Animalmodels, such as mice and rats, are essential tools in scientific researchessuch as development of medical and veterinary discoveries.
People started usingdifferent animal models since the discovery of science itself. However, the usageof animals in research differs in different views of individuals. Even so, itis undeniable that animal-based researches has been part of every medicaldiscovery for more than hundreds of years. Because of this, there is a rapidtechnological advances and animal studies remains a need for scientificresearches today and even in future.
The most commonly used laboratoryanimal models are rats and mice. According to the Foundation for BiomedicalResearch (FBR), 95% of all laboratory animals are mice and rats. Researchers andscientists prefer rodents since they are small, easily housed and maintained,and can adapt well to new surroundings. They reproduce quickly and have a shortlife span of two to three years (Melina, 2010), which enablesresearchers to have several generations of offsprings within a reasonableperiod of time (Johnson, 2012). And also rodentsare relatively inexpensive compared to other animal models such as rabbits,cats, or dogs and it can be bought in large quantities from commercialproducers. Most mice and rats used in a clinical trial is of the same strain orbreed, for they are somewhat genetically identical, the only difference is thegenders. Another reason is that according to a website article, humans and miceshare almost 95% of genes which made them an effective model for the human body(Undersatanding Animal Research, 2017) and is appropriatefor use to answer many research questions said Jenny Haliski, a representativefor the National Institute of Health (HIH) Office of the Laboratory AnimalWelfare. Majority of the commonly used mice in laboratories are albino.
This isdue to a common mutation in tyrosinase gene. In which tyrosinase is one of thekey enzymes in mammalian melanin synthesis (Ramsden & Riley, 2014). ICR strain,an albino, is a mouse model of Swiss origin and descended from the original twomale and seven female albino non-inbred mice (Research Models and Services, n.d.). This outbred strainwas named after the Institute of Cancer Research in the USA. The mice strain hasa docile nature, excellent reproductive and maternal instincts, rapid growthrate and low incidence of spontaneous tumor (Research Models and Services, n.d.
). Hlywka et al.(2013) used both male and female ICR mice to determine the effects of arruva,an R, R-monatin salt isomer in a repeated 90-day oral toxicity study. Another studyconducted by Seto et al (2012) used two-week-old ICR mice to determine thecausative agent of hemorrhagic fever with renal syndrome (HFRS) which later leadsto pulmonary disease in laboratory mice. In cancer research using ICR mice,Moon et al.
(2014) conducted a sub-acute toxicity study with repetitiveintramuscular injection of cervical cancer vaccines on female ICR mice. In which,the female ICR mice exposed to cervical cancer vaccines did not show any toxicresponse. ICR strain mice can be used inalmost all types of researches – oncology, immunology, toxicology, neurology,etc. However, ICR mice that comes from different sources may also give rise todifferent or even contradictory results.