Isolation and characterization of polymorphic microsatellite markers in the blowflies Lucilia illustris and Lucilia sericata

Thirteen polymorphic microsatellite loci were developed for blowflies for use in studies of genetic differentiation in wild populations of Lucilia illustris, to detect the possible occurrence of bottlenecks and to study changes in genetic variation in laboratory populations of Lucilia sericata following artificial bottlenecks. In this preliminary study it was revealed that heterozygosity was lower than expected in wild populations and genetic variation had been lost in the laboratory population despite being kept at a large size.     

Using FTA® cards to store avian blood samples for genetic studies. Their application in sex determination

FTA® cards were used for long‐term storage of avian blood samples. Blood DNA was extracted by a simple method and used in PCR for sex identification of adult and nestling Great Grey Shrikes Lanius excubitor.     

Isolation and characterization of microsatellites in Pacific white shrimp Penaeus (Litopenaeus) vannamei

Five polymorphic microsatellite loci were characterized for Penaeus (Litopenaeus) vannamei. Loci were isolated using a partial Sau3A1 genomic library by the sequencing of randomly selected clones and by a biotinylated (CT)₁₀ and (GT)₁₀ probes screening procedure. The last strategy resulted in the most useful data. About 40% of the clones showed a previously reported satellite/microsatellite (PVS1), reducing the chance of finding new microsatellite regions. Whereas two of the microsatellite loci with more than 10 alleles will be useful for mating analysis in a breeding program, the others might prove useful for population genetic studies.     

How costly is clutch formation in the Audouin's Gull Larus audouinii?

During the Audouin's Gull's breeding season at the Ebro Delta in 1993, 24 fresh eggs from eight three-egg clutches (modal clutch-size) were collected at the peak of the laying period. Eggs were processed to obtain formalin-fixed yolks, which were halved and stained using the potassium dichromate method. Digitized images of the yolks were examined to assess the daily rates of yolk deposition. We used these data in combination with egg compositional analysis to build a model of energy demands during the formation of an average clutch in Audouin's Gull. To show how the different parameters of clutch formation affect the daily energy investment peak, we performed a simulation analysis in which the rapid yolk development (RYD) period, the follicle triggering interval (FTI), the laying interval (LI) and the albumen synthesis period (ASP) were allowed to vary simultaneously. In our sample, the mean RYD period was seven days with a range from six to eight days. There were no significant differences in yolk volume among eggs in a clutch, but albumen volume was significantly smaller in third eggs. According to our model the albumen synthesis of the a-egg coincides with the energy demand peak for clutch formation. This peak represents an increase by ca. 42% in female energy requirements. Values obtained from the simulation analysis showed that only the ASP of the a-egg and the RYD durations of the second and third follicles produced noticeable reductions in peak energy investment. We predict that in gulls, whose laying intervals seem to be kept constant, significant increases of the durations of the RYD periods of second and third eggs, or even significant reductions of yolk size of these eggs, may operate simultaneously to match the energy demands during clutch formation to the prevailing food conditions.     

体外重构STUB1介导α-1抗胰蛋白酶突变体Z蛋白泛素化修饰反应体系

α-1抗胰蛋白酶Z型突变体蛋白(α-1 antitrypsin Z-mutant protein, ATZ)是引发α-1抗胰蛋白酶缺陷症(α-1 antitrypsin deficiency, AATD)的主要原因,研究ATZ蛋白的泛素化修饰和降解对于治疗AATD具有重要意义。STUB1是一种重要的E3泛素连接酶,参与调节多种蛋白质的泛素化修饰。然而,STUB1是否参与ATZ的泛素化修饰尚未明确。本研究首先将ATZ和STUB1的编码基因克隆到pET28a质粒,构建了这2个蛋白的表达质粒。随后,将重组质粒转入大肠杆菌表达系统,在优化诱导条件实现了重组蛋白的异源表达。通过金属螯合亲和层析技术纯化得到目的蛋白,并通过蛋白质谱分析验证了其氨基酸序列的准确性。利用纯化的ATZ和STUB1重组蛋白,构建了一个体外泛素化修饰反应体系。实验结果显示,在ATP、E1泛素激活酶和E2泛素结合酶的协同作用下,STUB1成功催化了ATZ的泛素化修饰。本研究提供了一种体外获得Z型突变体ATZ纯化蛋白的方法,并确认了STUB1介导ATZ的泛素化修饰功能,推进了对α-1抗胰蛋白酶Z型突变体蛋白在细胞内降解过程的调控机制的理解。     

转录因子在植物干旱应激中的功能研究进展

转录因子是一种多功能蛋白,在感知应激信号、应答相应应激基因表达及传导应激信号中起着关键作用。干旱是影响植物生长发育的主要非生物胁迫之一。为了适应干旱环境,植物发展了复杂的分子机制,其中转录因子可同时控制多种途径调控干旱应激,是操纵调控和应激响应途径的有力工具。近年来,越来越多的植物转录因子的功能被阐明,了解转录因子在干旱应激的功能,对植物的工程抗旱有重要的实践意义。综述转录因子在植物干旱应激中的功能研究进展,以期为今后转录因子的研究和利用提供理论依据,培育具有较强抗旱能力的植物。     

Environmental Supply Chain Cooperation and Its Effect on the Circular Economy Practice‐Performance Relationship Among Chinese Manufacturers

Due to resource scarcity and environmental degradation, a new development concept emphasizing environmental concerns, called the circular economy (CE), has been enacted in legislation in China. This environmental management concept can be implemented at three levels, namely, region, industrial zone, and individual enterprise, with the objective of boosting economic development while lessening environmental and resource challenges. Environmental supply chain cooperation (ESCC), an approach that utilizes customer and supplier cooperation in environmental management, has been initiated among Chinese enterprises. Using survey data collected from 396 Chinese manufacturers, we examine the role of ESCC practices in influencing the relationship between implementing CE practices and the achievement of performance outcomes by testing the moderation and mediation effects of ESCC practices on the CE practice‐performance relationship through hierarchical regression analysis. Our data analyses indicate that ESCC practices are useful by moderation and, in some cases, essential by mediation, for Chinese manufacturers seeking to realize the performance targets desired in CE practices. The results highlight the need for Chinese manufacturers to improve supply chain coordination in their implementation of CE. On the policy side, our research findings suggest that ESCC practices are beneficial and, in some cases, necessary for the development of CE in China.     

Common and rare species respond to similar niche processes in macroinvertebrate metacommunities

Ecologists have long investigated why communities are composed of a few common species and many rare species. Most studies relate rarity to either niche differentiation among species or spatial processes. There is a parallel between these processes and the processes proposed to explain the structure of metacommunities. Based on a metacommunity perspective and on data on stream macroinvertebrates from different regions of Brazil, we answer two questions. 1) Are sets of common and rare species affected by similar niche and spatial processes? 2) How does the community composition of common and of rare species differ? The main hypothesis we test is that common species are mainly affected by environmental factors, whereas rare species are mostly influenced by dispersal limitation. We used variation partitioning to determine the proportion of variation explained by the environment and space in common and rare species matrices. Contrary to our expectations, evidence supported the idea that both common and rare species are affected mainly by environmental factors, even after controlling for the differing information content between common and rare species matrices. Moreover, the abundance of some common species is also a good predictor of variation in rare species matrices. Niche differences are unlikely to be the sole cause of patterns of rarity in these metacommunities. We suggest that sets of common and rare species react to similar major environmental gradients and that rare species also respond to processes that operate at a more fine‐grained spatial scale, particularly biotic interactions. We extend the view that species sorting is the dominant process structuring metacommunities and argue that future studies focusing on rarity would benefit from a metacommunity perspective.