排序方式: 共有5条查询结果,搜索用时 0 毫秒
1
1.
2.
AKIYOSHI TAKAHASHI YUTAKA AMEMIYA AKIKAZU YASUDA HIROSHI MEGURO HIROSHI KAWAUCHI 《Fisheries Science》2002,68(5):1073-1080
Several pituitary hormones, including adrenocorticotropin (ACTH), melanotropin (MSH) and β-endorphin, are generated from a common precursor protein, proopiomelanocortin (POMC). In fish, in addition to steroidogenesis of ACTH and melanogenesis of MSH, immunomodulating activity has been found in some POMC-related peptides. To investigate the functions of these peptides in the homologous system, it is necessary to establish a convenient detection method for the peptides. The present study aimed to establish a method for the detection of POMC-related peptides in bigeye tuna Thunnus obesus using a small amount of tissue sample, but not requiring peptide purification. We first determined the nucleotide sequence of tuna POMC cDNA. The cDNA was composed of 1084 base pairs (excluding the poly A tail) that encoded POMC consisting of 222 amino acids. We then fractionated an acid-acetone extract of one pituitary by reverse-phase high performance liquid chromatography (HPLC) and determined the molecular weight of each separated peptide by mass spectrometry. Consequently, we detected eight POMC-related peptides by comparing the values to the deduced amino acid sequence. Thus, the present study enabled the detection of POMC-related peptides from a small amount of tissue without the use of several purification steps. 相似文献
3.
Strong latitudinal gradients in species composition were revealed by two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA) of 41 species of epipelagic fishes and squids in 513 gillnet collections by research vessels of Hokkaido University over a huge area of the northern North Pacific during the summers of 1978–1993. Salmonids inhabited northern subarctic water and skipjack tuna (Euthynnus pelamis) and flying squid (Ommastrephes bartrami) inhabited the region of the Subarctic Boundary, but distinct boundaries between species groups and sample groups were lacking, largely because abundant species, such as Pacific saury (Cololabis saira) and Pacific pomfret (Brama japonica), migrated across most of this region during the summer. Longitudinal differences were not pronounced, but some species, including Japanese sardine (Sardinops melanostictus) and Japanese anchovy (Engraulis japonicus), were only found in the western Pacific. Pacific saury was more common in the western Pacific, whereas sockeye salmon (Oncorhynchus nerka) was concentrated in the eastern Pacific. Interannual fluctuations in the latitude of species groups were most closely correlated with changes in sea surface temperatures. In the western Pacific, 1982, 1983, 1985, 1987-88, and 1992-93 were cool years when subarctic and transitional assemblages were found farther to the south than other years. Temperature and salinity at various depths were highly correlated with each other and with first-axis DCA ordinations scores. Long-term trends in community structure were not apparent during the 1.6 decades. 相似文献
4.
5.
Tomio NISHIMURA Akane MEGURO Sachiko HASEGAWA Yoshiko NAKAGAWA Masafumi SHIMIZU Hitoshi KUNOH 《Journal of General Plant Pathology》2002,68(4):390-397
To survey endophytic actinomycetes as potential biocontrol agents against fungal diseases of mountain laurel, young plants
of mountain laurel (Kalmia latifolia L.) were used as an isolation source. From a total of 73 actinomycetes isolates obtained from leaves, stems and roots of test
plants, Streptomyces sp. AOK-30 was selected, because i) it had a broad and intense antimicrobial spectrum against various yeasts and fungal pathogens
of Ericaceae, ii) it grew on the multiplication and rooting media for tissue culture for this plant, and iii) the tissue-cultured
seedlings that had been treated with this isolate became resistant to Pestalotia disease without any adverse growth effects
such as malformation, dwarfing, discolorization and defoliation. This isolate was identified as Streptomyces sp., based on cultural, physiological and morphological characteristics. The present results indicate that isolate AOK-30
is a potential biocontrol agent against diseases of mountain laurel.
Received 10 September 2002/ Accepted in revised form 22 November 2002 相似文献
1