Genome-Wide Identification and Immune Response Analysis of Serine Protease Inhibitor Genes in the Silkworm, Bombyx mori

In most insect species, a variety of serine protease inhibitors (SPIs) have been found in multiple tissues, including integument, gonad, salivary gland, and hemolymph, and are required for preventing unwanted proteolysis. These SPIs belong to different families and have distinct inhibitory mechanisms. Herein, we predicted and characterized potential SPI genes based on the genome sequences of silkworm, Bombyx mori. As a result, a total of eighty SPI genes were identified in B. mori. These SPI genes contain 10 kinds of SPI domains, including serpin, Kunitz_BPTI, Kazal, TIL, amfpi, Bowman-Birk, Antistasin, WAP, Pacifastin, and alpha-macroglobulin. Sixty-three SPIs contain single SPI domain while the others have at least two inhibitor units. Some SPIs also contain non-inhibitor domains for protein-protein interactions, including EGF, ADAM_spacer, spondin_N, reeler, TSP_1 and other modules. Microarray analysis showed that fourteen SPI genes from lineage-specific TIL family and Group F of serpin family had enriched expression in the silk gland. The roles of SPIs in resisting pathogens were investigated in silkworms when they were infected by four pathogens. Microarray and qRT-PCR experiments revealed obvious up-regulation of 8, 4, 3 and 3 SPI genes after infection with Escherichia coli, Bacillus bombysepticus, Beauveria bassiana or B. mori nuclear polyhedrosis virus (BmNPV), respectively. On the contrary, 4, 11, 7 and 9 SPI genes were down-regulated after infection with E. coli, B. bombysepticus, B. bassiana or BmNPV, respectively. These results suggested that these SPI genes may be involved in resistance to pathogenic microorganisms. These findings may provide valuable information for further clarifying the roles of SPIs in the development, immune defence, and efficient synthesis of silk gland protein

Political Economy of Industrial Keiretsu Groups in Japan and their Impact on Foreign Trade with the United States

The postwar transformation of the international environment has caused economic issues to become a main source of contention among industrial states. The trade imbalance between Japan and its trading partners became a major source of conflict. Reciprocity of access and opening the market of Japan became the main point of debate and the major issue affecting relations between Japan and the United States. While the distinction between the domain of domestic and international politics increasingly is blurred, different domestic political economies create bilateral political and economic conflict. The structure and politics of intercorporate groups or vertical keiretsu are a major feature of Japan's industrial structure and political economy. This case study examines how vertical keiretsu in the automobile and home electric appliance industries affect the Japanese political economy and international trade. A political economy approach focuses on the political context of economic phenomena by analyzing both political and economic variables. Case studies of keiretsu were used in order to gain an understanding of Japan's political economy. A number of propositions or assumptions about the political economy and the dynamics of keiretsu were examined in these studies. It was found that vertical keiretsu influences the industrial sector, trade, and foreign policies in Japan. Japan's industrial policies cannot fully be understood without taking keiretsu into consideration. Scholars have not yet fully considered vertical keiretsu as major actors in the Japanese political process. Their political influence on industrial policies has largely been overlooked. Vertical keiretsu in the automobile and home electric appliance industries were found in the case studies to have been shaping industrial policies since the early post war years. Findings about the nature of Japan's political economy help to explain the conflictive bilateral relationships between Japan and the United States. The findings also show that understanding political economies of nations is increasingly important as the world economy grows and greater trade interaction is imminent