What is repeat masking?

What is repeat masking?

RepeatMasker is a program that screens DNA sequences for interspersed repeats and low complexity DNA sequences. Currently over 56% of human genomic sequence is identified and masked by the program.

What is the repeating of a gene sequence called?

Repeated sequences (also known as repetitive elements, repeating units or repeats) are patterns of nucleic acids (DNA or RNA) that occur in multiple copies throughout the genome.

What are the two types of repetitive DNA sequences?

Repetitive DNA can be divided into two classes: the tandem repetitive sequences (known as satellite DNA) and the interspersed repeats.

What are the benefits of repetitive repeats in the plant genome?

They exhibit cohesive and concerted evolution caused by molecular drive, leading to high sequence homogeneity. Repetitive sequences accumulate variations in sequence and copy number during evolution, hence they are important tools for taxonomic and phylogenetic studies, and are known as “tuning knobs” in the evolution.

How do you use RepeatModeler?

Steps to run RepeatModeler

  1. rename the sequences in assembly fasta file to have simple names eg.
  2. call the assembly fasta file ‘ref.fa’
  3. format the assembly fasta file for RepeatModeler: (don’t need to bsub this to a farm; it’s very fast)

How do you cite RepeatModeler?

Please use the following for the RepeatModeler software: Smit, AFA, Hubley, R. RepeatModeler Open-1.0. 2008-2015 www.repeatmasker.org>.

What are inverted repeat sequences?

An inverted repeat (or IR) is a single stranded sequence of nucleotides followed downstream by its reverse complement. These repeated DNA sequences often range from a pair of nucleotides to a whole gene, while the proximity of the repeat sequences varies between widely dispersed and simple tandem arrays.

What are tandemly arranged repeats?

= A tandem repeat is a sequence of two or more DNA base pairs that is repeated in such a way that the repeats lie adjacent to each other on the chromosome. Tandem repeats are generally associated with non-coding DNA. In some instances, the number of times the DNA sequence is repeated is variable.

How do repeat sequences contribute to genetic variation?

They contribute to the variability in the genome via their sites of insertion leading to deletions being formed (and hence genetic disorders if gene function is perturbed) or producing hot spots for recombination or leading to copy number changes in a gene.

What are pseudogenes and repetitive DNA?

Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Most arise as superfluous copies of functional genes, either directly by DNA duplication or indirectly by reverse transcription of an mRNA transcript. Most non-bacterial genomes contain many pseudogenes, often as many as functional genes.

Why are there so many repetitive sequences in our genome?

While many of the data files are unique (e.g. protein coding sequences), the formatting information must be far simpler in content. The requirement for reduced information content in formatting signals is the most basic reason that repetitive DNA sequences are essential to genome function.

How do you identify a repetitive sequence?


  1. Censor is a tool to rapidly identify repetitive elements by comparison to known repeats.
  2. It uses WU-BLAST for speed and sensitivity, and can conduct DNA-DNA, DNA-protein, or translated DNA-translated DNA searches of genomic sequence.

What aremasked genomes/sequences?

Masked genomes/sequence refer to genomic sequence that has been scanned for some type of internal sequence and then has those sequences converted to “X”. Usually, repeat sequences are identified and masked as these cause sequence comparison algorithms to spend a lot of time identifying and matching these sequences.

When to use repeat masked genomes in Coge?

Usually, repeat sequences are identified and masked as these cause sequence comparison algorithms to spend a lot of time identifying and matching these sequences. It is recommend to use repeat masked genomes in CoGe when given an opportunity for a whole genome comparisons (e.g. in SynMap )

How does RepeatMasker search for repetitive sequence?

RepeatMasker searches for repetitive sequence by aligning the input genome sequence against a library of kno … RepeatMasker is a popular software tool widely used in computational genomics to identify, classify, and mask repetitive elements, including low-complexity sequences and interspersed repeats.

What are the different types of masking sequences?

Masking sequences come in two general flavors Hard mask: Masked sequence is converted to “X” Soft mask: Masked sequence is converted to lower-case ATCG For a popular repeat sequence identification program see: RepeatMasker.