Sharp dose- and time-dependent toxicity of mercuric chloride at the cellular level in sea urchin embryos.
Sea urchin embryos ( Sphaerechinus granularis) offer the opportunity to analyse toxicity towards cell division and stages of early development. Mercuric chloride (HgCl(2)) arrested early development at the level of the first cell cycle. The toxic effect occurred in a very sharp concentration range around 7 microM HgCl(2). At sub-toxic concentrations of HgCl(2), the morphology and kinetics of early development were comparable to control embryos. The time-dependence of toxicity was short; a 5-min exposure to the toxic concentration of 10 microM HgCl(2) was sufficient to provoke developmental dysfunction whereas continuous exposure to 5 microM HgCl(2) allowed development to occur normally. The effects on early development over this range of concentrations were specific to HgCl(2) toxicity since other heavy metal chlorides had no effect at 30 microM. Thus, the sea urchin model may provide new clues to the molecular mechanisms of HgCl(2) toxicity.
Marc
Julie
J
Station Biologique de Roscoff, Université Pierre et Marie Curie (UFR 937), Centre National de la Recherche Scientifique (CNRS, UMR 7127), BP 74, 29682 Roscoff Cedex, France.
Maguer
Cécile
C
Bellé
Robert
R
Mulner-Lorillon
Odile
O
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000187:drug effects*; D047108:Embryonic Development; D004785:Environmental Pollutants / Q000633:toxicity*; D008627:Mercuric Chloride / Q000633:toxicity*; D012617:Sea Urchins; D013997:Time Factors
D004785:Environmental Pollutants; D008627:Mercuric Chloride