Isolation and Tissue Distribution of an Insulin-Like Androgenic Gland Hormone (IAG) of the Male Red Deep-Sea Crab, Chaceon quinquedens.

Amanda Lawrence,Jum Chung,Shadaesha Green

doi:10.3390/md15080241

Abstract

The insulin-like androgenic gland hormone (IAG) found in decapod crustaceans is known to regulate sexual development in males. IAG is produced in the male-specific endocrine tissue, the androgenic gland (AG); however, IAG expression has been also observed in other tissues of decapod crustacean species including Callinectes sapidus and Scylla paramamosain. This study aimed to isolate the full-length cDNA sequence of IAG from the AG of male red deep-sea crabs, Chaceon quinquedens (ChqIAG), and to examine its tissue distribution. To this end, we employed polymerase chain reaction cloning with degenerate primers and 5′ and 3′ rapid amplification of cDNA ends (RACE). The full-length ChqIAG cDNA sequence (1555 nt) includes a 366 nt 5′ untranslated region a 453 nt open reading frame encoding 151 amino acids, and a relatively long 3′ UTR of 733 nt. The ORF consists of a 19 aa signal peptide, 32 aa B chain, 56 aa C chain, and 44 aa A chain. The putative ChqIAG amino acid sequence is most similar to those found in other crab species, including C. sapidus and S. paramamosain, which are clustered together phylogenetically.

Highlights

Insulin-like androgenic gland hormone (IAG) is produced by the male endocrine organ referred to as the androgenic gland (AG) and is unique to male crustaceans
To examine translational control of insulin-like androgenic gland hormone (IAG), we analyzed putative translational motifs of IAG sequences in 15 other crustacean species listed from GenBank together with ChqIAG
ChqIAG differentiates itself from other crustacean IAG sequences by exhibiting a 733 nt long 30

Summary

Introduction

Insulin-like androgenic gland hormone (IAG) is produced by the male endocrine organ referred to as the androgenic gland (AG) and is unique to male crustaceans. This gland, first described in the blue crab, Callinectes sapidus, is located near the sub-terminal region of the vas deferens, surrounded by muscles of the coxopodite of the last thoracic leg [1]. AG implantation into a female isopod, Armadillidium vulgae, resulted in the development of male sexual traits [4]. In female Cherax quadricarinatus, AG implantation caused the development of male secondary sexual characteristics including red patching on the propodus and the inhibition of vitellogenesis [5]. The structure of IAGs (=AGHs) share six conserved cysteine residues with that of vertebrate insulin, whereas the rest of the primary sequences show much less similarity [6,7,8,9,10,11]

Objectives

Methods

Conclusion