Description:

In all living organisms, genome replication is essential for their development and maintenance. In the genome of simple organisms, such as bacteria and small eukaryotic deoxyribonucleic acid (DNA) viruses, DNA replication starts from a well-characterised single origin. In complex eukaryotes, such as metazoans, DNA replication starts from dozens of thousands of origins spread along the different chromosomes. This high number of origins, together with the technical problems encountered in finding reliable methods for their large-scale mapping, made difficult their characterisation. However, owing to the new genome-wide approaches developed in the past few years, we have now a better understanding of how replication origins are established in higher eukaryotes. These studies have shown an intrinsic correlation between replication origins and other genome features, such as gene transcription and epigenetic regulation, and revealed an amazing flexibility in their usage.

Deoxyribonucleic acid (DNA) replication is an evolutionarily semi-conserved process that involves a mechanism to unwind the parent DNA strand, the synthesis of identical daughter strands, and steps to terminate the sequence. Owing to the massive amount of genetic information needed to be copied error-free, the replication of DNA within the mammalian chromosome is highly complex, requiring the simultaneous firing of multiple origins and processing of DNA at defined sites within the cells. This action requires the strict regulation and precise timing of numerous proteins, enzymes and substrates. These components critical to DNA replication will associate within these compartments in the cell to form replication factories during processing. Although many of the basic functions of DNA synthesis are well-defined, there is still much yet to be understood regarding the machinery involved in the initiation, synthesis and termination of mammalian DNA replication.

One of the fundamental characteristics of life is the ability of an entity to reproduce itself, which stems from the ability of the DNA molecule to replicate itself. The initiation step of DNA replication, where control over the timing and frequency of replication is exerted, is poorly understood in eukaryotes in general, and in mammalian cells in particular. The cis-acting DNA element defining the position and providing control over initiation is the replication origin. The activation of replication origins seems to be dependent on the presence of both a particular sequence and of structural determinants. In the past few years, the development of new methods for identification and mapping of origins of DNA replication has allowed some understanding of the fundamental elements that control the replication process. This review summarizes some of the major findings of this century, regarding the mechanism of DNA replication, emphasizing what is known about the replication of mammalian DNA.

Submit your manuscript at   https://www.imedpub.com/submissions/global-research-review.html or send us as an email attachment to submission@imedpublisher.com

With Regards

Barbara
Journal Coordinator
Global Journal of Research and Review