Repetitive DNA and Its Roles in Diverse Facets of Biology | Book Publisher International

 

‘‘C-value paradox’’ or ‘‘C-value enigma’’, has intrigued biologists for over half a century. Rapid advances in DNA sequencing are now providing compelling evidence showing that variation in DNA amount arises predominantly from differences in the frequency of polyploidy, abundance of non-coding repetitive DNA and the dynamics of the processes that amplify, erode and delete DNA. Repetitive elements (REs) comprise large proportions of eukaryotic genomes and are fundamental to the evolutionary process. REs can be classified as interspersed or tandem repeats. Interspersed repeats include transposable elements (e.g., retrotransposons), which encode proteins that facilitate their movement and proliferation in genomes. Tandem repeats (e.g., satellite DNAs) can form large blocks (e.g., megabases) of relatively short non-coding sequences in repeated arrays. Together, interspersed and tandem repeats comprise a major fraction of the prokaryotic and eukaryotic genomes.

 

REs exhibit an array of structural and evolutionary effects on genome evolution across species. TEs can be associated with genome rearrangement through various mechanisms, such as de novo TE insertion, TE insertion-mediated deletion, and homologous recombination between them. These rearrangements increase the genomic difference between genomes, and some specific rearrangements may lead to complex diseases. TEs transpose and insert themselves between genes; they can disrupt gene order, create gene duplications, or cause gene deletions. These structural changes can have significant effects on the organisation and function of the genome. Also, through recombination, TEs can serve as recombination sites in the genome, promoting genomic rearrangements. Recent studies reveal that chromosome-specific repetitive elements and small RNA-based chromatin regulation have been repeatedly adapted to guide epigenetic regulation of a chromosome. In the present book, we explore several aspects of Repetitive DNA ranging from chromosome to transcriptional regulation. At the chromosomal level roles of RE in Centromere organisation, histone and kinetochore dynamics evolution, viability and degeneration are reviewed using representative examples. Epigenetic and roles of repetitive DNA in human diseases have been recognised as niche areas by researchers furthering the role of RE in gene regulation, sex chromosome differentiation, are its major contribution to genomes.

 

Author(s) Details

Kiran Kumar Halagur Bhoge Gowda

Affiliated to Nrupathunga University, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/mono/978-81-991027-6-7