An insulin-like androgenic gland hormone gene in the mud crab, Scylla paramamosain, extensively expressed and involved in the processes of growth and female reproduction

Jun 15, 2014General and comparative endocrinology

A hormone gene like insulin in mud crabs is widely active and linked to growth and female reproduction

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

A full-length cDNA of insulin-like androgenic gland hormone (IAG) was isolated from the mud crab, Scylla paramamosain.

The Sp-IAG gene consists of 4 exons and 3 introns.
IAG expression was detected in type I and type II androgenic gland cells.
Sp-IAG was expressed in various tissues, not limited to the androgenic gland.
Expression levels of Sp-IAG in ovaries increased significantly at the mature stage, suggesting a role in inhibiting oocyte growth and vitellogenesis.
During the molting cycle, Sp-IAG expression decreased from postmolt to premolt stages, then increased after molting.
These findings indicate that IAG may be involved in regulating both ovarian development and somatic growth in crustaceans.

AI simplified

Insulin-like androgenic gland hormone (IAG) produced by androgenic gland (AG) in male crustaceans is regarded as a key regulator of sex differentiation. As a member of the insulin/insulin-like growth factor family, IAG is also likely involved in regulating somatic growth. In this study, a full-length cDNA of IAG (termed Sp-IAG) was isolated from the mud crab, Scylla paramamosain. Genomic DNA of Sp-IAG was also cloned, analysis of which reveals that Sp-IAG gene is organized in a 4 exon/3 intron manner. RNA in situ hybridization analysis detected positive signals in both type I and type II AG cells. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that Sp-IAG was expressed not only in AG, but also in many other tissues. Sp-IAG expression levels in ovaries were examined at different stages of ovarian development (stages I to V); it was found that the expression was maintained at low levels during undeveloped stage (stage I) to late vitellogenic stage (stage IV) and then increased significantly at mature stage (stage V), suggesting that Sp-IAG may participate in inhibiting oocyte growth and vitellogenesis. The expression pattern of Sp-IAG during the molting cycle of the first stage crabs (C1) was also determined. Sp-IAG expression level continuously decreased from 0 h C1 (postmolt) crabs to 96 h C1 (premolt) crabs, and then increased significantly in the newly molted second stage crabs (C2, postmolt). The combined results suggested for the first time that IAG is involved in regulating ovarian development and somatic growth in crustaceans.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

An insulin-like androgenic gland hormone gene in the mud crab, Scylla paramamosain, extensively expressed and involved in the processes of growth and female reproduction

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief