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HC70AL Final Presentation Chris McQuilkin June 4th, 2009 Gene One: AT4G36540 • A transcription factor involved in DNA binding • A bHLH Gene – “basic Helix-Loop-Helix” refers to the structure of the protein – bHLH genes are found in Eukaryotes and are highly conserved across species AT4G36540 What is the Structure of the Gene? T-DNA Insertion LB Site Translational Start Codon Intron 1 116 Translational Stop Codon Forward Primer 288 Exon 1 85 Intron 2 180 Exon 2 Total length= 1,714 base pairs 92 Intron 3 207 Exon 3 91 Reverse Primer Intron 4 134 Exon 4 91 93 Exon 5 331 Where is the Gene Active? CM Arabidopsis RT-PCR Gene: AT4G36540 (Leaf and Silique cDNA) GDNA ScDNA LcDNA 100 bp •Why is there no band in the positive control? RT-PCR Forward Primer Intron Forward Primer Ch al az al Se ed Ch Co al at az /G al lo Se bu ed la r Co St at ag /P e re gl ob ul ar Fl St or ag al e Bu d/ Re pr od uc tiv e Le af /V eg et at iv O vu e le /R Se ep ed ro /2 du Se 4ct ed iv H lin r e Po g/ s 3 tD Fe ay rt s ili Af za te tio r n Im bi bi tio n (3 D AI ) St em /V eg et Se at ed iv /P e re gl ob ul ar St ag e mRNA Accumulation Where is the Gene Active? mRNA accumulation 2500 2000 1500 Series1 1000 500 0 Plant region/ stage of development Where is the Gene Active? Promoter Cloning Strategy of Promoter Activity Analysis Arabidopsis Genomic DNA •PCR amplification of upstream region •With Gene- specific Primers •And High Fidelity DNA Polymerase PCR Product pENTR /D-TOPO vector Ligation : Population of Recombinant Plasmid (vector+PCR product) and NON-recombinant plasmid (vectory only) Transformation of competent E.coli cells Screening for E.coli cells harboring recombinant plasmid Confirmed Recombinant plasmid DNA: Verifying the authenticity of recombinant plasmid DNA by Restriction Enzyme Digestion DNA sequences : verification of the cloned Promoter Region by Sequencing Analysis. Sequence Analysis and confirmed identity of the cloned upstream region Recombinant Plasmid DNA + BetaGluronidase (GUS) gene carrying T-DNA Vector Krista Templeton and Auni Hovanesian, HC70AL 2008 Promoter Cloning PCR of AT4G3540 Promoter Region 1 hr 120 volts *Two fragments were amplified by PCR ~1.7 kb= Expected Size of PCRamplified promoter ~0.8 kb= Unexpected PCR product Positive Control iProof Polymerase 1 kb Ladder Promoter Cloning Expected Plasmid alone= 2.5 kb AscI-Digested pENTR Plasmid DNA From Six E. coli Colonies Expected Plasmid + Promoter= 4.2kb Observed= 2.5kb and 3.5 kb Gene one: Genotyping 1 hr, 120 volts Wild-type Control Gene one: Genotyping 04/16/2009 1 hr, 120 volts Why are there two bands in the Lanes 1 and 3? ~1000 base pairs ~900 base pairs ~250 base pairs Hemizygous Hemizygous ~250 bases Homozygous Hemizygous What is the expected size of the T-DNA band? What is the expected size of the Wild-Type Band? 887 Bases Concatamers T-DNA Insertion Site LB LB Reverse Primer Translational Start Codon Forward Primer Intron 1 119 116 288 Exon 1 85 Intron 2 180 Exon 2 92 Translational Start Codon Intron 3 207 Exon 3 91 Intron 4 134 Exon 4 91 93 Exon 5 334 331 Nomarski Observation Mutant Embryo and wild-type embryo show no phenotypic differences Nomarski Observation Mutant seed coat and wild- type seed coat show no phenotypic differences Results • Three hemizygous and one homozygous T-DNA plants were identified – Two bands were observed in each of the lanes containing DNA with a T-DNA insert • Gene AT4G36540 mRNA accumulation was observed in both the leaf and silique of Arabidopsis Results • The promoter did not insert into any of the E. coli plasmids that were screened. – Four of the colonies contained an unidentified insert about 1 kb long • No phenotypic changes were observed in either the hemizygous or homozygous TDNA Arabidopsis plants using Nomarski Observation Conclusion • AT4G36540 is not lethal, or there may be another DNA sequence that codes for the same protein • Although no phenotypic differences were observed in the seed coat or embryo using Nomarski, there could be differences that are more subtle or appear at different stages of development What next? • Look further for phenotypic changes in Arabidopsis mutants—examine different tissues and more stages of development • Sequence the unidentified DNA fragment taken up by the E. coli C600 plasmids • Repeat PCR of the promoter – Excise the band containing recombined plasmid DNA, and repeat transformation – If a promoter is identified, use GUS to study where the gene is expressed • Grow more plants from the identified mutant lines • Repeat sequencing reaction of region between LB and T-DNA primers to confirm location of the T-DNA insert Gene Two: AT1G75240 • A homeobox gene • Homeobox genes regulate development and cell differentiation – A homeobox is a sequence • They are found in animals, plants, and fungi AT1G75240 What Is The Structure of the Gene? Predicted T-DNA Insert LB Reverse Primer Forward Primer 330 77 97 927 Translational Start Codon Total Length: 1,685 Base Pairs 254 Translational Stop Codon Where is the Gene Active? AT1G75240 mRNA in Arabidopsis Leaf and Silique 1 hr 120 volts Leaf cDNA Silique cDNA Tubulin mRNA AT1G75240 mRNA Gene is active in the silique but not the leaf 3500 3000 2500 2000 1500 1000 500 0 Developmental Stages Seed/Post-Mature Green Stage (18- Seed/Mature Green Stage Seed/Cotyledon Stage (7-8DAP) Ovule/Reproductive Embryo Proper/Mature Embryo Proper/Heart Stage Average mRNA Accumulation Where is the Gene Active? mRNA Accumulation of AT1G75240 Series1 Genotyping 100 bp LBb1 Control WT Control Arabidopsis 12 Arabidopsis 11 Arabidopsis 10 Arabidopsis 9 Arabidopsis 8 Arabidopsis 7 Arabidopsis 6 Arabidopsis 5 Arabidopsis 4 Arabidopsis 3 Arabidopsis 2 Arabidopsis 1 100 bp Results • All the plants screened were wild-type Conclusion • The chance of getting all wild-type plants is extremely low, so it is possible that the Salk Institute sent the wrong kind of plant Thank you! • • • • • • • Anhthu Bui Brandon Chen Bob Goldberg Daisy Robinton Ingrid Nelson Kristin Gill Min Chen SRB Contig Sequencing Contig Length: 50.7 KB Approach • Contig entered into three online databases that look for predicted genes: FGENESH, GENSCAN, and GeneMark 2,000 1 240 396 - 507 1134 - 1442 628- 729 759-846 999-1097 396-507 1134-1642 1324-1428 999-1092 1901 - 18431901- 459- 572 281- 427 2,001 3272 -2550 -2550 -2086 2126-2351 2990 2894 3046 4,000 Approach • Predicted Genes were entered into a BLAST search to see if the predicted gene matched Expressed Sequence Tags (ESTs) found in other species Approach • Whole Contig was searched for DNA repeats Results: GENSCAN Accession Number E-value Description 1 BP033723.1 1e-110 Lotus Japonicus 2 FN014331.1 1e-52 Petunia axillaris subsp. axillaris pool of root and petal tissue 3 GO259467 3e-26 Tissue from peanut Arachis hypogaea 4 EX522455.1 0.0 Trichome from stem of Medicago sativa 5 FK023593.1 8e-77 cDNA from Glycine max (soy bean) Predicted Gene (BLASTN) Results: GENSCAN Predicted Protein (tBLASTn) Accession Number E-value Description 1 Y18169 5e-70 Pisum sativum mitochondrial ccb248 gene and partial rps7 gene. 2 FM179380 2e-10 Vitis vinifera complete mitochondrial genome, cultivar Pinot noir clone ENTAV115 3 L40816 3e-35 4 DQ008791 5e-60 Thottea tomentosa large subunit ribosomal RNA gene, partial sequence; mitochondrial 5 AC144406 4e-14 Medicago truncatula clone mth2-5h18, complete sequence. 2e-41 hypothetical protein NitaMp002 [Nicotiana tabacum]. Predicted Protein (BLASTp) 4 5 YP_173352 No significant match Results: FGENESH Accession Number E-value Description 1 EX527626 0.0 MTGland_A031_2007-05-22/MTGlandA031_B09_039_1 Medicago truncatula A17 glandular trichome Medicago truncatula cDNA, mRNA sequence 2 CD721224 2e-25 Chardonnay Vitis vinifera 3 GD544655 1e-40 Scarlet Runner Bean globular-stage suspensor region 5 FN014331 9e-88 Pool of root and petal tissue of Petunia axillaris 6 FF554629.1 9e-143 Vigna Unguiculata 1 Y18169 18e-118 Pisum sativum mitochondrial ccb248 gene and partial rps7 gene. 6 AC144406 8e-18 Medicago truncatula clone mth2-5h18, complete sequence CAB43024 2e-118 cytochrome c biogenesis protein [Pisum sativum] Predicted Gene (BLASTn) 4 Predicted Protein (tBLASTn) Predicted Protein (BLASTp) 1 Results: GeneMark Predicted Protein (tBLASTn) Accession Number (of Lowest E-Value) E-value Description 1 AC192958 1e-13 Medicago truncatula chromosome 2 BAC clone mte1-45m19, complete sequence 2 AC147537 1e-23 Medicago truncatula clone mth2-133k2, complete sequence. 3 EX527626 3e-113 Glandular trichome Medicago truncatula 13 BA000042 1e-18 Nicotiana tabacum mitochondrial DNA, complete genomeLength=430597 15 L40816 5e-25 Glycine max mitochondrion polymorphic marker DNA sequence. 16 L40816 7e-46 Glycine max mitochondrion polymorphic marker DNA sequence. 17 AC145156 1e-50 Medicago truncatula clone mth2-7h6, complete sequence. 18 DQ647831 1e-108 Chlorokybus atmophyticus large subunit ribosomal RNA gene, partial sequence; mitochondrial. Results: Gene Mark 19 BA000042 1e-41 Nicotiana tabacum mitochondrial DNA, complete genome. 20 AP004975 1e-26 Lotus japonicus genomic DNA, chromosome 5, clone: LjT21J12, TM0158, complete sequence. 21 AP004975 7e-17 Lotus japonicus genomic DNA, chromosome 5, clone: LjT21J12, TM0158, complete sequence. 23 XM_002336124 2e-12 Populus trichocarpa predicted protein, mRNA. 32 FM179380 5e-29 Vitis vinifera complete mitochondrial genome, cultivar Pinot noir clone ENTAV115. 33 AC144406 7e-29 Medicago truncatula clone mth2-5h18, complete sequence.