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Melatonin cycle in the fiddler crab Uca pugilator and influence of melatonin on limb regeneration
Author(s) -
Tilden Andrea R.,
Rasmussen Paul,
Awantang Ruth M.,
Furlan Scott,
Goldstein Jessica,
Palsgrove Michael,
Sauer Angeline
Publication year - 1997
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.1997.tb00347.x
Subject(s) - melatonin , eyestalk , fiddler crab , biology , medicine , darkness , endocrinology , photoperiodism , circadian rhythm , radioimmunoassay , crustacean , ecology , botany , hormone
Tilden AR, Rasmussen P, Awantang RM, Furlan S, Goldstein J, Palsgrove M, Sauer A. Melatonin cycle in the fiddler crab Uca pugilator and influence of melatonin on limb regeneration. J. Pineal Res. 1997; 23:142–147. © Munksgaard, Copenhagen Abstract Melatonin was measured over 24 hr in the eyestalks of Uca pugilator by means of radioimmunoassay; crabs were acclimatized either to a LD 12:12 photoperiod or constant darkness. A significant peak occurred at 13.00 hr in the LD 12:12 crabs. A photophase peak in melatonin has only been reported in one other species, also a crustacean. In constant darkness, two melatonin peaks occurred, one at 16.00 hr and the other 12 hr later; these results suggest that the melatonin cycle is a true circadian rhythm. HPLC with ultraviolet‐visible detection was used to confirm the identity of melatonin immunoactivity. The influence of melatonin on regeneration of the walking legs was also examined: eyestalks were either removed or left intact, and limb bud length was measured every other day for at least 17 days in control and melatonin‐treated crabs (60 μg ml ‐1 seawater). Melatonin significantly increased the rate of limb regeneration in both eyestalk‐intact and eyestalk‐removed groups; this is contrary to results of regeneration studies in other phyla, in which similar melatonin concentrations inhibited regeneration.