Verification and tissue-specific expression of nifU-like gene from the amphioxus Branchiostoma belcheri

Abstract

A nifU-like gene exhibiting similarity to nifU of nitrogen fixation gene cluster was identified for the first time from the gut cDNA library of amphioxus Branchiostoma belcheri. Both RT-PCR and Northern blotting as well as in situ hybridization histochemistry verified that the cDNA represents an amphioxus nifU-like gene rather than a microbial contaminant. The nifU-like gene encodes a protein of 164 amino acid residues including a highly conserved U-type motif (C-X₂₆-C-X₄₃-C), and shares 66–86% identity to NifU-like proteins from a variety of species including vertebrates, invertebrates and microbes. It is expressed in a tissue-specific manner in the digestive system including epipharyngeal groove, endostyle, hepatic caecum and hind-gut and in the gill, ovary and testis. Taken together, it is highly likely that NifU-like protein plays some tissue-dependent and critical role in amphioxus.

• Amphioxus
• Branchiostoma
• NifU
• nifU-like gene
• expression

• AAH28800
• XP213811
• AAH53823
• CAE50167

Acknowledgements

This work was supported by Ministry of Science and Technology (MOST) of China (2005AA626010) and National Science Foundation of China (NSFC; 30470203).