|Inserted element||HMS-Beagle||Expression data|
|Affected gene(s)||ovo||Viability / fertility|
|Causes allele(s)||ovoD1rv23||Stock availability||none publicly available|
|Chromosomal location||X ( 4E2 )||Sequence location|
|Member of Large Scale Dataset(s)|
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|Detailed Mapping Data|
(computed by FlyBase)
4E2 ( near gene of known cytology )
|Alleles and Phenotypes|
female sterile | recessive
|Phenotype Manifest In|
germarium cap cell
germline cell | embryonic stage
nurse cell fusome
Mutant germaria are agametic. In 2 day old mutant females, many germaria still contain one to five cap cells, although some germaria completely lack cap cells.
Homozygous ovaries have an agametic phenotype.
ovoD1rv23 females carrying two copies of ovo-2b have ovaries with a variety of defects. Egg chambers in which follicle cells have failed to migrate and degenerating ovarioles are seen. Egg chambers develop to maturity in rare cases, giving rise to short, abnormal eggs which have ventralised eggshells and fused dorsal appendages.
Ovaries of homozygous females are devoid of germ cells.
ovoD1rv23 have no adverse effect on the development of the germline in XY traF.Hsp83 pseudofemales; the pseudo-ovaries are filled with a multitude of undifferentiated germ cells.
Addition of otuhs.PN modestly improves the ovoD1rv23 phenotype. In mutant females homozygous for ovoD1rv23 and with one copy of otuhs.PN, the number of ovary lobes seen with at least one egg chamber increases. However a small number of egg chambers per ovary are seen, with almost all of these displaying a tumorous phenotype, and those without this phenotype have a mixture of tumorous and nurse-like cells. In addition there is some improvement in the degree of oogenic differentiation as the frequency of germ cell clusters with hts positive ring canals or nurse-like cells increases. However chambers remain small and do not progress beyond stage 4. The addition of more than one copy of otuhs.PN have no extra effect. The addition of otuhs.PN to ovoD1rv23/ovoM1, ovoD1rv23/ovoM2 or ovoD1rv23/ovoe8F mothers leads to an increase in the number of eggs produced, though in no case is hatching observed.
XX tra1/tra4 pseudomales that are also homozygous for ovoD1rv23 show an increase in the frequency of atrophic gonads compared to XX tra1/tra4 pseudomales. Non-oogenic gonads, with spectrosomes and multibranched fusomes are also seen (at the same frequency as XX tra1/tra4 pseudomales). Oogenic gonads are not seen in XX tra1/tra4 pseudomales carrying otuhs.PN that are also homozygous for ovoD1rv23. In each case the frequency of non-oogenic gonads is increased compared to XX tra1/tra4 pseudomales also homozygous for ovoD1rv23.
In homozygous mutant germaria, very few ovary lobes contain any egg chambers. Few germ cells are found, those germ cells that are found usually have no spectrosome or fusome material. In those rare cases that do, fusomes are small and poorly branched indicating aberrant and aborted differentiation early in gametogenesis. Those rare egg chambers that are found are also small and have no nurse cells. ovoe7E/ovoD1rv23 mutants have egg chambers arrested in pre-vitellogenic stages.
The ovary phenotype of homozygous ovoD1rv23 females is partially suppressed if they are also carrying mle1/mle5 or mle1/mle14. The ovary phenotype is of ovoD1rv23/ovoD1rv22 females partially suppressed if they are also carrying mle1/mle1. The phenotype is not affected if the females are also carrying SxlM4 or SxlM1. The phenotype is not affected if the females are also carrying msl-2138/msl-2138 or msl-2138/msl-21. ovoD1rv23/ovoD1rv22; mle9/mle14 ovaries are phenotypically mosaic, containing germ cells of both male and female morphology. The mosaicism can be at the level of whole ovaries or ovarioles. ovoD1rv23/ovoD1rv23; mle1/mle5 ovaries most often contain germ cells of male morphology rather than female morphology. This phenotype is partially suppressed by SxlM1; ovaries more often contain germ cells of female morphology rather than male morphology.
Ovaries of homozygous females contain germline chambers in less than 20% of cases. Ovaries of ovoD1rv23/ovoD1rv22 females contain germline chambers in less than 20% of cases.
Homozygous female embryos contain the normal number of germ cells. Most homozygous female first instar larvae have the wild-type number of germ cells, although by the end of the third larval instar many homozygous female larvae have a reduced number or no germ cells.
XX females have agametic ovaries. ovoD1rv23/Y pseudofemales (carrying traHsp83.PS) have ovaries that contain large numbers of tumorous egg cysts. XX homozygotes transformed into pseudomales with tra1/tra4 show pseudotestes characteristic of group 1, either empty or containing only undifferentiated germ cells.
In contrast to a previous study (FBrf0046291) no significant reduction in the number of germ cells in female homozygous embryos was detected. Any early reduction in germ cell numbers is either transient or inconsistent. Many larval homozygous ovaries have near wild type morphology. Many larval ovaries of the agametic heteroallelic combination ovoD1rv23/ovoD1rv22 also have near wild type morphology. By late pupae homozygous gonads fail to produce egg chambers and germ cells that are present fail to differentiate.
Increased amounts of cuticular hydrocarbons.
Ovaries are atrophic and have no germ cells. Rare, escaping germ cells are usually found as single cells or small clusters in a single ovariole, though they sometimes form cysts. ovo-,trahs.PB XY ovaries have abundant germ cells. The germ cells of XO ovo- males have the crystals characteristic of XO males and are fully populated with male germ cells of all stages.
The survival of 2X ovoD1rv23/ovoD1rv22 germline cells is enhanced in an mle1/mle5 background. Surviving cells usually form small ovarian tumours. SxlM1 partially rescues the morphology of the otu mutant ovarian tumour cells.
Phenotypic category: svb+ ovo-.
The germ cells of homozygous females die. Homozygous females also heterozygous for fl(2)d1 (at 29oC) or fl(2)d2 (at 25oC) have small ovaries with a few ovarioles containing mainly multicellular cysts and cysts with 16 cells resembling young egg chambers.
Lack of egg chamber formation.
Germ cell death occurs during early gastrulation in female homozygotes. This phenotype is suppressed in females also homozygous for Sxlf1. The soma is wild-type.
Gene activity is not detectable. Viable. Male germ line is fertile, female germ line has no vitellogenic egg chambers.
used in assay
|Data on Genetic Line|
|Origin as a multiple insertion line|
|Progenitor(s) within the Genome|
|Related Aberration or Balancer|
|Stocks ( 0 )|
|Synonyms & Secondary IDs|
|Secondary FlyBase IDs|
|References ( 19 )|