By gathering the genotypes we plan to use for our research at our institute, we will be able to synchronize the breeding schedules. Backcrossing with "fresh" breeder mice is a required to maintain a healthy genetic status of inbred strains, and through synchronization of the breeding schedules, we can use the same breeder males for several strains, thus reducing the total number of breeder mice needed at our institute.

This is an application for breeding of mouse strains currently in use for cardio-metabolic research. In this breeding project, we have included several genotypes. For the mice with expected phenotypes due to mutations in metabolic genes, the mice are expected to gain more weight compared to normal mice. Obesity might become an issue when these genotypes are fed a calorie-enriched diet. This is however not relevant in a breeding project. Immuno-compromised strains are more susceptible to infections. However, when housed in a clean animal facility this risk of infection is minimal. Atherogenic mouse strains are susceptible to develop atherosclerosis. Unlike humans, however, mice atherosclerosis never rupture, and won't result in more advanced cardiovascular disorders, like stroke. The Coagulation deficiency strains are the only models with a potentially harmful phenotype in this project. There is an expected delay in coagulation time in case of injury. Overall, we evaluate the stress levels imposed by the genotype/phenotype to be mild.

This application is a breeding application for colony maintenance and generation of study animals. Study animals will be used for experiments described by other FOTS approvals.

We have minimized the number of breeders to three breeding pairs/genotype. From experience we know that this number should be sufficient to provide us with enough animals for ongoing research, and at the same time we make sure to maintain a healthy breeding colony. By combining all relevant genotypes currently in use, and the ones planned introduced, we will synchronize the backcrossing events to avoid random genetic drift. Through synchronization, we reduce the number of "fresh" male mice needed to re-introduce healthy genomic material. All experiments we perform (covered by other FOTS approvals), both male and female mice will be included to avoid gender-bias in our results. Form time to time surplus animals will be born. At our institute we always welcome both new and old members of our research groups to improve animal handling skills and learn novel techniques relevant to our research. Our policy is to always make use of surplus animals for this purpose.

This application is a breeding application for colony maintenance and generation of study animals. The general well-being of the animals will be monitored closely by the KPM staff on a daily basis, and by the researchers involved in this project. We can not avoid spontaneous illness in some individuals or injuries through fighting within a cage. During our previous breeding project (FOTS approval 22322), we experienced spontaneous death of mothers and pups. The issue appeared across all genotypes and background strains. As a preventive measure, the KPM staff has provided softened food for cages with mothers and weening litters. Survival of mothers and litters has, as a consequence, greatly improved, and we will continue this strategy in this project. We will consider every case in collaboration with the KPM staff and make the best decisions based on their knowledge and expertise. Suffering or sick animals will be terminated.

This breeding project will use transgenic mouse models and adequate control strains. The models can roughly be categorized into these following groups: Control strains: C57BL/6 J and N: Used as wild type mice. Pep/Boy: Expresses the CD45.1 isoform on leukocytes. Useful for immune cell transplantation studies. Metabolic strains: ApoE, Ldlr and Ldlr-CD45.1: Established atherosclerosis models. We have crossed Ldlr with Pep/Boy mice to obtain Ldlr-CD45.1 mice. Useful for immune cell transplantation studies. DNA-repair deficiency strains: Neil3, EndoV, Mutyh, Ogg1, Alkbh1, Alkbh2 and Alkbh3 are DNA-repair enzymes with roles in epigenetic regulation. DNA-repair deficiency with atherosclerosis: DNA-repair deficiency strains crossed with ApoE KO are included in breeding project. Immune function deficiency strains: Nlrp3: Dampened inflammation due to deficiency of the NLRP3-inflammasaome CD38: Surface molecule on immune cells, affecting phago-lysosomes and cell migration. Rag2: No functional T- and B-cells. Rag2/Il2r double KO: More immunodeficient than Rag2 due to additional mutation in Il2r. Coagulation deficiency strains: B6.129S2-F5tm1Dgi/J, B6;SJL-Tg(Alb-F5)3Dgi/J, B6.129S2-F5tm2Dgi/J: Pro-longed coagulation time, with implications for thrombus formation. Other strains: Tet2, Dnmt3a-loxP: These genes affects clonal hematopoiesis, a novel mechanism our understanding of cardiovascular disease. NR3C2-loxP: Gene encodes mineral corticoid receptor, a protein known to affect blood pressure.