Drosophila melanogaster Peroxisome Biogenesis Factor 7plays a role in embryonic development

Abstract

Running title: Drosophila melanogaster Pex7Abstract Peroxisomes are organelles responsible for aspects of lipid metabolism and management of reactive oxygen species. Peroxisome Biogenesis Factor (Peroxin, Pex) genes encode proteins essential to peroxisome biogenesis or function. In yeast and mammals, PEROXIN7 acts as a cytosolic receptor protein that targets a subset of enzymes for peroxisome matrix import.Proteins targeted by PEROXIN7 contain a peroxisome targeting sequence 2 (PTS2) motif. The PTS2 was not found in the D. melanogaster homologs of proteins that are PEROXIN7 targets in yeast or mammals, however comparative genomics suggest a Pex7 homolog is present in the D.melanogaster genome. Herein we report novel, tissue-specific patterns for transcription and translation of Pex7 in the D. melanogaster embryo that appear to be strongest in presumptive neuronal lineages. We also show that targeted somatic Pex7 knockout in neural precursors via targeted somatic CRISPR knockout affected survival of mutant embryos. Pex7 over-expression via Gal4-UAS also reduced adult survival but was not deleterious at the embryo stage. Notably, targeted somatic rescue of Pex7 in the neural precursors of Pex7 homozygous mutants also impaired embryo survival. We conclude that D. melanogaster has tissue-specific developmental requirements of Pex7 expression. This may be related to the requirement for peroxisomemediated lipid synthesis in cells of the central nervous system. Baron et al., 2016). Together, these data suggest that D. melanogaster Pex7 function is required for normal development of a specific subset of cells, likely of neuronal lineage. Materials and Methods Drosophila stocks, embryo collection and viability assays