A Database of Drosophila Genes & Genomes

FB2008_07, released August 8, 2008
 

Gene Dmel\hb

General Information
SymbolDmel\hbSpeciesD. melanogaster
NamehunchbackAnnotation symbolCG9786
Feature typeprotein_coding_geneFlyBase IDFBgn0001180
Created / Updated2003-12-01/2003-12-01
Genomic Location
Chromosome (arm)3RRecombination map3-48
Cytogenetic map85A5-85A5Sequence location3R:4,517,038..4,523,540 [-]
Map ( GBrowse ) detailed view
hide Summary Information
Automatically generated summary

See sections below for more information
The gene hunchback is referred to in FlyBase by the symbol hb (CG9786, FBgn0001180). It has the cytological map location 85A5. Its sequence location is 3R:4517038..4523540. Its molecular function is described as: DNA binding; transcription activator activity; specific RNA polymerase II transcription factor activity; zinc ion binding. It is involved in the biological processes described with 19 unique terms, many of which group under: anatomical structure development; anterior/posterior axis specification; tripartite regional subdivision; embryonic pattern specification; regulation of biological process; regulation of developmental process; axis specification; regulation of metabolic process; open tracheal system development; central nervous system development. 119 alleles are reported. The phenotypes of these alleles are annotated with 74 unique terms, many of which group under: thoracic segment; organ system; embryonic segment; cephalopharyngeal skeleton; embryonic nervous system; embryonic abdomen; nervous system; embryonic neuron; extended germ band embryo; embryonic head. It has 2 annotated transcripts and 2 annotated polypeptides.

External Summaries
hide Phenotypic Description from the Red Book (Lindsley & Zimm 1992)
Gene/Allele symbols may differ from current usage
hb: hunchback
Homozygotes for null alleles of hb (class I alleles of Lehmann and Nusslein-Volhard) are embryonic lethals of the gap type. Gastrulation abnormal; no cephalic fold; cell death evident at 6 hr later becoming extensive, predominantly in the neuroectoderm; germ band extension curtailed at 50% of embryonic length. After germ band shortening embryos lack thoracic and labial segments; cephalopharyngeal skeleton present but poorly formed; head involution fails. Seventh and eighth abdominal segments fused by the deletion of parasegment 13; A1 segment 1.5 times normal width, with eight to ten deranged denticle rows compared to the normal number of four, and a widened region of naked cuticle. Filzkorper material reduced; posterior spiracles fail to evert. Three ventral ganglia absent; gap appears between suboesophogeal region of ventral nerve cord and more posterior trunk ganglia. Extreme mutants display a reduced number of stripes of ftz expression at cellular blastoderm; the first stripe is widened and followed by a narrowed gap of nonexpression preceding the second stripe; the last pair of stripes are fused (Carroll and Scott, 1986, Cell 45: 113-26). Hypomorphic alleles display variably less severe disruption depending on allele (hbDrv6 = hbb2 = hbe21 > hbb7 > hbDrv9), the least severe, hbDrv9 lacking only T2. Class II alleles (Lehmann and Nusslein-Volhard) resemble the null alleles except that some or all of the prothorax and A7 are retained. The class III allele retains the labial segment as well. Class IV alleles lack only the mesothoracic segment. Class V mutants exhibit segment transformations as well as gaps and are described separately below. Temperature sensitive period of hbts1 during first four hr of development. hb/+ offspring produced from homozygous oogenic clones develop normally; homozygous embryos resulting from such clones display enhanced zygotic phenotype; gnathal, thoracic, and the first three abdominal segments replaced by two or three segments of abdominal identity in mirror image relation to the more posterior abdominal segments; weak alleles without maternal effect; extra doses of hb+ in female without effect on phenotype of hb offspring. The anterior zone of hb expression extended posteriorly by six additional cells in the absence of Kr+; conversely the zone of Kr expression expanded anteriorly by six to eight cells in hb mutants; posterior zone appears insensitive to Kr constitution (Jackle, Tautz, Schuh, Seifert, and Lehmann, 1986, Nature 324: 668-70). hb+ appears to set the boundaries of Ubx expression (White and Lehmann, 1986, Cell 47: 311-21); zone of Ubx expression expanded in both anterior and posterior directions in hb mutant embryos at the stage of full germ band elongation; segmental disposition of expression characteristically deranged prior to the advent of cell death. Although Ubx expression in the ventral nerve chord at the stage of fully shortened germ band extends from parasegments 5-13, Ubx protein detected in parasegments 1, 7-12 and 14 in hb12, 3 and 7-14 in hb1, and head to parasegment 1 plus parasegments 7-12 and 14 in hb7 (White and Lehmann). Phenotypic effects of ftz and hb in double mutants additive in thorax and anterior abdomen, but more severe than expected in head and posterior regions.
hb6
hb6/hb6 embryos lack meso- and metathorax, but nine abdominal segments are formed, the most anterior being T2 transformed into A1 and the next the normal A1.
hb7
Homozygous embryos lack labium and all thoracic segments; head and gnathal segments transformed into posterior abdominal segments as is A1. Expressed only in homozygotes, not in hemizygotes; hb7/Df(3R)hb displays class III phenotype. Lethality of hb7 homozygotes not rescued by Dp(3;Y)P92 which is able to cover the other alleles; attempts to implicate a linked lethal mutation negative.
hb11
As in the case of hb7, resembles a class I mutant, but with transformation of gnathal and first abdominal segments into posterior abdominal segments. Expression in homozygotes more extreme than in hemizygotes.
hbD1: hunchback-Dominant
A gain-of-function mutation; viable both in heterozygous and homozygous condition. Phenotype resembles that of pbx; insensitive to additional doses of hb+ but suppressed by extra doses [e. g., five copies of BXC+ (Lewis)]; enhanced in heterozygous combination with null alleles of ftz.
hbD2
Homozygous lethal; lethal when heterozygous to hb null alleles (e.g. hb12). Has two dominant phenotypes: 1) homeotic transformation of parasegment six to parasegment five, resembling that produced by bxd pbx; 2) a pair-rule segmentation defect, consisting of partial deletion of even-numbered abdominal segments, principally A2 and A4. Homozygote shows more extreme expression of both phenotypes; penetrance and expressivity of first effect enhanced in double heterozygous combination with null alleles of ftz (e.g. hbD2/ftzr14); second phenotype enhanced by Df(2R)eve, such that only a few adult escapers of the doubly heterozygous genotype are observed. Also has a recessive phenotype, revealed either when homozygous or heterozygous to an hb null allele; deletion of parasegment 13 and reduction of filzkorper; labial and thoracic segments normal. Thus, affects posterior, but not anterior, domain of hb+ function. Viable in trans to some hypomorphic alleles that do not affect parasegment 13 (e.g. hb6).
hide Detailed Mapping Data
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
85A5-85A5  
Limits computationally determined from genome sequence between P{lacW}l(3)L4740L4740 and P{EP}D1EP473  
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
85A3-85B1
(determined by in situ hybridisation)  
85A1-85B1
(determined by in situ hybridisation)  
85A-85B
(determined by in situ hybridisation)  
85A3-85A3
(determined by in situ hybridisation)  
85A3-85B1
(determined by in situ hybridisation)  
Experimentally Determined Recombination Data
Location
Left of (cM)
Right of (cM)
Notes
3-48.3
 
Molecular Map Data
Gene Order (in direction of increasing cytology)
References
Gene Order (overall orientation not stated)
References
hide Gene Model & Products
Please see the GBrowse view of Dmel\hb for information on other features
detailed view FBtr0081951 FBtr0081950 FBpp0081431 FBpp0081432 FBti0041913
Comments on Gene Model
DGC clone LD34229 appears problematic: incomplete CDS
hide Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Associated CDS (aa)
FBtr0081951
  3002
  758
FBtr0081950
  3350
  758
Additional Transcript Data & Comments
Reported size (kB)
3.2, 2.9 (sequence analysis)
3.5, 3.2, 3.0, 2.8, 2.6 (northern blot)
3.2, 2.9 (northern blot)
Comments
Complete exon/intron structure not defined but these are called "class B" transcripts by the authors because they initiate at a downstream exon.
RNA-protein and protein-protein interaction assays indicate that nos protein forms a ternary complex with the RNA-binding domain of pum protein and the NREs (nanos response element) in the 3\\' UTR of maternal hb mRNA.
hb transcript is expressed in two domains in the embryo. The anterior domain is bcd dependant, and expression is lost between 20 and 50% egg length, in bcd mutants the anterior boundary of hb expression is reduced to 20% egg length.
Complete intron/exon structure not worked out. This is called a "class A" transcript by authors because it initiates at the 5\\' most leader exon.
Sequences within the first intron of this hb transcript were studied for binding of bcd protein and used to study transcriptional activation. Five biding sites were identified and a bcd binding consensus sequence was identified. These sequences are not responsive in a bcd mutant background.
Sequences upstream of the start site of transcription for this hb transcript were studied for binding of bcd protein and used to study transcriptional activation. Five biding sites were identified and a bcd binding consensus sequence was identified. These sequences are not responsive in a bcd mutant background.
External Data
Crossreferences
hide Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kD)
Length (aa)
Theoretical pI
RefSeq ID
GenBank protein
hb-PA  
FBpp0081432  
83.1  
758  
7.24  
hb-PB  
FBpp0081431  
83.1  
758  
7.24  
Additional Polypeptide Data & Comments
Reported size (kD)
758 (aa); 83 (kD predicted)
Comments
hb protein is shown to specifically bind DNA from the bx regulatory region of Ubx. Three hb binding sites were characterized in theis region.
External Data
Linkouts
PANTHER - Protein classification by function, families, and pathways
Crossreferences
InterPro domains - A database of protein families, domains, and functional sites
TRANSFAC - Eukaryotic transcription factors, their genomic binding sites, and DNA-binding profiles
  • R02484
  • R02486
  • R02609
  • R02610
  • R02611
  • R02612
  • R02613
  • R02614
  • R02615
  • R02616
  • R02617
  • R02618
  • R03718
  • T00395
hide Sequences Consistent with the Gene Model
DDBJ /
EMBL /
GenBank
DNA sequence
Protein sequence
Name
 
 
UniProtKB/Swiss-Prot
UniProtKB/TrEMBL
    Maps to
    Does NOT map to
    Identified with
    hide Mapped Features & Mutations
    Please see GBrowse or insertion reports for information on insertions of transgenic constructs and features not listed here
    Type
    Symbol & Location
    Additional Notes
    References
    aberration junction
    comment=The deficiency breakpoint maps to a HindIII-XbaI restriction fragment.
    evidence=experimental
    linked_to=HindIII-XbaI_rfrag
    aberration junction
    In(3R)hb[bs23].bk2
    3R:4,519,886..4,521,124
    comment=The inversion breakpoint maps to a HindIII-XbaI restriction fragment.
    evidence=experimental
    linked_to=HindIII-XbaI_rfrag
    aberration junction
    comment=The deficiency breakpoint maps to an EcoRI-EcoRI restriction fragment.
    evidence=experimental
    linked_to=EcoRI-EcoRI_rfrag
    aberration junction
    In(3R)hb[D2].bk2
    3R:4,525,227..4,525,505
    comment=The inversion breakpoint maps to a BamHI fragment.
    evidence=experimental
    linked_to=BamHI-BamHI_rfrag
    enhancer
    comment=from GB:U17742; tll_enhancer; tll and hkb act on this region to control posterior hb expression in the blastoderm stage embryo; contains tll binding sites.
    evidence=experimental
    point mutation
    evidence=experimental
    na_change=C4519232A
    pr_change=Y215|hb-PA,Y215|hb-PB
    reported_na_change=C?A
    reported_pr_change=Y215@
    point mutation
    comment=TGG to TGA
    evidence=experimental
    na_change=G4519109A
    pr_change=W256|hb-PA,W256|hb-PB
    reported_na_change=G?A
    reported_pr_change=W256@
    point mutation
    evidence=experimental
    na_change=T4519021A
    pr_change=Y286N|hb-PA,Y286N|hb-PB
    reported_na_change=T?A
    reported_pr_change=Y286N
    point mutation
    evidence=experimental
    na_change=G4518944A
    pr_change=M311I|hb-PA,M311I|hb-PB
    reported_na_change=G?A
    reported_pr_change=M311I
    point mutation
    reported_na_change=G?A
    evidence=experimental
    na_change=G4518756A
    pr_change=R374H|hb-PA,R374H|hb-PB
    reported_pr_change=R374H
    point mutation
    reported_na_change=C?T
    evidence=experimental
    na_change=C4518448T
    pr_change=Q477|hb-PA,Q477|hb-PB
    reported_pr_change=Q477@
    point mutation
    reported_na_change=G?A
    comment=TGG to TGA
    evidence=experimental
    na_change=G4518416A
    pr_change=W487|hb-PA,W487|hb-PB
    reported_pr_change=W487@
    point mutation
    reported_na_change=C?T
    evidence=experimental
    na_change=C4518055T
    pr_change=Q608|hb-PA,Q608|hb-PB
    reported_pr_change=Q608@
    point mutation
    reported_na_change=G?A
    evidence=experimental
    na_change=G4517748A
    pr_change=C710Y|hb-PA,C710Y|hb-PB
    reported_pr_change=C710Y
    point mutation
    reported_na_change=T?C
    evidence=experimental
    na_change=T4517665C
    pr_change=C738R|hb-PA,C738R|hb-PB
    reported_pr_change=C738R
    protein binding site
    hb-protein_bind-6
    3R:4,524,373..4,524,388
    bound_moiety=hb-XP
    comment=binding site Hb7
    evidence=experimental
    protein binding site
    hb-protein_bind-7
    3R:4,524,272..4,524,287
    evidence=experimental
    comment=binding site Hb6
    bound_moiety=hb-XP
    protein binding site
    hb-protein_bind-8
    3R:4,524,061..4,524,076
    bound_moiety=hb-XP
    comment=binding site Hb5
    evidence=experimental
    protein binding site
    hb-protein_bind-9
    3R:4,523,967..4,523,982
    bound_moiety=hb-XP
    comment=binding site Hb4
    evidence=experimental
    protein binding site
    hb-protein_bind-10
    3R:4,522,755..4,522,770
    bound_moiety=hb-XP
    comment=binding site Hb3
    evidence=experimental
    protein binding site
    hb-protein_bind-11
    3R:4,522,643..4,522,655
    bound_moiety=bcd-XP
    comment=binding site B1
    evidence=experimental
    protein binding site
    hb-protein_bind-12
    3R:4,522,594..4,522,613
    bound_moiety=bcd-XP
    comment=binding site B2
    evidence=experimental
    protein binding site
    hb-protein_bind-13
    3R:4,520,998..4,521,009
    bound_moiety=Kr-XP
    comment=binding site Kr2
    evidence=experimental
    protein binding site
    hb-protein_bind-14
    3R:4,520,981..4,520,996
    bound_moiety=hb-XP
    comment=binding site Hb2
    evidence=experimental
    protein binding site
    hb-protein_bind-15
    3R:4,520,681..4,520,692
    bound_moiety=Kr-XP
    comment=binding site Kr1
    evidence=experimental
    protein binding site
    hb-protein_bind-16
    3R:4,520,590..4,520,604
    bound_moiety=bcd-XP
    comment=binding site A1
    evidence=experimental
    protein binding site
    hb-protein_bind-17
    3R:4,520,497..4,520,512
    bound_moiety=hb-XP
    comment=binding site Hb1
    evidence=experimental
    protein binding site
    hb-protein_bind-19
    3R:4,520,378..4,520,389
    bound_moiety=bcd-XP
    comment=binding site A3
    evidence=experimental
    protein binding site
    hb-protein_bind-20
    3R:4,517,471..4,517,502
    bound_moiety=pum-XP
    evidence=experimental
    comment=pum protein binds to hb mRNA at the NRE (nos response element).
    protein binding site
    hb-protein_bind-1
    3R:4,527,306..4,527,326
    bound_moiety=tll-XP
    comment=medium strong binding site
    evidence=experimental
    protein binding site
    hb-protein_bind-2
    3R:4,527,125..4,527,152
    bound_moiety=tll-XP
    comment=strong binding site
    evidence=experimental
    protein binding site
    hb-protein_bind-3
    3R:4,526,813..4,526,831
    bound_moiety=tll-XP
    comment=medium strong binding site
    evidence=experimental
    protein binding site
    hb-protein_bind-4
    3R:4,526,654..4,526,687
    bound_moiety=tll-XP
    comment=strong binding site
    evidence=experimental
    protein binding site
    hb-protein_bind-5
    3R:4,524,457..4,524,472
    bound_moiety=hb-XP
    comment=binding site Hb8
    evidence=experimental
    protein binding site
    hb-protein_bind-21
    3R:4,527,523..4,527,542
    bound_moiety=tll-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-22
    3R:4,520,526..4,520,534
    evidence=experimental
    bound_moiety=bcd-XP
    protein binding site
    hb-protein_bind-23
    3R:4,520,539..4,520,547
    bound_moiety=bcd-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-24
    3R:4,527,487..4,527,503
    bound_moiety=tll-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-25
    3R:4,520,452..4,520,465
    bound_moiety=bcd-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-26
    3R:4,527,002..4,527,022
    bound_moiety=tll-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-27
    3R:4,520,555..4,520,563
    bound_moiety=bcd-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-28
    3R:4,527,236..4,527,255
    bound_moiety=tll-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-29
    3R:4,520,482..4,520,496
    bound_moiety=bcd-XP
    evidence=experimental
    protein binding site
    hb-protein_bind-30
    3R:4,520,505..4,520,511
    bound_moiety=bcd-XP
    evidence=experimental
    regulatory region
    hb-reg_element-3
    3R:4,523,042..4,524,208
    comment=1.2kb fragment extending from HindIII site to 6bp downstream from splice acceptor site; sufficient to reproduce wild type ovarian pattern of hb expression.
    evidence=experimental
    regulatory region
    hb-reg_element-4
    3R:4,519,886..4,520,634
    comment=region sufficient for wild type expression of the 2.9kb hb transcript in the anterior domain.
    evidence=experimental
    regulatory region
    hb-reg_element-5
    3R:4,517,523..4,517,554
    comment=NRE (nos response element) hb1
    evidence=experimental
    comment=A region containing hb1 and hb2 is sufficient to confer nos-dependent regulation of hb expression.
    regulatory region
    hb-reg_element-6
    3R:4,517,471..4,517,502
    comment=NRE (nos response element) hb2
    evidence=experimental
    comment=A region containing hb1 and hb2 or two copies of hb2 is sufficient to confer nos-dependent regulation of hb expression.
    regulatory region
    hb-reg_element-1
    3R:4,526,860..4,527,389
    comment=Blastoderm embryo posterior expression element; region drives expression of lacZ in a posterior stripe at 15% egg length and in a posterior cap.
    evidence=experimental
    linked_to=EcoRI-RsaI_rfrag
    regulatory region
    hb-reg_element-2
    3R:4,526,517..4,526,863
    comment=Blastoderm embryo posterior expression element; region drives expression of lacZ in a central stripe at 50% egg length and a posterior stripe at 15% egg length.
    evidence=experimental
    linked_to=RsaI-SmaI_rfrag
    rescue fragment
    evidence=experimental
    linked_to=BglII-KpnI_rfrag
    rescue fragment
    comment=partial rescue
    evidence=experimental
    linked_to=BamHI-BamHI_rfrag
    sequence variant
    comment=A deletion of 10 nucleotides starting in amino acid 150 (exact position unspecified) results in a nonsense frameshift before the first finger domain.
    evidence=experimental
    hide External Data
    Linkouts
    DEDB - Drosophila exon database: splicing graphs
    Crossreferences
    EPD - Eukarytoic Promoter Database, an annotated collection of POL II promoters
    hide Expression Data
    FlyBase-Curated Data
    Transcript and
    Protein data
    Please see the FlyBase Gene Expression Report for details of gene expression from the literature.
    hide Summary of Transcript Expression
    Stage
    Tissue/Position
    Reference
     embryonic stage | embryonic cycle 13
     embryonic stage | stage 4
     embryonic stage | early
     embryonic stage | 2-6hr
     embryonic stage | embryonic cycle 14
     adult stage | female
     embryonic stage | early
     embryonic stage | stage >8
     embryonic central nervous system
     embryonic stage | stage 4
     oogenesis stage,adult stage | stage S7-S11
     nurse cell
     embryonic stage | 0-8hr
     embryonic stage | stage 4
     embryonic stage | embryonic cycle 11-13
     embryonic stage | early
     embryonic stage | stage 4
     embryonic stage | early
     embryonic stage | embryonic cycle 14
     embryonic stage | stage 4
    Marker for
      Subcellular Localization
      CV Term
      hide Summary of Polypeptide Expression
      Stage
      Tissue/Position
      Reference
       embryonic stage | early
       embryonic stage | stage 9-11
       tritocerebral neuroblast | subset
       embryonic stage
       embryonic stage | early
       embryonic stage | stage 9-11
       deuterocerebral neuroblast | subset
       embryonic stage | stage 15-17
       EW1 neuron
       embryonic stage | stage 4
       embryonic stage | early
       ubiquitous
       embryonic stage
       embryonic stage | stage 9-11
       protocerebral neuroblast | subset
       embryonic stage | stage 4
       anterior
       embryonic stage | early
       embryonic stage | early
       embryonic stage | early
       embryonic stage | early
       embryonic stage | stage 15-17
       GW neuron
       oogenesis stage
       embryonic stage | early
       ubiquitous
      Marker for
        Subcellular Localization
        CV Term
        hide External Data & Images
        Linkouts
        FLIGHT - Cell culture data for RNAi and other high-throughput technologies
        FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
        GEO (NCBI) - Gene expression data: microarray and other high-throughput technologies
        FlyExpress - Embryonic expression images (BDGP data)
        hide Alleles & Phenotypes
        hide Summary of Allele Phenotypes
        Lethality
        Allele