Extending FuGE into other domains Andrew Jones School of Computer Science, University of Manchester

FuGE Status Functional Genomics Experiment-[OM/ML] Milestone 1 release: Sept 2005 –UML (Object Model) –XML Schema Milestone release being tested by MGED for MAGE-2 We are looking at testing it in PSI context –As a basis for GelML and Gel IML –For Investigation structure, sample prep etc.

mzData mzData v 1.05 is the current release Question: How do we integrate mzData into proteome workflows? –Details of sample prep –Other separation techniques FuGE could be used in different ways: –Giving mzData a context within a workflow OR –As a basis for future mzData versions

Experiment retrofitting mzData FuGE can store Software, Equipment, Contact mzData has similar concepts FuGE has Protocol / ProtocolApplication –This is the mechanism for storing parameters and parameter values –Slightly different from parameter definition in mzData There is not always a 1:1 mapping between mzData concept and FuGE concept

An mzData–FuGE hybrid format? mzData could sub-class from FuGE elements Would require some changes in structure –Some would appear relatively arbitrary Few major benefits at this stage, given that current structure is being implemented –May be worth considering for mzData v 2, if FuGE is successful in other domains

Referencing an mzData file with FuGE Protocol ProtocolApplication MaterialExternalData Protocol definition says “See ExternalData file for parameters” (rather than storing params in Protocol) mzData file File format definition Parser will exist to extract data / parameters from mzData file Material can be used to describe the sample. This connects the MS data with a separation workflow inputMaterialoutputData

Referencing an mzData file with FuGE

Referencing an mzData file with FuGE Reference to the Data object that lives elsewhere in the document

Referencing an mzData file with FuGE Reference to the Protocol object:

Referencing an mzData file with FuGE etc…

mzData conclusions Referencing an mzData file from FuGE will give mass spec data a context in a proteome workflow Retrofitting the model is likely to require structural changes –Not likely to be welcomed if it is already being implemented May be benefits for major future revisions using some FuGE concepts –Will be demonstrated by successful deployment of FuGE in other domains

Using FuGE for GelML, Gel IML

Existing Gel Models PEDRo Frank Gibson’s gel extension GELI Gla-PSI model (Jones 2003) AGML ( Swiss 2D PAGE In-house models from software companies … and various others that I’ve forgotten! What features do we want for GelML?

Extending FuGE into a gel model Concepts of FuGE to understand –Protocol / ProtocolApplication –Material –Data Should be extended with more specific types Software and Equipment could be extended –But use of ontology terms may suffice Demo models of gel separation and gel data –Mainly structural, fine details must be worked out in PSI context

Stage 1 - replace FuGE Root … This allows GelML to inherit all FuGE functionality

Stage 2 - represent a gel …

Stage 2 - represent a gel … Extend from FuGE Material type Add whatever attributes required

Stage 3 - represent gel separation A reference to the Gel material on which the separation takes place … closing tags

Example schema for a gel separation A reference to the Gel material on which the separation takes place … closing tags Extend from ProtocolApplication This allows definition of input and output samples

Example schema for a gel separation A reference to the Gel material on which the separation takes place … closing tags Reference the details of the gel used

Example XML for gel separation

Example XML for gel separation Define input materials for the separation Reference to the Material used as input specified elsewhere: etc.

Example XML for gel separation Reference the Protocol that defines this gel separation

Example XML for gel separation Reference the details of the gel used KDa 50000KDa

… Example XML – define output spots Could also define output materials e.g. PhysicalGelSpot

1D Gels Gel1D and GelLane defined separately GelLane has own ProtocolApplication to reference its inputMaterials The separation within a lane, produces PhysicalBands –These can go on for further treatment

Gel data: Gel IML Demo model of gel images and spots –Will demo very simple example here –More complex gel spot model can be discussed Some issues with representing data in XML

Representing a gel image … FuGE.ExternalData allows a reference to an external file Could give additional attributes by extending this base type

Example Gel Image XML Note: Pixel sizes are in fact redundant (this could be deduced from image)

<GelDataSet xmlns=" identifier="PSI.GelDataSet.1001" storage=" Matrix of values goes here or matrix could be in an external file "> Sample XML for Gel Spots

Ways to take this forward For separation (GelML) –Decide what additional attributes and associations required –Extend ProtocolApplication and Material For Gel IML –Extend Data, Dimension, DimensionElement –These give facilities for linking to Investigation structure –We have some demo models of these parts –Important – Involve software manufacturers!

UML or XSD? Depends on expertise of developers FuGE exists as UML and XML Schema XML Schema auto-generated from UML –Can build UML and output XML Schema OR –Extend directly from XML Schema Need weekly conference call involving interested participants

Benefits of using FuGE Format gets model of Investigation for free –Method for linking experimental factors to Data dimensions Protocol system is very flexible –E.g. for storing sample prep details Ontology reference system works for simple term list and complex concepts Future integration with other ‘omics

…. some other issues for discussion

Issues with multidimensional data in XML 2 ways of representing multi-dimensional data in XML: Option 1: Define data dimensions in XML and store data in a non-XML multi-dimensional array –Need more than just an XML parser to “understand” the data values Option 2: Define data dimensions and store values with the leaf elements ( DimensionElements ) –For large data sets, XML is a highly inefficient structure for representing multi-dimensional data

Option 1: Data Dimensions for gel electrophoresis Data Dimension (Variables) Dimension (Gel Spots) Dimension (Spot Measures) DE (2h) DE (4h) DE (1h) DE (Spot1) DE (Spot2) DE (YCoord) DE (Area) DE (XCoord) DE (Intensity) Matrix of values ordered DE (Spot3000) … DE (Spot3) ordered

Option 1: Data Dimensions for gel electrophoresis Data Dimension (Variables) Dimension (Gel Spots) Dimension (Spot Measures) DE (2h) DE (4h) DE (1h) DE (Spot1) DE (Spot2) DE (YCoord) DE (Area) DE (XCoord) DE (Intensity) Matrix of values ordered DE (Spot3000) … DE (Spot3) ordered Result is 3011 references 3 dimensions + 3 variables spots +4 spot measures +1 to matrix of values Coordinates define where in matrix to find value: e.g. 1 hour time point, spot 255, Area is at position [ ] Note: This does not imply that spots with the same ID number on different gels correspond with each other. We need a different mechanism for this! ordered

Option 2: Data Dimensions for gel electrophoresis Data DE (Spot3) DE (Spot1) DE (Spot2) DE (Spot3000) DE (2h) DE (4h) DE (1h) DE (Area) Value = [ ] DE (XCoord) Value = [ ] DE (Intensity) Value = [ ] DE (YCoord) Value = [ ]

Option 2: Data Dimensions for gel electrophoresis Data DE (Spot3) DE (Spot1) DE (Spot2) DE (Spot3000) DE (2h) DE (4h) DE (1h) DE (Area) Value = [ ] DE (XCoord) Value = [ ] DE (Intensity) Value = [ ] DE (YCoord) Value = [ ] Result is references 3 variables X3000 spots X4 spot measures Values defined with the DimensionElements As data volumes become larger, or the number of dimensions increase, using pure XML is a highly inefficient structure for representing this kind of data. Imagine extra variables are being tested: Time course (4 time points), drug dose (5 doses) and strain (5), average of 3000 gel spots, say 4 spot measures This is 4 X 5 X 5 X 3000 X 4 = 1.2 million references The XML parser would be very slow!! Compared with 3018 references in the first case… This works because the data matrix can be loaded into memory and can have direct access to positions.

Restriction vs. Extension Note FuGE is supposed to be used by extending core classes –i.e. giving additional attributes or associations May be cases where we want to restrict parts of FuGE –E.g. may not want a type of ProtocolApplication to have input or output data Problem is that there is no good way of doing this in XML or UML or code! –xs:restriction is not well supported for complex types –May be best to do this with documentation

Use of general relationships vs. specific Example: ProtocolApplication has input and output materials Is a Gel2D an “inputMaterial” or do we want a specific association from GelSeparation? Do we want a typed output – SeparatedGel, for use with a defined scanning event etc. Do we want to use outputMaterials association for SeparatedGel or a new specific association? –Should outputMaterials include gel spots… These are all discussion issues

Some other issues to solve How to relate spots across gels –May also be measures associated with these values (ratios, relative abundance, confidence indicators etc.) –This could be another Data object that contains some of the same Dimensions How to relate different channels on a DIGE gel

Data Dimension (RelatedSpots) Dimension (SingleSpots) Dimension (Spot Measures) RelatedSpotGroup 2CompVolume CompositeArea Matrix of values ordered RelatedSpotGroup 1 RelatedSpotGroup 3 SingleSpot1 SingleSpot2 SingleSpot3 Related Spots across gels ordered Typical value of SingleSpot = SpotGroup1.123 i.e. this is a reference to how to find the single spot in the other data set

Related Spots across gels For the microarray case, is it implied that the features match across dimensions – this is not true for gel electrophoresis One way to define it is to specify a list of composite spots

DIGE data in FuGE Data Dimension (DIGE Conditions) Dimension (DIGESingleSpots) Dimension (Spot Measures) Condition 2 Matrix of values ordered Condition 1 Spot1 Spot2 Spot3 Area Volume Composite SpotID Ratio