Acetylcholinesterase activity in embryonic and larval development of Artemia salina leach (crustacea phyllopoda)

Abstract

Acetylcholinesterase (AChE) activity has been studied in Artemia salina embryos and larvae by quantitative, histochemical, and electrophoretic methods. An AChE activity is present in dehydrated encysted gastrulae and remains low in rehydrated developing embryos, showing at hatching an increase that becomes faster during the nauplius stages (twice the gastrula activity at the nauplius I1 stage), and continues linearly in the first metanauplius stages. The histochemical staining, faint and diffuse in dehydrated gastrulae, in more advanced embryos becomes localized in cell membranes and stronger in differentiating tissues; most AChE activity is localized in the nervous and muscular cells, and a fainter one in the differentiating metanauplius segments. Dehydrated cysts show one electrophoretic AChE band, that is no longer detectable in rehydrated embryos and larvae, while two other bands appear, that migrate more slowly; in advanced larval stages, the more cathodic band is predominant. In dehydrated cysts, isoelectric focusing separates three AChE bands with isoelectric points (IP) at pH 5.0, 5.7, and 5.9; in hydrated embryos and larvae, the band at pH 5.0 is absent and another is seen at pH 5.5. Eserine, DFP, and BW284c51 inhibit the enzyme activity strongly and cause paralysis of larvae; also tubocurarine blocks the motility. These results are discussed in relation to the differentiation of the neuromuscular system and to the development of motility. As a hypothesis, in early embryonic stages, before any neuromuscular differentiation is evident, a cholinergic-like system might regulate non-neural cell activities and interactions, associated with embryogenetic events,

Is a mollusc an evolved bent metatrochophore? A histochemical investigation of neurogenesis in Mytilus (Mollusca: Bivalvia)

“…Afterwards the pioneering fibres, as they elongate towards the anterior pole according to the bilateral symmetry of the adult body, may exert a neural induction (Dorresteijn & Graffy, 1993) visualized by plasma membrane AChE activity of ectodermal cell rows. This has been found along other pioneer axons (Raineri & Falugi, 1983).…”

Nervous system development in the fairy shrimpBranchinellasp. (Crustacea: Branchiopoda: Anostraca): Insights into the development and evolution of the branchiopod brain and its sensory organs

“…With the advent of TEM‐techniques and fluorescent markers, numerous researchers embarked on the process of documenting in detail the nervous system and the distribution of neuro‐active substances (Elofsson, ; Elofsson and Dahl, ; Lake, ; Elofsson and Lake, ; Rasmussen, ; Elofsson and Klemm, ; Aramant and Elofsson, ; Nässel et al, ; Myhrberg et al, ; Raineri and Falugi, ; Blanchard, ; Elofsson and Hagberg, ; Sinakevitch et al, ; Strausfeld, ).…”

“…All the investigations into postembryonic nervous system development in Anostraca (Benesch, ; Raineri and Falugi, ; Blanchard, ; Harzsch and Glötzner, ; Wildt and Harzsch, ; Duman‐Scheel et al, ), however, as well as most of the studies cited above are based on species of the genus Artemia only.…”

Three (―)-cytisine derivatives and 1-hydroxyquinopimaric acid as acetylcholinesterase inhibitors

“…Raineri and Falugi [26] studied AChE activity in embryos and larvae of Artemia salina . According to them, AChE activity is present in dehydrated cystic gastrulas and remains low in rehydrated developing embryos.…”