Outside the cave, temperature and humidity are important factors impacting on community diversity. As the temperature in all seasons in the cave is stable and the humidity is always high (above 90%), the temperature and humidity have weak correlation to community diversity in caves.
By observing the distribution of tadpoles of Rana chaochiaoensis within its habitat, the distribution frequency of tadpoles in different stages under different vegetation coverage, water depth and temperature was calculated and analyzed. The results showed that tadpoles of development Stage Ⅰ and Ⅱ tend to select areas with vegetation coverage of 41%-70%, but selection of vegetation coverage is not obvious by Stage Ⅲ. Only tadpoles of Stage Ⅱ tend to select areas of 0.11-0.30 m water depth. Tadpoles of Stages Ⅰ and Ⅲ do not obviously select for water depth, and there were no tadpoles of Stage Ⅲ in areas deeper than 0.31 m. As tadpoles mature, selection of water depth gradually changes to a preference for shallow water from Stage Ⅰ to Ⅲ. Tadpoles of Stage Ⅰ and Ⅱ tend to select areas of water temperature between 19-25 ℃. Selection of water temperature is not obvious in tadpoles of Stage Ⅲ, and there were no tadpoles of Stage Ⅲ in areas of 8-13 ℃.
Researching the mechanisms between species with close relationships or similar trophic levels that allow them to coexist is a central issue of community ecology. The study results are helpful to identify resource use traits and niche differentiation of sympatric species and to the biodiversity conservation of a region. Syrmaticus humiae, Lophura nycthemera and Arborophila rufogularis are sympatric species at Nanhua part in the Ailaoshan National Nature Reserve. Their relationship is genetically closed and their trophic niche is similar. Comparing trophic niche breadth and overlapping index for 18 ecological factors of spring foraging site among the three pheasants, the results showed that S. humiae held the least eurytopic factors (value of trophic niche breadth bigger than 0.8) (one factor) and the most stenotopic factors (its value less than 0.8) (four factors) of the three pheasants. L. nycthemera held three eurytopic and two stenopic factors, while A. rufogularis showed the reverse of S. humiae with six eurytopic and no stenotopic factors respectively. There were five factors with a high degree overlap in the niche overlapping index between S. humiae and L. nycthemera, while there were only four factors between S. humiae and A. rufogularis and two between L. nycthemera and A. rufogularis. Of the overlapping factors, shrub coverage, leaf litter coverage and seed density were common with a high degree overlap in the niche overlapping index among the three pheasants. The results of a one-way ANOVA indicated that five factors (aspect, tall tree density, herb coverage, seed density and density of edaphic animal) were not significant, while distance to open fields, distance to road and shrub coverage were significant for the three pheasants. Other factors were significant between any two species. The results of a principal component analysis showed that the cumulative percentage is 85.6% in the first 7 principal components for S. humiae, is 86.0% in the first 6 principal components for L. nycthemera and is 79.0% in the first 5 principal components for A. rufogularis. Factors affecting the selection of foraging sites in the three pheasants concentrate in the first 3 principal components. The factors difference of foraging sites among the three pheasants showed a state of mosaic, which meant that there was a separation of niches among the three species. The factor combination of each species prior selection was different as well the importance of each factor was also different.
The authors investigated the fish resources in the Dulong River, Irrawaddy basin from October to November, 2004. Twenty six sampling sites were established and 883 fish specimens were collected in different altitudes and habitats. The analysis revealed that: (1) the fish biomass in both the main stream and its tributaries descend when the altitude ascends; (2) fish species diversity descends when the altitude ascends. The Shannon-Wiener index and the species evenness in the main stream are higher than those in the tributaries; (3) except for Schizothorax (Schizothorax) dulongensis and Oreoglanis macropterus, the occurrences of all the other five species are significantly related to the changes in altitude.
Habitat selection of Tibetan Snow Cocks in shrub vegetation was investigated in Lhasa, Tibet during March and April of 2005. Fourteen parameters have been measured, including: altitude, slope, slope aspect, position on slope, vegetation cover, plant type and other environmental parameters. The results showed that Snow Cocks like foraging in areas where the vegetation cover is small and close to residents' houses;Snow Cocks like roosting in areas where the vegetation coverage is low, grass types are few, the cover of grasses is low, with large rocks and close to residents' houses. From the results we found that the activities of Snow Cocks in research areas rely on human activities.
Embryonic development of Folsomia candida was investigated by light microscope. The morphological changes and developmental course of cleavage, blastula, gastrula, tissue differentiation and the stage before hatching were observed. The results indicated that the eggs of F. candida were laid together in small patches. The fresh eggs were milk white in color and had a diameter of 110-126 μm. The surface of the egg shells were covered with fine granules. At the end of the embryonic development, the diameter of embryo membranes reached to 180-185 μm. The cleavage form of F. candida is holoblastic. The whole embryo development of F. candida spans 7-10 days.
The ray-finned fishes are the most diverse and successful within the vertebrates and their genomes vary widely in size. Previous studies suggested that two rounds of genome duplications have been involved in vertebrate evolution.The recent studies on comparative genomics have further suggested that a third round of fish-specific genome duplication (FSGD) in ray-finned (actinopterygian) fishes might have occurred at about 350 million years ago, during the divergence between teleost fish and basal actinopterygian lineages. Therefore, FSGD might be related to the increase in species number and biological diversity during this time. Further studies on comparative genomics and functional genomics will be needed to confirm the hypothesis.
Many countries have launched genomic studies for aquatic farming animals since the Agriculture Ministry of America initiated genomic studies for five kinds of aquatic farming animals in 1997. At the end of 2005, genetic linkage maps of approximately 17 briny or limnetic farming animals have been published. Of these 17 species, the rainbow trout and the Atlantic salmon have high-density linkage maps with over 1 000 markers; the tilapia, the channel catfish, the black tiger shrimp, the Japanese flounder and the European sea bass have middle-density linkage maps with 400-1 000 markers; the remaining 10 species, including the Thailand walking catfish, the Chinese Zhikong scallop, the common carp, the Japanese yellowtail amberjack and the American oyster, have low-density linkage maps with less than 400 markers. The framework and development of genetic linkage maps of aquatic farming animals facilitated QTL mapping associated with interesting economic traits, such as growth, resistance and development. However, QTL mapping was only studied preliminarily in a few species with middle or high density linkage maps, such as salmonids (the rainbow trout, the Atlantic salmon and the Arctic char), the tilapia, the channel catfish and the Japanese flounder. Genetic linkage maps with higher resolution and fine QTLs mapping are the keys to implementing genetic technology in interesting economic traits and also have the power to successfully carry out molecular marker or gene assistant selection breeding in aquatic farming animals.
The anti-HIV-1 research history of ribosome inactivating proteins (RIPs) can be traced back to McGrath's work in 1989. They are important representatives, which guide further research, of natural anti-HIV products or leading compounds. The enzymatic activities and anti-HIV-1 actions of RIPs were introduced initially in this paper, followed by a detailed discussion about the potential anti-HIV-1 mechanisms. The discussion mainly focuses on the relationships with anti-HIV-1 enzymatic activities, induction of apoptosis of HIV-1 infected cells and responding cell signaling, the production of reactive oxygen species, the HIV-1 integrase inhibition effect. The anti-HIV-1 structure-functional relationship of RIPs and the structural modifications were also covered. Systemic and intensive studies of RIPs' antiviral actions will increase their possibility as clinical anti-HIV/AIDS agents.
Crustaceans have been shown to possess a primitive immune system that relies mainly on phagocytosis, encapsulation and agglutination. Haemocytes play important roles in crustacean immune responses. It is generally agreed that haematopoietic tissue (HPT) and haematopoietic stem cells are responsible for the production and supply of haemocytes. Most crustacean mature haemocytes were classified into three types by using light microscopy in the past few years. Recently, the monoclonal antibody technique has been used in identifying the types of some crustacean haemocytes, which was proved to be more accurate than classical methods. The cytochemical characteristics and function of different haemocyte subpopulations show significantly difference, suggesting a role for these cells in particular functions. It is demonstrated that total haemocyte counts (THC) changed obviously in crustacean immune response. Generally, the haemocytes defense action in crustaceans relies mainly on phagocytosis when the pathogen is very small, and the microorganism was killed in haemocytes. When a microorganism or parasite is bigger than 10 μm, encapsulation and agglutination played a more important role. Moreover, the immune response of crustacean is very complex, during which cell co-operation and communication, and immune factors interaction are necessary. The study on the structure of HPT and the production mechanism of haemocytes, the establishment of classification standard of haemocyte subpopulations, the function and interaction of immune factors should be the main focus in the future.
The utilization of caves is a rather rare phenomenon in nonhuman primates, found almost exclusively in those members of the genus Trachypithecus that share a preference for forest on limestone (karst) hills in Vietnam and southern China. Here we report a new case of usage of caves as overnight sleeping shelters by François' or black langurs (Trachypithecus françoisi) at Mayanghe National Nature Reserve in Yanhe County, Guizhou Province, China. We tentatively address three possible hypotheses that may account for the use of caves in François' langurs at Mayanghe: shelter against climatic conditions, acquisition of minerals and protection from predators.