Sequence, linkage mapping and early developmental expression of the intestinal-type fatty acid-binding protein gene (fabp2) from zebrafish (Danio rerio).
The intestinal fatty acid-binding protein (I-FABP) shows binding specificity for long-chain fatty acids and is proposed to be involved in uptake of dietary fatty acids and their intracellular transport. We have determined the sequence of the gene encoding I-FABP in zebrafish. The zebrafish I-FABP gene contains four exons interrupted by three introns. Radiation hybrid mapping assigned the I-FABP gene to linkage group 1. A 924 bp sequence 5' upstream of the initiation codon in the I-FABP gene contained several putative cis-acting regulatory elements. In adult zebrafish, reverse transcription-polymerase chain reaction (RT-PCR) detected I-FABP mRNA in intestine, brain, liver, muscle and testis. Quantitative RT-PCR demonstrated that I-FABP mRNA was most abundant in intestine, followed by brain. I-FABP mRNA levels were very low in muscle, testis, heart, liver, skin and ovary. RT-PCR using total RNA extracted from zebrafish embryos detected I-FABP mRNA as early as 12 h post-fertilization. Whole-mount in situ hybridization to zebrafish embryos detected I-FABP mRNA in the yolk syncytial layer (YSL) at early somitogenesis. Later during embryonic development the I-FABP mRNA was detected in the intestinal bulb, liver and pancreas primordium. Expression in YSL, liver or pancreas has not been previously reported for fish or mammalian I-FABP genes and may be related to specific physiological differences between fishes and mammals.
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS, Canada B3H 4J1.
Mukesh K
MK
Sharma
Eileen M
EM
Denovan-Wright
Agnes
A
Degrave
Christine
C
Thisse
Bernard
B
Thisse
Jonathan M
JM
Wright
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics*; D003001:Cloning, Molecular; D005091:Exons; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000737:chemistry; D008040:Genetic Linkage; D007438:Introns; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012313:RNA / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D021101:Radiation Hybrid Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution; D014158:Transcription, Genetic; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000096:biosynthesis* / Q000235:genetics*
D002352:Carrier Proteins; C497193:FABP2 protein, zebrafish; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D012333:RNA, Messenger; D029961:Zebrafish Proteins; D012313:RNA