csw^e13d.3 germline clone mosaics cause maternal effect lethality. Embryos derived from mothers with germline clones that exhibit a corkscrew cuticle phenotype (56%) have slight paternal rescue of the germline clone phenotype, embryos that do not receive a wild type copy from their father (44%), null embryos, die with a 'U'-shaped cuticle phenotype.

Abnormal development of terminal internal structures. Syncytial and cellular blastoderm embryos show reduced posterior tll domain. hb remains as a posterior cap and the seventh ftz stripe expands posteriorly, both due to lack of hkb repressing activity.