Molecular Characterization And Expression Pattern Of Allatostatin Gene And Its Natural Antisense Transcript In The Prawn, Macrobrachium Rosenbergii

Allatostatin is one of the largest neuropeptide families in invertebrates. In insects, they can not only inhibit the biosynthesis and release of juvenile hormone, but also affect some physiological process through modulating the muscle extraction. However, to date, the structure and expression of the gene encoding allatostatins have not been reported in any species other than insects, as well as their regulators.In our present study, we selected the prawn, Macrobrachium rosenbergii, which is the commercially important organism, as the experimental materials. By screening of a central nervous system cDNA library from the prawn, two cDNA clones were isolated and sequenced. One encodes an allatostatin precursor of 701 amino acids and is 2,855 bp in full length (named as Macro-AST A). Another encodes the naturally occurring antisense transcript of Macro-AST A (named as asMacro-AST A) and is 2,182 bp in full length. The deduced precursor of Macro-AST A was conceptually split into at least 35 FGLamide allatostatins at dibasic cleavage sites, which belongs to 29 isoforms. asMacro-AST A contains a longest possible open reading frame of 159 bp that encods a 53 amino acids peptide. Blast searches did not identify significant homology with any other known genes or proteins in the DDJ/EMBL/GenBank database. Comparison of the nucleotide sequence of asMacro-AST A with Macro-AST A revealed that an 843 bp region between them was fully complementary (from 882 bp to 1,725 bp in asMacro-AST A and from 2,004 bp to 2,847 bp in the Macro-AST A). This is the first report of allatostatin gene in Crustacea and the first endogenous antisense transcript of all identified allatostatin genes.Using semi-quantitative RT-PCR and Southern blotting analysis, expression of Macro-AST A were detected in different tissues and developmental stages and its copy...