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-X(26)-C-X(43)-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 hindgut 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: Department of Marine Biology, Ocean University of China, Qingdao, 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: D020121:5' Untranslated Regions; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002816:Chordata, Nonvertebrate / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D016000:Cluster Analysis; D018387:Codon, Initiator; D018388:Codon, Terminator; D017124:Conserved Sequence; D018076:DNA, Complementary; D015870:Gene Expression; D006651:Histocytochemistry; D017403:In Situ Hybridization; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family; D009586:Nitrogen Fixation / Q000235:genetics*; D009928:Organ Specificity; D010802:Phylogeny; D011506:Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D020121:5' Untranslated Regions; D018387:Codon, Initiator; D018388:Codon, Terminator; D018076:DNA, Complementary; D011506:Proteins