Presentation on theme: "Cacao BAC Library Construction and Physical Mapping."— Presentation transcript:
Cacao BAC Library Construction and Physical Mapping
Tissue Harvesting 50 grams Young, expanding leaves were harvested after 12h of dark period
Nuclei Isolation Chromosomal Band (Large in-tact HMW DNA) Lambda HMW DNA ladder 50 kb >500kb
Serial Digest with HindIII Plugs were subject to a serial partial digestion using HindIII for 20 minutes varying the amount of enzyme. The ideal amount produces a smear from 100kb to 350kb. 1.5U HindIII for 20 was chosen for this library kb 100kb
First Size Selection The gel section removed was not subject to EtBr staining and UV exposure. The DNA in the size range from 150kb to 350kb was cut into 3 sections and loaded into the second size selection gel. 350kb 100kb
Second Size Selection The center part of the gel consists of Low Melting Point Agarose. The DNA migrates into the LMP removing small, trapped fragments and will be eluted for ligation and cloning.
Recombinant Colonies Blue/White Screening: White colonies contain BAC vector + insert, Blue colonies vector with no insert
Automated Colony Arraying: Genetix Q-Bot
BAC Characterization Gel 1 Insert Vector 96 Random BAC clones were digested with a rare cutter and resolved by PFGE for insert size determination
BAC Characterization Gel 2
Insert Size Distribution Insets range from 60kb-450kb Average insert size is 140kb 0% Empty Vectors
Next Steps Decondense 384-well plates to 96-well format Test different restriction enzymes to determine which combination gives the most bands per clone Optimize protocol for each BAC library Begin High-Throughput Fingerprinting
Construction of Physical Map of Cacao High-Information Content Fingerprinting (HICF) Technique: Restriction Digestion SNaPshot Labeling Capillary Electrophoresis Fragment Analysis and Assembly
BAC library DNA extraction DNA digestion DNA Labeling Fragment analysis FPC Capillary Electrophoresis Labeled DNA samples run on 3730 DNA analyzer DNA extracted from BAC library using a 96 well alkaline-lysis miniprep 5-enzyme restriction digest of BAC DNA Digested DNA is labeled with 4 fluorescent dyes (FingerPrinted Contigs) software OVERVIEW
BAC Fingerprinting: Restriction Digest and SNaPshot Labeling HindIII - Green XbaI - Yellow BamHI - Blue XhoI - Red HaeIII – blunt ends AA TTCGA GATCC GG TCGAG TC AGATC These enzymes may change once the protocol is optimized; but the overhangs would be the same.
Raw data from capillary electrophoresis processed by GeneMapper. High-throughput and automated High level of accuracy ABI3730 DNA Analyzer
Samples plot data is exported to be further analyzed in FPMiner.
Batch data analysis in FPMiner Fragments are assigned a size and converted to a digitized fingerprint for contig assembly
Example of digitized fingerprint data in FPC. This data is the contig (clones assembled because of similar banding patterns) of one of the two control clones we use in each plate.
Milestones and Timeline BAC Library Construction – 1 st BAC library (HindIII) Completed – 2 nd BAC library (EcoRI) Completed – 3 rd BAC library Completed Preliminary data collection – In progress Begin fingerprinting of HindIII BAC – September 8, 2008 – Total number of clones to fp: 36,864 – CUGI will process 4,608 clones per week Wetlab portion of the Physical Map of the HindIII BAC library: Estimated completion – December 1, 2008 Data analysis portion of the Physical Map available WEBFPC : Estimated completion – January 1, 2009