共查询到20条相似文献,搜索用时 0 毫秒
1.
Summary Trypsin from the hepatopancreas ofMacrobrachium lamarrei showed optimum activity at pH 7.5 and temperature 45°C. The enzyme activity increased with the increase in incubation period and enzyme concentration. Michaelis constant of the enzyme was 2.38×10–2 M.Acknowledgments. The authors are thankful to University Grants Commission, India for the award of a Junior Research Fellowship. 相似文献
2.
J. W. McBeth 《Cellular and molecular life sciences : CMLS》1970,26(2):144-145
Zusammenfassung Die Carotinoide der GarneleBetaeus harfordi bestehen zu über 93% aus Astaxanthin und seinen Estern. Die tiefblaue äusserliche Farbe wird durch ein Chromoproteid mit unverestertem Astaxanthin gebildet.
Contribution from the Scripps Institutiom of Oceanography. This research was supported by Research Grant No. GB-5332x-1 from the National Science Foundation awarded to Dr. D. L. Fox. 相似文献
Contribution from the Scripps Institutiom of Oceanography. This research was supported by Research Grant No. GB-5332x-1 from the National Science Foundation awarded to Dr. D. L. Fox. 相似文献
3.
J W McBeth 《Experientia》1970,26(2):144-145
4.
In crustaceans, all the steps in the assimilation of food take place in the hepatopancreas. To facilitate the study of this organ, a method for the dissociation of cell types was developed. The hepatopancreas of the prawn Palaemon serratus was mechanically dissociated and the cells separated by Percoll density-gradient centrifugation. The E and R cells had similar densities of around 1.05 g/ml. The F cells were separated into two distinct fractions with densities of 1.075 and 1.082 g/ml. The B cells sedimented at a density of 1.12 g/ml. The ratio between the two populations of F cells was found to vary during the intermolt cycle while B cells disappeared after the molt. When the density gradient fractions were incubated with 3H-leucine, incorporation was highest in the F cell fractions. Measurements of alpha-amylase activity, indicated that the two populations of F cells may be derived from the same cell type. 相似文献
5.
Y. Arlot-Bonnemains A. Van-Wormhoudt P. Favrel M. Fouchereau-Péron G. Milhaud M. S. Moukhtar 《Cellular and molecular life sciences : CMLS》1986,42(4):419-420
Summary A molecule immunologically related to salmon calcitonin has been detected in the hemolymph of the shrimpPalaemon serratus. Its concentration varies inversely with the calcium level during the molt cycle; a maximum (14 ng/ml) is found in the post-molt stage and a minimum (0.5 ng/ml) during the premolt stage. 相似文献
6.
7.
Chymotrypsin gene expression during the intermolt cycle in the shrimpPenaeus vannamei (Crustacea; Decapoda) 总被引:1,自引:0,他引:1
A. Van Wormhoudt D. Sellos A. Donval S. Plaire-Goux G. Le Moullac 《Cellular and molecular life sciences : CMLS》1995,51(2):159-163
InPenaeus vannamei, chymotrypsin is present as two isoenzymes in the hepatopancreas. The enzyme has been localized in F-cells by immunocytochemistry using a specific antibody. By in situ hybridization, with a 510 pb cDNA probe encoding for the first 170 amino acids of the shrimp chymotrypsin, mRNA was localized in the same cells. Gene expression was followed during the intermolt cycle by measuring changes in specific activity in crude extracts, and by the estimation of mRNA levels by Northern blots using the same probe. The increase in specific activity in premolt is preceded in early premolt by an increase in the amount of chymotrypsin mRNA. A second increase is observed in postmolt, suggesting a different mode of regulation of gene expression. 相似文献
8.
9.
Penaeidins, a family of antimicrobial peptides from penaeid shrimp (Crustacea, Decapoda) 总被引:13,自引:0,他引:13
Destoumieux D Munoz M Bulet P Bachère E 《Cellular and molecular life sciences : CMLS》2000,57(8-9):1260-1271
The production of antimicrobial peptides represents a first-line host defense mechanism of innate immunity that is widespread
in nature. Only recently such effectors were isolated in crustacean species, whereas numerous antimicrobial peptides have
been characterized from other arthropods, both insects and chelicerates. This review presents findings on a family of antimicrobial
peptides, named penaeidins, isolated from the shrimp Penaeus vannamei. Their structure and antimicrobial properties as well as their immune function will be discussed through analyses of penaeidin
gene expression and peptide distribution upon microbial challenge.
Received 21 January 2000; received after revision 10 March 2000; accepted 10 March 2000 相似文献
10.
11.
Résumé Nous avons étudié l'ultrastructure des «corps en bulbe d'oignon» dans l'organe-X du pore sensoriel ou l'organe de Bellonci de la crevetteParatya tasmaniensis. L'ultrastructure des «corps en bulbe d'oignon» consistent en éléments tabulaires, que nous supposons Être du réticulum endoplasmique agranulaire, orienté dans deux directions. Dans les éléments tubulaires se trouvent des structures semblables aux lysosomes. 相似文献
12.
13.
S. Harpaz D. Kahan M. Moriniere P. Porcheron 《Cellular and molecular life sciences : CMLS》1987,43(8):901-902
Summary Ecdysteroid titers were determined in the hemolymph of adult freshwater prawn,Macrobrachium rosenbergii, during various stages of the molt cycle, using radioimmunoassay. A comparison was made between hormone levels in males which undergo normal molt and dominant males of the population which periodically commit cheliped autotomy. The latter is a recently discovered phenomenon whereby a male voluntarily sheds off both its long claws at molt, once the ratio between body length and combined claw length reaches a ceiling level of about 13. Shortly before an autotomizing molt, hormone levels were about three times higher than on the eve of a normal molt.10 November 1986 相似文献
14.
G. Walker 《Cellular and molecular life sciences : CMLS》1977,33(12):1603-1604
Summary Ammonium ions alone will activate both vesicula and inseminated spermatozoa ofBalanus balanoides. Maximum activity, however, occurs when inseminated spermatozoa are treated with the blood and oviducal gland fluid ofB. balanoides.Acknowledgments. I should like to thank Mr K. White for the ammonia determinations and Prof. D. J. Crisp and Dr P. A. Gabbott for useful discussions. 相似文献
15.
W Ghidalia R Vendrely Y Coirault C Montmory O Prou-Wartelle 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,284(1):69-72
The process of coagulation of the hemolymph in Macropipus puber (L.) Crustacea Decapod depends on one or several plasmatic factors and on a thermo-labile cellular factor which does not seem to be specific. The existence of these factors has been demonstrated. 相似文献
16.
17.
R Vendrely W Ghidalia Y Coirault C Montmory M O Brouard O Prou-Wartelle 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,285(10):1069-1072
Electrophoretical and immuno-electrophoretical analysis of plasma, serum and some plasmatic extracts of Macropipus puber (L). have evidenced the presence in the plasma of a component absent in the serum. This component which disappears from the plasmatic extracts after their coagulation must therefore plays a role in the clotting processes. 相似文献
18.
M Charmantier-Daures 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,284(8):655-658
When eyestalk-removal and pereiopod-removal, followed by intensive regeneration, are realized together on the same animal, their accelerative effect on the moulting rate is lower than the effect of only one of these two processes. The critical stage of pereiopod regeneration varies between the moulting stages C4 to D1 according to the physiological state of the Crab. 相似文献
19.
20.