FB2026_02 , released June 18, 2026
Gene: Dmel\Lhr
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General Information
Symbol
Dmel\Lhr
Species
D. melanogaster
Name
Lethal hybrid rescue
Annotation Symbol
CG18468
Feature Type
protein_coding_gene
FlyBase ID
FBgn0034217
Gene Model Status
Current
Stock Availability
11 publicly available
Gene Summary
Lethal hybrid rescue (Lhr) encodes a protein required to repress transposable element and satellite DNA expression. It also has a gain-of-function phenotype of causing lethality in F1 male hybrids between D. melanogaster and D. simulans. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
All Summaries
Also Known As

HP3, mel-Lhr

Key Links
Genomic Location
Cytogenetic map
54B7-54B7
Sequence location
Recombination map
2-82
RefSeq locus
NT_033778 REGION:17431032..17432219
Sequence
Get Decorated FASTA
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
NCBI
UCSC
Ensembl
PopFly
Function
Gene Ontology (GO) Annotations (10 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
enables protein binding
inferred from physical interaction with FLYBASE:Hmr; FB:FBgn0001206
(Satyaki et al., 2014, Thomae et al., 2013)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
enables DNA binding
inferred from electronic annotation with InterPro:IPR004210
(InterPro Project Members, 2004-)
Biological Process (3 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
involved_in mitotic sister chromatid segregation
inferred from mutant phenotype
(Thomae et al., 2013)
involved_in telomere maintenance
inferred from mutant phenotype
(Satyaki et al., 2014)
involved_in transposable element silencing by heterochromatin formation
inferred from mutant phenotype
(Satyaki et al., 2014, Thomae et al., 2013)
Terms Based on Predictions or Assertions (0 terms)
Cellular Component (5 terms)
Terms Based on Experimental Evidence (5 terms)
CV Term
Evidence
References
located_in chromocenter
inferred from direct assay
(Greil et al., 2007, Brideau et al., 2006)
located_in chromosome, telomeric region
inferred from direct assay
(Thomae et al., 2013)
located_in chromosome, telomeric repeat region
inferred from direct assay
(Satyaki et al., 2014)
located_in heterochromatin
inferred from direct assay
(Swenson et al., 2016, Maheshwari and Barbash, 2012, Brideau and Barbash, 2011, Brideau et al., 2006)
located_in pericentric heterochromatin
inferred from direct assay
(Satyaki et al., 2014)
Terms Based on Predictions or Assertions (0 terms)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Snapshot
Lethal hybrid rescue (Lhr) encodes a protein required to repress transposable element and satellite DNA expression. It also has a gain-of-function phenotype of causing lethality in F1 male hybrids between D. melanogaster and D. simulans. [Date last reviewed: 2019-03-14]
Gene Group (FlyBase)
MADF-BESS DOMAIN TRANSCRIPTION REGULATORS -
The MADF-BESS domain transcription regulators include a variety of activators and corepressors and chromatin modifying proteins. BESS domains are often present in combination with MADF domains. The BESS domain mediates protein-protein interactions. (Adapted from FBrf0155780 and FBrf0224045).
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
Lhr: Lethal hybrid rescue
When Drosophila simulans carries Lhr, classes of hybrids between D. simulans and D. melanogaster that do not ordinarily survive are recovered. Crosses of D. melanogaster females by D. simulans males, which ordinarily produce only daughters, produce sons and daughters in a 1:1 ratio. Crosses of D. simulans females to D. melanogaster males, which ordinarily produce only sons, produce 86% sons and 14% daughters. Crosses of C(1)RM - bearing D. melanogaster females to D. simulans males, which normally produce only sons, yield a few daughters when the D. simulans males carry Lhr.
Summary (Interactive Fly)

chromatin factor - contains BESS motif found in boundary element proteins - along with Hybrid male rescue interacts with HP1 to repress transcripts from satellite DNAs and many families of transposable elements - gain-of-function phenotype causing lethality in F1 male hybrids between D. melanogaster and D. simulans

Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\Lhr for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q95RV3)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
Comments on Gene Model

Gene model reviewed during 5.44

Gene model reviewed during 5.50

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
Lhr-RA
FBtr0086917
NM_137366
1188
334
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
Lhr-PA
FBpp0086073
38.6
334
9.90
Q95RV3
NP_611210
AAF57867
Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Crossreferences
InterPro - A database of protein families, domains and functional sites
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Lhr using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

1.41

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 3
organism

Comment: maternally deposited

(Fisher et al., 2012)
embryonic stage 4 -- 6
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 7 -- 8
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 9 -- 10
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 11 -- 12
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 13 -- 16
organism | ubiquitous
(Fisher et al., 2012)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
day 5 of adulthood | male -- day 7 of adulthood | male
spermatozoon
(Wasbrough et al., 2010)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in chromocenter
inferred from direct assay
(Greil et al., 2007, Brideau et al., 2006)
located_in chromosome, telomeric region
inferred from direct assay
(Thomae et al., 2013)
located_in chromosome, telomeric repeat region
inferred from direct assay
(Satyaki et al., 2014)
located_in heterochromatin
inferred from direct assay
(Swenson et al., 2016, Maheshwari and Barbash, 2012, Brideau and Barbash, 2011, Brideau et al., 2006)
located_in pericentric heterochromatin
inferred from direct assay
(Satyaki et al., 2014)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Lhr in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Bulk Downloads
RNA-Seq RPKM values for all genes
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 1 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 16 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Lhr
Transgenic constructs containing regulatory region of Lhr
Aberrations (Deficiencies and Duplications) ( 2 )
Inferred from experimentation ( 2 )
Gene disrupted in
Df(2R)Exel7147
(Ryder, 2004.4.26)
Df(2R)k08901
(Barbash, 2011.12.8)
Inferred from location ( 2 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
viable, with Dcr-2UAS.cDa, Scer\GAL4elav.PLu
viable, with Scer\GAL4Mef2.PR
viable, with Scer\GAL4pnr-MD237
Sterility
Allele
female semi-sterile | progressive
female semi-sterile | recessive
Other Phenotypes
Allele
suppressor of variegation, with P{SUPor-P}KV00108, Scer\GAL4Act.PU
Phenotype manifest in
Allele
Orthologs
Downloads
Download All DIOPT Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (0)
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (0)
Mus musculus (laboratory mouse) (0)
Xenopus tropicalis (Western clawed frog) (0)
Danio rerio (Zebrafish) (0)
Caenorhabditis elegans (Nematode, roundworm) (2)
Cele\B0205.10
1 of 14
Yes
Yes
Cele\B0379.7
1 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (0)
Arabidopsis thaliana (thale-cress) (0)
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (0)
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Lhr. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    Functional Complementation Data
    Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
    Interactions
    Summary of Physical Interactions
    Interaction Browsers
    View in FlyBase Interactions Browser   View in MIST tool (external link)
    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Lhr - Boh1
    anti tag coimmunoprecipitation, Identification by mass spectrometry, anti bait coimmunoprecipitation
    (Lukacs et al., 2021)
    Lhr - Boh2
    anti bait coimmunoprecipitation, Identification by mass spectrometry, anti tag coimmunoprecipitation
    (Lukacs et al., 2021)
    Lhr - Cenp-C
    anti bait coimmunoprecipitation, western blot, anti tag coimmunoprecipitation, peptide massfingerprinting
    (Thomae et al., 2013)
    Lhr - HP6
    two hybrid, anti tag coimmunoprecipitation, western blot, peptide massfingerprinting
    (Thomae et al., 2013, Brideau and Barbash, 2011)
    Lhr - Hmr
    anti tag coimmunoprecipitation, anti tag western blot, peptide massfingerprinting, anti bait coimmunoprecipitation, western blot, two hybrid, Identification by mass spectrometry
    (Lukacs et al., 2021, Satyaki et al., 2014, Thomae et al., 2013)
    Lhr - Nlp
    anti bait coimmunoprecipitation, Identification by mass spectrometry
    (Lukacs et al., 2021)
    Lhr - Nph
    anti bait coimmunoprecipitation, Identification by mass spectrometry
    (Lukacs et al., 2021)
    Lhr - REPTOR-BP
    two hybrid array
    (Shokri et al., 2019)
    Lhr - Su(var)205
    anti tag coimmunoprecipitation, peptide massfingerprinting, anti bait coimmunoprecipitation, Identification by mass spectrometry, western blot, anti tag western blot, two hybrid
    (Lukacs et al., 2021, Alekseyenko et al., 2014, Satyaki et al., 2014, Thomae et al., 2013, Brideau and Barbash, 2011, Brideau et al., 2006)
    Summary of Genetic Interactions
    Interaction Browsers
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    External Data
    Linkouts
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    2R
    Recombination map
    2-82
    Cytogenetic map
    54B7-54B7
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    54B7-54B7
    Limits computationally determined from genome sequence between P{EP}l(2)k01209EP2177&P{lacW}k11012a and P{lacW}l(2)k07433k07433
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location

    2-82

    (FlyBase, 2016)

    2-86.2

    (Comeron et al., 2012)
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (11)
    Genomic Clones (14)
     

    Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete

    cDNA Clones (4)
     

    Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequenced
    BDGP DGC clones
    Other clones
      Drosophila Genomics Resource Center cDNA clones

      For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

      cDNA Clones, End Sequenced (ESTs)
      BDGP DGC clones
      Other clones
        RNAi and Array Information
        Linkouts
        DRSC - Results frm RNAi screens
        Antibody Information
        Laboratory Generated Antibodies
         

        polyclonal

        (Satyaki et al., 2014)

        monoclonal

        (Thomae et al., 2013)
        Commercially Available Antibodies
         
        Cell Line Information
        Publicly Available Cell Lines
         
          Other Stable Cell Lines
           
          Other Comments

          The Hmr and Lhr proteins form a heterochromatic complex with Su(var)205 in D. melanogaster. Hmr and Lhr are required to repress transcripts from satellite DNAs and many families of transposable elements. They are also required to help regulate the length of telomeres (which in Drosophila are composed of domesticated transposable elements).

          (Satyaki et al., 2014)

          The Dsim\Lhr ortholog of Lhr does not appear to affect satellite DNA transcription in D. simulans, but it does have a role in repressing transcription of transposable elements in this species.

          (Satyaki et al., 2014)

          Upregulation of transposable element transcription is seen in hybrids between D. melanogaster and D. simulans, but this is unlikely to be the direct cause of hybrid lethality.

          (Satyaki et al., 2014)

          The Hmr and Lhr proteins form a centromeric complex in D. melanogaster which is required for proper chromosome segregation during mitosis. Both an increase and a decrease in complex levels result in mitotic defects, indicating that this function is extremely dose sensitive. Alteration of the levels of the complex also result in an increase in transcription from transposable elements.

          (Thomae et al., 2013)

          The orthologous D. simulans Dsim\Hmr and Dsim\Lhr proteins also bind each other in coimmunoprecipitation experiments and also localise to the centromere (although Dsim\Hmr also shows a prominent non-centromeric localisation).

          (Thomae et al., 2013)

          The level of Hmr expression in D melanogaster is substantially higher than the expression of the orthologous Dsim\Hmr gene in D. simulans. Conversely, the expression of the D. simulans Dsim\Lhr gene is higher than the expression of the orthologous Lhr gene in D. melanogaster. Hybrids derived from a cross between D. melanogaster females and D. simulans males thus have an elevated amount of the Hmr-Lhr protein complex compared to the parent species, and the complex is delocalised, being bound to numerous interbands along all chromosome arms in the hybrids. Hybrid males and females show a massive increase in transcription from transposable elements, but as the effect is not sex-specific, this is presumably not the the main cause of the lethality of hybrid males.

          (Thomae et al., 2013)

          DNA-protein interactions: genome-wide binding profile assayed for Lhr protein in Kc167 cells; see Chromatin_types_NKI collection report. Individual protein-binding experiments listed under "Samples" at GEO_GSE22069 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE22069).

          (Filion et al., 2010)
          Relationship to Other Genes
          Source for database merge of
          Additional comments
          Nomenclature History
          Source for database identify of

          Source for identity of: Lhr CG18468

          (Barbash et al., 2006)
          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (8)
          Datasets (1)
          Study focus (1)
          Experimental Role
          Project
          Project Type
          Title
          • transgene_used
          FBGSE22069
          Protein profiling reveals five principal chromatin types in Drosophila cells.
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 30 )
          Sequence Crossreferences
          NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
          GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
          GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
          RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
          UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
          UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
          Other crossreferences
          AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
          BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
          DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
          EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
          FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
          FlyMine - An integrated database for Drosophila genomics
          InterPro - A database of protein families, domains and functional sites
          KEGG Genes - Molecular building blocks of life in the genomic space.
          MARRVEL_MODEL - MARRVEL (model organism gene)
          Linkouts
          BioGRID - A database of protein and genetic interactions.
          Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
          DroID - A comprehensive database of gene and protein interactions.
          DRSC - Results frm RNAi screens
          Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
          FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
          FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
          Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
          Flygut - An atlas of the Drosophila adult midgut
          Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
          MIST (protein-protein) - An integrated Molecular Interaction Database
          References (67)