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TSUYOSHI OHIRA HIDEKAZU KATAYAMA KATSUMI AIDA HIROMICHI NAGASAWA 《Fisheries Science》2003,69(1):95-100
ABSTRACT: Until now, six crustacean hyperglycemic hormones (CHH) designated Pej-SGP-I, -II, -III, -V, -VI and -VII have been characterized in the kuruma prawn Penaeus japonicus . All CHH consist of 72 amino acid residues and have an amidated carboxyl (C)-terminus. In the present study, we expressed Pej-SGP-III in methylotrophic yeast Pichia pastoris in order to obtain a large quantity of recombinant CHH possessing biological activity. A cDNA encoding Pej-SGP-III that had been previously cloned was processed by polymerase chain reaction (PCR) and the resulting product was ligated into an expression vector. Pichia pastoris was transformed with this vector after which a recombinant Pej-SGP-III was expressed having an additional amino acid residue (glycine) at the C-terminus (rPej-SGP-III-Gly), a form considered to be a putative precursor of this hormone. rPej-SGP-III-Gly secreted into the culture medium was purified by reversed-phase HPLC, and amidated using a peptidylglycine alpha-amidating enzyme. The amidated rPej-SGP-III (rPej-SGP-III) showed hyperglycemic activity in in vivo bioassay almost comparable to that of the natural Pej-SGP-III. rPej-SGP-III thus obtained will be a useful tool not only for its physiological study but also for the determination of its 3-D structure. 相似文献
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Evidence of a local spawning site of marine eels along northeastern Japan, based on the distribution of small leptocephali 总被引:3,自引:0,他引:3
YOBUO KIMURA MICHAEL J. MILLER GEN MINAGAWA SHUN WATANABE AKIRA SHINODA JUN AOYAMA TADASHI INAGAKI KATSUMI TSUKAMOTO 《Fisheries Oceanography》2006,15(2):183-190
Evidence of recent spawning by several species of marine eels of the families Congridae, Ophichthidae, and Nettastomatidae was found over the continental shelf along the coast of northeastern Japan in October 2003. Sixty‐three leptocephali of at least three taxa that ranged from 3.8 to 12.3 mm total length were collected in a relatively small area, just to the south of Cape Shioya, primarily over the 100‐and 200‐m‐depth contours. The leptocephali of Gnathophis nystromi nystromi were the most abundant, followed by those of G. nystromi ginanago. This spawning area is located in an area that appeared to include water originating from the Tsugaru Warm Current and is further south than the typical latitude of the cold water of the Oyashio First Intrusion. These findings suggest that some species of marine eels may not migrate past the slope to spawn, and that the oceanographic features of the region may provide favorable conditions for the growth and retention of leptocephali in the area to the south of Cape Shioya. 相似文献
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Satoshi TSUKAMOTO Taichi HARA Atsushi YAMAMOTO Yuki OHTA Ayako WADA Yuka ISHIDA Seiji KITO Tetsu NISHIKAWA Naojiro MINAMI Ken SATO Toshiaki KOKUBO 《The Journal of reproduction and development》2013,59(1):33-39
Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule
degradation and many other cellular functions. However, little is known about lysosomal
function during early embryogenesis. Here, we found that the number of lysosomes increased
after fertilization. Lysosomes were abundant during mouse preimplantation development
until the morula stage, but their numbers decreased slightly in blastocysts. Consistently,
the protein expression level of mature cathepsins B and D was high from the one-cell to
morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs
targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were
developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes
also caused developmental retardation, resulting in accumulation of lipofuscin. Our
findings highlight the functional changes in lysosomes in mouse preimplantation
embryos. 相似文献
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Ryutaro AIZAWA Megumi IBAYASHI Tomomi HATAKEYAMA Takayuki TATSUMI Satoshi TSUKAMOTO 《The Journal of reproduction and development》2021,67(1):73
Mature mammalian oocytes contain lipid droplets (LDs), which are neutral lipid storage organelles critically important for energy metabolism. In mice, maternal obesity, induced by long-term (> 3 months) high-fat feeding, contributes to the accumulation of LDs in mature oocytes. However, few studies have investigated the influence of short-term high-fat feeding on LD content. In this study, we demonstrated that 3 weeks of high-fat feeding is sufficient to increase LD content and intracellular triacylglycerol levels. Using a two-step centrifugation technique to release LDs into the perivitelline space, we found that short-term high-fat feeding increased the level of LDs in MII oocytes and that 3 days of high-fat feeding were sufficient to increase efficiency of LD release. Collectively, our study suggests that short-term high fat feeding can have a higher impact on lipid metabolism during oocyte maturation. 相似文献