Dissecting_behavioural_traits_of_the_Grasshopper_mouse

Recently, the Tripodi lab at the LMB-MRC in Cambridge recently succeeded in importing and successfully breeding a wild strain of mice, caught in the Arizona desert, the Onychomys torridus, also known as the "grasshopper mouse". These muridae, unlike mus musculus, show a very prominent and innate predatory instinct. Northern Grasshopper Mice are highly predatory, and their skulls and teeth resemble those of flesh-eating carnivores such as cats and dogs. Their forelimbs, equipped with elongated fingers and claws, have developed great dexterity, so they are able to manipulate captured prey. These Mice have a complex social system, using howling vocalizations to broadcast information on sex, identity, body size, and location. Grasshopper Mice prey primarily on grasshoppers, crickets, beetles, and notably are resistant to scorpion venom. These muridae, unlike mus musculus, show a very prominent and innate predatory instinct. Predatory behaviour is a magnificent example of an instinctive behaviour that largely depends on the ability to direct precise movements towards a target. Some animals display a highly developed predatory instinct, cats are a fine example, others a poor one. In these species, predatory behaviour is innate and likely genetically predetermined. Albeit capable of generating target oriented motion, laboratory mice show poor predatory skills. As the name suggests they chase and capture grasshoppers and they pursue a variety of moving targets. They morphological and phylogenetic vicinity to the mus musculus might allow us to investigate what changes in circuit organization and neuronal properties underlie the evolution of predatory behaviour or the loss of it. We believe that the Onychomys represents an exciting opportunity to study the evolution of instinct to an unprecedented level of genetic and neural circuit detail. We also believe that it might pave the way to a different approach to the study of animal behaviour, where the selection of the appropriate animal is strictly dictated by the behaviour that one intends to study. Recent advancements in viral circuit tracing and manipulation that we pioneered combined with the improvement in CRISPR genome editing approach truly offers the opportunity to reach the same degree of genetic understanding that was, until now, only possible in mice. However, at the very foundation of such approach, lies the possibility to obtain detailed genome information of the proposed new animal model.