Molecular Structure and Organization of Crustacean Hyperglycemic Hormone Genes of Penaeus monodon

Abstract

The Crustacean hyperglycemic hormone (CHH) has been shown to exist as multiple molecular forms in several crustacean species. In Penaeus monodon, a gene encoding CHH (so-called Pem-CHH1) was recently described. In this study, the molecular structures of two other CHH genes (Pem-CHH2 and Pem-CHH3) are reported. Both the Pem-CHH2 and Pem-CHH3 genes contain three exons that are separated by two introns that are similar to the structure of other genes in the same family. An analysis of the upstream nucleotide sequences of each Pem-CHH gene has identified the putative promoter element (TATA box) and putative binding sites for several transcription factors. The binding sites for CREB, Pit-1, and AP-1 were found upstream of all three Pem-CHH genes. A Southern blot analysis showed that at least one copy of each Pem-CHH gene was located within the same 10 kb genomic DNA fragment. These results suggest that the CHH genes are arranged in a cluster in the genome of P. monodon, and that their expression may be modulated by similar mechanisms.

Eyestalk transcriptome and methyl farnesoate titers provide insight into the physiological changes in the male snow crab, Chionoecetes opilio, after its terminal molt

“…Indeed, the MOIH that was identified in the spider crab showed two functions, mandibular organ inhibiting, and hyperglycemic effects 13 . Based on the alignment of amino acid sequences of the snow crab CHH and other known MOIHs, we found that the snow crab CHH shared high similarity to MOIHs of other decapods with six well-conserved cysteine residues 29 , 41 , suggesting that the snow crab CHH may act as a MOIH. Therefore, an obvious decrease in its expression pattern after the terminal molt might activate MF synthesis.…”

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“…In recent years, insulin-like peptides and insulin-like growth factor have been discovered in invertebrates, and these polypeptides have similarity in sequence and function with insulin and insulin-like growth factors (Gricourt et al, 2003;Lebel et al, 1996;Masumura et al, 2000;Sevala et al, 1993;Wu and Brown, 2006). Most studies on these key factors in crustaceans have focused on gene cloning, gene function and enzyme activity (Chang et al, 2010;Hsiao et al, 2002;Jeon et al, 2012;Wiwegweaw et al, 2004). There were also some studies on mRNA expression of these genes (Martinez-Quintana et al, 2014;Schein et al, 2005), but most of them focused on carbohydrate digestion, transportation or regulation.…”