药西瓜UDP-糖基转移酶基因的克隆与表达分析

为明确药西瓜UDP-糖基转移酶催化葫芦素形成葫芦素配糖体的表达规律,以药西瓜品种"WM9"叶片为供试材料,采用RT-PCR技术克隆药西瓜UDP-糖基转移酶基因,并对编码蛋白进行分析。通过实时荧光定量PCR(qRT-PCR),以ACTIN为内参基因,分析获得的2个药西瓜UDP-糖基转移酶基因在不同组织器官中的表达规律。结果表明:克隆得到2个UDP-糖基转移酶基因,分别为1 546 bp和1 559 bp的cDNA全长序列,命名为UDP-E1和UDP-E2。对扩增获得的序列进行生物学信息分析,确定UDP-E1基因的完整开放阅读框(ORF)为1 314 bp,可编码氨基酸437个,理论分子量为49.02 ku,等电点为5.99,属稳定蛋白,Genbank登录号MK576125。UDP-E2基因的ORF为846 bp,可编码氨基酸281个,理论分子量为32.78 ku,等电点为5.23,属不稳定蛋白,Genbank登录号MK576126。这2个基因属于糖基转移酶超家族。UDP-E1和UDP-E2均与香瓜、黄瓜的UDP-糖基转移酶基因序列相似性最高。在各组织器官中,UDP-糖基转移酶均有表达,且在茎中表达水平最低,叶中表达水平最高。     

Polarized epithelium-sperm co-culture system reveals stimulatory factors for the secretion of mouse epididymal quiescin sulfhydryl oxidase 1

Spermatozoa acquire fertilization ability through post-translational modifications. These membrane surface alterations occur in various segments of the epididymis. Quiescin sulfhydryl oxidases, which catalyze thiol-oxidation reactions, are involved in disulfide bond formation, which is essential for sperm maturation, upon transition and migration in the epididymis. Using castration and azoospermia transgenic mouse models, in the present study, we showed that quiescin sulfhydryl oxidase 1 (QSOX1) protein expression and secretion are positively correlated with the presence of testosterone and sperm cells. A two-dimensional in vitro epithelium-sperm co-culture system provided further evidence in support of the notion that both testosterone and its dominant metabolite, 5α-dihydrotestosterone, promote epididymal QSOX1 secretion. We also demonstrated that immature caput spermatozoa, but not mature cauda sperm cells, exhibited great potential to stimulate QSOX1 secretion in vitro, suggesting that sperm maturation is a key regulatory factor for mouse epididymal QSOX1 secretion. Proteomic analysis identified 582 secretory proteins from the co-culture supernatant, of which 258 were sperm-specific and 154 were of epididymal epithelium-origin. Gene Ontology analysis indicated that these secreted proteins exhibit functions known to facilitate sperm membrane organization, cellular activity, and sperm-egg recognition. Taken together, our data demonstrated that testosterone and sperm maturation status are key regulators of mouse epididymal QSOX1 protein expression and secretion.     

Evidence of density-dependent effects on population variation of Japanese sardine (Sardinops melanosticta) off Korea

Interannual variation of some biological parameters for the Japanese sardine, Sardinops melanosticta, population in Korean waters was investigated using scientific surveys and fisheries information since the late 1970s. The abundance and geographical coverage of sardine eggs were high (peak in 1986) and broad when spawning biomasses were high in the mid 1980s, and vice versa in the late 1970s and the early 1990s. Also, feeding and spawning areas based on fisheries information exhibited the same pattern of expansion/contraction as seen in ichthyoplankton surveys. Annual Gonadal Somatic Index (GSI) in spawning season (February to April) and the size at age 1 of sardine were reduced during the high abundance period. It is suggested that density‐dependent effects on the reproduction and growth of the sardine population in Korean waters existed.     

SWAT模型之初步探讨

由美国农业部农业研究中心（USDA-ARS）研发的分布式水文模型:水土评估工具（SWAT）,具有强大的物理机制。近年来,它被认为是最适合模拟在不同土壤、土地利用和管理大流域中,长期土地管理对于水、土沙、营养物质及农业化学物质的影响。介绍SWAT模型的原理及基础数据库之建立,并搜集SWAT模型应用研究之文献（1999-2008年）,以统计分析SWAT模型目前的研究现况,作为日后应用SWAT模型进行相关研究之参考。     

中国2种螟蛾科幼虫的形态记述(鳞翅目)

详细记述了中国螟蛾科二化螟Chilo suppressalis(Walker)和三化螟Tryporyza incertulas(Walker)幼虫的形态特征,并提供了形态特征图。所有标本均保存在中国计量学院生命科学学院标本室。图2参7     

Stochasticity dominates assembly processes of soil nematode metacommunities on three Asian mountains

Nematodes play an important role in ecosystems; however, very little is known about their assembly processes and the factors influencing them. We studied nematode communities in bulk soils from three Asian mountain ecosystems to determine the assembly processes of free-living nematode metacommunities and their driving factors. On each mountain, elevations span a range of climatic conditions with the potential to reveal assembly processes that predominate across multiple biomes. A phylogenetic nu...     

土壤NO_x气体释放研究进展

营养元素的迁移转化是生态学及环境科学研究领域的一个重要课题,土壤微生物活动产生的NOx气体作为大气中NOx的重要排放源之一,日益受到人们的关注。NOx在大气中具有很强的化学活性,通过参与大气中光化学反应而影响到其它温室气体的浓度,且在对流层O3和OH自由基的光化学反应中起着决定性作用,同时也是酸沉降中HNO3的生成源,在平流层NOx是消耗臭氧层的痕量气体之一。本文综合分析了土壤NOx产生及排放机理;影响土壤NOx排放的主要因素;土壤NOx气体排放通量的测定及其模型估算方法。并在此基础上,提出今后应把土壤微生物系统以及土壤硝化、反硝化作用机理作为以后的研究重点,运用同位素技术和各种模型手段进行较大范围的时空尺度上的连续观测研究。     

Genetic diversity of avian paramyxoviruses isolated from wild birds and domestic poultry in Taiwan between 2009 and 2020

Avian paramyxoviruses (APMVs) belonging to the subfamily Avulavirinae within the family Paramyxoviridae. APMVs consist of twenty-two known species and are constantly isolated from a wide variety of avian species around the world. In this study, the APMV isolates obtained from wild birds and domestic poultry during 2009–2020 in Taiwan were genetically characterized by phylogenetic analysis of their complete fusion protein gene or full-length genome. As a result, 57 APMV isolates belonging to seven different species were obtained during this period and subsequently identified as APMV-1 (n=17), APMV-2 (n=1), APMV-4 (n=25), APMV-6 (n=8), APMV-12 (n=2), APMV-21 (n=2) and APMV-22 (n=2). Sanger sequencing was performed to provide 22 full-length genome sequences and 35 complete fusion protein gene sequences for the APMV isolates. Phylogenetic analysis showed that the recovered viruses were closely related to Eurasian strains, except five class I APMV-1 and four APMV-4 isolates were related to North America strains. Our findings provided more evidence for the intercontinental transmission of APMVs between Eurasia and North America by wild birds. In addition, according to the criteria of the classification system based on complete fusion protein gene sequences, three novel genotypes within APMV-2, APMV-12, and APMV-22 were identified. Together, this investigation provided a broader perspective on the genetic diversity, evolution, and distribution of APMVs in multiple avian host species sampled in Taiwan.