hth^64-1/hth^64-1 mutant embryos exhibit severe defects in Malpighian tubule migration and organization as compared to wild type, with shorter and less organized tubules that do not reach the anterior region of the body cavity, certain segments of the tubules fail to undergo convergent extension, the lumen of these tubules is wider than normal and irregular in shape, the leading loop fails to form properly, there is a small but significant decrease in the number of Cut-positive cells in the anterior Malpighian tubule, and a significant decrease in the number of stellate cells, but there is no loss of the tip cell and the tip cells extend long filopodia and seem as active and motile as those in wild type embryos.

The lymph gland is virtually eliminated in mutants.

Homozygous embryos show loss and dorsal localisation of lateral chordotonal (LCh5) neurons in the abdominal segments.

The LCh5 neurons are located in a more dorsal position than normal and have abnormal orientation in some abdominal segments in homozygous embryos. In addition, the number of LCh5 neurons is reduced, with nearly all abdominal segments containing only 3 dorsal chordotonal neurons. There is a reduction in the total number of PNS neurons, with on average a loss of 3-4 dorsal PNS neurons, 3-4 lateral PNS neurons and 10-12 ventral PNS neurons.