Table 1. Phenotypic series of Pa-cad^RNAi and Pa-Wnt1^RNAi embryos.

Range of RNAi phenotypes categorized into three classes. Class ‘H’ embryos displayed head only or head plus posteriorly undifferentiated tissue, only found in Pa-cad^RNAi. Class ‘T’ embryos form the head and some thoracic segments properly, but are truncated after either T2 or T3; this was the most common Pa-cad^RNAi and Pa-Wnt1^RNAi phenotype. Class ‘A’ embryos were observed in both Pa-cad^RNAi and Pa-Wnt1^RNAi. These embryos developed complete head and thorax with defects in abdominal segmentation, usually tapering at the posterior. Control Pa-H₂O embryos were wild type in appearance.