Plant Cell Applied Biosystems SYBR(R) Cells-to-CT(TM) Kits
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via ISI Web of Science (187)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bensen, R. J.
Right arrow Articles by Briggs, S. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bensen, R. J.
Right arrow Articles by Briggs, S. P.
Agricola
Right arrow Articles by Bensen, R. J.
Right arrow Articles by Briggs, S. P.

THE PLANT CELL, Vol 7, Issue 1 75-84, Copyright © 1995 by American Society of Plant Biologists


RESEARCH ARTICLES

Cloning and Characterization of the Maize An1 Gene

R. J. Bensen, G. S. Johal, V. C. Crane, J. T. Tossberg, P. S. Schnable, R. B. Meeley and S. P. Briggs
Pioneer Hi-Bred International, Inc., P.O. Box 1004, Johnston, Iowa 50131

The Anther ear1 (An1) gene product is involved in the synthesis of ent-kaurene, the first tetracyclic intermediate in the gibberellin (GA) biosynthetic pathway. Mutations causing the loss of An1 function result in a GA-responsive phenotype that includes reduced plant height, delayed maturity, and development of perfect flowers on normally pistillate ears. The an1::Mu2-891339 allele was recovered from a Mutator (Mu) F2 family. Using Mu elements as molecular probes, an An1-containing restriction fragment was identified and cloned. The identity of the cloned gene as An1 was confirmed by using a reverse genetics screen for maize families that contain a Mu element inserted into the cloned gene and then by demonstrating that the insertion causes an an1 phenotype. The predicted amino acid sequence of the An1 cDNA shares homology with plant cyclases and contains a basic N-terminal sequence that may target the An1 gene product to the chloroplast. The sequence is consistent with the predicted subcellular localization of AN1 in the chloroplast and with its biochemical role in the cyclization of geranylgeranyl pyrophosphate, a 20-carbon isoprenoid, to ent-kaurene. The semidwarfed stature of an1 mutants is in contrast with the more severely dwarfed stature of GA-responsive mutants at other loci in maize and may be caused by redundancy in this step of the GA biosynthetic pathway. DNA gel blot analysis indicated that An1 is a single-copy gene that lies entirely within the deletion of the an1-bz2-6923 mutant. However, homozygous deletion mutants accumulated ent-kaurene to 20% of the wild-type level, suggesting that the function of An1 is supplemented by an additional activity.


This article has been cited by other articles:


Home page
J HeredHome page
T. L. Slewinski, Y. Ma, R. F. Baker, M. Huang, R. Meeley, and D. M. Braun
Determining the Role of Tie-dyed1 in Starch Metabolism: Epistasis Analysis with a Maize ADP-Glucose Pyrophosphorylase Mutant Lacking Leaf Starch
J. Hered., November 1, 2008; 99(6): 661 - 666.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
G. Chuck, R. Meeley, and S. Hake
Floral meristem initiation and meristem cell fate are regulated by the maize AP2 genes ids1 and sid1
Development, September 15, 2008; 135(18): 3013 - 3019.
[Abstract] [Full Text] [PDF]


Home page
ScienceHome page
A. Boualem, M. Fergany, R. Fernandez, C. Troadec, A. Martin, H. Morin, M.-A. Sari, F. Collin, J. M. Flowers, M. Pitrat, et al.
A Conserved Mutation in an Ethylene Biosynthesis Enzyme Leads to Andromonoecy in Melons
Science, August 8, 2008; 321(5890): 836 - 838.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
R. Jonczyk, H. Schmidt, A. Osterrieder, A. Fiesselmann, K. Schullehner, M. Haslbeck, D. Sicker, D. Hofmann, N. Yalpani, C. Simmons, et al.
Elucidation of the Final Reactions of DIMBOA-Glucoside Biosynthesis in Maize: Characterization of Bx6 and Bx7
Plant Physiology, March 1, 2008; 146(3): 1053 - 1063.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
J. Li, T.-J. Wen, and P. S. Schnable
Role of RAD51 in the Repair of MuDR-Induced Double-Strand Breaks in Maize (Zea mays L.)
Genetics, January 1, 2008; 178(1): 57 - 66.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
D. R. Holding, M. S. Otegui, B. Li, R. B. Meeley, T. Dam, B. G. Hunter, R. Jung, and B. A. Larkins
The Maize Floury1 Gene Encodes a Novel Endoplasmic Reticulum Protein Involved in Zein Protein Body Formation
PLANT CELL, August 1, 2007; 19(8): 2569 - 2582.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
J. Li, L. C. Harper, I. Golubovskaya, C. R. Wang, D. Weber, R. B. Meeley, J. McElver, B. Bowen, W. Z. Cande, and P. S. Schnable
Functional Analysis of Maize RAD51 in Meiosis and Double-Strand Break Repair
Genetics, July 1, 2007; 176(3): 1469 - 1482.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
T. Chung, C. S. Kim, H. N. Nguyen, R. B. Meeley, and B. A. Larkins
The Maize Zmsmu2 Gene Encodes a Putative RNA-Splicing Factor That Affects Protein Synthesis and RNA Processing during Endosperm Development
Plant Physiology, June 1, 2007; 144(2): 821 - 835.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. Prisic and R. J. Peters
Synergistic Substrate Inhibition of ent-Copalyl Diphosphate Synthase: A Potential Feed-Forward Inhibition Mechanism Limiting Gibberellin Metabolism
Plant Physiology, May 1, 2007; 144(1): 445 - 454.
[Abstract] [Full Text] [PDF]


Home page
J Exp BotHome page
E. Bortiri and S. Hake
Flowering and determinacy in maize
J. Exp. Bot., March 3, 2007; (2007) erm015v1.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Bot.Home page
R. Ming, J. Wang, P. H. Moore, and A. H. Paterson
Sex chromosomes in flowering plants
Am. J. Botany, February 1, 2007; 94(2): 141 - 150.
[Abstract] [Full Text] [PDF]


Home page
J BiochemHome page
C. Ikeda, Y. Hayashi, N. Itoh, H. Seto, and T. Dairi
Functional Analysis of Eubacterial ent-Copalyl Diphosphate Synthase and Pimara-9(11),15-Diene Synthase with Unique Primary Sequences
J. Biochem., January 1, 2007; 141(1): 37 - 45.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Bot.Home page
E. R. Valdivia, D. J. Cosgrove, and A. G. Stephenson
Role of accelerated style senescence in pathogen defense
Am. J. Botany, November 1, 2006; 93(11): 1725 - 1729.
[Abstract] [Full Text] [PDF]


Home page
Plant Cell PhysiolHome page
F. Bai and D. A. DeMason
Hormone Interactions and Regulation of Unifoliata, PsPK2, PsPIN1 and LE Gene Expression in Pea (Pisum sativum) Shoot Tips
Plant Cell Physiol., July 1, 2006; 47(7): 935 - 948.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
T.-J. Wen, F. Hochholdinger, M. Sauer, W. Bruce, and P. S. Schnable
The roothairless1 Gene of Maize Encodes a Homolog of sec3, Which Is Involved in Polar Exocytosis
Plant Physiology, July 1, 2005; 138(3): 1637 - 1643.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. P. Briggs and T. Singer
Genetic Networks
Plant Physiology, June 1, 2005; 138(2): 542 - 544.
[Full Text] [PDF]


Home page
GeneticsHome page
F. Chardon, B. Virlon, L. Moreau, M. Falque, J. Joets, L. Decousset, A. Murigneux, and A. Charcosset
Genetic Architecture of Flowering Time in Maize As Inferred From Quantitative Trait Loci Meta-analysis and Synteny Conservation With the Rice Genome
Genetics, December 1, 2004; 168(4): 2169 - 2185.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. Prisic, M. Xu, P. R. Wilderman, and R. J. Peters
Rice Contains Two Disparate ent-Copalyl Diphosphate Synthases with Distinct Metabolic Functions
Plant Physiology, December 1, 2004; 136(4): 4228 - 4236.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
M. Tanurdzic and J. A. Banks
Sex-Determining Mechanisms in Land Plants
PLANT CELL, June 1, 2004; 16(suppl_1): S61 - S71.
[Full Text] [PDF]


Home page
Plant CellHome page
O.-A. Olsen
Nuclear Endosperm Development in Cereals and Arabidopsis thaliana
PLANT CELL, June 1, 2004; 16(suppl_1): S214 - S227.
[Full Text] [PDF]


Home page
Plant CellHome page
Y. Asakura, T. Hirohashi, S. Kikuchi, S. Belcher, E. Osborne, S. Yano, I. Terashima, A. Barkan, and M. Nakai
Maize Mutants Lacking Chloroplast FtsY Exhibit Pleiotropic Defects in the Biogenesis of Thylakoid Membranes
PLANT CELL, January 1, 2004; 16(1): 201 - 214.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
K. M. Arthur, Z. Vejlupkova, R. B. Meeley, and J. E. Fowler
Maize ROP2 GTPase Provides a Competitive Advantage to the Male Gametophyte
Genetics, December 1, 2003; 165(4): 2137 - 2151.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
B. P. May, H. Liu, E. Vollbrecht, L. Senior, P. D. Rabinowicz, D. Roh, X. Pan, L. Stein, M. Freeling, D. Alexander, et al.
Maize-targeted mutagenesis: A knockout resource for maize
PNAS, September 30, 2003; 100(20): 11541 - 11546.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
B. Shen, C. Li, Z. Min, R. B. Meeley, M. C. Tarczynski, and O.-A. Olsen
sal1 determines the number of aleurone cell layers in maize endosperm and encodes a class E vacuolar sorting protein
PNAS, May 27, 2003; 100(11): 6552 - 6557.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
M. Singh, P. E. Lewis, K. Hardeman, L. Bai, J. K. C. Rose, M. Mazourek, P. Chomet, and T. P. Brutnell
Activator Mutagenesis of the Pink scutellum1/viviparous7 Locus of Maize
PLANT CELL, April 1, 2003; 15(4): 874 - 884.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
M. G. Kocsis, P. Ranocha, D. A. Gage, E. S. Simon, D. Rhodes, G. J. Peel, S. Mellema, K. Saito, M. Awazuhara, C. Li, et al.
Insertional Inactivation of the Methionine S-Methyltransferase Gene Eliminates the S-Methylmethionine Cycle and Increases the Methylation Ratio
Plant Physiology, April 1, 2003; 131(4): 1808 - 1815.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
J. R. Dinges, C. Colleoni, M. G. James, and A. M. Myers
Mutational Analysis of the Pullulanase-Type Debranching Enzyme of Maize Indicates Multiple Functions in Starch Metabolism
PLANT CELL, March 1, 2003; 15(3): 666 - 680.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. Huang, R. E. Cerny, Y. Qi, D. Bhat, C. M. Aydt, D. D. Hanson, K. P. Malloy, and L. A. Ness
Transgenic Studies on the Involvement of Cytokinin and Gibberellin in Male Development
Plant Physiology, March 1, 2003; 131(3): 1270 - 1282.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
X. Cui, A.-P. Hsia, F. Liu, D. A. Ashlock, R. P. Wise, and P. S. Schnable
Alternative Transcription Initiation Sites and Polyadenylation Sites Are Recruited During Mu Suppression at the rf2a Locus of Maize
Genetics, February 1, 2003; 163(2): 685 - 698.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
J. Shi, H. Wang, Y. Wu, J. Hazebroek, R. B. Meeley, and D. S. Ertl
The Maize Low-Phytic Acid Mutant lpa2 Is Caused by Mutation in an Inositol Phosphate Kinase Gene
Plant Physiology, February 1, 2003; 131(2): 507 - 515.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
L. Hubbard, P. McSteen, J. Doebley, and S. Hake
Expression Patterns and Mutant Phenotype of teosinte branched1 Correlate With Growth Suppression in Maize and Teosinte
Genetics, December 1, 2002; 162(4): 1927 - 1935.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
S. Fu, R. Meeley, and M. J. Scanlon
empty pericarp2 Encodes a Negative Regulator of the Heat Shock Response and Is Required for Maize Embryogenesis
PLANT CELL, December 1, 2002; 14(12): 3119 - 3132.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
C. Schnee, T. G. Kollner, J. Gershenzon, and J. Degenhardt
The Maize Gene terpene synthase 1 Encodes a Sesquiterpene Synthase Catalyzing the Formation of (E)-beta -Farnesene, (E)-Nerolidol, and (E,E)-Farnesol after Herbivore Damage
Plant Physiology, December 1, 2002; 130(4): 2049 - 2060.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
S. E. Lid, D. Gruis, R. Jung, J. A. Lorentzen, E. Ananiev, M. Chamberlin, X. Niu, R. Meeley, S. Nichols, and O.-A. Olsen
The defective kernel 1 (dek1) gene required for aleurone cell development in the endosperm of maize grains encodes a membrane protein of the calpain gene superfamily
PNAS, April 16, 2002; 99(8): 5460 - 5465.
[Abstract] [Full Text] [PDF]


Home page
J. Bacteriol.Home page
T. Dairi, Y. Hamano, T. Kuzuyama, N. Itoh, K. Furihata, and H. Seto
Eubacterial Diterpene Cyclase Genes Essential for Production of the Isoprenoid Antibiotic Terpentecin
J. Bacteriol., October 15, 2001; 183(20): 6085 - 6094.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
C. M. Papa, N. M. Springer, M. G. Muszynski, R. Meeley, and S. M. Kaeppler
Maize Chromomethylase Zea methyltransferase2 Is Required for CpNpG Methylation
PLANT CELL, August 1, 2001; 13(8): 1919 - 1928.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
M. M. Kater, J. Franken, K. J. Carney, L. Colombo, and G. C. Angenent
Sex Determination in the Monoecious Species Cucumber Is Confined to Specific Floral Whorls
PLANT CELL, March 1, 2001; 13(3): 481 - 493.
[Abstract] [Full Text]


Home page
Plant Physiol.Home page
V. L. Chandler and S. Wessler
Grasses. A Collective Model Genetic System
Plant Physiology, March 1, 2001; 125(3): 1155 - 1156.
[Full Text]


Home page
Plant Physiol.Home page
M. Freeling
Grasses as a Single Genetic System. Reassessment 2001
Plant Physiology, March 1, 2001; 125(3): 1191 - 1197.
[Full Text]


Home page
Plant Physiol.Home page
S. L. Blauth, Y. Yao, J. D. Klucinec, J. C. Shannon, D. B. Thompson, and M. J. Guiltinan
Identification of Mutator Insertional Mutants of Starch-Branching Enzyme 2a in Corn
Plant Physiology, March 1, 2001; 125(3): 1396 - 1405.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. R. Wessler
Plant Transposable Elements. A Hard Act to Follow
Plant Physiology, January 1, 2001; 125(1): 149 - 151.
[Full Text]


Home page
Proc. Natl. Acad. Sci. USAHome page
A. M. Casa, C. Brouwer, A. Nagel, L. Wang, Q. Zhang, S. Kresovich, and S. R. Wessler
Inaugural Article: The MITE family Heartbreaker (Hbr): Molecular markers in maize
PNAS, August 29, 2000; 97(18): 10083 - 10089.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
S. D. Lahiri and L. A. Allison
Complementary Expression of Two Plastid-Localized sigma -Like Factors in Maize
Plant Physiology, July 1, 2000; 123(3): 883 - 894.
[Abstract] [Full Text]


Home page
J. Biol. Chem.Home page
H. Kawaide, T. Sassa, and Y. Kamiya
Functional Analysis of the Two Interacting Cyclase Domains in ent-Kaurene Synthase from the Fungus Phaeosphaeria sp. L487 and a Comparison with Cyclases from Higher Plants
J. Biol. Chem., January 28, 2000; 275(4): 2276 - 2280.
[Abstract] [Full Text] [PDF]


Home page
Plant Physiol.Home page
D. N.P. Doan, H. Rudi, and O.-A. Olsen
The Allosterically Unregulated Isoform of ADP-Glucose Pyrophosphorylase from Barley Endosperm Is the Most Likely Source of ADP-Glucose Incorporated into Endosperm Starch
Plant Physiology, November 1, 1999; 121(3): 965 - 975.
[Abstract] [Full Text]


Home page
Plant Physiol.Home page
V. Walbot
Genes, Genomes, Genomics. What Can Plant Biologists Expect from the 1998 National Science Foundation Plant Genome Research Program?
Plant Physiology, April 1, 1999; 119(4): 1151 - 1156.
[Full Text]


Home page
Plant Physiol.Home page
C. Linnestad, D. N.P. Doan, R. C. Brown, B. E. Lemmon, D. J. Meyer, R. Jung, and O.-A. Olsen
Nucellain, a Barley Homolog of the Dicot Vacuolar-Processing Protease, Is Localized in Nucellar Cell Walls
Plant Physiology, December 1, 1998; 118(4): 1169 - 1180.
[Abstract] [Full Text]


Home page
Plant Physiol.Home page
M. W. Smith, S. Yamaguchi, T. Ait-Ali, and Y. Kamiya
The First Step of Gibberellin Biosynthesis in Pumpkin Is Catalyzed by at Least Two Copalyl Diphosphate Synthases Encoded by Differentially Regulated Genes
Plant Physiology, December 1, 1998; 118(4): 1411 - 1419.
[Abstract] [Full Text]


Home page
JCBHome page
L. M. Roy and A. Barkan
A SecY Homologue Is Required for the Elaboration of the Chloroplast Thylakoid Membrane and for Normal Chloroplast Gene Expression
J. Cell Biol., April 20, 1998; 141(2): 385 - 395.
[Abstract] [Full Text] [PDF]


Home page
Genes Dev.Home page
G. Chuck, R. B. Meeley, and S. Hake
The control of maize spikelet meristem fate by the APETALA2-like gene indeterminate spikelet1
Genes & Dev., April 15, 1998; 12(8): 1145 - 1154.
[Abstract] [Full Text]


Home page
Proc. Natl. Acad. Sci. USAHome page
J. Bohlmann, G. Meyer-Gauen, and R. Croteau
Plant terpenoid synthases: Molecular biology and phylogenetic analysis
PNAS, April 14, 1998; 95(8): 4126 - 4133.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
O.-A. Olsen
Endosperm Developments
PLANT CELL, April 1, 1998; 10(4): 485 - 488.
[Full Text]


Home page
Proc. Natl. Acad. Sci. USAHome page
E. H. Coe
Potentials of the National Corn Genome Initiative
PNAS, March 3, 1998; 95(5): 2029 - 2032.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
E. Babiychuk, M. Fuangthong, M. Van Montagu, D. Inze, and S. Kushnir
Efficient gene tagging in Arabidopsis thaliana using a gene trap approach
PNAS, November 11, 1997; 94(23): 12722 - 12727.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
H. Kawaide, R. Imai, T. Sassa, and Y. Kamiya
ent-Kaurene Synthase from the Fungus Phaeosphaeria sp. L487. cDNA ISOLATION, CHARACTERIZATION, AND BACTERIAL EXPRESSION OF A BIFUNCTIONAL DITERPENE CYCLASE IN FUNGAL GIBBERELLIN BIOSYNTHESIS
J. Biol. Chem., August 29, 1997; 272(35): 21706 - 21712.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
J. Bohlmann, C. L. Steele, and R. Croteau
Monoterpene Synthases from Grand Fir (Abies grandis). cDNA ISOLATION, CHARACTERIZATION, AND FUNCTIONAL EXPRESSION OF MYRCENE SYNTHASE, (-)-(4S)-LIMONENE SYNTHASE, AND (-)-(1S,5S)-PINENE SYNTHASE
J. Biol. Chem., August 29, 1997; 272(35): 21784 - 21792.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
P. Urban, C. Mignotte, M. Kazmaier, F. Delorme, and D. Pompon
Cloning, Yeast Expression, and Characterization of the Coupling of Two Distantly Related Arabidopsis thaliana NADPH-Cytochrome P450 Reductases with P450 CYP73A5
J. Biol. Chem., August 1, 1997; 272(31): 19176 - 19186.
[Abstract] [Full Text] [PDF]


Home page
ScienceHome page
M. Frey, P. Chomet, E. Glawischnig, C. Stettner, S. Grün, A. Winklmair, W. Eisenreich, A. Bacher, R. B. Meeley, S. P. Briggs, et al.
Analysis of a Chemical Plant Defense Mechanism in Grasses
Science, August 1, 1997; 277(5326): 696 - 699.
[Abstract] [Full Text]


Home page
Proc. Natl. Acad. Sci. USAHome page
J. Vicente-Carbajosa, S. P. Moose, R. L. Parsons, and R. J. Schmidt
A maize zinc-finger protein binds the prolamin box in zein gene promoters and interacts with the basic leucine zipper transcriptional activator Opaque2
PNAS, July 8, 1997; 94(14): 7685 - 7690.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
B. S. Vogel, M. R. Wildung, G. Vogel, and R. Croteau
Abietadiene Synthase from Grand Fir (Abies grandis). cDNA ISOLATION, CHARACTERIZATION, AND BACTERIAL EXPRESSION OF A BIFUNCTIONAL DITERPENE CYCLASE INVOLVED IN RESIN ACID BIOSYNTHESIS
J. Biol. Chem., September 20, 1996; 271(38): 23262 - 23268.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page