What are the characteristics of the C57 breed in white rats?

1921 year.

Little used Lathrop mice as inbreeding, and mated male and female mice to breed C57. In C57, the black coat color was fixed, and the adult Little named the sixth subline of C57BL as C57BL 6, and the tenth subline as C57BL 10, and then maintained them to this day. In 1947, it was introduced from Little to Jackson Lab. in the United States

Formation of C57BL 6J; 1951 from Jackson LabIntroduced to the NIH, the C57BL 6N sublineage was formed. In the sixties, he went to the Japanese Laboratory Animal Research Institute, and in 1986, he was introduced to the Chinese Academy of Sciences from the Japanese Laboratory Animal Research Institute.

Shanghai Laboratory Animal Center. It was reintroduced from the United States in 2001.

Normal values of body weight in C57 mice: Male: Body weight (g) Day < 12g < 2313 15g 24 2816 18g 29 3519 21g 36 4522 24g 45 63 Female:

Weight (g) days old< 12g < 2313 15g 24 3116 18g 32 5219 21g 53 7722 24g 78 105

Special properties: breast cancer.

The incidence is low, there is an eye defect, resistance to radioactivity, and it is resistant to Mycobacterium tuberculosis.

Sensitive, with some resistance to the mouse pox virus, interferon.

High yield, sensitive to pertussis susceptibility factors. It is commonly used in carcinogenic research.

Reproductive performance: farrowing rate: 89 95% Average litter size: Fetal interval: 28 36 days Weaning survival rate: 87 93%.

Fvb N is at The National Institutes of Health (NIH).

It was successfully bred and later in the 37th generation by The Jackson Laboratories Jackson.

Introduced in the laboratory, it is called FVB NJ.

【Experimental mouse food intake】A mouse is about a gram at birth, up to 12 15 grams after one month of lactation, and can reach more than 20 grams after lactation and feeding months, becoming an adult mouse for experimental needs. The feeding amount for an adult mouse is 4 to 8 g days.

Experimental mice] evolved from the mus musculus. It is widely distributed all over the world, and has been bred into more than 1,000 inbred lines and independent outbred groups after long-term artificial breeding and selection. As early as the 17th century, mice were used for experiments, and now they have become the most widely used and well-studied mammalian experimental animals.

Adult mice have a diet of 5 8 g and a water intake of 4 7 ml.

Adult mice were fed 4 8 g a day and drank 4 7 ml a day.

It doesn't make a difference, many people refer to C57BL as C57 for shortBL means black black.

There are more than a dozen varieties of C57BL experimental mouse subdivisions, and the most commonly used is C57BL 6J. If it is not clearly stated, this is the default term.

Since the invention of mouse gene knockout technology, it has traditionally been used to prepare model mice with mouse embryonic stem cells with 129 genetic backgrounds, and then backcrossed (back-cross) on inbred mice such as C57BL 6 for more than 10 generations to perform most biomedical research such as immunology, cancer, neurology, etc. It takes at least more than 2 years to backcross, which causes a lot of time and money losses to scientific researchers. For example, biological experiments are often carried out such as cell and organ transplantation.

Most of the mice we obtained from animal quotient were pure mice such as C57BL 6 or Balb C, and very few large numbers of 129 mice were used for experiments. If the model mice prepared from the 129 strain ES cells do not have enough generations of backcross on the C56BL 6 strain, they will carry a lot of 129 mouse antigen. When the cells are transplanted into C57BL 6 and other suburban mice, the body of the recipient mouse will kill the transferred cells or produce tolerance due to immune rejection.

Moreover, due to the complex genetic background of the 129 strain, the model mice of the 129 strain often cannot obtain good reproducible experimental results, so it is also necessary to backcross the inbred mice such as C57BL 6. On the other hand, because the number of backcrosses is not the same, it will also lead to poor reproducibility of experimental results. This is a big disadvantage for biological research, especially for pharmaceutical companies, safety assessment centers, drug testing departments, etc.

This is also a big drawback for the development and production of standard model animals. The 129 strain generally needs to be backcrossed for a longer period of time to stabilize the traits of the model mice. Therefore, if the gene can be directly targeted with C57BL6 ES cells, the model mice of the C57BL6 strain will be directly obtained.

The advantage of the 129 strain of ES cells commonly used today is that they are relatively leathery and easy to manipulate. Correspondingly, there are very few ES cell lines with C57BL 6 genetic background that can be used for gene targeting. It's also hard to get.

Moreover, in general, C57BL 6 ES cell is relatively delicate, for example, mycoplasma contamination is easy to cause no germline transmission. In foreign countries, it is generally $35,000 to make 129 genetic background model mice, while to develop model mice with C57BL 6 ES cells, ** is generally between $50,000 and $80,000. Despite the cost of money, it is worth it in many ways to prepare C57BL6 knockout mice.

For example, it increases the competitiveness of scientific research and saves the time of Islam.

Knockout mice, a kind of mouse used for genetic experiments, are mostly bought from abroad.

Mountain mouse, we call it mountain mouse here, if it's so big.

Rats in the city, rats in the countryside.

What is this, haven't heard of it.

SV129 What kind of rat is a rat, you must know it!

c57 I haven't used it. But I guess there are a few reasons for your question. For one, C57 mice are very sensitive to pain and cold compared to other mice.

Is it true that the response to punishment is stronger when studying behavior? Second, C57 mice have a clear preference for alcohol and can actively drink alcohol. And it can be addictive to morphine.

Is it relevant to the study of nerves? Third, the sales of C57 mice are very large. In the United States, C57 black mice account for 50% to 65% of the mice sold to the laboratory (wiki), because the amount of this mouse is very large, so it is very thoroughly studied.

The more commonly used mice, the more commonly used. Finally, black rats are very commonly used when making genetically modified animals. If the black mouse and the white mouse cross, then the suitable offspring should be black and white, and it can be picked out directly.

I don't know why the Shanghai Institute of Neurology uses these C57s. But after getting used to mice like B c Nude and Nod Sicd, I have to sympathize with the experimenters who use such ferocious mice as C57.