New and Improved Animal Model: Humanised Mice Anna Smith - S47477849 VETS1060 University of Queensland - School of Veterinary Science Professor Malcolm Jones
Introduction Animal models are utilised throughout the scientific community to facilitate biomedical researchfi This research can be used in the creation of lifesaving medical services and treatmentsfi While there are many animal models that can be usedti the most common used throughout these practices are genetically modified or humanised micefi Due to their similarities to human anatomy and physiology and ability to carry complementary DNAs (DNA) these mice are able to assist in the analysis of gene function and regulationfi (4) Purpose Humanised mice are utilised throughout biomedical research as researchers are able to target the genes of these mice and create 'knock-in' mouse models in which the mouse sequence is replaced by human DNAfi (4)Through this technique they can also even control genetic expressionfi These mice are a staple choice for research as there is a small gap between the genes of humans and mice which is made even smaller when humanisedfi (5) Benefits Between humans and mice there are approximately 30ti 000 genes of which 95% are sharedfi The use of humanised mice increases this numberfi Due to this humanised mice are a stable choice for lab testing across biomedical researchfi These is also a significant economic advantage as mice are physically small thus requiring little storage space and resourcesfi They also have a short gestation time that yields a large number of offspringti this coupled with their rapid development and short life spanti means that large numbers of mice can be produced safely for experimental usefi (3) Requirements within a laboratory (100) According to Code of Practice for the Housing and Care of Laboratory Miceti Ratsti Guinea Pigs and Rabbits published by the Department of Primary Industries (2) the mice have the following requirements when utilised in a laboratory: · Housing > Should aim to encompass behavioural and physiological needs > Disruption to social grounds should remain at a minimum · Nutrition and Water > Palatable diet that provides the nutrition requirements appropriate to species > Feed stored in vermin-proof rooms > Consideration around the young and handicapped > Portable water that is accessible as all times · Enclosures > Meets space requirements > Compatible with behavioural and physiological needs > Provides comfort > Easy access to animal · Health monitoring > Consider source and species of animals and husbandry practicesfi > Ensure health policy is created and adopted > If negative health on the animal is likelyti it must be submitted to the AEC · Monitoring and records > System of assessment and recording needs to be implemented
> Records maintained for 4 yearsfi Figure 1 Minimum requirements. (2) Species Single or group housing or Animal weight Min floor area * (cm2 per ani- mal) MICE breeding animals single group breeding (g) Any <30 31-40 70 >40 Pair Extra females + litter 200 60 100 300 150 per extra female Min height **