Gene Mapping

Gene mapping is an important tool for locating a specific gene to a particular region of a chromosome and to determine its relative distances between genes and molecular markers on the chromosome.

Method

• Somatic hybridization
  Cell hybridization, also known as cell fusion, is the fusion of two cells from different sources into a new cell. Most somatic cell hybridization involves crossing human cells with somatic cells (hybrid cells) from mice, rats, or hamsters. This newly produced fusion cell is called a hybrid cell, which contains different chromosomes from both parents.
• Clone panel method
  The clone panel method is a simple and useful gene positioning method designed for hybrid cells that retain or lose human chromosomes and sometimes overlap. In addition, hybrid cells can be specially stained to identify human and mouse chromosomes to help gene localization.
• Fluorescent in situ hybridization
  The fluorescent in situ hybridization method is used to detect a DNA sequence or the disease gene within a cell using the fluorescent probe. In FISH, a short sequence of DNA complementary to our DNA sequence or gene is artificially synthesized and labeled with the fluorescent dye. If the complementary sequence of the gene of our interest is present on a chromosome, the probe will hybridize with it and give the fluorescent signal.

Procedure

Take the process of FISH as an example:

• Selection of target sequence: select target using computational analysis
• Designing the probe: the probe is a single-stranded sequence of DNA or RNA complementary to our gene of interest
• Sample preparation: paraffin-embedded tissues, FFPE tissues, tumor cells, cell culture, or chromosomal suspension are some common sample types for FISH analysis
• Denaturation: a higher temperature or denaturing agents are used for generating single-stranded target DNA for hybridization
• Hybridization process: interphase or metaphase chromosomes are the best choice for performing FISH efficiently
• Results and interpretation: visualize the slide under the fluorescent microscope, if the probe hybridized properly on its complementary sequence, it emits two fluorescent signals

Fig. 1 The illustration of the complete process of fluorescence in situ hybridization.

Types

• Genetic-linkage Mapping
  Physical mapping is to make a gene map from the DNA molecular level. It represents the actual distance between different genes (including genetic markers) on the chromosome, measured in base pairs. Therefore, the physical map is finally expressed in the precise DNA base pair sequence, thereby illustrating the DNA molecular structure of the gene.
• Physical Mapping
  Genetic mapping (genetic mapping) is to study the meiosis of the family, and to draw the distance between gene loci based on the understanding of the segregation trend of two genes. It indicates the linkage relationship and relative distance between genes, and is calculated and expressed by the recombination rate in centimorgans (cM).

Features

• High degree of parallelism: it is conducive to the rapid comparison and reading of the maps displayed by the gene chip, and the efficiency is greatly improved
• Diversity: it provides multi-indicator determination of samples
• Miniaturization: the amount of samples required is very small, and it can also save the amount of reagents and reduce costs
• Automation: it reduces costs and ensures quality

Applications

Gene mapping is used in biomedical studies, agricultural investigations, microbiology, anthropology, paleobiology (in particular, paleoanthropology), evolutionary researches, and many others fields.

• For biomedical studies, in particular, for detecting genes that are responsible for complex diseases
• Understand the molecular mechanisms of a particular disease
• Agricultural plant investigations: provide the essential data according to the genes with the high economic importance sequence, localization, and linkage

Related Products

Fluorescence Microscope

A fluorescence microscope is an optical microscope that uses fluorescence to observe samples. It illuminates a target with a specific wavelength of light, which causes the target to absorb the light and emit a longer wavelength. This causes the target to glow within an otherwise dark field of view. Fluorescence microscopes use a highly sensitive detector to measure only the emitted light from the target, enabling high-resolution observation and imaging.

Water Bath

A water bath is laboratory equipment made from a container filled with heated water. It is used to incubate samples in water at a constant temperature over a long period of time. Most water baths have a digital or an analogue interface to allow users to set a desired temperature. A laboratory water bath is a preferred heat source for heating flammable chemicals instead of an open flame to prevent ignition.

Laboratory Incubator

An incubator is a device used to grow and maintain microbiological cultures or cell cultures. It is made up of a chamber with a regulated temperature. An incubator maintains optimal temperature, humidity, and other conditions such as the CO2 and oxygen content of the atmosphere inside. Incubators are essential for much experimental work in cell biology, microbiology, and molecular biology.

STEMart provides you with a variety of gene mapping technology equipment or consumables to meet your various R&D and application needs. If you have any questions or requirements for gene mapping technology, please feel free to contact us.