title: 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.
authors.affiliation: Laboratory 202, Department of Marine Biology, Ocean University of China, 5 Yushan Road, Qingdao 266003, People's Republic of China. biolilei@yahoo.com.cn
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
authors.forename: Chunxin
authors.initials: C
authors.lastname: Fan
authors.forename: Zhenhui
authors.initials: Z
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Luan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002816:Chordata, Nonvertebrate / Q000235:genetics* / Q000378:metabolism; D005260:Female; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D051381:Rats; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; C088637:NifU protein, Bacteria