Transcriptional regulation of FABP expression in flight muscle of the desert locust, Schistocerca gregaria

Abstract

FABP is the most abundant cytosolic protein in developed flight muscle of adult locusts, but it is completely absent in nymphs. During the two weeks following adult ecdysis, FABP rises to 18% of the total soluble proteins. Its mRNA increases steadily up to day 8, before it gradually declines until reaching a low concentration at day 15, which remains constant for the rest of the animal's life. Using a PCR primer combination specific for a 597 bp sequence of intron 1, we have developed a reverse transcription PCR assay to quantify the amount of primary transcript present in muscle tissue at various ages. The FABP gene is not transcribed prior to metamorphosis; its primary transcript rises rapidly during the first two days of adult life, and remains close to maximal until day 5. Subsequently its level rapidly declines, ultimately reaching values of less than 0.02% of the maximal level. The correlation between primary transcript, mRNA and FABP content were analyzed by modeling transcription, translation and degradation with computer modeling software. The computer simulation is in good agreement with the experimentally obtained data, suggesting that the control of FABP expression in locust flight muscle occurs predominantly at the level of transcription initiation.

Cloning and sequence of the gene encoding the muscle fatty acid binding protein from the desert locust, Schistocerca gregaria

“…Vertebrate heart FABPs are also highly homologous to the Drosophila cDNA, as are the FABPs found in adipocytes, brain, the retina, and nerve cells (myelin P2 protein), which together with muscle FABP form a subfamily of fatty acid binding proteins that branched out less than 300 million years ago, long after the vertebrate-invertebrate divergence that occurred more than 600 million years ago (Matarese et al, 1989). Another member of this subfamily appears to be a protein found in the brain of the moth, Manduca sexta, which has been described as a cellular retinoic acid-binding protein (Mansfield et al, 1998) We have previously demonstrated that the locust FABP gene described here is indeed expressed in locust flight muscles (Zhang and Haunerland, 1998). Using a primer combination specific for a 597 bp sequence located in the first intron (1722 bp upstream of exon II), we carried out RT-PCR from total RNA of locust flight muscle, amplifying only unprocessed primary transcript.…”

“…Up to 800,000 copies of pri- mary transcript/ng RNA can be found at this time, equivalent to ෂ0.5% of the total RNA. Several days later, when FABP approaches its maximal value, the primary transcript levels decrease 10,000-fold (Zhang and Haunerland, 1998). These findings are suggestive of a very strong promoter that can be tightly controlled.…”

Structure, linkage mapping and expression of the heart‐type fatty acid‐binding protein gene (fabp3 ) from zebrafish (Danio rerio)

“…All ILBP genes studied to date consist of four exons of almost identical coding capacity interrupted by three introns of varying size. The muscle-type FABP gene from the desert locust is the sole exception in that it lacks intron 2 [13]. While the coding sequence and structure of the ILBP genes have been conserved, following duplication of the ancestral gene the regulatory elements in their gene promoters have not, giving rise to specific temporal and spatial patterns of expression for members of this multigene family.…”

Structure and chromosomal location of the rat gene encoding the heart fatty acid‐binding protein

“…We have demonstrated earlier in locust muscle [25] that the RT‐PCR detection of FABP‐primary transcript can be used as a sensitive and quantitative measure for the expression of the FABP gene. A similar approach should allow detection of transient changes in gene expression of the rat FABP gene, for example in response to physiological stimuli.…”