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


Reported nucleotide change:


Amino acid change:

V305M | ovo-PB; V176M | ovo-PC; V305M | ovo-PE

Reported amino acid change:


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

Mutation creates a new in-frame AUG codon in the open reading frame in exon 2.

Nucleotide substitution: G1572A.

Amino acid replacement: V176M.

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

Females carrying ovoD2 in an ovo-/+ background show dominant female sterility. Heterozygous females contain only a few eggs.

The dominant ovoD2 phenotype is significantly enhanced by one copy of Df(2R)vg135, Df(2R)stil-A or Df(2R)stil-B, but is not significantly enhanced by one copy of stil1, stil4 or stil5. The dominant enhancement of the ovoD2 phenotype by Df(2R)vg135 is partially suppressed by a transgene carrying stil+. This suggests that the strong interaction between Df(2R)vg135 and ovoD2 is due to the deletion of two genes, one of which is stil.

In heterozygous females oogenesis is arrested. In the presence of either P{ovo-lacZ.B} or P{ovoM-D1} fertility of heterozygous females is significantly improved, average number of eggs laid rises from 2 to 30 and 24, respectively. For P{ovo-lacZ.B} up to 10% of eggs laid develop to adults, for P{ovoM-D1} only a small fraction of eggs develop. P{ovoM373} does not detectably change the ovoD2 phenotype.

Heterozygous females lay only very few eggs. Introduction of ovoB.T:Ecol\lacZ significantly increases the number of eggs laid. Laid eggs do not show any signs of development.

Most egg chambers of ovoD2/+ heterozygous ovaries arrest around oogenic stage 6 and very few vitellogenic oocytes are found. Two types of abnormal egg chambers occur. Pseudonurse cell chambers, where the egg chambers contain more than 15 nurse cells (though not usually more than 25) contain 0-2 oocyte nuclei. The second type of egg chamber contains largely undifferentiated germ cells, of indeterminate sex.

Phenotypic category: svb+.

Oogenesis in heterozygous females is mainly arrested prior to stage 6.

Permeable eggs.

Heterozygous females are fully sterile.

Most egg chambers arrest before vitellogenesis. Fertility is restored by the presence of two copies of ovo+.

Most of the egg chambers of heterozygous females fail to initiate vitellogenesis. The more advanced egg chambers often show a variety of abnormalities, such as permeability, flaccidity, absence of the anterior end of the chorion, fused dorsal appendages, egg chambers with more than 16 nuclei and occasionally, small ovarian tumours. Less than 30% of the wild-type number of eggs are laid per day. The soma is wild-type. Transheterozygotes with either ovoM1, ovoM2 or ovoD1rv20 have germ cells resembling early spermatocytes.

Mutant gene activity works in opposition to wild type activity. Viable. Male germ line is fertile, female germ line has permeable eggs.

Heterozygous females are completely sterile, producing only a few eggs throughout their lifetime, all of which fail to develop.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
NOT suppressed by

ovoD2 has decreased fecundity | dominant | female phenotype, non-suppressible by Sxlf2

ovoD2 has decreased fecundity | dominant | female phenotype, non-suppressible by Sxlf18

ovoD2 has decreased fecundity | dominant | female phenotype, non-suppressible by SxlfPb

ovoD2 has decreased fecundity | dominant | female phenotype, non-suppressible by Sxlf9

Phenotype Manifest In
Enhanced by

ovoD2 has phenotype, enhanceable by snf1

Additional Comments
Genetic Interactions

The ovoD2/+ phenotype can be partially suppressed by alleles of Sxl, enhanced by snf1 and enhanced by alleles of otu.

The number of vitellogenic eggs produced by ovoD2 heterozygous females is increased by Sxlf7,M1, SxlfP7B0, SxlfP7C2, SxlfLS, SxlM1 or Sxlf7,M1, but not SxlfPb, Sxlf9, Sxlf2 or Sxlf18.

Xenogenetic Interactions

The fraction of ovoD2/+ females that produce eggs is increased if the females express Mmus\Zfp339A.hs using a 1 hour heat shock at 37oC; 16-68% of the heat shocked females produce eggs, compared to 4% of control ovoD2/+ females. However, almost all the eggs laid by the ovoD2/+ females carrying Mmus\Zfp339A.hs fail to hatch.

The dominant female sterility of ovoD2 can be fully or partially rescued by ovo::Bole\ovoODM or ovo::Bole\ovoODP, depending on the transgenic line used.

Complementation and Rescue Data
Rescued by

One copy of P{ovo.S-7.2} fully rescues the sterility of heterozygous females.

Images (0)
Stocks (3)
Notes on Origin

Clonal analysis shows that the dominant female sterile effect of ovoD2 is germ line autonomous.

Sxl alleles that have no known effect on the soma do not suppress the ovoD2 phenotype.

Intermediate ovo phenotype.

Partially suppresses the female-specific gonadal dysgenesis caused by hybrid dysgenesis at 27.5oC.

Shows a dominant interaction with otu alleles: more extreme mutant phenotype as assayed by reduction in number of egg chambers at stage 10 or further developed.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
Reported As
Symbol Synonym
Name Synonyms
Secondary FlyBase IDs
    References (27)