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Linha 23: Linha 23:
 
| ''exuperantia'' (exu) || Testis and ovary || Reducion of head; defective gastrulation || RNA-binding protein || Needed to transport ''bcd'' mRNA from nurse cells to oocyte
 
| ''exuperantia'' (exu) || Testis and ovary || Reducion of head; defective gastrulation || RNA-binding protein || Needed to transport ''bcd'' mRNA from nurse cells to oocyte
 
|-
 
|-
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| ''hunchback'' (hb) || See Zygotic anteroposterior gap class
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| ''hunchback'' (hb) || See '''Zygotic Anteroposterior Gap Class'''
 
|-
 
|-
 
| ''staufen'' (stau) || Maternal germ line, emryonic central nervous system || Most abdominal segments missing, no pole cells, also head defects || Double-stranded RNA-binding protein || Required for ''bicoid'' mRNA localization and polar granule assembly
 
| ''staufen'' (stau) || Maternal germ line, emryonic central nervous system || Most abdominal segments missing, no pole cells, also head defects || Double-stranded RNA-binding protein || Required for ''bicoid'' mRNA localization and polar granule assembly
Linha 119: Linha 119:
 
| ''frizzled-2'' (fz-2) || Apparently redundant with ''fz''  
 
| ''frizzled-2'' (fz-2) || Apparently redundant with ''fz''  
 
|-
 
|-
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| ''hedgehog'' (hh) || Posterior compartments of larval segments and imaginal discs || Posterior compartment replaced with mirror image of anterior compartment ||  
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| ''hedgehog'' (hh) || Posterior compartments of larval segments and imaginal discs || Posterior compartment replaced with mirror image of anterior compartment || Secreted sinaling molecule (TGF-β super family) || Maintains ''wg'' and indirectly ''en''. defines source of segmental morphogen
 +
|-
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| ''patched'' (ptc) || In anterior compartments || Defects in segmentation and eye development || Multipass transmembrane protein || Parto of the receptor complex for ''hh''
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|-
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| ''smoothened'' (smo) || In anterior compartments || Defects in various tissues including epidermis, wing, and eye || G protein-associated transmembrane receptor || Part of the receptor complex for ''hh''; causes segregation of posterior from anterior compartmente cells
 +
|-
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| ''wingless'' (wg) || Transcription starts at blastoderm stage and produces 14 narrow stripes by extended germ band stage, marking the posterior of each parasegment. || Ventral cuticle a continuous lawn of denticles, indicating deletion of 3/4 of each segmental unit || Secreted signaling molecule (''Wnt'' family) || Maintains ''en''
 
|}
 
|}
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{| border="1"
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|+ '''Homeotic Genes and Related Genes'''
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|-
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! Gene !! Expression Pattern !! Mutant Phenotype !! Molecular Nature !! Developmental Function
 +
|-
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| ''abdominal A'' (abd-A) || Trancribed in PS 7-13 of extended germ band || Transforms PS 7-9 to PS 6 || Transcriptional regulator (homeodomain) || Represses ''Ubx''; activates ''wg'', ''dpp''; specifies a.p. body pattern
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|-
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| ''Abdominal B'' (Abd-B) || Transcribed in PS 10-14 of extended germ band || Transforms PS 10-14 to PS 9 || Transcriptional regulator (homeodomain) || Represses ''Ubx''; specifies a.p. body pattern
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|-
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| ''Antennapedia'' (Antp) || Transcription starts in blastoderm; mainly PS 4, also in posterior parasegments. Thoracic imaginal discs. || Transforms PS4, 5 to PS 3 || Transcriptional regulator (homeodomain) || Specifies a.p. body pattern
 +
|-
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| ''Deformed'' (Dfd) || Transcription in preblastoderm stage in PS 1; later also PS 0. Eye-antennal disc. || Deletion of mandibular and maxillary segments || Transcriptional regulator (homeodomain) || Activates itself; specifies a.p. body pattern
 +
|-
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| ''labial'' (lab) || Transcription in extended germ band anterior to cephalic furrow and in posterior midgut || Deletes labial derivatives || Transcriptional regulator (homeodomain) || Specifies a.p. body pattern
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|-
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| ''Polycomb-group'' (Pc-G) || || Multiple homeotic transformations || || Maintains inhibition of inactive homeotic genes
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|-
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| ''Sex combs reduced'' (Scr) || Transcription in PS 2 in blastoderm; later PS 3 epidermis and mesoderm, and abdominal ganglia || Transforms PS3 to PS 4 and PS2 to PS1 || Transcriptional regulator (homeodomain) || Specifies a.p. body pattern
 +
|-
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| ''trithorax-group'' (trx-G) || || Multiple homeotic transformations || || Maintains inhibition of active homeotic genes
 +
|-
 +
| ''Ultrabithorax'' (Ubx) || Transcrition starts in cellular blastoderm, mainly in PS 6, but at lower levels in PS5-13; more in even-numbered parasegments. Neuromeres; metathoracic discs. || Transforms PS 5, 6 to PS 4 || Transcriptional regulator (homeodomain) || Represses ''Scr''; represses ''Antp''; activates itself; activates ''wg'', ''dpp''; selector gene
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|}
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{| border="1"
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|+ '''Maternal Dorsoventral System'''
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|-
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! Gene !! Expression Pattern !! Mutant Phenotype !! Molecular Nature !! Developmental Function
 +
|-
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| '' cactus'' (cac) || Maternal; action in embryo || Ventralizing || Genetic regulator || Inhibits entry of ''dl'' protein to nuclei
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|-
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| ''dorsal'' (dl) || Transcription in nurse cells; uniform mRNA in oocyte and egg; ventral-dorsal gradient of protein in preblastoderm nuclei || Embryos become tubes of dorsal epidermis. Some haploinsufficient alleles. || Genetic regulator || Activates ''twi'', ''sna''; represses ''zen'', ''dpp''; morphogen for dorsoventral pattern
 +
|-
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| ''easter'' (ea) || Maternal, released from embryo into preivitelline space || Similar to ''dl''. Also weak ventralizing gain-of-function alleles. || Serine proteases || Activation of ''spz'' (''Tl'' ligand)
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|-
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| ''gastrulation defective'' (gd) || Maternal, released from embryo into perivitelline space || Similar to ''dl'' || Serine protease || Activation of ''spz'' (''Tl'' ligand)
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|-
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| ''gurken'' (grk) || Maternal; needed in oocyte || Ventralizing; affects eggshell and embryo || Growth factor-like || Ligand for top protein; dorsalizing signal from oocyte
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|-
 +
| ''nudel'' (ndl) || Maternal; needed in follicle cells || Similar to ''dl'' || Protease activity || Contributes to ventral polarizing activity
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|-
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| ''pelle'' (pll) || Maternal, acts in embryo || Similar to ''dl'' || Protein kinase || Signal transduction from ''Tl'' to ''cac''
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|-
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| ''pipe'' (pip) || Maternal; needed in follicle cells || Similar to ''dl'' || Glycosaminoglycan-modifying enzyme || Localized contribution to ventral polarizing activity
 +
|-
 +
| ''snake'' (snk) || Maternal, released from embryo into perivitelline space || Similar to ''dl'' || Serine protease || Activation of ''spz'' (''Tl'' ligand)
 +
|-
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| ''spätzle'' (spz) || Maternal, released from embryo into perivitelline space || Similar to ''dl'' || || Ligand for ''Tl'' protein
 +
|-
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| ''Toll'' (Tl) || Maternal; uniform distribution of protein in egg plasma membrane || Similar to ''dl''. Gain-of-function alleles ventralize, producing denticle belts all around. || Receptor tyrosine kinase || Activated ventrally by ''spz''; releases ''dl'' from ''cac'', permits ''dl'' to enter nucleus
 +
|-
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| ''torpedo'' (top) || Maternal; needed in follicle cells || Similar to ''grk'' || Growth factor receptor || Receptor for ''grk'', inhibits ''pip'', thus orienting ventral polarizing activity.
 +
|-
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| ''tube'' (tube) || Maternal; acts in embryo || Similar to ''dl'' || Adapter protein || Signal transduction from ''Tl'' to ''cac''
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|-
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| ''windbeutel'' (wbl) || Maternal; needed in follicle cells || Similar to ''dl'' || Enzyme associated with endoplasmic reticulum || Contributes to ventral polarizing activity.
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|}
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{| border="1"
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|+ '''Zygotic Dorsoventral Class'''
 +
|-
 +
! Gene !! Expression Pattern !! Mutant Phenotype !! Molecular Nature !! Developmental Function
 +
|-
 +
| ''decapentaplegic'' (dpp) || Transcription in preblastoderm on dorsal side, curling around to ventral at poles. (see also '''Compartment-Related Genes''') || Loss of amnioserosa and reduction of dorsal epidermis. Viable alleles produce multiple defects in imaginal disc derivatives. || Signaling molecule (TGF-β homologue) || Forms morphogen gradient with maximum dorsally. Promotes amnioserosa and epidermis; inhibits neurogenesis
 +
|-
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| ''short gastrulation'' (sog) || Protein synthesized blastoderm cells in ventral || Dorsalizes embryo || Plasma membrane protein || '''antagonizes''' ''dpp''; specifies d.v. pattern
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|-
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| ''snail'' (sna) || Transcription in mid-ventral strip of prospective mesoderm || Loss of mesoderm || Transcriptional regulator (zinc finger domain) || Inhibits expression of other d.v. patterning genes in prospective mesoderm.
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|-
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| ''tolloid'' (tld) || Released from blastoderm cells into extracellular space || Ventralizes embryo || Metalloprotease || Cleaves extracellular domain of ''sog'', especially in presence of ''dpp''; specifies d.v. pattern
 +
|-
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| ''twist'' (twi) || Transcription in mid-ventral strip of prospective mesoderm and mesectoderm || Loss of mesoderm || Transcriptional regulator (basic helix-loop-helix domain) || Specifies dorsoventral pattern
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|-
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| ''zerknüllt'' (zen) || Transcription in preblastoderm stage on dorsal side || Loss of amnioserosa and optic lobe || Transcriptional regulator (homeodomain) || Promotes amnioserosa formation
 +
|}
 +
 +
{| border="1"
 +
|+ '''Compartment-Related and Other Genes'''
 +
|-
 +
! Gene !! Expression Pattern !! Mutant Phenotype !! Molecular Nature !! Developmental Function
 +
|-
 +
| ''Achaete'' (Ac) || Proneural cells, prospective sensory bristles || Lack of sensory bristles and neurons || Transcriptional regulator (bHLH domain) || Many functions, incl. patterning around d.v. compartment boundary in wing
 +
|-
 +
| ''apterous'' (ap) || Dorsal compartments of wing and haltere discs || Wings and halteres missing || Transcriptional regulator (homeodomain) || Required for wing (haltere) outgrowth; selector gene
 +
|-
 +
| ''cubitus interruptus'' (ci) || Anterior compartment of each segment || Disturbed segmentation || Transcriptional regulator (zinc finger domain) || Activates ''wg'' and ''dpp'' in response to ''hh'' signaling
 +
|-
 +
| ''decapentaplegic'' (dpp) || In strip of cells anterior to a.p. compartment boundary (see also '''Zygotic Dorsoventral Class''') || Abnormal wing patterns || Secreted protein (TGF-β superfamily) || Morphogen for anteroposterior pattern of wing and haltere
 +
|-
 +
| ''Distalless'' (Dll) || Expressed around leg dorsoventral compartment boundary || Loss of legs and antennae || Transcriptional regulator (homeodomain) || Required for outgrowth of legs and antennae
 +
|-
 +
| ''fringe'' (fng) || Dorsal wing and haltere compartments || Loss of wings and halteres || Secreted protein || Juxtaposition of cells with and without ''fringe'' activates ''wg+''
 +
|-
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| ''hedgehog'' (hh) || see '''Zygotic Segment Polarity Class'''
 +
|-
 +
| ''optomotor-blind'' (omb) || Prospective CNS and epidermal regions || || Transcriptional regulator || Target of ''dpp'' in patterning of wing and abdominal segments
 +
|-
 +
| ''scute'' (sc) || Similar to ''Achaete''
 +
|-
 +
| ''spalt'' (sal) || In endoderm and parts of wing imaginal disc || || Transcriptional regulator (zinc finger domain) || Target of ''dpp'' in wing patterning
 +
|-
 +
| ''vestigial'' (vg) || In prospective appendages of wing and haltere imaginal discs || Loss of wings and halteres || Putative transcriptional regulator || Specification of wing and haltere as opposed to thorax
 +
|}
 +
 +
== Ver também ==
 +
* [[Biologia III]]
 +
* [[Carlos Eduardo Winter]]
 +
* [[Projeto Biologia do Desenvolvimento]]
 +
 +
[[Categoria: Projetos da Wikoleculares]]

Edição das 15h20min de 25 de novembro de 2006

Maternal Anteroposterior Axis
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
dicephalic (dic) Maternal Abnormal position of nurse cells relative to oocyte Contributes to anteroposterior polarity of nurse cell oocyte complex
gurken (grk) Oocyte Eggs ventralized with dorsal appendages reduced or missing Similar to vertebrate transforming growth factor alpha (TGF-α), ligand for torpedo Establishes first posterior and then dorsal identity of ovarian follicle cells
spindle (spn) (several loci) Maternal germ line Disturbed anteroposterior polarity of oocyte Determination of prospective oocyte among cystocytes
torpedo (trp) Ovarian follicle cells Similar to grk Receptor tyrosine kinase, receptor for grk Same as grk
Maternal Anterior Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
bicoid (bcd) mRNA transcribed in nurse cells and transported to anterior of oocyte. Translated during cleavage. Protein forms anteroposterior gradient. Head and thorax replaced with mirror image of telson Transcriptional regulator (homeodomain and paired repeat) Activates hb transcription; acts as a morphogen on embryonic genes; expressed anteriorly
exuperantia (exu) Testis and ovary Reducion of head; defective gastrulation RNA-binding protein Needed to transport bcd mRNA from nurse cells to oocyte
hunchback (hb) See Zygotic Anteroposterior Gap Class
staufen (stau) Maternal germ line, emryonic central nervous system Most abdominal segments missing, no pole cells, also head defects Double-stranded RNA-binding protein Required for bicoid mRNA localization and polar granule assembly
swallow (swa) Maternal germ line Reduction of head; cellularization defects Rna-binding protein Required for localization of bcd mRNA
Maternal Posterior Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
cappuccino (capu) Maternal Abdominal segments A2-A7 missing; no pole cells Putative transmembrane receptor Required for polar granule assembly
nanos Transcription in oocyte and nurse cells. Partial localization to polar granules. Only this localized mRNA is translated. Absence of abdomen; pole cells normal RNA-binding protein, translational repressor Inhibits translation of maternal hb mRNA and hastens its destruction, hence allows activation of kni in posterior.
oskar (osk) Maternal germ line Similar to capu Required for polar granule assembly, localizes nos mRNA
pumilio (pum) Transcription maternal. Protein probably localized to posterior Most of abdomen missing; pole cells normal RNA-binding protein Recruits nos protein to hb mRNA
spire (spir) Maternal Similar to capu Actin-binding protein Required for polar granule assembly
staufen (stau) See maternal anterior system
tudor (tud) Male and female germ line Similar to capu Required for pole cell formation
vasa (vas) Transcription in nurse cells and oocyte; mRNA uniform in early embryo. Protein localized in posterior of oocyte, egg, and in pole cells. Similar to capu RNA helicase Required for pole cell formation
Maternal Terminal Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
NTF-1 Transcriptional inhibitor Inhibits transcription of hkb and tll
torso (tor) Transcription in nurse cells. Transport to oocyte, where protein distributed uniformly in plasma membrane. Absence of labrum, reduction of head skeleton, absence of A8 and telson; gain of function; suppression of segmentation in thorax and abdomen Tyrosine kinase receptor, likely receptor for active trunk protein Activates tll hkb by inhibiting NTF-1
torsolike (tsl) Protein secreted by anterior and posterior ovarian follicle cells probably associates with vitelline envelope near egg poles Similar to tolr (loss of function only) Modifying protein Generates active form of trunk near egg poles
Trunk (trk) Maternal mRNA translated in early embryo, protein released into preivitelline space Similar to tor Secreted protein Probably ligand of tor, after processing by tsl
Zygotic Anteroposterior Gap Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
empty spiracles Transcription during blastoderm 78-67% EL; later, in cells forming tracheal pits and spiracles Defects in antennal segment, tracheal system Transcriptional regulator (homeodomain) Specifies procephalic segments
giant (gt) Initial transcription at preblastoderm stage 82-60% and 33-0% EL; changes later Defects in or absence of labrum, labium, and abdominal segments Transcriptional regulator (Leucine zipper) Activates Scr; represses Kr
huckebein (hkb) Anterior and posterior ends of blastoderm Defects in terminal body structures and gut Transcriptional regulator (zinc finger domain) Specifies terminal structures in concert with tll
hunchback (hb) Maternal mRNA initially uniform; protein forms anteroposterior gradient. Embryonic transcription 100-50% EL and 20-10% EL. Posterior domain long-lasting. Embryonic: deletion of labium, thorax, aA7/pA8 (PS 13). No pure maternal effect, but if mother and sperm are hb-, then deletion of all mouthparts and thoracic segments and A1-A3, with mirror duplication of abdomen. Transcriptional regulator (zinc finger domain) Represses kni; represses Kr at high level and activates at low level; regulates eve; regulates h, run, ftz; activates Antp (with ftz); represses Ubx
knirps (kni) Transcription starts at preblastoderm stage forming zone 45-30% EL. Ventral patch and narrow ring form in atnerior by cellular blastoderm stage. Replacement of A1-A7 by single A-type segment Transcriptional regulator (zinc finguer) Represses Kr; regulates h, run, eve, ftz; represses Abd-B and Antp
Krüppel (Kr) Transcription starts at preblastoderm stage in central zone, eventually expanding to 60-30% EL. Later also posterior patch and patch in head. Purely embryonic. Head normal, deletion of thorax and A1-A5. Duplicated inverted A6. Trancriptional regulator (zinc finguer) Activates kni; represses gt; regulates eve; regulates h, run, ftz; represses Scr; activates Antp; represses Abd-B
orthodenticle (otd) Narrow band (75-92% EL) in anterior blastoderm Defects in eyes and anterior head parts Transcriptional regulator (homeodomain, paired domain) Activated by bcd and tor, otd - along with ems - specifies procephalic segments
tailless (tll) Transcription in termini of preblastoderm embryo Head skeleton reduced but labrum present. Hindgut, Malpighian tubules absent. Transcriptional regulator (steroid receptor family) Activates hb; represses Kr; represses kni; activates h
Zygotic Pair-Rule Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
even-skipped (eve) Transcription starts at preblastoderm stage; 7 stripes corresponding to parasegments 1, 3, 5, etc., by cellularization stage. Fades during gastrulation. Abolishes segmentation, giving lawn of denticles. Weak alleles delete odd parasegments. Transcriptional regulator (homeodomain) Represses ftz, odd, run; activates itself; activates en; represses wg; activates Dfd
fushi tarazu (ftz) Transcription starts at preblastoderm stage; 7 stripes corresponding to parasegments 2, 4, 6, etc., by cellularization. Fades during germ band extension. Deletes even parasegments Transcriptional regulator (homeodomain) Activates itself; activates en; activates Antp; activates Ubx; represses wg
hairy (h) Transcription starts at preblastoderm stage; 7 stripes + dorsal head patch by time of cellularization. Fades during gastrulation. Range from deletion of odd parasegments to formation of lawn of denticles. Also loss of labral tooth. Other alleles give extra hairs in adult. Transcriptional regulator (helix-loop-helix domain) Represses run, ftz; activates eve
paired (prd) Transcription starts at preblastoderm stage; 8 stripes with dorsal head patch by cellularization. During germ band extension stripes 2-7 split and then fade. Deletions about 1 segment wide starting in middle of denticle band affecting mainly odd abdominal segments Transcriptional regulator (homeodomain) Activates wg, en
runt (run) Transcription starts at preblastoderm stage; 7 stripes. After cellularization, patter becomes single-segment stripes, which persist through germ band extension. Deletions more than 1 segment wide centered on T2, A1, A3, A5, A7, with mirror duplication of what is left Transcriptional regulator (novel) Represses h, eve; activates ftz
Zygotic Segment Polarity Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
engrailed (en) Transcription starts at blastoderm stage and produces 14 narrow stripes by extended germ band stage, marking the anterior of each parasegment. Expression in posterior compartments of larval imaginal discs Ventral cuticle a continuous lawn of denticles. Less severe alleles delete even-numbered parasegments Transcriptional regulator (homeodomain) Maintains hh and indirectly wg activity; selector gene defining posterior compartment
frizzled (fz) Various imaginal discs Variable orientation of wing hairs, irregular ommatidia in eye Seven-pass transmembrane receptor Receptor for wg
frizzled-2 (fz-2) Apparently redundant with fz
hedgehog (hh) Posterior compartments of larval segments and imaginal discs Posterior compartment replaced with mirror image of anterior compartment Secreted sinaling molecule (TGF-β super family) Maintains wg and indirectly en. defines source of segmental morphogen
patched (ptc) In anterior compartments Defects in segmentation and eye development Multipass transmembrane protein Parto of the receptor complex for hh
smoothened (smo) In anterior compartments Defects in various tissues including epidermis, wing, and eye G protein-associated transmembrane receptor Part of the receptor complex for hh; causes segregation of posterior from anterior compartmente cells
wingless (wg) Transcription starts at blastoderm stage and produces 14 narrow stripes by extended germ band stage, marking the posterior of each parasegment. Ventral cuticle a continuous lawn of denticles, indicating deletion of 3/4 of each segmental unit Secreted signaling molecule (Wnt family) Maintains en
Homeotic Genes and Related Genes
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
abdominal A (abd-A) Trancribed in PS 7-13 of extended germ band Transforms PS 7-9 to PS 6 Transcriptional regulator (homeodomain) Represses Ubx; activates wg, dpp; specifies a.p. body pattern
Abdominal B (Abd-B) Transcribed in PS 10-14 of extended germ band Transforms PS 10-14 to PS 9 Transcriptional regulator (homeodomain) Represses Ubx; specifies a.p. body pattern
Antennapedia (Antp) Transcription starts in blastoderm; mainly PS 4, also in posterior parasegments. Thoracic imaginal discs. Transforms PS4, 5 to PS 3 Transcriptional regulator (homeodomain) Specifies a.p. body pattern
Deformed (Dfd) Transcription in preblastoderm stage in PS 1; later also PS 0. Eye-antennal disc. Deletion of mandibular and maxillary segments Transcriptional regulator (homeodomain) Activates itself; specifies a.p. body pattern
labial (lab) Transcription in extended germ band anterior to cephalic furrow and in posterior midgut Deletes labial derivatives Transcriptional regulator (homeodomain) Specifies a.p. body pattern
Polycomb-group (Pc-G) Multiple homeotic transformations Maintains inhibition of inactive homeotic genes
Sex combs reduced (Scr) Transcription in PS 2 in blastoderm; later PS 3 epidermis and mesoderm, and abdominal ganglia Transforms PS3 to PS 4 and PS2 to PS1 Transcriptional regulator (homeodomain) Specifies a.p. body pattern
trithorax-group (trx-G) Multiple homeotic transformations Maintains inhibition of active homeotic genes
Ultrabithorax (Ubx) Transcrition starts in cellular blastoderm, mainly in PS 6, but at lower levels in PS5-13; more in even-numbered parasegments. Neuromeres; metathoracic discs. Transforms PS 5, 6 to PS 4 Transcriptional regulator (homeodomain) Represses Scr; represses Antp; activates itself; activates wg, dpp; selector gene
Maternal Dorsoventral System
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
cactus (cac) Maternal; action in embryo Ventralizing Genetic regulator Inhibits entry of dl protein to nuclei
dorsal (dl) Transcription in nurse cells; uniform mRNA in oocyte and egg; ventral-dorsal gradient of protein in preblastoderm nuclei Embryos become tubes of dorsal epidermis. Some haploinsufficient alleles. Genetic regulator Activates twi, sna; represses zen, dpp; morphogen for dorsoventral pattern
easter (ea) Maternal, released from embryo into preivitelline space Similar to dl. Also weak ventralizing gain-of-function alleles. Serine proteases Activation of spz (Tl ligand)
gastrulation defective (gd) Maternal, released from embryo into perivitelline space Similar to dl Serine protease Activation of spz (Tl ligand)
gurken (grk) Maternal; needed in oocyte Ventralizing; affects eggshell and embryo Growth factor-like Ligand for top protein; dorsalizing signal from oocyte
nudel (ndl) Maternal; needed in follicle cells Similar to dl Protease activity Contributes to ventral polarizing activity
pelle (pll) Maternal, acts in embryo Similar to dl Protein kinase Signal transduction from Tl to cac
pipe (pip) Maternal; needed in follicle cells Similar to dl Glycosaminoglycan-modifying enzyme Localized contribution to ventral polarizing activity
snake (snk) Maternal, released from embryo into perivitelline space Similar to dl Serine protease Activation of spz (Tl ligand)
spätzle (spz) Maternal, released from embryo into perivitelline space Similar to dl Ligand for Tl protein
Toll (Tl) Maternal; uniform distribution of protein in egg plasma membrane Similar to dl. Gain-of-function alleles ventralize, producing denticle belts all around. Receptor tyrosine kinase Activated ventrally by spz; releases dl from cac, permits dl to enter nucleus
torpedo (top) Maternal; needed in follicle cells Similar to grk Growth factor receptor Receptor for grk, inhibits pip, thus orienting ventral polarizing activity.
tube (tube) Maternal; acts in embryo Similar to dl Adapter protein Signal transduction from Tl to cac
windbeutel (wbl) Maternal; needed in follicle cells Similar to dl Enzyme associated with endoplasmic reticulum Contributes to ventral polarizing activity.
Zygotic Dorsoventral Class
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
decapentaplegic (dpp) Transcription in preblastoderm on dorsal side, curling around to ventral at poles. (see also Compartment-Related Genes) Loss of amnioserosa and reduction of dorsal epidermis. Viable alleles produce multiple defects in imaginal disc derivatives. Signaling molecule (TGF-β homologue) Forms morphogen gradient with maximum dorsally. Promotes amnioserosa and epidermis; inhibits neurogenesis
short gastrulation (sog) Protein synthesized blastoderm cells in ventral Dorsalizes embryo Plasma membrane protein antagonizes dpp; specifies d.v. pattern
snail (sna) Transcription in mid-ventral strip of prospective mesoderm Loss of mesoderm Transcriptional regulator (zinc finger domain) Inhibits expression of other d.v. patterning genes in prospective mesoderm.
tolloid (tld) Released from blastoderm cells into extracellular space Ventralizes embryo Metalloprotease Cleaves extracellular domain of sog, especially in presence of dpp; specifies d.v. pattern
twist (twi) Transcription in mid-ventral strip of prospective mesoderm and mesectoderm Loss of mesoderm Transcriptional regulator (basic helix-loop-helix domain) Specifies dorsoventral pattern
zerknüllt (zen) Transcription in preblastoderm stage on dorsal side Loss of amnioserosa and optic lobe Transcriptional regulator (homeodomain) Promotes amnioserosa formation
Compartment-Related and Other Genes
Gene Expression Pattern Mutant Phenotype Molecular Nature Developmental Function
Achaete (Ac) Proneural cells, prospective sensory bristles Lack of sensory bristles and neurons Transcriptional regulator (bHLH domain) Many functions, incl. patterning around d.v. compartment boundary in wing
apterous (ap) Dorsal compartments of wing and haltere discs Wings and halteres missing Transcriptional regulator (homeodomain) Required for wing (haltere) outgrowth; selector gene
cubitus interruptus (ci) Anterior compartment of each segment Disturbed segmentation Transcriptional regulator (zinc finger domain) Activates wg and dpp in response to hh signaling
decapentaplegic (dpp) In strip of cells anterior to a.p. compartment boundary (see also Zygotic Dorsoventral Class) Abnormal wing patterns Secreted protein (TGF-β superfamily) Morphogen for anteroposterior pattern of wing and haltere
Distalless (Dll) Expressed around leg dorsoventral compartment boundary Loss of legs and antennae Transcriptional regulator (homeodomain) Required for outgrowth of legs and antennae
fringe (fng) Dorsal wing and haltere compartments Loss of wings and halteres Secreted protein Juxtaposition of cells with and without fringe activates wg+
hedgehog (hh) see Zygotic Segment Polarity Class
optomotor-blind (omb) Prospective CNS and epidermal regions Transcriptional regulator Target of dpp in patterning of wing and abdominal segments
scute (sc) Similar to Achaete
spalt (sal) In endoderm and parts of wing imaginal disc Transcriptional regulator (zinc finger domain) Target of dpp in wing patterning
vestigial (vg) In prospective appendages of wing and haltere imaginal discs Loss of wings and halteres Putative transcriptional regulator Specification of wing and haltere as opposed to thorax

Ver também

Disponível em "http://wiki.cecm.usp.br/wiki/index.php?title=Genes_controlling_pattern_formation_in_Drosophila_embryogenesis&oldid=8617"