| Summary: | 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. === Medicine, Faculty of === Medical Genetics, Department of === Graduate
|
|---|
