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41.
Structure of the Bombyx mori fibroin light-chain-encoding gene: upstream sequence elements common to the light and heavy chain. 总被引:21,自引:0,他引:21
Yoshimi Kikuchi Kazuyuki Mori Satoshi Suzuki Kazunori Yamaguchi Shigeki Mizuno 《Gene》1992,110(2):151-158
Two overlapping genomic clones containing the fibroin light-chain (Fib-L)-encoding gene (Fib-L) were obtained from the cosmid library of the silkworm, Bombyx mori J-139, by hybridization with the Fib-L cDNA clone. Sequencing of the 14.6-kb region revealed that Fib-L was 13472 bp long containing seven exons, and that the gene contained a large first intron which occupied about 60% of the gene. Comparison of restriction patterns of the J-139 Fib-L with those of eight other B. mori breeds producing normal-level fibroin demonstrated that considerable restriction-fragment length polymorphisms were present in regions containing the first intron and the 3′-flanking sequence. However, sizes of the Fib-L mRNA and the Fib-L polypeptide were very similar among the nine breeds tested, suggesting that the exon sequences and the splice signals were all well conserved. 5′-Flanking regions of Fib-L and the fibroin heavy-chain (Fib-H)-encoding gene (Fib-H) compared in this study contained three 18-30-bp sequences of high similarity and many 8-10-bp common elements, six of which coincided with the binding sites of homeodomain proteins. Gel retardation assays with the nuclear extracts of the posterior and middle silk glands suggested that protein factors present in the posterior silk-gland nuclei could bind to a set of those common upstream elements. 相似文献
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本文报导四川省西部鱼类寄生粘孢子虫粘体虫属六新种,即异型粘体虫,新种Myxosoma disparis sp.nov.,四川粘体虫,新种Myxosoma sichuanensis sp.nov.,光唇粘体虫,新种Myxosoma acrossochilusi sp.nov.鳅粘体虫,新种Myxosoma nemachilusi sp.nov.斜囊粘体虫,新种Myxosoma obliqua sp.nov.,雅安粘体虫,新种Myxosoma yaanensis sp.nov.。 相似文献
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Abstract The vitellogenic period of gypsy moth ovarian development starts on day 3 of the pupal stage and continues through adulthood. During this period, rapid increases occur in follicle size, protein content, and wet weight of the ovary. Patency is observed on day 3 of the pupal stage.
Pre-vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre-vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.
Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female-specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.
A highly sensitive double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process. 相似文献
Pre-vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre-vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.
Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female-specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.
A highly sensitive double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process. 相似文献
46.
Incorporation of fatty acids by Streptococcus mutans 总被引:1,自引:0,他引:1
Masaru Sato Hironori Tsuchiya Hideki Tani Kohji Yamamoto Ryozo Yamaguchi Hiroshi Nitta Nobutake Kanematsu Isamu Namikawa Nobuhiko Takagi 《FEMS microbiology letters》1991,81(1):117-121
In a series of investigations into the cariogenicity of Streptococcus mutans, we studied the incorporation of exogenous fatty acids with reference to glucosyltransferase secretion and membrane fatty acid changes. When cells were grown with different fatty acids, both saturated and unsaturated fatty acids were readily incorporated into the membrane lipids and were biotransformed and elongated preferentially to the longer 16- and 18-carbon-chain fatty acids. This incorporation and chain-elongation led to significant changes in fatty acids composition. By adding fatty acids to the medium, it was possible to appropriately modify the degree of unsaturation and the relative ratio between specific fatty acids in the membrane lipids of S. mutans. 相似文献
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Preparation of colloidal gold for staining proteins electrotransferred onto nitrocellulose membranes 总被引:1,自引:0,他引:1
This paper describes a simple method of preparing colloidal gold for staining protein blots. Colloidal gold was prepared from 0.005 or 0.01% HAuCl4 by the addition of formalin as a reductant and potassium hydroxide. Staining of small cell carcinoma tissue extract blotted onto nitrocellulose membranes with this colloidal gold solution resulted in the appearance of a large number of clear wine-red bands. The sensitivity of gold staining was 60 times higher than that of Coomassie brilliant blue staining and almost comparable to that of silver staining of proteins in polyacrylamide gel. The sensitivity of this method was also satisfactory in comparison with that of enzyme immunoblotting. The colloidal gold prepared by this method is usable for routine work. 相似文献
50.
New preparation method for 9-anthryldiazomethane (ADAM) as a fluorescent labeling reagent for fatty acids and derivatives 总被引:6,自引:0,他引:6
A preparation method for 9-anthryldiazomethane (ADAM) as a fluorescent labeling reagent for carboxylic acids is described. 9-Anthraldehyde hydrazone is oxidized with an organic oxidant, N-chlorosuccinimide, in an organic solvent such as ethyl acetate to give ADAM, and then the reaction mixture is directly used as the reagent solution for the derivatization of carboxylic acids. Both the oxidation and the derivatization reaction are carried out at room temperature, and an aliquot of the derivatization mixture is directly injected into a chromatograph. 9-Anthrylmethyl ester derivatives formed from ADAM and various carboxylic acids are sufficiently separated on a reversed-phase column and are sensitively detected fluorometrically. The present method was applied to the high-performance liquid chromatographic determination of long and short chain fatty acids, keto acids, and hydroxy acids. 相似文献