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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
Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype

Polytene chromosomes normal.

Nature of the lesion

Insert stated as cause: undefined Insertion upstream of the h promoter.

Insertion of a 7kb gypsy element about 5kb upstream of the h promoter.

Insertion components
Carried on aberration
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

Numerous ectopic bristles are present on h1/h26 wings, both in intervein regions (79% penetrance) and on the L2 wing vein (100% penetrance).

h1 flies raised at 18oC occasionally have ectopic bristles anterior to the anterior dorso-central bristle, while flies raised at 25oC do not show this phenotype.

h1 animals have a higher density of notal microchaetae, however these bristles still approximately align into rows as seen in wild-type.

Homozygous clones give rise to ectopic wing vein bristles and thoracic microchaetae.

Flies have ectopic bristles on the wing surface.

Ectopic glia accompany ectopic nerves in the pupal wing, which occur mostly along the longitudinal wing veins. Ectopic glial cells are present even on those ectopic veins that have reversed polarity.

Extra neuron mutant.

Extra sense organs formed on wing surface. Campaniform sensillae preferentially form on the proximal end of the L3 vein, bristles form nearer the tip, and sense organs of intermediate size form in between the bristles and campaniform sensillae. Scanning electron microscope measurements of distribution of sense organs along the wing axis suggests that h is active in metamorphosis and has a pattern of expression that is dependent upon the position in the proximal-distal axis.

Semilethal when heterozygous with strong h alleles.

Homozygotes display ectopic bristles on the L2 wing vein.

70% of homozygotes survive to adulthood. Homozygous adults have extra bristles. Homozygotes have minor defects in segmentation, that are apparent both in the larva and the adult; a few segments are wholly or partially deleted. The fourth abdominal segment is most frequently affected, although other segments in the head, thorax or abdomen may also be affected. The frequency and severity of the segmentation phenotype is increased in trans with other lethal h alleles. h1/h41 flies have ectopic bristles on the scutellum, halteres and head capsule.


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

h1/h26 has visible phenotype, suppressible | partially by dgrn[+]/dgrnDK

Enhancer of
Phenotype Manifest In
Enhanced by

h1 has mesothoracic tergum & macrochaeta | ectopic phenotype, enhanceable by pad1

Suppressed by

h1/h26 has wing cell phenotype, suppressible by dgrn[+]/dgrnDK

h1/h26 has wing sensillum | ectopic phenotype, suppressible | partially by dgrn[+]/dgrnDK

h1 has microchaeta | ectopic & scutellum phenotype, suppressible by amosTft

h1 has phenotype, suppressible by ac1

h1 has phenotype, suppressible by ac2

h1 has phenotype, suppressible by ac3

Enhancer of

h1/h[+] is an enhancer of eye phenotype of Hsap\MAPTUAS.cWa, Scer\GAL4GMR.PF

h1/h1 is an enhancer of denticle belt | embryonic stage | absent phenotype of nkd2

h1 is an enhancer of mesothoracic tergum & macrochaeta | ectopic phenotype of pad1

Additional Comments
Genetic Interactions

h1 nkd3 double homozygous, h1/h1 nkd3/nkd13 double mutant or h1/h1 nkd2/nkd3 double mutant embryos exhibit defective denticle belts.

dgrnDK/+ suppresses the formation of ectopic wing bristles seen in h1/h26 flies, predominantly within the intervein regions.

pad1 h1 double mutants raised at 25oC display ectopic bristles at positions on the notum where no ectopic bristles are found in either single mutant. These new positions include dorso-central bristles closer to the thoracic midline and additional bristles between the anterior and posterior scutellars. Ectopic bristles on the double mutant are mostly located in the posterior half of the notum, while ectopic bristles tend to be found in the anterior half in pad1 single mutants.

The ectopic microchaetae seen on the scutellum in h1 flies are suppressed by amosTft.

h1/h- is viable, whereas nkdunspecified h1/h- is lethal. nkd3 h1 or nkd4 h1 clones give rise to a rough eye phenotype and loss of wing margin bristles.

h1 rhove-1 / h1 rhove-1 flies have ectopic bristles running between longitudinal veins.

Introduction of acT52.2 construct into an ac- sc- h- background causes ectopic bristles to appear along wing vein L5.

Df(1)ase-1; h1 double mutants have four-fold fewer bristles in the L2 vein than h1 mutants alone. Although h1 has no effect on the anterior wing margin bristles itself, the recurved bristles of Df(1)ase-1; h1 double mutants are more wild type than those of Df(1)ase-1, though the mutant phenotype of the stout mechanosensory bristles is more extreme.

Xenogenetic Interactions
Complementation and Rescue Data
Rescued by
Partially rescued by

h1 is partially rescued by hcosh

h1 is partially rescued by htRa


When in combination with hhs.P1 the ectopic bristle phenotype is completely suppressed. The temperature sensitive period for the bristle phenotype is 6-11 hours post-pupariation. Segmentation phenotype can be rescued by hcosh and htRa, but the extra bristle phenotype cannot.

Images (1)
Stocks (205)
Notes on Origin

Mohr, 11th Dec. 1918.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (2)
Reported As
Name Synonyms
Secondary FlyBase IDs
    References (39)