What Are Genetic Markers?

A genetic marker is a gene that is used as a marker in genetic analysis, also known as a marker gene. In recombination experiments, it is mostly used to determine recombinant and amphipathic types. As a marker gene, its function may not be well researched, but the mutation trait is clear, so it is easy to measure. Although genes related to biochemical traits are commonly used for microorganisms, genes related to morphological traits are often used for higher organisms. Centromeres are also useful as genetic markers. In microbial genetics, genetic markers are also divided into two types: selective markers (or selective genes) and non-selective markers (or non-selective genes).

Genetic markers

Genetic markers

Genetic marker

Since the mid-19th century,

Morphological markers

Morphological Markers refer to the external characteristics of animals (such as coat color, body shape, appearance, skin structure, etc.) that are visible to the naked eye or are measured by instruments. Genetic characteristics are identified by this morphological, physiological, and eco-geographic distribution waiting signs. Relationships, taxonomy and identification between species. The morphological marker study species are based on the description of individual traits, and the conclusions obtained are often incomplete, and the quantitative traits are difficult to exclude the environmental impact, and a rigorous analysis is required for biostatistical knowledge. However, it is simpler and more convenient to study the inheritance of quality traits with intuitive markers. At present, this method is still an effective means and plays an important role.

Genetic marker cytology marker

Cytological Genetic Markers (Cytological Genetic Markers) refers to the analysis of the number and morphology of chromosomes of treated animals, mainly including: karyotype and band type and deletion, duplication, translocation, inversion, etc. The karyotype characteristics of a species, that is, the stability of chromosome number, morphology, and behavior are relative, so it can be used as a genetic marker to determine the chromosome on which a gene is located and the relative position on a chromosome. A chromosome is a carrier of genetic material and is genetic. Carriers, chromosomal mutations will inevitably lead to genetic mutations in organisms, which is an important source of genetic mutations. By comparing the number and structure of chromosomes of animals and their close ancestors, tracing the origin and evolution of animals, detecting the genetic characteristics of animals, and providing a better method for animal breeding.

Genetic marker biochemical marker

Biochemical genetic markers (Biochemical Genetic Markers) are based on certain biochemical traits in animals as genetic markers, mainly referring to blood type, serum proteins and isoenzymes. Since the 1960s, protein electrophoresis has been widely used as a main method for detecting genetic characteristics. Protein electrophoresis mainly detects changes in soluble proteins and isoenzymes in plasma and blood cells. Through the detection of a series of proteins and isoenzymes, it can provide genetic variation in animal breeds and genetic relationships between breeds. useful information. However, proteins and isoenzymes are the expression products of genes, and non-genetic material itself, their performance is susceptible to environmental and developmental conditions; these factors determine that protein electrophoresis has certain limitations, but protein electrophoresis technology is easy to operate, Fast and relatively low testing costs, it is still one of the more widely used methods in the study of genetic characteristics. Biochemical genetic markers are economical and convenient, and are more polymorphic than morphological markers and cytogenetic markers. Has been widely used in species origin and taxonomy research and animal breeding.

Genetic markers immunological markers

Immune Genetic Markers are genetic markers based on the immunological characteristics of animals. They mainly refer to: red blood cell antigen, white blood cell antigen, and thymus cell antigen. As early as 1900, Ehrlich and Morgenroth pointed out that there are antigens on the surface of goat red blood cells, and proved that these antigens have individual differences. In the early 1980s, people turned to the research of leukocyte antigens, that is, the major histocompatibility complex (MHC), MHC. Important traits have important relationships with disease and physiological traits. According to the specificity of the lymphocyte antigens of the animals, the differences among the breeds, individuals, disease resistance and parent-child relationship were studied.

Genetic markers

Molecular markers (Molecular Genetic Markers) are genetic markers based on nucleotide sequence variations in genetic material between individuals, and are a direct reflection of DNA-level genetic polymorphisms. Compared with several other genetic markers-morphological markers, isozyme markers, and cell markers, DNA molecular markers have the following advantages: most molecular markers are codominant, and the selection of recessive agronomic traits is very convenient; The genomic variation is extremely rich, and the number of molecular markers is almost unlimited; at different stages of biological development, DNA from different tissues can be used for marker analysis; molecular markers reveal mutations from DNA; appear neutral and do not affect the expression of the target trait No linkage with bad traits; the detection method is simple and rapid. With the development of molecular biology technology, there are now dozens of DNA molecular marker technologies, which are widely used in crop genetics and breeding, genome mapping, gene mapping, plant relationship identification, gene bank construction, gene cloning and so on.