UBC Theses and Dissertations
Isolation and study of two mutants affecting motor activity in Drosophila melanogaster. Williamson, Rodney, L.M.
Mitants of Prosophila melanogaster which are paralysed by exposure to one temperature, but recover mobility at another temperature may aid in the investigation of the neural and muscular components which govern motor activity. With the help of a mechanical screening method, a recessive sex-linked temperature-sensitive paralytic mutant (parats -53°9) was discovered among the progeny of ethyl methane- sulphonate-treated males and attached-X females. Parats flies which had been raised at 22°C were paralysed within 5 seconds after transfer to 29°C, but quickly regained mobility when returned to 22°C. When left at 29°C for prolonged periods, the flies gradually regained mobility. Further studies indicated that the time required for recovery following an increase in temperature was directly related to the magnitude and rate of the temperature rise. Temperature-sensitive paralysis was seen only in adult flies. The abnormal movements which are characteristic of the behavioural mutants Hk1P, Hk2T , Sh⁵, when linked to parats in males,were quickly stopped and started by temperature shifts from 22°C to 29°C and 29°C to 22°C, respectively. The possible significance of these observations is discussed. parats/M(1)0 females exhibited temperature-sensitive paralysis. The possibility that the chromosome bearing the M(1)0 mutation might also carry a deletion or mutant allele of parats has not yet been investigated. A sex-linked dominant mutation which caused abnormal movements of the head and appendages under ether anaesthesia as well as shuddering movements in unetherised flies was also discovered. The mutation was called Shuddering (Shu – 55.1). The shuddering movements could be temporarily suppressed by feeding the flies media containing LiCl but not NaCl, NH₄Cl or KCl. The evidence presented in this and other studies suggests that the effects of parats and Shu mutations upon motor activity are mediated through their effects upon the nervous system.
Item Citations and Data