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101.
黄方亮 《生物信息学》2015,13(2):116-119
为了探索加快细菌基因组研究的方法,利用ABI PGM测序平台测定了1株单细胞硫还原地杆菌的基因组序列。测序共获得1.4 Gbp数据,平均读长为177 bp。通过多个拼接软件并采用合适的组装策略,得到一个完整细菌基因组3.55 Mbp和一条完整质粒序列110 kbp。测定基因组序列与参考基因组kn400序列的相似性达到94%,参考基因组91%的基因能在测定基因组中找到相似基因。通过本研究表明采用ABI PGM测序平台结合灵活的拼接策略可快速构建细菌基因组精细图谱,为进一步的功能注释及深入的信息分析提供准确的数据,大大加快研究进程。  相似文献   
102.
鄱阳湖是小天鹅(Cygnus columbianus)和白鹤(Leucogeranus leucogeranus)极为重要的越冬地,它们均主要以沉水植物苦草(Vallisneriaspp.)冬芽为食,且通过觅食空间生态位分化减少种间竞争。近年来,鄱阳湖苦草冬芽锐减导致大量小天鹅和白鹤由自然生境转移到南昌五星白鹤保护小区的藕塘觅食。大量小天鹅和白鹤集中在小片藕塘觅食可能导致种间竞争强度增加。因此,本研究以五星白鹤保护小区藕塘为研究地点,于2021年11月10日至25日,采用瞬时扫描法和焦点动物法调查了藕塘与白鹤混群和不与白鹤混群时小天鹅的日间行为、单次取食时间和每分钟摄食成功频次,并采用单因素方差分析或Mann-WhitneyU检验对数据进行统计分析。结果表明,小天鹅日间行为主要以觅食(45.59%)、运动(17.05%)和休息(15.92%)为主。小天鹅和白鹤混群时的觅食行为比例和单次觅食时间显著高于不混群时,表明小天鹅主要通过增加觅食时间以应对种间竞争的负面影响,满足能量需求。小天鹅混群时的每分钟摄食成功频次显著高于不混群时,这可能是由于小天鹅通过摆动脚蹼或者扁平喙啄食的方式较难取食...  相似文献   
103.
Approximately 4000 mature seeds from 350 trees in nine populations (12–75 trees per population) of Siberian stone pine were investigated for multiple embryos (polyembryony). Haploid megagametophytes and embryos were genotyped for eight allozyme loci. Eight-yone seeds (2.11%) had more than 1 embryo. Of these, 71 seeds had 2 embryos (1.85%), 6 seeds had 3 embryos (0.16%), 3 seeds had 4 embryos (0.08%) and 1 seed had 6 embryos (0.026%). Allozyme comparison of megagametophytes and embryos could distinquish two types of polyembryony in 56 of the 81 seeds. In 28 seeds (50%) the polyembryony was polyzygotic (independent fertilizations of more than one egg cell in the ovule); 25 seeds (45%) had most likely monozygotic polyembryony (genetically identical embryos resulting from the cleavage of a single proembryo) and 3 seeds had both genetically different and genetically identical embryos. To the best of our knowledge, this is the first genetic evidence for the form of polyembryony in conifer seeds.  相似文献   
104.
Phenotype and allelic frequencies for ABO, MNSs, P, Rh, Kell, Duffy, and Diego blood groups, as well as for transferrins (Tf), haptoglobins (Hp), phosphoglucomutase 1 (PGM1), adenylate kinase (AK), 6-phosphogluconate dehydrogenase (PGD), and acid phosphatase (AcP) are described in 9–10 adjoining populations of Reindeer Chukchi. Additionally, one of three presently existing territorial subgroups of Siberian Eskimos was studied. The total sample size ranges from 931 to 1,066 in Chukchi, and from 99 to 102 in Eskimos, depending on the genetic system studied. Substantially reduced samples for Kidd and ABO secretion were investigated solely in the Reindeer Chukchi. Significant heterogeneity of allelic frequencies has been observed among Chukchi populations (χ = 378.47, P < 0.001). Summed genetic heterogeneity between Reindeer Chukchi and Siberian Eskimos was also found to be highly significant (χ = 186.54, P < 0.001). Both groups can be readily discriminated with only four outliers: NS , P1, R1, and Pa. Random genetic drift is suggested to be responsible for a large proportion of heterogeneity of allelic frequencies at the MNSs, P, and Rh blood-group system sites both among the Chukchi and Eskimos. Conversely, stabilizing selection is assumed as the principal agent maintaining homogeneous allelic frequencies at the AcP locus within the Chukchi subdivisions, whereas disruptive selection may be considered as a major factor leading to different pa frequencies between Chukchi and Eskimos.  相似文献   
105.
Sperm from the electroejaculate of captive Siberian tigers (Panthera tigris altaica) penetrated zona pellucida-free hamster ova in vitro, evidenced by a decondensation reaction. This assay, when used in conjunction with semen analysis, may be useful in assessing the fertility potential of males of this and other related felids. Such information is an important step in developing successful long-term management strategies for captive and wild populations of this severely endangered species.  相似文献   
106.
植物学和医药在科学启蒙时期是合而不分的。东西文化相同。中国古代本草(ancient Chinese materia medica),欧洲中世纪的药物书籍(European medieval herbals),共同证明这件史实。欧洲17—18世纪经典的植物著述,是那个时代医生们业余的工作成果;19世纪亚洲美洲的植物志,以及植物地理知识,基本上是舍弃医药职业从事植物研究之先锋植物学家的成绩。现代植物学知识和方法,更是研究中草药不能缺少而且不可忽略的基础。试举三例说明,职业植物学家如何以正确鉴定和合法命名,解决国际间药物交流问题,并怎样以植物解剖知识澄清药材商品素质混乱情形。凡是能力强工作负责的药用植物学家,都是热心的环境保护者,因为他们工作的地方,既是标本馆实验室,又是野外的大自然;他们确知,自然没有任何取之不尽用之不竭的资源,更没有丰富的药物资源。加之以人们无情地挖掘,任意地采集,无数有药用价值的植物,己遭到不可挽救的毁灭,绝了种!有的也接近灭绝的危运。再看未来,植物学家除了研究植物本体之外,更加上唤起民众爱惜自然植被保护环境的重要职责,并且筛选有利于人畜保健的植物,逐一研究其生境与其成活的环境条件,和农业科学家合作引种驯化,以达成合理利用中草药植物资源的要求。  相似文献   
107.
Summary A Chromatographic survey of flavonoids in the various flower color mutants of the 28-chromosome Siberian Iris (series Sibiricae subseries Sibiricae) was conducted using mutants of known genotype (Vaughn 1974). Mutants at the C locus contain the malvidin glycoside ensatin, indicating that this gene locus may control methylation of delphinidin. Clear white, a mutation at the W locus, results in the production of flavones in excess.  相似文献   
108.
Sylvie Crasquin 《Geobios》1984,17(3):341-351
The study of the distribution of Ostracode superfamiliesin the Dinantian of Northern France, Belgium and South Canadian Rockies leads us to establish a new Bairdiacean and Paraparchitacean ecozone. In a confined environment Kloedenellacea become more important. This association is characteristic of carbonate shelf sedimentation in warm climatic conditions. Russian and American bibliography strengthen our conclusions.  相似文献   
109.
Food habits of three sympatric carnivore mammals in the Tsushima islands of Japan were studied during 1986–91. Scats of the Tsushima marten (n=1236), the Siberian weasel (n=218) and the Tsushima leopard cat (n=350) were collected monthly and the food items were determined by scat contents analysis. Marten was omnivorous showing a high level of diversity of food throughout the year. The important foods for marten were fruits and berries from spring to autumn, insects in summer and autumn and small mammals all year round. Leopard cat preferred to hunt wood/mice and birds, and remained a flesh meat specialist throughout the year. Weasel was intermediate between marten and leopard cat, but was slightly biased towards the flesh meat eater. The three carnivores do not compete against one another for food, except for small rodents. A conflict for food between leopard cat and weasel was suggested to be more intense than that of other combinations based on diet overlapping. Marten may be characterized as an opportunistic generalist. When interspecific competitors existed, or human disturbance to the habitat occurred, the preferential flexibility of the marten to alternative food resources might become more advantageous than the other two species.  相似文献   
110.
Lateenoglobivalvulina nov. gen. (Biseriamminoidea, Foraminifera) is introduced for biserial tests with a coiled initial part and a rectilinear evolute terminal part. The test has globular chambers progressively increasing in dimension. The shape of the test in axial section is isosceles triangle with a vertex angle of 90–100° or higher. The genus includes three species: Lateenoglobivalvulina spiralis (Morozova, 1949), Lpergrata (Konovalova, 1962) and Larguta (Konovalova, 1962). The new genus belongs to the subfamily Globivalvulininae Reitlinger, 1950 emend. herein and to the family Globivalvulinidae Reitlinger, 1950, superfamily Biseriamminoidea Chernysheva, 1941. Lateenoglobivalvulina evolved from Globivalvulina Schubert, 1921 during the Pennsylvanian, it inhabited the Boreal Realm during the Pennsylvanian-Kungurian and it migrated to the southwest Paleotethys Ocean during the Sakmarian-Kubergandian.  相似文献   
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