scholarly journals Embryonic Development of the American Lobster (Homarus americanus): Quantitative Staging and Characterization of an Embryonic Molt Cycle

1991 ◽  
Vol 180 (3) ◽  
pp. 355-371 ◽  
Author(s):  
S. M. Helluy ◽  
B. S. Beltz
Keyword(s):  
Embryonic Development ◽  
Homarus Americanus ◽  
American Lobster ◽  
Molt Cycle

Valorization of American lobster ( Homarus americanus ) cooking waters: preparation and characterization of a food ingredient

2021 ◽  
Author(s):  
Ariane Tremblay ◽  
Ronan Corcuff ◽  
Charles Goulet ◽  
Samuel B. Godefroy ◽  
Alain Doyen ◽  
...  
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Food Ingredient

scholarly journals Purification and characterization of a digestive cysteine proteinase from the American lobster (Homarus americanus)

1989 ◽  
Vol 263 (2) ◽  
pp. 439-444 ◽  
Author(s):  
M V Laycock ◽  
T Hirama ◽  
S Hasnain ◽  
D Watson ◽  
A C Storer
Keyword(s):  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Gel Filtration ◽  
Homarus Americanus ◽  
Exchange Chromatography ◽  
American Lobster ◽  
Digestive Juice ◽  
Effects Of Ph ◽  
Km Value

A new cysteine proteinase was isolated from the digestive juice of the American lobster (Homarus americanus). The enzyme was purified by a combination of affinity and ion-exchange chromatography and gel filtration. The cysteine proteinase accounted for 80% of the proteolytic activity in the lumen of the hepatopancreas. The most potent heavy-metal inhibitors were Hg, Cu, and Ag ions. Inhibition by organic proteinase inhibitors, including E-64 [L-trans-epoxysuccinyl-leucylamido-(4-guanidino)butane] and activation of the enzyme by 2-mercaptoethanol and dithiothreitol are characteristic of cysteine proteinases. Several similarities to papain are noted and include the N-terminal sequence, of which 22 of the first 28 amino acids are identical. Some notable differences are the higher Mr of 28,000 compared with 23,350 for papain, and the low isoelectric point (pI 4.5) of the lobster enzyme. The effects of pH and temperature on catalytic activity of the lobster proteinase were studied with benzyloxycarbonylalanine p-nitrophenyl ester as the substrate. The kcat./Km value was effectively temperature-independent between 10 and 60 degrees C. The pH-activity profile for the lobster enzyme revealed four apparent protonation states, of which only two are active.

Identification and characterization of a cDNA encoding a crustin-like, putative antibacterial protein from the American lobster Homarus americanus

2007 ◽  
Vol 44 (13) ◽  
pp. 3333-3337 ◽  
Author(s):  
Andrew E. Christie ◽  
Szymon Rus ◽  
Christopher C. Goiney ◽  
Christine M. Smith ◽  
David W. Towle ◽  
...  
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Antibacterial Protein ◽  
Identification And Characterization

Characterization of SSRs from the American lobster,Homarus americanus

2006 ◽  
Vol 7 (2) ◽  
pp. 330-332 ◽  
Author(s):  
ANDREA HODGINS-DAVIS ◽  
STEVEN ROBERTS ◽  
DIANE F. COWAN ◽  
JELLE ATEMA ◽  
MICHAEL BENNIE ◽  
...  
Keyword(s):  
Homarus Americanus ◽  
American Lobster

Characterization of Exoskeletal Proteins from the American Lobster, Homarus americanus

1998 ◽  
Vol 119 (1) ◽  
pp. 189-199 ◽  
Author(s):  
Marjaana Nousiainen ◽  
Kate Rafn ◽  
Lene Skou ◽  
Peter Roepstorff ◽  
Svend Olav Andersen
Keyword(s):  
Homarus Americanus ◽  
American Lobster

Effects of Reproduction upon Molting and Growth in Female American Lobsters (Homarus americanus)

1988 ◽  
Vol 45 (5) ◽  
pp. 805-821 ◽  
Author(s):  
K. Nelson ◽  
D. Hedgecock ◽  
W. Borgeson
Keyword(s):  
Growth Rates ◽  
Homarus Americanus ◽  
Control Group ◽  
American Lobster ◽  
Cycle Duration ◽  
Female Size ◽  
Molt Cycle ◽  
Young Females ◽  
Long Day ◽  
Short Days

American lobster (Homarus americanus) females characteristically extrude eggs (E) in the summer of the year following a summer or autumn molt (M), but young females may extrude in the same year. The subsequent M is delayed until after hatching, resulting in the former case in a 2-yr reproductive molt cycle, measuring from M to M. Adult female lobsters were exposed to periods of short days (8 h light: 16 h dark) followed by long day onset (L) (16 h light: 8 h dark) at different times with respect to M, or as controls were kept under continuous long-day conditions. In this way were generated molt cycles with delayed or undelayed extrusions, as well as ones with incomplete vitellogeneses resulting from too-long delayed L, and molt cycles in which vitrellogenesis did not begin (control group). Delayed L results in delayed E and M, as measured either in days or in day-degrees above 6 °C. An incompleted vitellogenesis following a too-long delayed L changes neither the duration of the molt cycle nor its characteristic positive correlation with female size; the duration of molt cycles containing either delayed or undelayed E appears in contrast to become independent of size. Intermolt intervals following prior E are shorter than those following anovulatory cycles. Retention of the clutch to hatching is associated with an additional increment to the intermolt interval. The results suggest that following E, a "reproductive" program replaces the "somatic" program of control of molt cycle duration. Incompleted vitellogeneses are associated with significantly smaller molt increments and growth rates than in the evidently avitellogenic continuous long-day control group, even though intermolt duration and its relation to size remain the same. Growth rates of molt cycles containing incompleted vitellogeneses are significantly higher than ones containing E only if that is delayed. Differential dependence of molt cycle duration and growth rate measures upon size and temperature indicate that molting and growth are distinct and rather independently controlled processes in adult lobsters, however tightly linked they may be in juveniles. Implications for molting and reproduction in the natural environment are discussed.

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