Genetic Mapping: Navigating the Human Genome
Efforts to advance understanding of the human body and each of its intricate components have provided groundbreaking information, slowly unraveling the complexity of our most essential systems and facets. The Human Genome Project (HGP) is an international campaign focused on establishing the base pairs that make up human DNA.
One of the primary goals of this project concerns developing genetic mapping, a tool used to discern new genes and their respective functions. The objective of this method focuses on placing an array of molecular markers onto their respective locations on a genome. Molecular markers come in a variety of forms but are most commonly DNA molecules contained within a sample taken from an organism. Markers refer to the characteristic patterns of DNA bases. Genes can be viewed as a specific type of marker in the formation of a genomic map. Also known as linkage mapping, genetic mapping helps scientists distinguish the locus of a gene and the distance between genes. It can also be useful in examining the distance between various sites within a gene.
In order to create a genetic map, researchers must collect DNA samples – typically blood, saliva, or tissue – from family members in which a certain genetic disorder or trait is present and subsequently determine any genetic patterns or similarities within the familial DNA. Once these genetic markers have been developed, scientists can infer the inheritance of certain genes. The closer two markers are located on a chromosome, the greater the likelihood that they will be passed down together during reproduction. The more genetic markers that exist on a gene map, the greater chance that one of these indicators will be located near a disease-causing gene, therefore making it easier for experimenters to concentrate on the gene.
Genetic mapping provides an exact identification of the location of a gene within the human genome and its precise location on a specific chromosome. Among its many functions, this tool can offer evidence that a disease transmitted from parent to child is correlated with one or more genes. These maps have been used to uncover genes responsible for rare, single-gene inherited disorders like Duchenne muscular dystrophy and cystic fibrosis. They have also proven helpful in recognizing the genetic influence on disorders such as asthma, diabetes, psychiatric conditions, and cancer.
The HGP has made several astonishing advancements. An early accomplishment developed dense maps of markers evenly spaced across the entire human genome. Successful genetic mapping has the ability to reduce the time and effort required to determine a gene and its significance from several years down to months or, in some cases, weeks.
Picture Source: news.yale.edu
