The approximate boundaries of the dia2 deletion map to a NheI-XbaI restriction fragment; the position of the restriction fragment on the reference sequence was inferred by a FlyBase curator.
dia2 homozygotes in which maternal Rho1 function is reduced (derived from Rho172O heterozygous females) nearly all die as embryos, with defects in head involution, ventral cuticle or the completion of dorsal closure.
13% of the progeny of dia2 Rho172O double heterozygous females die as embryos, largely with defects in head involution. These embryos show dramatic alterations in amnioserosal cell behaviour compared to wild type; during germband retraction, amnioserosal cells along all the germband of the mutant embryos form long persistant cell extensions extending over neighbouring epidermal cells. The protrusions are especially prominent caudally, but are also observed laterally and anteriorly. Long protrusions are occasionally seen from epidermal cells and amnioserosal cells also extend abnormal processes over one another as well as over epidermal cells. Dorsal closure in these embryos is otherwise normal, except that drop-out cells appear much earlier in dorsal closure than normal.