FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\CecB
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General Information
Symbol
Dmel\CecB
Species
D. melanogaster
Name
Cecropin B
Annotation Symbol
CG1878
Feature Type
protein_coding_gene
FlyBase ID
FBgn0000278
Gene Model Status
Current
Stock Availability
4 publicly available
Gene Summary
Cecropin B (CecB) encodes an helicoidal antibacterial peptide with activity against Gram-negative bacteria. It is mostly expressed at the pupal stage. [Date last reviewed: 2019-03-07] (FlyBase Gene Snapshot)
All Summaries
Also Known As

Cecropin, Cec, crpB

Key Links
Genomic Location
Cytogenetic map
99E2-99E2
Sequence location
Recombination map
3-100
RefSeq locus
NT_033777 REGION:30213315..30213797
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 (0 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (0 terms)
Biological Process (8 terms)
Terms Based on Experimental Evidence (8 terms)
CV Term
Evidence
References
involved_in antibacterial humoral response
inferred from expression pattern
(Kylsten et al., 1990)
inferred from direct assay
(Samakovlis et al., 1990)
involved_in defense response to bacterium
inferred from expression pattern
(Gordon et al., 2008)
involved_in defense response to Gram-negative bacterium
inferred from direct assay
(Samakovlis et al., 1990)
involved_in defense response to Gram-positive bacterium
inferred from direct assay
(Samakovlis et al., 1990)
involved_in defense response to insect
inferred from expression pattern
(Tattikota et al., 2020)
involved_in defense response to virus
(Carboni et al., 2022)
involved_in humoral immune response
inferred from expression pattern
(Verleyen et al., 2006)
involved_in response to Gram-negative bacterium
(Carboni et al., 2022)
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
involved_in antibacterial humoral response
inferred from biological aspect of ancestor with PANTHER:PTN002212115
(GO Reference Genome Project, 2011-)
inferred from electronic annotation with InterPro:IPR000875, InterPro:IPR020400
(InterPro Project Members, 2004-)
involved_in defense response to Gram-negative bacterium
inferred from biological aspect of ancestor with PANTHER:PTN002212115
(GO Reference Genome Project, 2011-)
involved_in defense response to Gram-positive bacterium
inferred from biological aspect of ancestor with PANTHER:PTN002212115
(GO Reference Genome Project, 2011-)
Cellular Component (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
located_in extracellular region
inferred from direct assay
(Samakovlis et al., 1990)
located_in extracellular space
inferred from direct assay
(Liu et al., 2006, Verleyen et al., 2006)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
located_in extracellular region
inferred from electronic annotation with InterPro:IPR000875, InterPro:IPR020400
(InterPro Project Members, 2004-)
is_active_in extracellular space
inferred from biological aspect of ancestor with PANTHER:PTN002212115
(GO Reference Genome Project, 2011-)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the cecropin family. (P14956)
Protein Signatures (InterPro)
Summaries
Gene Snapshot
Cecropin B (CecB) encodes an helicoidal antibacterial peptide with activity against Gram-negative bacteria. It is mostly expressed at the pupal stage. [Date last reviewed: 2019-03-07]
Gene Group (FlyBase)
CECROPINS -
Cecropins are small, amphiphilic peptides with antibacterial activity. (Adapted from FBrf0241672.)
Protein Function (UniProtKB)
Cecropins have lytic and antibacterial activity against several Gram-positive and Gram-negative bacteria.
(UniProt, P14956)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
Cec: Cecropin
Three structural genes for three very similar cecropin proteins (cecropin A1, A2, and B), bacteriacidal proteins that are induced in adults in response to bacterial infection. All three cecropin genes are coordinately induced by injection of bacteria, although the B gene is expressed at a much lower level. Levels appreciable within one hour, peak at 6 hours and have generally returned to base line by 24 hours. Cecropins also induced by ingested bacteria.
Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\CecB 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 P14956)

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 5.49

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
CecB-RA
FBtr0085640
NM_079851
425
63
Additional Transcript Data and Comments
Reported size (kB)

0.4 (northern blot)

(Kylsten et al., 1990)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
CecB-PA
FBpp0085002
6.8
63
11.65
P14956
NP_524590
AAF57027
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)

63 (aa)

(Kylsten et al., 1990)
Comments

Small CecB-derived peptides identified by nano LC-MS/MS: pQAANVAATAR-amide, GIAQQAANVAATAR-amide, DATIQGLGIAQQAANVAATAR-amide.

(Verleyen et al., 2006)
External Data
Crossreferences
InterPro - A database of protein families, domains and functional sites
Linkouts
Sequences Consistent with the Gene Model
Nucleotide / Polypeptide Records
 
UniProt
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\CecB 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).

-0.44

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
larval stage
embryonic/larval hemocyte
(Samakovlis et al., 1990)
Additional Descriptive Data

Cecropin mRNAs are induced after injection of a bacterial suspension into adult abdomens. They can also be induced by feeding flies bacteria-containing food.

(Kylsten et al., 1990)

CecB transcripts are only detected in untreated animals in small amounts in early pupae and adults. They are strongly induced by bacteria. CecB transcripts are preferentially induced in early pupae as opposed to larvae or adults. CecB levels are lower than CecA in fat body and comparable in hemocytes.

(Samakovlis et al., 1990)
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
third instar larval stage
embryonic/larval hemolymph

Comment: infected with M. luteus and E. coli

peptides: GIAQQAANVAATAR

(Liu et al., 2006, Verleyen et al., 2006)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in extracellular region
inferred from direct assay
(Samakovlis et al., 1990)
located_in extracellular space
inferred from direct assay
(Liu et al., 2006, Verleyen et al., 2006)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\CecB 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
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
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 ( 3 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of CecB
Transgenic constructs containing regulatory region of CecB
Aberrations (Deficiencies and Duplications) ( 2 )
Inferred from experimentation ( 2 )
Gene disrupted in
Df(3R)ΔCecA-C
(Carboni et al., 2022)
Df(3R)R113
(Clark and Wang, 1997)
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\GAL4pnr-MD237
Other Phenotypes
Allele
flightless, with Scer\GAL4Mef2.PR
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) (0)
Anopheles gambiae (African malaria mosquito) (4)
Agam\CECA_ANOGA
5 of 12
Yes
Yes
Agam\CEC4
4 of 12
No
Yes
Agam\CECB_ANOGA
3 of 12
No
Yes
Agam\CECC_ANOGA
3 of 12
No
No
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:CecB. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Gene Symbol
Score
Source
Compara
Domainoid
eggNOG
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Drosophila melanogaster (Fruit fly) (3)
CecA1
7 of 13
CecA2
7 of 13
CecC
7 of 13
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
    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
    DroID - A comprehensive database of gene and protein interactions.
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    External Data
    Linkouts
    KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map
    3-100
    Cytogenetic map
    99E2-99E2
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    99E2-99E2
    Limits computationally determined from genome sequence between P{PZ}ncd05884 and P{lacW}l(3)s2500s2500
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location

    3-100

    (FlyBase, 2016)

    3-97.8

    (Comeron et al., 2012)
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (4)
    Genomic Clones (21)
    cDNA Clones (145)
     

    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
         
        Commercially Available Antibodies
         
        Cell Line Information
        Publicly Available Cell Lines
         
          Other Stable Cell Lines
           
            Other Comments

            Identified as a gene with significant level of mRNA cycling as assessed by expression analysis using high density oligonucleotide arrays with probe generated from adult heads harvested over six time points over the course of a day. Shows alteration in expression in a Clk mutant background.

            (McDonald and Rosbash, 2001)

            One of four structural genes for four very similar cecropin proteins (cecropin A1, A2, B and C), bacteriocidal proteins that are induced in adults in response to bacterial infection. All cecropin genes are coordinately induced by injection of bacteria, although the B gene is expressed at a much lower level. Cecropins also induced by ingested bacteria.

            (Lindsley and Zimm, 1992)

            Cell line from l(2)mbn strain responds to bacterial lipopolysaccharide and bacterial flagellin by strong transcriptional response of CecA1 and CecB.

            (Samakovlis et al., 1992)

            The Cec gene region contains three genes: CecA1, CecA2 and CecB. Cecropins are antibacterial peptides: transcripts appear within one hour after bacteria has been injected in to the haemocoel.

            (Kylsten et al., 1990)

            CecB is preferentially active in the early pupae.

            (Samakovlis et al., 1990)
            Relationship to Other Genes
            Source for database merge of
            Additional comments
            Nomenclature History
            Source for database identify of

            Source for identity of: CecB CG1878

            (Ye, 1999.11)
            Nomenclature comments
            Etymology
            Synonyms and Secondary IDs (19)
            Reported As
            Symbol Synonym
            CECB
            (Riahi et al., 2021)
            CG1878
            (Petersen et al., 2012, Zhang et al., 2010, Keleman et al., 2009.8.5, Perkins et al., 2009, Winterhalter and Fedorka, 2009, Hernandez-Romano et al., 2008, Pal et al., 2007, Valanne et al., 2007, Liu et al., 2006, Verleyen et al., 2006, FlyBase Curators, 2002-, De Gregorio et al., 2001, Irving et al., 2001)
            Cec
            (Ryu et al., 2008, Ren et al., 2007, Gottar et al., 2002, Engstrom et al., 2001)
            Cec B
            (An et al., 2012)
            CecB
            (Akyaw et al., 2025, Forfar et al., 2025, Kang et al., 2025, Rommelaere et al., 2025, Fioriti et al., 2024, Huang et al., 2024, Liang et al., 2024, Salminen et al., 2024, Xu et al., 2024, Zhou et al., 2024, Bossen et al., 2023, Chen et al., 2023, Odnokoz et al., 2023, Touré et al., 2023, Carboni et al., 2022, Deshpande et al., 2022, Shen et al., 2022, Waring et al., 2022, Wu et al., 2022, Yoo et al., 2022, Zhou et al., 2022, Girard et al., 2021, Okasha et al., 2021, Schoberleitner et al., 2021, Yamashita et al., 2021, Han et al., 2020, Krautz et al., 2020, Swanson et al., 2020, Hanson et al., 2019, Troha et al., 2018, Kavi et al., 2015, Bonnay et al., 2014, Chen et al., 2014, Salazar-Jaramillo et al., 2014, Taylor et al., 2014, Kockmann et al., 2013, Shen et al., 2013, Short and Lazzaro, 2013, Petersen et al., 2012, Chen et al., 2010, Dworkin et al., 2009, Sackton and Clark, 2009, Gilchrist et al., 2008, Gordon et al., 2008, Kwon et al., 2008, Curtis et al., 2007, Sackton et al., 2007, Waterhouse et al., 2007, Rehwinkel et al., 2004, Ramos-Onsins and Aguade, 1998)
            CecropinB
            (Sciambra and Chtarbanova, 2021)
            cec
            (Abdelsadik and Roeder, 2010, Comeron and Kreitman, 2000)
            cecB
            (Zhang et al., 2020, Huang et al., 2017, Fedorka et al., 2007, Lawniczak and Begun, 2004, McDonald and Rosbash, 2001, Lemaitre, 2000.12.20)
            cecropinB
            (El-Saadi et al., 2023)
            cedcB
            (Zsindely et al., 2009)
            crpB
            (Marshall and Sinclair, 2010, Winterhalter and Fedorka, 2009)
            Name Synonyms
            Cecropin
            (Marra et al., 2021, Vonkavaara et al., 2013, Moule et al., 2010, Zhao et al., 2010, Costa et al., 2009, Ryu et al., 2008, Brennan and Anderson, 2004, Steiner, 2004, Kurz and Ewbank, 2003, Ligoxygakis et al., 2002, Pletcher et al., 2002, Wiklund et al., 2002, Kimbrell and Beutler, 2001, Barillas-Mury et al., 2000, Martin-Blanco, 2000, Rutschmann et al., 2000, Govind, 1999, Han et al., 1998, Mathey-Prevot and Perrimon, 1998, Roos et al., 1997)
            Cecropin B
            (Schoberleitner et al., 2021, Ramond et al., 2020, Taylor et al., 2014, An et al., 2012, Felix et al., 2012, Longworth et al., 2012, Petersen et al., 2012, Ragab et al., 2011, Flatt et al., 2008, Gordon et al., 2008, Kleino et al., 2008, Pal et al., 2007, Zeitouni et al., 2007, Verleyen et al., 2006)
            Cecropin-B
            (Bonnay et al., 2014)
            Cecropin-B precursor
            (Hernandez-Romano et al., 2008)
            Cecropins
            (Ozakman and Eleftherianos, 2021)
            cecropin
            (Marshall and Sinclair, 2010, Persson et al., 2007, Zelinger and Heifetz, 2006, Zhou et al., 2005, Leclerc and Reichhart, 2004, Delaney and Anderson, 2002, Delaney and Anderson, 2001, Ando et al., 1999, Hoffmann et al., 1999, Meng et al., 1999, Hoffmann, 1997)
            cecropin B
            (Meister et al., 2000, Date, 1998.1.27, Date, 1998.1.27, Date, 1998.1.27, Date, 1998.1.27, Date, 1998.1.27, Date, 1998.1.27)
            cercropin B
            (Fedorka et al., 2007)
            Secondary FlyBase IDs
              Datasets (0)
              Study focus (0)
              Experimental Role
              Project
              Project Type
              Title
              Study result (0)
              Result
              Result Type
              Title
              External Crossreferences and Linkouts ( 81 )
              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/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
              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.
              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
              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
              Flygut - An atlas of the Drosophila adult midgut
              KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
              References (189)