Transgenic mouse strain B6.129P2-Axltm1Dgen/J to study the role of Axl (renew)
1. The purpose of the experiment is to breed mouse strain where lacZ gene has been inserted into Axl coding gene. The colony has been established previously (project 4480) and mice are used in various experiments (different projects have been performed and additional application have been accepted ). Main focus has been on the Axl expression in developing animals in putative stem cells as well as the role of axl after tissue injury for example after bleomycin treatment (project 6014). Furthermore, lacZ expressing mammary cells have been isolated and demonstrated that these cells are enriched mammary stem cells (project 5138).
The main purpose of keeping the axl lacz expressing colony is to further investigate the role axl has in development and after tissue injury and furthermore to assess the role of axl in tumor development in vivo (a new application will be made).
2. Animals are not expected to suffer pain or discomfort since the normal state in these animals does not cause pain. Nevertheless, they will be observed daily and their condition will be a subject for detailed evaluation. Animals suffering any unnecessary and not justified by the procedure discomfort and distress will be euthanized by cervical dislocation while under deep anesthesia. Depending on the duration and severity, symptoms which will be considered as a humane endpoints are (but not limited to): loss of weight by 20%, ruffled hair, hunched posture, paralysis, diarrhea, lethargy, dyspnea, persistent recumbency, dehydration.
3. Axl is a member of the TAM (Tyro-Axl-Mer) receptor tyrosine kinases (RTK) transmembrane receptor tyrosine kinase. TAM family regulates whole range of cellular responses. Axl, particularly, is expressed in embryonic tissues and plays a role in the neural and mesenchymal development. In adult tissues its expression is restricted to smooth muscle cells. Relative to normal expression, increased level of Axl is specific for various disease states. In patients suffering from cancer Axl expression is associated with metastatic lesions and with poor overall patient survival. Investigation of Axl role in animal development and its occurrence in whole range of stem cells became much easier since the mice strain, in which lacZ gene was inserted into Axl coding gene, has been established. Knowledge of Axl, its role, and its role in disease development show a potential and may contribute to future cancer treatments.
4. Up to 1500 animals will be used. The mice strain is B6.129P2-Axltm1Dgen/J.
5. The purpose of this experiment is to breed mouse strain, in which lacZ gene was inserted into Axl coding gene. Expression of different genes, in this case Axl, differs between individuals. To understand importance of Axl in developing animals it is necessary to perform in vivo studies, since in vitro studies cannot mimic the whole body complexity. B6.129P2-Axltm1Dgen/J is a suitable model to perform study on expression in animals. In vitro studies allowed to investigate relevance of the model and enabled to establish experimental design. The number of animals are reduced by in vitro studies prior to in vivo experiment. Furthermore, animals will be used for both in vivo and ex vivo studies. As the breeders, the same animals will be used across the time. As for the establishment of the colony (project 4480). For breeding, we will use heterozygotes to benefit from increased production of offspring during the experiment. As the colony is established, the breeding will be performed according to the planed experiment in order to reduce the number of animals. The normal state in these animals does not cause pain and no painful procedures will be performed during breeding as mentioned by the Jackson laboratories and confirmed by observation during the establishment of the colony (project 4480). In order to select animals with targeted genotype, small biopsies are taken from the ear. This approach allow reduction of animals used in experiments. For breeding only heterozygotes are used. Homozygous wild type individuals are excluded from the colony, in order to exclude unwanted phenotype and decrease number of not-targeted allele amongst newborn pups. As the colony is established, the same procedure will be continued with particular focus on limiting inbred mice in order to maintain healthy animals in the colony.
The main purpose of keeping the axl lacz expressing colony is to further investigate the role axl has in development and after tissue injury and furthermore to assess the role of axl in tumor development in vivo (a new application will be made).
2. Animals are not expected to suffer pain or discomfort since the normal state in these animals does not cause pain. Nevertheless, they will be observed daily and their condition will be a subject for detailed evaluation. Animals suffering any unnecessary and not justified by the procedure discomfort and distress will be euthanized by cervical dislocation while under deep anesthesia. Depending on the duration and severity, symptoms which will be considered as a humane endpoints are (but not limited to): loss of weight by 20%, ruffled hair, hunched posture, paralysis, diarrhea, lethargy, dyspnea, persistent recumbency, dehydration.
3. Axl is a member of the TAM (Tyro-Axl-Mer) receptor tyrosine kinases (RTK) transmembrane receptor tyrosine kinase. TAM family regulates whole range of cellular responses. Axl, particularly, is expressed in embryonic tissues and plays a role in the neural and mesenchymal development. In adult tissues its expression is restricted to smooth muscle cells. Relative to normal expression, increased level of Axl is specific for various disease states. In patients suffering from cancer Axl expression is associated with metastatic lesions and with poor overall patient survival. Investigation of Axl role in animal development and its occurrence in whole range of stem cells became much easier since the mice strain, in which lacZ gene was inserted into Axl coding gene, has been established. Knowledge of Axl, its role, and its role in disease development show a potential and may contribute to future cancer treatments.
4. Up to 1500 animals will be used. The mice strain is B6.129P2-Axltm1Dgen/J.
5. The purpose of this experiment is to breed mouse strain, in which lacZ gene was inserted into Axl coding gene. Expression of different genes, in this case Axl, differs between individuals. To understand importance of Axl in developing animals it is necessary to perform in vivo studies, since in vitro studies cannot mimic the whole body complexity. B6.129P2-Axltm1Dgen/J is a suitable model to perform study on expression in animals. In vitro studies allowed to investigate relevance of the model and enabled to establish experimental design. The number of animals are reduced by in vitro studies prior to in vivo experiment. Furthermore, animals will be used for both in vivo and ex vivo studies. As the breeders, the same animals will be used across the time. As for the establishment of the colony (project 4480). For breeding, we will use heterozygotes to benefit from increased production of offspring during the experiment. As the colony is established, the breeding will be performed according to the planed experiment in order to reduce the number of animals. The normal state in these animals does not cause pain and no painful procedures will be performed during breeding as mentioned by the Jackson laboratories and confirmed by observation during the establishment of the colony (project 4480). In order to select animals with targeted genotype, small biopsies are taken from the ear. This approach allow reduction of animals used in experiments. For breeding only heterozygotes are used. Homozygous wild type individuals are excluded from the colony, in order to exclude unwanted phenotype and decrease number of not-targeted allele amongst newborn pups. As the colony is established, the same procedure will be continued with particular focus on limiting inbred mice in order to maintain healthy animals in the colony.