Abstract
Abstract: :
Purpose: A 5-bp deletion in the ELOVL4 (Elongation of Very Long Chain Fatty Acids - 4) gene was found to be associated with adMD/STGD3. To understand the biological role of this gene product, we characterized the genomic structure of the mouse ELOVL4 gene and studied its tissue distribution and developmental expression. Methods: A clone containing the genomic sequence of the mouse ELOVL4 gene was obtained by screening RPCI22 BAC Library with a probe generated from mouse cDNA clone. The BAC clone was sequenced and the genomic organization of the gene was subjected to bioinformatic analysis. ELOVL4 expression profiles were determined in different tissues( brain, kidney, liver, lungs, heart, spleen, skin, retina and eye (without retina) ) of adult mice by quantitative real-time PCR (qRT-PCR) and Northern analysis . A similar approach was used to investigate the expression pattern of the gene during mouse embryonic development (7, 11,15 and 17 days), and during postnatal development (1, 3, 5, 7, 10 and 15 days) of the brain, the eye and the skin in mice. Correlation of ELOVL4 gene expression with the presence of the protein in different stages of development was studied by Western blotting and immunohistochemistry. Results: The genomic structure of mouse ELOVL4 is similar to its human homologue. Mouse ELOVL4 gene contains 6 exon and codes for a protein of 312 amino acid long (314 in human). In wild type mice significant levels of ELOVL4 expression were found in the brain, retina, skin and in the eye-without-retina but not in tissues like kidney, liver, lungs, heart and spleen by qRT-PCR. The level of expression was highest in retina followed by skin, brain and eye. Northern analysis also supported the abobe observations. A significant level of expression was observed during early stages of embryonic development. In the postnatal eyes, expression was detected as early as at postnatal day one and increased throughout the profile of early postnatal development examined. Conclusions: In the mouse the ELOVL4 gene is expressed in brain, skin, and eyes with the highest level in the retina. Expression of this gene was observed during early embryonic development. Genomic organization of the mouse ELOVL4 gene is similar to its human homologue and therefore, it is a potential model for studying the function of ELOVL4 and the role of ELOVL4 mutants in pathogenesis.
Keywords: candidate gene analysis • gene/expression • retinal degenerations: cell biology