Description: A molecular marker is a fragment of DNA that is associated with a specific location within the genome. These markers can be nucleotide sequences that vary among individuals of a species, making them valuable tools for genetic identification. Molecular markers are used in various areas of biology, including genetics, biotechnology, and medicine. Their main characteristic is that they allow the identification of genetic variations without the need to know the function of the gene in question. This makes them especially useful in genetic association studies, where the aim is to correlate certain phenotypic traits with specific genetic variations. Additionally, molecular markers can be used to track the inheritance of genes in populations, facilitating the understanding of genetic diversity and species evolution. In summary, molecular markers are essential tools in modern genetic research, providing crucial information about the structure and function of the genome.
History: Molecular markers began to be developed in the 1980s with the advancement of molecular biology techniques. One of the most significant milestones was the introduction of the polymerase chain reaction (PCR) in 1983, which allowed for the amplification of specific DNA sequences. This facilitated the identification of genetic variations and the development of markers such as microsatellites and SNPs (single nucleotide polymorphisms). Over the years, technology has evolved, enabling the creation of genomic databases and the use of molecular markers in large-scale genomic association studies.
Uses: Molecular markers are used in a variety of applications, including individual identification in forensic genetics studies, crop improvement in agriculture through marker-assisted selection, and in medical research to identify genetic predispositions to diseases. They are also fundamental in species conservation, helping to track genetic diversity and population structure.
Examples: An example of a molecular marker is the microsatellite, which consists of short repeats of DNA sequences. These markers are widely used in studies of genetic diversity and in identifying relationships between species. Another example is SNPs, which are variations at a single nucleotide and are used in genetic association studies to identify genes related to diseases.
