Col1a2-iCre Mice

Catalog Number: C001528

Strain Name: C57BL/6JCya-Col1a2^{em1(P2A-iCre)}/Cya

Genetic Background: C57BL/6JCya

Reproduction: Homozygote x Homozygote or Heterozygote x Heterozygote

Strain Description

The COL1A2 gene encodes the pro-alpha2 chain of type I collagen, which forms a triple helical structure composed of two α1 chains and one α2 chain. Type I collagen is a fibrous protein widely present in most connective tissues, particularly in the extracellular matrix of bone, cornea, dermis, and tendons. It plays a crucial role in providing support and structural integrity within the extracellular matrix and is involved in various biological processes, including cell migration, cell adhesion, and cell signaling. Mutations in the COL1A2 gene have been linked to several disorders, including types I-IV osteogenesis imperfecta, Ehlers-Danlos syndrome type VIIB, classical Ehlers-Danlos syndrome, idiopathic osteoporosis, and atypical Marfan syndrome.

The Col1a2-iCre mice are constructed by integrating the codon-improved Cre recombinase (iCre) element into the stop codon of the mouse Col1a2 gene to mimic its expression pattern while maintaining the normal expression of the mouse Col1a2 gene. When Col1a2-iCre mice are crossed with mice containing loxP sites, the offspring can undergo sequence recombination between loxP sites mediated by the Cre recombinase in fibroblast cells.

Strain Strategy

The TAA stop codon of the mouse Col1a2 gene was replaced with the “P2A-iCre” cassette.

Validation Data

a. Method

Col1a2-iCre mice were mated with Rosa26-LSL-tdTomato mice to generate double heterozygotes. Deletion of the “stop element (LSL)” results in tdTomato protein expression in Cre-positive cells. When the offspring mice reach 6 weeks of age, mouse skin, heart, and lung tissues are collected and tdTomato protein distribution is analyzed by immunofluorescence (IF) to determine the expression of Cre recombinase.

b. Genotype

Cre+: Col1a2-iCre[KI/+];Rosa26-LSL-tdTomato[CKI/+];

Cre-: Rosa26-LSL-tdTomato[CKI/CKI].

c. Result

1) Expression of Cre recombinase in skin, heart, and lung tissues

Figure 1. Immunofluorescence (IF) staining of the skin, heart, and lung tissues. The results indicate that in Cre+ mice, tdTomato red fluorescence is present in the dermal layer of the skin, between myocardial cells in the heart, heart valves, and endocardium. Additionally, a significant amount of red fluorescence is detected in the alveoli and surrounding bronchi in the lungs, demonstrating Cre recombinase-mediated tdTomato expression in these tissues. However, in Cre- mice, there is no expression of Cre recombinase in the corresponding tissues of the skin, heart, and lungs.

d. Summary

In the Col1a2-iCre mice, Cre recombinase expression is primarily concentrated in fibroblasts. Cre activity can be detected in skin, heart, and lung tissues. This model can be used for tissue-specific research targeting fibroblasts.

Announcements

1. The insertion site of the Cre recombinase gene expression cassette in this strain is located on chromosome 6. Please avoid breeding with gene-edited mice targeting genes on the same chromosome as the Cre mouse when conducting mating.