Application of D-Crustacean Hyperglycemic Hormone Induces Peptidases Transcription and Suppresses Glycolysis-Related Transcripts in the Hepatopancreas of the Crayfish Pontastacus leptodactylus — Results of a Transcriptomic Study

Abstract

The crustacean Hyperglycemic Hormone (cHH) is a neuropeptide present in many decapods. Two different chiral isomers are simultaneously present in Astacid crayfish and their specific biological functions are still poorly understood. The present study is aimed at better understanding the potentially different effect of each of the isomers on the hepatopancreatic gene expression profile in the crayfish Pontastacus leptodactylus, in the context of short term hyperglycemia. Hence, two different chemically synthesized cHH enantiomers, containing either L- or D-Phe3, were injected to the circulation of intermolt females following removal of their X organ-Sinus gland complex. The effects triggered by the injection of the two alternate isomers were detected after one hour through measurement of circulating glucose levels. Triggered changes of the transcriptome expression profile in the hepatopancreas were analyzed by RNA-seq. A whole transcriptome shotgun sequence assembly provided the assumedly complete transcriptome of P. leptodactylus hepatopancreas, followed by RNA-seq analysis of changes in the expression level of many genes caused by the application of each of the hormone isomers. Circulating glucose levels were much higher in response to the D-isoform than to the L-isoform injection, one hour from injection. Similarly, the RNA-seq analysis confirmed a stronger effect on gene expression following the administration of D-cHH, while just limited alterations were caused by the L-isomer. These findings demonstrated a more prominent short term effect of the D-cHH on the transcription profile and shed light on the effect of the D-isomer on specific functional gene groups. Another contribution of the study is the construction of a de novo assembly of the hepatopancreas transcriptome, consisting of 39,935 contigs, that dramatically increases the molecular information available for this species and for crustaceans in general, providing an efficient tool for studying gene expression patterns in this organ.

Tyrosine Recombinase Retrotransposons and Transposons

“…There are Ngaro elements in the crustaceans; these are abundant and expressed in Calanus and Pontastacus (28,29). These elements lack the hydrolase ORF.…”

Effects of Luteinizing Hormone‐releasing Hormone Analog Injection on Intestinal Transcriptome in Grass Carp, Ctenopharyngodon idella

“…RNA‐seq is a powerful tool to unveil the global pathways in tissues and cells. For instance, the transcriptome changes after injecting d ‐crustacean hyperglycemic hormone in hepatopancreas of crayfish, Pontastacus leptodactylus , were analyzed by Illumina sequencing (Manfrin et al ). The changes of liver transcriptome in Gulf pipefish, Syngnathus scovelli , by estrogen exposure were demonstrated using RNA‐seq (Rose et al ).…”

Characterization, localization and temporal expression of crustacean hyperglycemic hormone (CHH) in the behaviorally rhythmic peracarid crustaceans, Eurydice pulchra (Leach) and Talitrus saltator (Montagu)

“…In Astacoidea, whilst the L-form of CHH is exclusively hyperglycemic, the D-Phe3 epimer exhibits moult-inhibitory (Yasuda et al 1994) and osmoregulatory activity (Serrano et al, 2003). Recently application of L-and D-Phe3 CHH isoforms and profiling of the hepatopancreas transcriptome indicates that the D-Phe3 form initiates short term but wide-ranging transcriptional regulation in this tissue, mainly downregulation, compared to L-isoform (Manfrin et al, 2013). Regarding the current study, only application of antisera able to discriminate between these epimers in T. saltator will shed light on whether the cell types observed in the present study, in fact, contain modified peptides.…”