Zebrafish Acetylcholinesterase Is Encoded by a Single Gene Localized on Linkage Group 7

Abstract

We cloned and sequenced the acetylcholinesterase gene and cDNA of zebrafish, Danio rerio. We found a single gene (ache) located on linkage group LG7. The relative organization of ache, eng2, and shh genes is conserved between zebrafish and mammals and defines a synteny. Restriction fragment length polymorphism analysis was allowed to identify several allelic variations. We also identified two transposable elements in non-coding regions of the gene. Compared with other vertebrate acetylcholinesterase genes, ache gene contains no alternative splicing at 5 or 3 ends where only a T exon is present. The translated sequence is 60 -80% identical to acetylcholinesterases of the vertebrates and exhibits an extra loop specific to teleosts. Analysis of molecular forms showed a transition, at the time of hatching, from the globular G4 form to asymmetric A12 form that becomes prominent in adults. In situ hybridization and enzymatic activity detection on whole embryos confirmed early expression of the acetylcholinesterase gene in nervous and muscular tissues. We found no butyrylcholinesterase gene or activity in Danio. These findings make zebrafish a promising model to study function of acetylcholinesterase during development and regulation of molecular forms assembly in vivo.

Acetylcholinesterase plays a non-neuronal, non-esterase role in organogenesis

“…As FN is distributed in a radially polarized manner within the gut tube, AChE-FN interactions are likely to facilitate endoderm cell polarization, orienting the radial rearrangements that are crucial to drive intestinal elongation. Moreover, the broad expression of AChE and FN during metazoan development, wound healing and regeneration (Anderson et al, 2008;Bertrand et al, 2001;Bicker et al, 2004;de Almeida et al, 2016;Drews, 1975;Ohta et al, 2009) suggests that AChE could regulate a wide variety of morphogenetic events across numerous species.…”

“…This esterase activity is the target of widely used pesticides and pharmaceuticals (Mileson et al, 1998;Pope et al, 2005), yet the broad expression of AChE outside of the nervous system (Anderson et al, 2008;Bertrand et al, 2001;Bicker et al, 2004;Drews, 1975) and similarity to adhesion molecules (Botti et al, 1998;Darboux et al, 1996) suggest that it has additional functions. Indeed, in neuronal and non-neuronal cell lines, AChE promotes cell-substrate adhesion (Inkson et al, 2004;Johnson and Moore, 1999;Sharma et al, 2001;Syed et al, 2008), polarized cell migration (Anderson et al, 2008), cytoskeletal organization (Dupree and Bigbee, 1994;Keller et al, 2001) and cell differentiation (Grisaru et al, 1999;Xiang et al, 2008), independently of its esterase activity (Layer et al, 1993).…”

Rapid neurobehavioural analysis based on the effects of an acetylcholinesterase inhibitor from Tephrosia purpurea in Zebrafish

“…Zebra fish AChE is the only ACh-hydrolyzing enzyme in this organism and it is highly homologous to mammalian AChE. 3 Also, the zebrafish genome does not express a functional butyrylcholine esterase, a related enzyme that can also hydrolyze Ach. 3 Hence in our study, we have used the Zebrafish as a model organism for humans to analyse the AChE inhibitory activity studies from herbals.…”

“…3 Also, the zebrafish genome does not express a functional butyrylcholine esterase, a related enzyme that can also hydrolyze Ach. 3 Hence in our study, we have used the Zebrafish as a model organism for humans to analyse the AChE inhibitory activity studies from herbals. AChE inhibitors can be used for the treatment of the autoimmune disease Myasthenia gravis , glaucoma, and Alzheimer’s disease.…”

Acetylcholinesterase plays a non-neuronal, non-esterase role in organogenesis

“…This esterase activity is the target of widely used pesticides and pharmaceuticals (Mileson et al, 1998;Pope et al, 2005), yet the broad expression of AChE outside of the nervous system (Anderson et al, 2008;Bertrand et al, 2001;Bicker et al, 2004;Drews, 1975) and similarity to adhesion molecules (Botti et al, 1998;Darboux et al, 1996) suggest that it has additional functions. Indeed, in neuronal and non-neuronal cell lines, AChE promotes cell-substrate adhesion (Inkson et al, 2004;Johnson and Moore, 1999;Sharma et al, 2001;Syed et al, 2008), polarized cell migration (Anderson et al, 2008), cytoskeletal organization (Dupree and Bigbee, 1994;Keller et al, 2001) and cell differentiation (Grisaru et al, 1999;Xiang et al, 2008), independently of its esterase activity (Layer et al, 1993).…”