title: Crustacean hyperglycemic hormone precursor transcripts in the hemocytes of the crayfish Procambarus clarkii: novel sequence characteristics relating to gene splicing pattern and transcript stability.
abstract: It was demonstrated in a previous study (Wu et al., 2012b) that crustacean hyperglycemic hormone (CHH) gene is expressed in the hemocyte of Procambarus clarkii. In the present study, 2 additional cDNAs (CHH2-L and tCHH2) from the hemocyte and a CHH gene (CHH2) from the abdominal muscle of the same species were cloned. Analyses of the cDNA and genomic sequences suggested that, similar to other previously reported CHH genes, 2 precursor transcripts (CHH2 and CHH2-L) would be derived from CHH2 gene through a process of RNA alternative splicing, and CHH2 and CHH2-L each encode a precursor containing a signal peptide, a CHH precursor-related peptide, and a mature peptide. Further, tCHH2 sequence consists of exon I, exon II, and a truncated segment of intron II of CHH2 gene, followed by a previously unknown 3'sequence. It is suggested that, because the truncation disrupts the highly conserved RNA splice acceptor site, the truncated segment is retained within tCHH2, resulting in encoding a precursor containing the typical precursor components except the mature peptide is truncated with only 40 residues. In addition, unlike 2 other previously identified transcripts (referred to as CHH1 and CHH1-L), CHH2-L, CHH2, tCHH2 contain in the 3'-UTRs 3-5 AU-rich elements (AREs). The data showed that multiple CHH genes are expressed in crayfish hemocytes. Novel sequence characteristics of the transcripts result in an RNA splicing pattern that yields a transcript (tCHH2) encoding a precursor with an atypical truncated mature peptide and possibly leads to a different expression dynamics of the precursors encoded by the ARE-containing transcripts.
authors.affiliation: Department of Biology, National Changhua University of Education, Changhua 50058, Taiwan.
authors.forename: Pei-Chen
authors.initials: PC
authors.lastname: Kung
authors.forename: Su-Hua
authors.initials: SH
authors.lastname: Wu
authors.forename: G Purna Chandra
authors.initials: GP
authors.lastname: Nagaraju
authors.forename: Wei-Shiun
authors.initials: WS
authors.lastname: Tsai
authors.forename: Chi-Ying
authors.initials: CY
authors.lastname: Lee
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics*; D003400:Astacoidea / Q000235:genetics*; D006434:Hemocytes / Q000378:metabolism*; D007447:Invertebrate Hormones / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020871:RNA Stability / Q000235:genetics / Q000502:physiology
chemical_list: D060829:Arthropod Proteins; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; C015947:hyperglycemic hormone, crustacean