Syntenic path assembly: Difference between revisions

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==Overview==
== Overview ==
The Syntenic Path Assembly is an option in [[SynMap]] to do a reference genome assembly of contigs using synteny to determine the order and orientation of the contigs.  To use this option, select "Order contigs by best syntenic path" under the Display Options tab.  When an assembly is generated, you may download the [[pseudoassembled]] sequence (contigs are joined using 100 "N"s.  "N" is the [[ambiguous nucleotide]] and while it may represent any nucleotide (A, T C, G), this permits the identification of where contigs were "glued" together by this algorithm.).


This algorithm also works quite well in aligning a WGS assembly between distally related organisms. See below for examples.
The Syntenic Path Assembly is an option in [[SynMap]] to do a reference genome assembly of contigs using synteny to determine the order and orientation of the contigs. To use this option, select "Order contigs by best syntenic path" under the Display Options tab. When an assembly is generated, you may download the [[Pseudoassembled]] sequence (contigs are joined using 100 "N"s. "N" is the [[Ambiguous nucleotide]] and while it may represent any nucleotide (A, T C, G), this permits the identification of where contigs were "glued" together by this algorithm.).  


===Definitions===
This algorithm also works quite well in aligning a WGS assembly between distally related organisms. See below for examples.
*WGS:  [[Whole-genome shotgun]]


== Alogrothm ==


[[Image:Screen shot 2011-02-18 at 1.38.59 PM.png|thumb|500px|center|Selecting the Syntenic Path Assembly option in [[SynMap]]]]
As implemented in SynMap:
[[Image:Screen shot 2011-02-18 at 1.58.23 PM.png|frame|center|Running a syntenic path assembly in SynMap.  When the results are returned, there is an option to download the assembled sequence (contigs are joined using 100 "N"s.  "N" is the [[ambiguous nucleotide]], as opposed to A,T,C,G).]]
 
#Identify and score each syntenic region
#Assign genome with fewer chromosomes/contigs to be reference
#For each chromosome in reference genome:
 
# sort all syntenic blocks that match reference genome according to position in reference genome # for ties in position, pick the syntenic block with the greater synteny score # flip contig if syntenic block is reversed
Thus, the tiling looks like:
<pre>
|-----A-----| |-----B-----| |-----C-----|
|-1-||-2-||-3-| |-4-||-5-||-6-| etc.,
</pre>
 
=== Definitions ===
 
*WGS: [[Whole-genome shotgun]]
 
<br> [[Image:Screen shot 2011-02-18 at 1.38.59 PM.png|thumb|center|500px]] [[Image:Screen shot 2011-02-18 at 1.58.23 PM.png|frame|center]]


==E. coli==
==E. coli==

Revision as of 21:33, 6 February 2012

Overview

The Syntenic Path Assembly is an option in SynMap to do a reference genome assembly of contigs using synteny to determine the order and orientation of the contigs. To use this option, select "Order contigs by best syntenic path" under the Display Options tab. When an assembly is generated, you may download the Pseudoassembled sequence (contigs are joined using 100 "N"s. "N" is the Ambiguous nucleotide and while it may represent any nucleotide (A, T C, G), this permits the identification of where contigs were "glued" together by this algorithm.).

This algorithm also works quite well in aligning a WGS assembly between distally related organisms. See below for examples.

Alogrothm

As implemented in SynMap:

  1. Identify and score each syntenic region
  2. Assign genome with fewer chromosomes/contigs to be reference
  3. For each chromosome in reference genome:
  1. sort all syntenic blocks that match reference genome according to position in reference genome # for ties in position, pick the syntenic block with the greater synteny score # flip contig if syntenic block is reversed

Thus, the tiling looks like:

|-----A-----| |-----B-----| |-----C-----| 
|-1-||-2-||-3-| |-4-||-5-||-6-| etc.,

Definitions


E. coli


Tetraodon (puffer fish): Takifugu rubripes and Tetraodon nigroviridis

Carnivora: Giant Panda (WGS Assembly) to Dog (reference genome)

Arabidopsis ecotypes: Columbia versus Landsberg erecta


Phoenix dactylifera L. (date palm) v. Oryza sativa japonica (Rice)

Cannabis sativa (marijuana) v. Prunus persica (peach)