Expression of the acetylcholinesterase gene during development of drosophila embryos.

The acetylcholinesterase (AChE) forms and the expression of the AChE mRNA in situ have been shown during the embryonic development of Drosophila melanogaster. The enzyme and its transcript were present well before the differentiation of the first neuroblasts. The non-CNS- specific AChE forms were responsible for the early AChE activity, and specific AChE form to the central nervous system (CNS) appeared when the CNS started to condense. Embryos deficient for the 5' end of the AChE gene expressed only the non-CNS-specific AChE forms,-- interestingly, the AChE transcript was present only in their CNS. The elimination of half of the CNS-specific AChE elevated the acetylcholine (ACh) level in the flies. These results imply that the non-CNS-specific AChE can also be non-neural, it is dispensable for the late embryonic development, and it does not substitute for the ACh hydrolysing capacity of the CNS- specific enzyme.