FlyBase Allele Report: Dmel\orb[mel]

General Information

Symbol

Dmel\orb^mel

Species

D. melanogaster

Name

maternal effect lethal

FlyBase ID

FBal0035315

Feature type

allele

Associated gene

Dmel\orb

Associated Insertion(s)

Carried in Construct

Key Links

Genomic Maps

JBrowse

Allele class

Mutagen

Delta2-3 transposase

Nature of the Allele

Allele class

Mutagen

Delta2-3 transposase

(Christerson and McKearin, 1994)

Progenitor genotype

orb^dec

(Christerson and McKearin, 1994)

Cytology

Description

Removal of the entire P-element and 500bp of orb genomic DNA from the P-element insertion site to within intron 2.

(Christerson and McKearin, 1994)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

deletion

3R:23,278,859..23,279,359 [-]

Comment:

Approximate extent of a deletion of about 500bp, which starts at the P{PZ}orb^dec insertion site.

(Christerson and McKearin, 1994, Lantz et al., 1994)

Variant Molecular Consequences

Associated Sequence Data

DDBJ / EMBL / GenBank

DNA sequence

Protein sequence

UniProtKB/Swiss-Prot

UniProtKB/TrEMBL

Expression Data

Reporter Expression

Additional Information

Statement

Reference

Marker for

Reflects expression of

Reporter construct used in assay

Human Disease Associations

Disease Ontology (DO) Annotations

Models Based on Experimental Evidence ( 0 )

Disease

Evidence

References

Modifiers Based on Experimental Evidence ( 0 )

Disease

Interaction

References

Comments on Models/Modifiers Based on Experimental Evidence ( 0 )

Disease-implicated variant(s)

Phenotypic Data

Phenotypic Class

abnormal mitotic cell cycle | embryonic stage (with orb^F343)

(Fang and Lerit, 2022)

lethal | maternal effect

(Christerson and McKearin, 1994)

lethal - all die during embryonic stage | dominant | maternal effect | partially

(Castagnetti and Ephrussi, 2003)

lethal - all die during embryonic stage | maternal effect

(Benoit et al., 2008, Lantz et al., 1994, Roth and Schupbach, 1994)

lethal - all die during embryonic stage | maternal effect (with orb^F303)

(Mansfield et al., 2002)

lethal - all die during embryonic stage | maternal effect (with orb^F343)

(Mansfield et al., 2002)

lethal - all die during embryonic stage | maternal effect | partially | recessive

(Mansfield et al., 2002)

majority die during embryonic stage (with orb^F343)

(Fang and Lerit, 2022)

partially lethal - majority die (with orb^F343)

(Fang and Lerit, 2022)

partially lethal - majority die | maternal effect

(Benoit et al., 2005)

some die during embryonic stage | maternal effect

(Benoit et al., 2008, Benoit et al., 2005, Lantz et al., 1994, Roth and Schupbach, 1994)

some die during embryonic stage | maternal effect (with orb^F303)

(Mansfield et al., 2002)

some die during embryonic stage | maternal effect (with orb^F343)

(Mansfield et al., 2002)

some die during embryonic stage | maternal effect | partially

(Castagnetti and Ephrussi, 2003)

some die during embryonic stage | partially | recessive

(Mansfield et al., 2002)

Phenotype Manifest In

dorsal appendage (with orb^F303)

(Mansfield et al., 2002)

dorsal appendage (with orb^F343)

(Masrouha et al., 2003)

dorsal appendage | maternal effect

(Roth and Schupbach, 1994)

egg (with orb^F343)

(Martin et al., 2003, Masrouha et al., 2003)

egg | dorsal

(Chang et al., 2001)

embryo (with orb^F303)

(Fang and Lerit, 2022)

embryo (with orb^F343)

(Fang and Lerit, 2022)

embryo | posterior

(Castagnetti and Ephrussi, 2003)

oocyte

(Huynh and St. Johnston, 2000)

ovary

(Juge et al., 2002)

synaptonemal complex

(Huynh and St. Johnston, 2000)

Detailed Description

Statement

Reference

Homozygous females produce a low level (15%) of maternal effect embryonic lethality.

(Benoit et al., 2008)

51% of embryos derived from homozygous females are undeveloped, 27% have a posterior patterning defects and 22% develop into adults. Those embryos that develop into adult females that are sterile. 65% of embryos derived from heterozygous female hatch.

(Castagnetti and Ephrussi, 2003)

100% of eggs laid by orb^mel/orb^F343 females are ventralised and unfertilised.

(Martin et al., 2003)

0% of eggs derived from orb^mel/orb^F343 females have wild-type dorsal appendages, 3.4% have fused dorsal appendages and 96.6% have no dorsal appendages. The eggs do not hatch.

(Masrouha et al., 2003)

Only 44% of eggs derived from homozygous females hatch. Only 6% of eggs derived from orb^mel/orb^F303 females hatch.

(Mansfield et al., 2002)

The pre-vitellogenic stages of oogenesis in mutant egg chambers appear to be completely normal. Eggs develop to become ventralised.

(Chang et al., 2001)

The restriction of the synaptonemal complex (SC) to one cell is delayed in orb^mel mutants; both pro-oocytes can still be in synapsis in region 2b. This delay in oocyte determination can also give rise to misplaced oocytes.

(Huynh and St. Johnston, 2000)

Almost 20% of embryos derived from orb^mel females hatch as larvae.

(Chang et al., 1999)

Females display reduction of dorsal eggshell structures, eggs develop posterior pattern defects.

(Leon et al., 1995)

Embryos display defects on the dorsal side of the embryo, fusion or absence of the dorsal appendages, reduction in the amount of orb mRNA enhances this phenotype. Some heterozygous orb^mel/orb^F343 embryos display absence of dorsal appendages, oocytes are small than normal and surrounded by columnar follicle cells and eggs are also smaller than normal. Homozygous embryos display abdominal segment deletions lack pole cells.

(Christerson and McKearin, 1994)

Dorsalization of chorion, posterior abdomen and pole cells fail to form.

(Lantz et al., 1994)

orb^mel/orb^F343 causes lateralization. Eggs are shortened and rounded posteriorly like dorsalized eggs but like ventralized eggs their dorsal appendages are fused dorsally, in 49% of eggs, or absent, in 46% of the eggs. 37% of the eggs contain embryos.

(Roth and Schupbach, 1994)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Enhanced by

Statement

Reference

orb^mel has lethal | embryonic stage | maternal effect phenotype, enhanceable by wisp⁸⁹/wisp[+]

(Benoit et al., 2008)

orb^mel has lethal | embryonic stage | maternal effect phenotype, enhanceable by wisp⁴⁰/wisp[+]

(Benoit et al., 2008)

orb^mel has lethal | embryonic stage | maternal effect phenotype, enhanceable by wisp^KG05287/wisp[+]

(Benoit et al., 2008)

orb^mel has lethal | embryonic stage | maternal effect phenotype, enhanceable by hrg^PAP45/hrg[+]

(Benoit et al., 2008)

orb^mel has lethal | embryonic stage | maternal effect phenotype, enhanceable by hrg^PAP21/hrg[+]

(Benoit et al., 2008)

Suppressed by

Statement

Reference

orb^F343/orb^mel has increased mortality during development phenotype, suppressible | partially by Plp^WT.Ubi.GFP

(Fang and Lerit, 2022)

orb^F343/orb^mel has abnormal mitotic cell cycle | embryonic stage phenotype, suppressible by Plp^WT.Ubi.GFP

(Fang and Lerit, 2022)

orb^mel has partially lethal - majority die | maternal effect | embryonic stage phenotype, suppressible by Pabp2^EP2264/Pabp2[+]

(Benoit et al., 2005)

orb^mel has partially lethal - majority die | maternal effect | embryonic stage phenotype, suppressible by Pabp2[+]/Pabp2⁵⁵

(Benoit et al., 2005)

orb^F303/orb^mel has lethal | maternal effect | embryonic stage phenotype, suppressible | partially by yps^JM2/yps^JM2

(Mansfield et al., 2002)

orb^mel has lethal | recessive | partially | maternal effect | embryonic stage phenotype, suppressible by yps^JM2/yps^JM2

(Mansfield et al., 2002)

NOT Enhancer of

Statement

Reference

orb^mel is a non-enhancer of some die during embryonic stage | maternal effect phenotype of CG15930^Q5/CG15930^m4

(Pozmanter et al., 2025)

NOT Suppressor of

Statement

Reference

orb^mel is a non-suppressor of some die during embryonic stage | maternal effect phenotype of CG15930^Q5/CG15930^m4

(Pozmanter et al., 2025)

Phenotype Manifest In

Enhanced by

Statement

Reference

orb^mel has ovary phenotype, enhanceable by hrg^PAP21

(Juge et al., 2002)

orb^mel has ovary phenotype, enhanceable by hrg^PAP45

(Juge et al., 2002)

NOT Enhanced by

Statement

Reference

orb^mel has phenotype, non-enhanceable by Mos^unspecified

(Ivanovska et al., 2004)

Suppressed by

Statement

Reference

orb^F343/orb^mel has embryo phenotype, suppressible | partially by Plp^WT.Ubi.GFP

(Fang and Lerit, 2022)

orb^F303/orb^mel has embryo phenotype, suppressible by Plp^WT.Ubi.GFP

(Fang and Lerit, 2022)

orb^F303/orb^mel has oocyte phenotype, suppressible | partially by yps^JM2/yps^JM2

(Martin et al., 2003)

NOT suppressed by

Statement

Reference

orb^F303/orb^mel has dorsal appendage phenotype, non-suppressible by yps^JM2/yps^JM2

(Mansfield et al., 2002)

NOT Enhancer of

Statement

Reference

orb^mel/orb^mel is a non-enhancer of egg | ventral phenotype of fs(1)K10^unspecified

(Chang et al., 2001)

Suppressor of

Statement

Reference

orb^mel is a suppressor | partially of dorsal appendage | maternal effect phenotype of CG15930^Q5/CG15930^m4

(Pozmanter et al., 2025)

NOT Suppressor of

Statement

Reference

orb^mel/orb^mel is a non-suppressor of egg | ventral phenotype of fs(1)K10^unspecified

(Chang et al., 2001)

Other

Statement

Reference

orb^F303/orb^mel, yps^JM2 has egg chamber phenotype

(Mansfield et al., 2002)

fs(1)K10^unspecified, orb^mel has egg | ventral phenotype

(Chang et al., 2001)

Additional Comments

Genetic Interactions

Statement

Reference

The percentage of maternal effect embryonic lethality seen in embryos derived from orb^mel homozygous females is increased by heterozygosity for one of wisp⁸⁹, wisp⁴⁰, wisp^KG05287, hrg^PAP45 or hrg^PAP21. The percentage of ventralised embryos is not increased by heterozygosity for one copy of wisp⁸⁹, wisp⁴⁰ or wisp^KG05287, but is enhanced by heterozygosity for one copy of hrg^PAP45 or hrg^PAP21.

Oogenesis is blocked at stage 8 in 34% of hrg^PAP21/+ ; orb^mel females.

(Benoit et al., 2008)

The maternal effect embryonic semi-lethality and ventralisation phenotypes due to orb^mel/orb^mel are partially suppressed when the mother also carries Pabp2^EP2264/+ or Pabp2⁵⁵/+.

(Benoit et al., 2005)

65% of embryos derived from BicC⁵/+ ; orb^mel/+ females hatch. Of the non-hatching embryos, 39% are bicaudal and 52% have head defects.

(Castagnetti and Ephrussi, 2003)

Wild-type patterns of microtubule distribution and cytoplasmic streaming are restored in half of orb^mel/orb^F303 oocytes if they are also homozygous for yps^JM2.

(Martin et al., 2003)

hrg^PAP21/+; orb^mel and hrg^PAP45/+; orb^mel lay almost no eggs. In these females oogenesis stops most frequently at stage 7/8 after which egg chambers degenerate, even though one or two stage 14 oocytes per ovary can be observed.

(Juge et al., 2002)

The failure of many eggs derived from orb^mel females to hatch is suppressed by yps^JM2/yps^JM2. The failure of most eggs derived from orb^mel/orb^F303 females to hatch is partially suppressed by yps^JM2/yps^JM2 (40% of eggs derived from the double mutant females hatch). The failure of eggs derived from orb^mel/orb^F343 females to hatch is very weakly suppressed by yps^JM2/yps^JM2; rare escapers complete embryogenesis and hatch. Eggs laid by yps^JM2 orb^mel/yps^JM2 orb^F303 females have fused, reduced or absent dorsal appendages. 5% of yps^JM2 orb^mel/yps^JM2 orb^F303 egg chambers are bipolar.

(Mansfield et al., 2002)

orb^mel/orb^mel, fs(1)K10^unspecified/fs(1)K10^unspecified eggs are dorsalised.

(Chang et al., 2001)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Comments

Images (0)

Mutant

Wild-type

Stocks (1)

Bloomington

58743

w^*; orb^mel/TM3, Ser¹

Notes on Origin

Discoverer

Comments

Mutation does not affect posterior follicle cell determination.

(Gonzalez-Reyes et al., 1995)

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (5)

Reported As

Symbol Synonym

Orb^Mel

(Pozmanter et al., 2025)

Orb^mel

(Pérez-Roldán et al., 2025)

orb^MEL

(Reveal et al., 2010)

orb^mel

(Fang and Lerit, 2022, Davidson et al., 2016, Rojas-Ríos et al., 2015, Costa et al., 2013, Rangan et al., 2009, Benoit et al., 2008)

Name Synonyms

maternal effect lethal

(Lantz et al., 1994)

Secondary FlyBase IDs

References (33)

Report Sections

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