Fig 1. Hyrax/HRPT2 is essential for normal larval development in Drosophila and is upstream of the cytoplasmic polyadenylation element-binding protein (CPEB) homolog Orb2.

The morphology of second instar larvae were compared between hyx^EY6898 homozygous and heterozygous mutants and wild type flies by stereomicroscopy (A–C) and hematoxylin and eosin histological staining (D). Shown in D., left to right, are longitudinal sections of hyx^EY6898 homozygous and heterozygous mutants and w¹¹¹⁸ larvae. The transcript levels of hyx/HRPT2 were measured by qRT-PCR in both hyx^EY6898 homozygous second instar larvae (E) and heterozygous adult (F) flies. Rescue of the hyx^EY6898 homozygous lethal phenotype was performed with an actin promoter-controlled GAL4 driven overexpression of the hyx/HRPT2 gene from the hyx^EY6898 allele (G–H). For comparison, results with the hyx^dEY2 excision mutant are also shown (H). Expression of the orb2 gene in hyx^EY6898 homozygous larvae and heterozygous adult flies (I–J) and adult orb2^BG02373 heterozygous and homozygous flies (K–L), and hyx/HRPT2 gene expression in orb2^BG02373 homozygous mutant flies (M) was quantified by qRT-PCR. For morphology experiments, at least 50 second instar larvae were examined for each genotype. All qRT-PCR data were from at least 9 data points comprising at least three independent biological repeats.