1 / 35

Indrani Datta Maria Gutierrez Jessica Blicharski Mentors : Dr. Shailesh Lal and Dr. Gautam Singh

Bioinformatics and Molecular Processes for the Discovery, Identification, and Cataloguing of Matrix Attachment Regions(Mars) & Helitrons. Indrani Datta Maria Gutierrez Jessica Blicharski Mentors : Dr. Shailesh Lal and Dr. Gautam Singh.

afia
Télécharger la présentation

Indrani Datta Maria Gutierrez Jessica Blicharski Mentors : Dr. Shailesh Lal and Dr. Gautam Singh

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bioinformatics and Molecular Processes for the Discovery, Identification, and Cataloguing of Matrix Attachment Regions(Mars) & Helitrons Indrani Datta Maria Gutierrez Jessica Blicharski Mentors : Dr. Shailesh Lal and Dr. Gautam Singh

  2. Cloning and Characterization of Sh2 gene from Zea mays ssp. parviglumis & nicaraguensis Maria Gutierrez SIBHI Mid-Term Presentation Oakland University

  3. Zea mays. ssp parviglumis (Teo1) & nicaraguensis (Teo2): Ancestor of Modern Day Maize • Teosinte: Wild grass domesticated by humans • All lineages of maize can be traced back to it’s primitive form Zea mays ssp. Parviglumis • Maize became distinct from Teosinte grass about 9,200 years ago • Cob size has fluctuated in growth 50x over from original 2 cm • Phenotype has changed, but has it’s genotype (as a result of domestication)

  4. Shrunken2 gene • Sh2 gene encodes a key enzyme involved in starch biosynthesis Glucose-1 PO4 ADP- Glucose + ATP → +PP ADP- Glucose Pyrophosphorylase • Null mutation of Sh2 gene, starch is not produced, hence maize kernels appear shrunken and not plump

  5. Shrunken2 gene • Has domestication altered the Sh2 gene of maize? • starch content of corn has increased (nutritional value) • Kernels are no longer covered by a stone-like, hard to digest fruitcase (quality) • Biggest corn ear found is almost 1 foot long (size) !!!

  6. Gene Structure of Shrunken2 Zea Mays 3’ 5’ • Sh2 gene contains 16 exons and 15 introns • Introns range from 150bp to 1,852bp in length • The translation initiation (AUG) and stop codon (UAG) are located in exons 2 and 15, respectively.

  7. A B E D F C The Main Objective of the Project AUG TAA 11 14 15 1 2 4 5 6 9 10 12 13 8 7 3 16 1 • Sh2 gene from Teosinte remains uncharacterized • Design PCR primers from the conserved region of Zea mays Sh2 gene and use them in PCR reactions on genomic DNA isolated from Teosinte (Teo1 and Teo2) • Amplify the cognate genomic sequence of Teo1 and Teo2 • Purify the band after electrophoresis • Sequence the band and compare with the sequence with Sh2 gene of Zea mays

  8. The Project Amplification of Teo1 &Teo2 of 5’ Amplification of B73 sh2 gene Amplification of Teo1 3’ • Amplification of B73 using primers from 5’ and 3’ • Use same primers on Teo1 and Teo2

  9. Expected Results • Sequence DNA of amplification from Teo1, compare it to sh2 sequence of B73 • Use same primer for Teo2 amplification • Determine gene structure of Teo1 and Teo2 by DNA sequencing

  10. Molecular and Genetic Analysis of a Maize Mutant Caused by a Helitron Insertion in Sh2 gene Jessica Blicharski SIBHI Mid-Term Presentation Oakland University

  11. Transposable Elements Gene Disruption Gene Restoration

  12. Helitrons • No duplication of host sequence • Insert between A and T • No terminal repeats • Transposition by rolling circle mechanism • Novel Family of Transposable Elements • Believed to play important role in genomic content of maize • Distinct Features from Class I & II

  13. A B E D F C Helitron insertion into Sh2 gene 3 11 14 15 1 2 4 5 6 9 10 12 13 8 7 1 AUG TAA • Helitron inserts into intron 11 of Sh2 gene • Knocks out gene function • No production of ADP- Glucose Pyrophosphorylase • “Shrunken” phenotype

  14. Restoration of function • Excision of helitron restores wild type phenotype (plump) • Found 4 “revertant” kernels in the field • Planted kernels and extracted genomic DNA from the leaves • Analyzed the extracted DNA using primers flanking the insertion site of the kernels

  15. PCR Analysis of Revertant Kernels • Helitron insertion in sh2 gene is >10,000 bp in length (will not amplify under our PCR parameters • Amplified wild type sized band in all 4 whole revertants • Sequence of the fragments indicated wild type sequence at the site of Helitron insertion • No footprints? 500bp

  16. PCR Analysis of Revertant Kernels Wild Type Sequence at the Site of Helitron Insertion

  17. Interpretation of the PCR Results -/+ sh2/sh2 Sh2/sh2 + Pollen Contamination + Sh2/sh2 PCR Contamination

  18. SNP rules out pollen contamination • sh2-7527 has a single base deletion (SNP) in intron 13 • PCR amplifed and sequenced intron 13 from all the revertants • Rev2’s wild phenotype was due to pollen contamination, but rev’s 1,3, and 4 showed no pollen contamination (contained strain specific SNP in inton 13)

  19. Experiment in Progress……. • Sequence gDNA containing both the site of helitron excision and the SNP in one fragment from the revertants • We are currently designing more PCR primers and optimizing PCR parameters to achieve this objective.

  20. Bioinformatics Processes for Indentification & Cataloguing of Matrix Attachment Regions (Mars) Indrani Datta SIBHI Mid term-Presentation Oakland University

  21. Chromosome: DNA Packing • Eukaryotic DNA is packed into Chromatin • Consists of chromosomal DNA and lots of proteins • Condense the DNA in smallest possible volume • Chromatin fibres are arranged in living cells as independent loops anchored to the nuclear matrix

  22. The Nuclear Matrix • Only 3% of nuclear proteins are the Nuclear Matrix or Scaffold Proteins. • Loops of 11nm fiber are attached to these proteins. • Loop Lengths: 5-120 kb (Average = 50 kb)

  23. Mar: A locus control element that engenders a position independent expression capability upon the associated gene(s) • Mars are 100-1000 bp sequences • Help to bind the chromatin loop to protein network known as nuclear matrix • Potential origin of replication • AT rich regions containing topoisomerase binding site • Sequences rich in transcription binding site • Contain curved DNA • Matrix Attachment Regions exist at the ends of expressed genes

  24. Our Purpose • Search and Obtain Annoted Mars sequences • Trying to find features ( consensus sequences) • By pattern matching with regular expression • Sources can be experiment or Journal paper • Creating a Database of Mars & Helitrons • Display information in a publicly available web site Genebank Background sequence Get Annoted Mars sequences Feature in annoted sequences Count # of occurance of feature in each Mar

  25. Obtaining Mars Sequences • Query the NCBI based on annotation • Retrieve records from Genbank • Sequences from Genomic DNA • Result • 59 records retrieved

  26. Some of the Result

  27. Database Schema • Contain five tables • Lrp ( contain information related to Mars or helitron sequence) • Sequence (contain informaion related to background sequence • Feature ( contain information related to patterns) • Featureloc (contain information related to feature start –stop in lrp) • Reference ( contain information related to journals)

  28. Populate the Database • Populated Sequence table • Contains information of Background sequence • Populated Lrp table • Contain either Mars or Helitron sequence • From background sequence

  29. Pattern matching • Patterns obtained from Journals • 39 regular expression • Tried pattern matching with all lrps • Search with regular expression with in annoted Mars • Result is shown in graph

  30. Pattern Matching Result

  31. Web site (http://genomecluster.secs.oakland.edu/patterns) Web site (http://genomecluster.secs.oakland.edu/patterns)

  32. In progress…… • Normalizing the pattern search result • Insertion of Helitron information in database • Web site will contain more feature information related to Mars & Helitrons

  33. Acknowledgement • Dr.Gautam B.Singh • Dr.Shaliesh Lal • Entire SIBHI Faculty • Guy Lima

  34. References • Singh Gautam B et. Al .Data Mining Algorithm for Discovering Matrix Association Regions(Mars) Proceedings of SPIE, 2000 4057 330-341 • Nikolaev L G et al. Construction of a chromosome specific library of human Mars and mapping of matrix attachment regions on human chromosome 19. Nucleic Acid Res, 1996 24(7)1330:1336 • http://www.plantcell.org/cgi/reprint/11/6/1117.pdf • http://en.wikipedia.org/wiki/Topoisomerase

  35. Thank You Questions ??

More Related