Clean lines

Clean lines [synonym inbred lines; lines (at higher organisms); pure culture, strains and clones (microorganisms)] - limited set of hereditary homogeneous organisms descended from a single common ancestor. Clean lines play an important role in various fields of experimental medicine and biology, such as Oncology, genetics tissue compatibility, immunogenetic, chemotherapy, radiology, treatment of radiation sickness, human genetics, Virology, etc.
Practical importance of clean lines is the possibility of control over genetic variability of separate signs or their combination of interest and scientific or practical side.
In the experimental practice to use hundreds of inbred mouse strains, dozens of strains of rats and hamsters and Guinea pigs, rabbits, chickens, and other animals (see Laboratory animals). Genetically pure lines are also strains of bacteria, actinomycetes - producers of antibiotics, strains of microorganisms, used in the manufacture of sera, vaccines, and so on

Pure lines (synonym inbred lines) is a bounded set of hereditary homogeneous organisms occurring in each generation from a common ancestor, or from one pair of closely related individuals (brother and sister). Included in the clean lines organisms are called inbred, containername or linear.
Inbreeding - literally means breeding in himself, i.e., mating animals that are in close relationship with each other.
The purpose of rational systems of breeding animals or plants, including inbreeding, is to control the genetic variability of the sign or combination of signs which are of interest of scientific or practical (often with Amateur) point of view.
Any natural population (see) animal or plant consists of hereditary diverse genotypes. Concentration (frequency) components of population genotypes it remains constant under the following conditions: 1) the population is indefinitely great; 2) its constituent individuals (genotypes) equally viable, fertile and without being constrained by spatial or any other barriers, can move freely on the territory of population and freely interbreed among themselves; 3) in the population there are no natural selection and mutation changes. As such ideal conditions in nature never implemented, the population always happen then slow, then faster change in concentrations (frequency) of its genotypes in one direction or another. The gradual transformation of the population is called genetic drift or genetic automatic process.
In contrast, inbreeding has resulted in the dismemberment of the population on its constituent biotypes, or clean lines, and reduce genetic variability. The rate of accumulation in insiderobama line of homozygotes depends on the degree of kinship mate individuals in every generation. This criterion is the basis of different systems of inbreeding.
Homozygosity line fastest achieved in sampledatabase organisms: in this case, after eight generations percentage of homozygotes in line reaches 100. A less efficient method of crossing brothers and sisters; when this system of inbreeding almost 100% homozygosis is achieved after 20 generations. With the decrease in the degree of kinship mate individuals (cousins and sisters, second cousins, and so on) falls and the rate of approximation of the line to 100% of homozygosity.
In practical inbreeding, especially as applied to laboratory animals (see), the most widely system brotherly-sisterly matings, as the most simple in technical terms and in relation to ease of documentation. To the genetic variability in line to minimize assumed that it must pass 40 generations of inbreeding. Catalinan animals play an important role in biomedical research. In agricultural practice catalinan animals and plants are the source of productivity resulting from the use of the phenomenon of heterosis in interlinear hybrids. Cm. also, Genetics, Variation.