defined concept of homologous organs

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Presentation transcript:

defined concept of homologous organs Richard Owen, 1843 defined concept of homologous organs Homeotic transformations of organs in plants… “Metamorphosis of Plants” Published by Johan Goethe, 1790

Wild type. APETALA1: PISTILLATA : AGAMOUS: "A" class "B" class "C" class

Wild type. APETALA1: PISTILLATA : AGAMOUS: "A" class "B" class "C" class

AP1 mRNA AG1 mRNA AP1 in AG1 mutant

~550 MYA

plena Shp1/2 Plena clade Ag Far AG clade

Central zone adaxial abaxial apical basal phyllotaxy

Abaxial domain Adaxial domain

adaxial abaxial Lateral primordia formation/polarity: abaxial identity: crabsclaw, YABBY, KANADI - arabidopsis adaxial identity: phantastica - Antirrhinum roughsheath - maize phabulosa - arabidopsis

Wild type Phb McConnell and Barton. 1998. Development 125:2935 1. Ad/ab polarity is needed for lateral expansion 2. Adaxial cells determine initiation of the axial meristem Wild type Phb

Wild Type phabulosa

Dominant Phabulosa/Phavulota mutations HomeoBox- Zipper DNA binding domain START Sterol binding domain

WT Phb

Triple knockout phenotype: Emery et al. 2003. Current Biology, Vol. 13, 1768–1774, Dominant Phb phenotype

Abaxial domain Adaxial domain Boundary required for Later growth of leaf blade Abaxial domain Adaxial domain

Abaxial determinants: Development 126, 4117-4128 (1999) Members of the YABBYgene family specify abaxial cell fate in Arabidopsis Kellee R. Siegfried1,*, Yuval Eshed1, Stuart F. Baum1, Denichiro Otsuga2, Gary N. Drews2 and John L. Bowman1,‡ KANADI regulates organ polarity in Arabidopsis Randall A. Kerstetter, Krista Bollman, R. Alexandra Taylor, Kirsten Bomblies & R. Scott Poethig 2001 Nature 411:706-8

Dominant Phabulosa/Phavulota mutations HomeoBox- Zipper DNA binding domain START Sterol binding domain

Carrington and Ambros 2003, Science 301:337

PTGS pathway in eukaryotes Carpel Factory (DCL1) Adapted from Williams and Rubin 2001, PNAS

Jacobsen et al. 1998. Development 126:5231

AGO is a component of the RISC RNA induced silencing complex Kidner and Martienssen, Nature. 2004 Mar 4;428(6978):81-4 Argonaut phenotypes AGO is a component of the RISC RNA induced silencing complex

miR165 WT PHB WT miR165 ago PHB ago

Abaxial domain Adaxial domain Boundary required for Later growth of leaf blade Abaxial domain Adaxial domain

Asymmetric expression of YAB3 requires KANADI function

PHABULOSA expression in the radialized (adaxialized) KANADI triple mutant

In tomato, YABBY is restricted to cytoplasmic dense cells at the margins of the ad/ab boundary

Emery et al. 2003. Current Biology, Vol. 13, 1768–1774,

Bohmert et al EMBO J 17:170-180

Meristem initiation/maintenance: Knotted -maize shoot apical meristemless -arabidopsis Meristem size: clavata1 clavata2 clavata3 Lateral organ polarity: Abaxial genes: crabsclaw, YABBY Kanadi Adaxial genes: phabulosa Phavoluta Revoluta Organ number and polarity: Carpel Factory Argonaute

Dominant Phabulosa/Phavulota mutations HomeoBox- Zipper DNA binding domain START Sterol binding domain

Bohmert et al EMBO J 17:170-180

adaxial abaxial Lateral primordia formation/polarity: abaxial identity: crabsclaw, YABBY, KANADI - arabidopsis adaxial identity: phantastica - Antirrhinum roughsheath - maize phabulosa - arabidopsis

Carrington and Ambros 2003, Science 301:337

Wild type. APETALA1: PISTILLATA : AGAMOUS: "A" class "B" class "C" class

AP1 mRNA AG1 mRNA AP1 in AG1 mutant

Dominant Phabulosa/Phavulota mutations HomeoBox- Zipper DNA binding domain START Sterol binding domain

Phv Adaxial domain Domain boundary Required for lateral growth

WT clv3 clv3 Fletcher et al. 1999. Science 283:1911-14

KANADI expression in the abaxial domain

Development 126, 4117-4128 (1999) Members of the YABBYgene family specify abaxial cell fate in Arabidopsis Kellee R. Siegfried1,*, Yuval Eshed1, Stuart F. Baum1, Denichiro Otsuga2, Gary N. Drews2 and John L. Bowman1,‡

Development 126, 4117-4128 (1999) Members of the YABBYgene family specify abaxial cell fate in Arabidopsis Kellee R. Siegfried1,*, Yuval Eshed1, Stuart F. Baum1, Denichiro Otsuga2, Gary N. Drews2 and John L. Bowman1,‡

Current Biology 2001, 11:1251–1260 Establishment of polarity in lateral organs of plants Yuval Eshed*, Stuart F. Baum, John V. Perea and John L. Bowman