Embryos that express both miraαTub67C.T:Avic\GFP-m6 and stauΔdRBD5.αTub67C.T:Hsap\MYC in a stau2 background show the stauΔdRBD5.αTub67C.T:Hsap\MYC posterior group phenotype in which embryos develop a normal head and thorax, but lack the abdomen.
None of the embryos laid by stau2, oskΔBRE mothers develop a bicaudal phenotype, and almost all form only one abdominal segment at the posterior. stau2, oskΔBRE, stauΔdRBD5.αTub67C.T:Hsap\MYC mothers lay embryos with significantly more abdominal denticle belts than seen in stau2,oskΔBRE alone. A third of embryos laid by stauΔloop2.αTub67C.T:Hsap\MYC, stau2, oskΔBRE mothers develop a bicaudal phenotype, another third show suppression of head development and partial or complete rescue of the abdomen.
Maternal-effect bicaudal phenotype is enhanced if mothers are also mutant for nebMot.
The addition of stauΔdRBD5.αTub67C.T:Hsap\MYC, or stauΔloop2.αTub67C.T:Hsap\MYC to stau2 mothers, produces embryos that show almost no rescue of the stau2 abdominal phenotype. The addition of stauΔN.αTub67C.T:Hsap\MYC, stau::Mdoa\stauDmMd.αTub67C.T:Hsap\MYC, or stauαTub67C.T:Hsap\MYC to stau2 mothers rescues the phenotypes seen in eggs laid by stau2 mothers.