Expression of 5-HT2A cDNA including the N-terminus, the extracellular region and the first transmembrane region in the antisense orientation is driven by a heat shock promoter.
Mutant embryos show abnormal germband extension movements. There is a desynchronization between germband extension and mesodermal and endodermal invaginations, and a premature termination of movements. The ventral midline closure is often incomplete, and pole cells abnormally positioned.