Flies homozygous for cni¹ are subviable (approximately 20% of the expected number hatch). They possess rough eyes, with fused ommatidia, aberrant cone cells, and missing, or ectopic, interommatidial bristles. Their postvertical, interocellar and ocellar bristles are largely missing, and the wings have a truncated vein 2.

Eggs from cni¹ mothers are ventralised and both ends differentiate into anterior structures.

Eggs from cni¹/cni^AA12 females are ventralised (reduction of dorsal appendages), while the anterior and posterior structures differentiate correctly.

The oocytes of cni^CF5/cni¹ females are ventralized. In 70% of cni¹/cni^AA12 mutants, the nucleus fails to move to the dorsal/anterior corner and is mislocalized at the posterior pole.

cni¹/cni^AA12 females lay ventralised eggs with apparently normal anterior-posterior polarity. The oocyte nucleus is localised normally in the egg chambers of these females. Expression of cni^hs.PP in a cni¹ background (using heat shock) during early oogenesis (stages 1-3) leads to ventralised eggshells. Expression between stage 3 and 6 leads to a complete rescue of the cni¹ phenotype, producing eggs that can undergo normal embryonic development. Expression during late stages of oogenesis (stages 8-14) is unable to rescue the cni¹ mutant phenotype. Expression of cni^hs.PP in a cni¹ background (using heat shock) during mid-oogenesis produces eggs with a partial rescue of the cni¹ phenotype. Three egg phenotypes can be distinguished. The first shows normal anterior-posterior (AP) polarity associated with a spot of dorsal appendage material located at different positions along the AP axis of the egg. The second lacks AP polarity, having a micropyle at both ends, but shows a rescue of the dorsoventral chorion pattern. The third is a novel phenotype showing a posterior ring of dorsal appendage material accompanied by a narrowing in the terminal portion of the egg. The eggs with the posterior ring of dorsal appendage material can be divided into two subgroups based on the type of structures induced at the posterior tip. The first group show posterior chorion structures resembling an aeropyle. The second group have a posterior tip with anterior structures such as a micropyle. Expression of cni^hs.PP in a cni¹ background (using heat shock) after stage 7 of oogenesis does not rescue the cni¹ phenotype with regard to oocyte nuclear migration; 70% of the egg chambers show a posterior localisation of the oocyte nucleus. Heat shock earlier than or during stage 6 leads to normal dorsal-anterior positioning of the oocyte nucleus in all egg chambers. Heat shock between late stage 6 and stage 7 leads to a large fraction of egg chambers with oocyte nuclei at intermediate positions.

cni^CF5/cni¹ females produce weakly ventralized egg chambers. Eggs laid have lost their dorsalmost fates and have a single medially fused dorsal appendage.

Homozygous embryos exhibit a germline-dependent ventralised phenotype. cni¹/cni^AA12 transheterozygotes have mutant egg chambers.

Homozygous embryos lack all dorsal appendage material and are completely symmetrical along the dorsal ventral axis. Eggs also lack anterior posterior polarity and form a second micropyle at the posterior pole due to duplication of anterior follicle cell fates at the posterior pole. Most cni^AA12/cni¹ heterozygous embryos have one reduced dorsal appendage, few have a posterior micropyle, and a third of the eggs contain no embryo. twi expression domain show a duplication of the mesodermal analgen.

cni¹ has ocellar bristle phenotype, suppressible by cnir^cniUTR.PB

cni¹ has postocellar bristle phenotype, suppressible by cnir^cniUTR.PB

cni¹ has wing vein phenotype, suppressible by cnir^cniUTR.PB

cni¹ has wing vein L2 phenotype, suppressible by cnir^cniUTR.PB

cni¹ has egg phenotype, suppressible by grk::cni^{cni100-145.cBa}

cni¹, grk::CHOp24^{CHOp24intra.cBa} has egg phenotype

Df(2L)H60-3/cni¹, Scer\GAL4^{VP16.mat.αTub67C}, grk^UAS.cBa has egg phenotype