Open Close
General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Key Links
Nature of the Allele
Mutations Mapped to the Genome
Additional Notes
Nucleotide change:


Reported nucleotide change:
Amino acid change:

Q44term | cni-PA; Q44term | cni-PB; Q44term | cni-PC

Reported amino acid change:


Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype
Nature of the lesion

Amino acid replacement: Q44term.

Nucleotide substitution: C220T.

Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

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/cniAA12 females are ventralised (reduction of dorsal appendages), while the anterior and posterior structures differentiate correctly.

Heterozygosity for Df(2L)JS7 causes synthetic lethality in a cniAA12/cni1 background. Rare and severely malformed escapers can be recovered.

The oocytes of cniCF5/cni1 females are ventralized. In 70% of cni1/cniAA12 mutants, the nucleus fails to move to the dorsal/anterior corner and is mislocalized at the posterior pole.

cni1/cniAA12 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 cnihs.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 cnihs.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 cnihs.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.

cniCF5/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/cniAA12 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 cniAA12/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.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by

Df(2L)JS7, cniAA12/cni1 has lethal phenotype, suppressible by cnircniUTR.PB

Phenotype Manifest In
Suppressed by

cni1 has ocellar bristle phenotype, suppressible by cnircniUTR.PB

cni1 has wing vein phenotype, suppressible by cnircniUTR.PB

cni1 has wing vein L2 phenotype, suppressible by cnircniUTR.PB

cni1 has egg phenotype, suppressible by grk::cnicni100-145.cBa

Additional Comments
Genetic Interactions

The synthetic lethality found in a synthetic cniAA12/cni1 and Df(2L)JS7 heterozygous background can be suppressed through expression of cnircniUTR.PB.

cnircniUTR.PB suppresses the loss of postvertical and ocellar bristles and the wing venation defects of cni1 homozygous flies, but not the rough eye phenotype and the loss of interocellar bristles.

Expression of grkScer\UAS.cBa under the control of Scer\GAL4mat.αTub67C.T:Hsim\VP16 in a cni1/Df(2L)H60-3 background results in eggs with variable amounts of dorsal appendage material. The eggs lack dorsal-ventral and frequently even anteroposterior polarity (in 30% of cases), illustrated by a patchy induction of the dorsal appendage material around the entire egg circumference and the presence of a posterior micropyle.

Eggs laid by homozygous cni1 females containing one copy of grk::CHOp24CHOp24intra.cBa exhibit normal anterior-posterior polarity, although some eggs are partially ventralised.

Eggs laid by cni1 homozygous mutant females carrying one copy of grk::cnicni100-145.cBa exhibit normal anteroposterior polarity and show slight and variable rescue of the dorsoventral axis.

grk::ylgrk1-275.yl1826-1984 exhibits no function in a cni1 homozygous background.

Xenogenetic Interactions
Complementation and Rescue Data
Not rescued by

Expression of cni+t.T:Myc rescues cni1 germline and somatic defects.

Images (0)
Stocks (2)
Notes on Origin

S. Roth.


Phenotypic data included in FBrf0051973.

Strong cni allele.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (12)