Génomes

Génomes, or genomes in English, denote the complete set of genetic material present in an organism or cell. A genome includes all of its genes as well as the noncoding sequences that regulate, structure, and duplicate genetic information. In many organisms the genome is organized into a nuclear genome, contained in chromosomes, and, in eukaryotes, separate organellar genomes such as mitochondrial and, in plants and some algae, chloroplast genomes. Some organisms, particularly viruses, carry RNA genomes rather than DNA.

Genomes vary enormously in size and composition. They may be composed of DNA or RNA; the vast majority of organisms are DNA-based. The coding regions, or genes, represent a portion of the genome, while large fractions are made up of regulatory elements and repetitive sequences. Size does not strictly reflect organismal complexity; evolutionary processes shape genome content and architecture.

Genome sequencing aims to determine the exact order of nucleotides in an organism’s genome. Modern methods, including next-generation sequencing, produce reference genomes, which are annotated to identify genes and functional elements. Public databases host many genomes to support comparative genomics, evolutionary studies, and biomedical research.

Applications include understanding genetic variation, identifying disease-associated variants, informing breeding in agriculture, and exploring evolution and diversity. Challenges remain, such as assembling highly repetitive regions, detecting structural variation, and interpreting noncoding DNA. Ethical, legal, and social considerations accompany genome data sharing and clinical use.