Contents
What is contig alignment?
A contig is defined as a contiguous sequence assembled from a set of sequence fragments, typically by string matching and local sequence alignment. Contig assembly refers to the process of assembling many sequence fragments into one long genomic sequence or a few long contigs (Figure 3-1).
How do you read a Quast report?
Reading the QUAST output report: GC (%) is the total number of G and C nucleotides in the Assembly, divided by the total length of the Assembly. N50 is the length for which the collection of all contigs of that length or longer covers at least half (50%) the total base content of the Assembly.
Is a contig a gene?
A contig–from the word “contiguous”–is a series of overlapping DNA sequences used to make a physical map that reconstructs the original DNA sequence of a chromosome or a region of a chromosome. A contig can also refer to one of the DNA sequences used in making such a map.
How do you align a contig?
How to run the Align Contigs tool
- Use input contigs as reference. If no reference sequence is available, the contigs can be aligned using themselves as a reference.
- Use selected reference(s). When a reference sequence is available, the contigs can be aligned to the reference.
What does it mean to index a reference genome?
Hi dear, Genome indexing is one type pre processing to compress the size of text and to make queries fast.
What is Quast?
QUAST stands for QUality Assessment Tool. QUAST can evaluate assemblies using reference genomes, as well as without reference genomes. QUAST produces detailed reports, tables and plots which show the different aspects of assemblies.
How to align to genome with alternate contigs?
We align in an alternate contig aware (alt-aware) manner, which we also call alt-handling. This is the main focus of the tutorial. The decision to align to a genome with alternate haplotypes has implications for variant calling. We discuss these in section 5 using the callset generated with the optional tutorial steps outlined in section 4.
What is the ideogram of a reference genome?
The ideogram is from the Genome Reference Consortium website and showcases GRCh38.p7. The zoomed region illustrates how regions in blue are full of Ns. Analysis set reference genomes have special features to accommodate sequence read alignment. This type of genome reference can differ from the reference you use to browse the genome.
Is it possible to align draft genomes with mauve?
It is also possible to align draft genomes, where each genome is represented by a list of contigs. If one or more genomes are represented by a sequence list, and progressiveMauve is chosen as the algorithm, Geneious will concatenate the contigs from each genome into a single sequence for the alignment.
How is GATK used to map reference genomes?
Within GATK documentation, we outline how to map reads in an alternate contig aware manner and discusses some of the implications of mapping reads to reference genomes with alternate contigs. GATK tools allow for use of a genomic [intervals list that tells tools which regions of the genome the tools should act on.