exex extra-extra [Drosophila melanogaster (fruit fly)] - Gene

Summary

Official Symbol: exexprovided by FlyBase
Official Full Name: extra-extraprovided by FlyBase
Primary source: FLYBASE:FBgn0041156
Locus tag: Dmel_CG8254
See related: AllianceGenome:FB:FBgn0041156
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Drosophila melanogaster
Lineage: Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota; Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Ephydroidea; Drosophilidae; Drosophila; Sophophora
Also known as: CG8254; dhb9; dHb9; dHB9; DHB9; Dmel\CG8254; Exex; hb9; Hb9; HB9
Summary: Predicted to enable sequence-specific double-stranded DNA binding activity. Involved in axon target recognition; central nervous system development; and neuroendocrine cell differentiation. Predicted to be active in nucleus. Is expressed in several structures, including anlage in statu nascendi; embryonic/larval midgut primordium; ganglia; primary motor neurons; and segmentally-repeated neuroblast. Human ortholog(s) of this gene implicated in Currarino syndrome. Orthologous to human MNX1 (motor neuron and pancreas homeobox 1). [provided by Alliance of Genome Resources, Jan 2025]
Orthologs: all
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Genomic context

Location:: 66A21-66A21; 3-21 cM

Exon count:: 3

Annotation release	Status	Assembly	Chr	Location
Release 6.54	current	Release 6 plus ISO1 MT (GCF_000001215.4)	3L	NT_037436.4 (7948186..7951563)
Release 5.57	previous assembly	Release 5 (GCF_000001215.2)	3L	NT_037436.3 (7941286..7944663)

Chromosome 3L - NT_037436.4 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

found that segment specific cell death of some dHb9 expressing motor neurons occurs throughout the metamorphosis period and continues into the post-eclosion period
Title: dHb9 expressing larval motor neurons persist through metamorphosis to innervate adult-specific muscle targets and function in Drosophila eclosion.
Data identify Robo2 and Robo3 as key effectors of Hb9 in regulating nervous system development.
Title: The homeodomain transcription factor Hb9 controls axon guidance in Drosophila through the regulation of Robo receptors.
Hb9 governs neuronal specification and differentiation and activates expression of Nos and fd59a in the Drosophila CNS
Title: Genome-wide identification of Drosophila Hb9 targets reveals a pivotal role in directing the transcriptome within eight neuronal lineages, including activation of nitric oxide synthase and Fd59a/Fox-D.
the single ortholog of Dbx1/2 contributes to the development of specific subsets of interneurons via cross-repressive, lineage-specific interactions with the motoneuron-promoting factors eve and hb9 (exex)
Title: dbx mediates neuronal specification and differentiation through cross-repressive, lineage-specific interactions with eve and hb9.
Hb9 regulates neuronal fate by restricting expression of Lim3 and Eve proteins. Hb9 plays a role in intercellular signaling for the establishment of neuronal fate. Hb9 and Eve regulate each other's expression through Groucho-dependent crossrepression.
Title: Drosophila homeodomain protein dHb9 directs neuronal fate via crossrepressive and cell-nonautonomous mechanisms.
Drosophila HB9 is required in a subset of motoneurons and interneurons for establishing proper axon projections
Title: Drosophila HB9 is expressed in a subset of motoneurons and interneurons, where it regulates gene expression and axon pathfinding.

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Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Homology

NCBI Orthologs

Orthologs from OrthoDB

Gene Ontology Provided by FlyBase

Function	Evidence Code	Pubs
enables DNA binding	IEA Inferred from Electronic Annotation more info
enables DNA-binding transcription factor activity, RNA polymerase II-specific	IEA Inferred from Electronic Annotation more info
enables sequence-specific double-stranded DNA binding	IBA Inferred from Biological aspect of Ancestor more info

Process	Evidence Code	Pubs
involved_in axon target recognition	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in central nervous system development	IBA Inferred from Biological aspect of Ancestor more info
involved_in central nervous system development	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in nervous system development	TAS Traceable Author Statement more info	PubMed
involved_in neuroendocrine cell differentiation	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in neuron projection morphogenesis	IBA Inferred from Biological aspect of Ancestor more info
involved_in regulation of DNA-templated transcription	IEA Inferred from Electronic Annotation more info