The role of during embryonic development.

Peroxisomes are organelles in eukaryotic cells responsible for processing several types of lipids and management of reactive oxygen species. A conserved family of peroxisome biogenesis (, ) genes encode proteins essential to peroxisome biogenesis or function. In yeast and mammals, PEROXIN7 (PEX7) acts as a cytosolic receptor protein that targets enzymes containing a peroxisome targeting signal 2 (PTS2) motif for peroxisome matrix import. The PTS2 motif is not present in the homologs of these enzymes. However, the fly genome contains a gene (CG6486) that is very similar to yeast and human PEX7. We find that is expressed in tissue-specific patterns analogous to differentiating neuroblasts in embryos. This is correlated with a requirement for Pex7 in this cell lineage as targeted somatic knockout in embryonic neuroblasts reduced survival. We also found that over-expression in the same cell lineages caused lethality during the larval stage. Targeted somatic over-expression of a transgene in neuroblasts of homozygous null mutants resulted in a semi-lethal phenotype similar to targeted knockout. These findings suggest that has tissue-specific requirements for during embryo development.