Presentation is loading. Please wait.

Presentation is loading. Please wait.

Microarray data analysis towards the understanding the role of hzy in the formation of rhabdomeres Ashwini Oke School of Informatics, Indiana University.

Similar presentations


Presentation on theme: "Microarray data analysis towards the understanding the role of hzy in the formation of rhabdomeres Ashwini Oke School of Informatics, Indiana University."— Presentation transcript:

1 Microarray data analysis towards the understanding the role of hzy in the formation of rhabdomeres Ashwini Oke School of Informatics, Indiana University

2 Drosophila compound eye 2

3 Rhabdomeres carry out the light reaction Montell, C. 1999 3

4 Formation ? ? InitiationElongationMaintenance 4

5 hzy is required for rhabdomere formation and phototransduction Development 130, 4383-4392 (2003) 5

6 hzy is a transcription factor 6

7 The phototransduction pathway The EMBO Journal (2001) 20, 4414–4422, doi:10.1093/emboj/20.16.4414 7

8 Known targets of hzy 8

9 Goals  Identify targets of hzy using oligonucleotide expression arrays  Determine the stage of rhabdomere formation that requires hzy  Identify DNA binding site for hzy  Understand the regulation of hzy itself 9

10 Identifying regulatory targets of hzy 10

11 Microarray design www.scq.ubc.ca/wp-content/cDNAarray.gif DGRC-2 Oligonucleotide Arrays Genotypes: WildType - cnbw Mutant - hzy - otd;hzy Time Points: 48 hr APF 72 hr APF 96 hr APF Replicates: 4 independent samples for each time point 11

12 DGRC-2 arrays ooooooooooooooooooo Probes ~14,400 probes representing 93.5% of the genome Negative Controls Blank Spotting_Solution Exogenous targets Positive Controls Housekeeping genes 12

13 tiff image from the scanner 13

14 GenePix Pro records spot intensities 14

15 GenePix Pro creates.gpr file 15

16 Analysis workflow R2.5.1 Bioconductor Packages: LIMMA, OLIN, MARRAY 16

17 Preprocessing Scanned Image Heat PlotDensity plot 17

18 Normalization A = log 2 average intensity for the two channels M = log ratio of intensities for the two channels Genes Blank Spotting Solution Arabidopsis 18

19 Normalization within array LOESS Local polynomial regression fit 19

20 Normalization between arrays Rawwithin array normalization between arrays normalization LIMMA: Linear models for Microarray Data 20

21 Density Plots after normalizations 21

22 Differential analysis 22

23 Volcano plot 23

24 at 72 hr APFat 96 hr APF (12 total)(28 total) GeneMP Gbeta76C-3.750 ninaC-3.650 Arr2-3.410.00002 Trp-2.160.00011 CG8889-2.680 CG31313-2.350.00002 TotB-2.50 nimB2-2.250.00002 CG5172-2.840.00001 PIP82-2.120.00002 Osi18-2.450.00004 CG10953-2.350.00038 24 GeneMP Rh6-4.941.00E-05 Rh2-5.133.00E-05 Arr1-3.257.00E-05 Trp-2.750.00015 Gbeta76C-4.120.00021 CG2650-3.565.00E-05 Ank2-2.210.00018 Trpl-6.513.00E-05 CG8889-2.640.00029 CG42330-10.750.00329 rdga-2.550.00452 Sr-CI-2.650.00028

25 Gene Ontology GO Database provides a vocabulary to describe gene and gene products  Cellular Component Eg : Cytoplasmic, Nuclear, plasma membrane  Molecular Function Eg : Enzyme activity, protein binding  Biological Process Eg : Apoptosis, cell adhesion, phototransduction 25

26 Classifying genes by GO At 72 hr APF At 96 hr APF 26

27 otd : Another transcription factor regulating rhabdomere formation cnbw hzy;otd otdhzy cnbw 27

28 Results from microarray analysis of hzy;otd double mutant 28

29 hzy is required during elongation 29 Time point48 hr APF72 hr APF96 hr APF # down regulated genes 01228 EM data No difference between cnbw and hzy hzy mutant has irregular rhabdomeres hzy mutant has malformed rhabdomeres

30 Identifying DNA binding site for hzy 30

31 hzy has been shown to bind to a motif upstream of eyeG  Development 130, 4383-4392 (2003) 31 TAATNNNATTA

32 MEME MEME is a tool for discovering motifs in a group of related DNA or protein sequences Primary targets of hzy should have a conserved binding site in their promoter region 32

33 Motif search : 72 APF targets meme 72.fas -dna -nmotifs 5 -mod zoops -revcomp -minw 3 -maxw 15 Down regulated genes 33

34 A true motif should be conserved  For each of the hzy targets at 72 hr APF, find orthologs in other groups of Drosophila  Retrieve 500 b upstream of each gene  Run MEME on promoter regions from each specie 34

35 Motif is conserved across orthologs 35

36 Understanding the regulation of hzy 36

37 Locating the promoter region 1.4 kb 0.8 kb Apitz, H. 2002. Dros.Inf.Serv.85:118-120. 37

38 Promoter testing with Gal4-UAS system X Gal4UASReporterPromoter 38 ElementResult 0.8 kb upstream of hzyEye specific GFP expression 1.4 kb upstream of hzyGFP in eye and some other organs

39 Conserved regions 39

40 Future Directions 40  RT PCR to confirm targets  Search hzy promoter region for known TFBS

41 Thank you 41  Dr. Andrew Zelhof  Dr. Haixu Tang  Dr. Qunfeng Dong  Monalisa Mishra PhD  Andreas Rechsteiner PhD  Jacqueline Lopez


Download ppt "Microarray data analysis towards the understanding the role of hzy in the formation of rhabdomeres Ashwini Oke School of Informatics, Indiana University."

Similar presentations


Ads by Google