Human Genome. Structural Aspects
Abstract
The human genome, as the genome of all mammals and birds, are mosaic of isochores, which are
very long streches (>> 100 kb) of DNA that are homogeneous in base composition. Isochores can be
divided in a small number of families that cover a broad range of GC levels (GC is the molar ratio of
guanine+cytosine in DNA). In the human genome, we fi nd fi ve families, which are (going from GCpoor to GC- rich) L1, L2, H1, H2 and H3. This organization has important consequences, as is the case of the concentration of genes, their regulation, transcription levels, rate of recombination, time of replication, etc. Furthermore, the existence of isochores has as a consequence the so called “compositional correlations”, which means that as long as sequences are placed in diff erent families of isochores, all
of their regions (exons and their three codon positions, introns, etc.) change their GC content, and as
a consequence, both codon and amino acids usage change in each isochore family. Finally, we discuss
the origin of isochores within an evolutioary framework.
Downloads
Copyright (c) 2021 Guillermo Lamolle, Héctor Musto
This work is licensed under a Creative Commons Attribution 4.0 International License.
The authors retain their copyright and assign to the journal the right of first publication of their work, which will be simultaneously subject to the Creative Commons Attribution 4.0 International License. that allows sharing the work as long as the initial publication in this magazine is indicated.
