Mudanças entre as edições de "Genes controlling pattern formation in Drosophila embryogenesis"
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| ''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'' | | ''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'' | ||
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| + | |+ '''Zygotic Anteroposterior Gap Class''' | ||
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| + | ! Gene !! Expression Pattern !! Mutant Phenotype !! Molecular Nature !! Developmental Function | ||
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| + | | ''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 | ||
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| + | | ''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'' | ||
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| + | | ''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'' | ||
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| + | | ''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'' | ||
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| + | | ''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'' | ||
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| + | | ''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'' | ||
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| + | | ''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 | ||
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| + | | ''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'' | ||
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Edição das 17h24min de 24 de novembro de 2006
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
