Výlet na konec genomu 1. Jak se kopírují telomery
| Title in English | Excursion to the End of the Genome 1. How Telomeres Are Copied |
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| Authors | |
| Year of publication | 2017 |
| Type | Popularization text |
| MU Faculty or unit | |
| Citation | |
| Description | Plant, animal, bacterial and even viral genomes can be classified on the basis of various criteria, e. g. with respect to their biochemical characteristics there are DNA vs. RNA genomes; based on their complexity they can be divided into groups containing genomes with low and high complexity; finally, considering their arrangement we talk about circular and linear genomes. Circular genomes are formed by DNA or RNA that resembles a circle. The simplest way to replicate a circular genome is to start its amplification from a specific locus of origin and to continue along around the whole strand, until the very first and the very last nucleotide are covalently bound and so the circle is completely finished. Circular genomes are generally less complex and smaller than the linear ones. It is not an exception that the whole bacterial or viral genome is represented by a single molecule. Increased complexity is observed when linear genomes are studied. Plant and animal genomes are usually formed by many different molecules – chromosomes (generally, 2n is a number in units, tens and even thousands of chromosomes). In contrast to circular genomes, the linear ones have to overcome two basic problems in their existence – how to replicate their ends and how to protect them. The protection is ensured by nucleoprotein complexes. In plants and mammals, the replication and maintenance of chromosome ends is provided by an enzyme called telomerase, but there are many different ways and possibilities to solve the end replication problem. This article focuses on various mechanisms that are capable of maintaining the chromosome ends in linear genomes. |
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