What is segmental duplication genetics?
What is segmental duplication genetics?
Segmental duplications (also termed “low-copy repeats”) are blocks of DNA that range from 1 to 400 kb in length, occur at more than one site within the genome, and typically share a high level of (>90%) sequence identity (reviewed by Eichler [2001]).
What are the types of duplication?
Gene duplication can occur by several mechanisms, including whole-genome duplication (WGD) and single gene duplication. Single gene duplication includes four types, tandem (TD), proximal (PD), retrotransposed (RD), DNA-transposed (DD) and dispersed duplication (DSD) (Freeling, 2009; Hahn, 2009; Wang et al., 2012b).
What happens during duplication of DNA?
In chromosomal duplications, extra copies of a chromosomal region are formed, resulting in different copy numbers of genes within that area of the chromosome.
How long is a segmental duplication in DNA?
Segmental Duplication. Segmental Duplications (SDs) are long DNA sequences (typically defined as being > 1kb in length) that have nearly identical sequences (90-100%) and exist in multiple locations as a result of duplication events.
What are the two types of segmental duplications?
Two Types of Segmental Duplications [2] 1. Interchromosomal – Sequence duplicated onto non-homologous chromosomes. 2. Intrachromosomal – Sequence duplicated onto the same chromosome, often into the same chromosome region. These duplications are typically referred to as “region- or chromosome-specific low-copy repeats (LCR)”.
How many duplications are there in the human genome?
Approximately 5.2% of the human genome consists of segmental duplications or “duplicons”; ie, regions of more than 1 kb with >90% identified that are present more than once in the genome. Segmental duplications are either intrachromosomal (on the same chromosome, 3.9%), or interchromosomal (on different chromosomes, 2.3%).
Are there any duplications in the same chromosome?
Intrachromosomal – Sequence duplicated onto the same chromosome, often into the same chromosome region. These duplications are typically referred to as “region- or chromosome-specific low-copy repeats (LCR)” [1] Samonte, R. and Eichler, E. (2002). Segmental duplications and the evolution of the primate genome. Nat Rev Genet. 3: 65 – 72.