The roles of spartin in Drosophila circadian clock

Hereditary spastic paraplegias (HSPs) are a group of neurological disorders characterized by muscle weakness and progressive spasticity in lower limb. Troyer syndrome is an autosomal recessive form of HSPs caused by a frame-shift mutation in the spartin (SPG20) gene encoding SPARTIN protein. Drosophila Troyer syndrome model was developed, wherein spartin mRNA expression was abolished, and named spartin1. While we measured the locomotor behavior of spartin1 flies, we noticed that spartin1 flies manifested long circadian period of ~ 27hr. These data suggested that SPARTIN might play a role in circadian clock system. In spartin1 flies, the levels of PERIOD (PER) and TIMELESS(TIM) protein were lower than those of control flies, w1118, during the night time in daily LD cycles, which was well correlated with lowerper and timmRNA levels. Intriguingly, light mediated degradation of TIM protein was impaired in spartin1 flies, consistent with high levels of TIM protein at the early day in LD cycles. In spartin1flies, hyper-phosphorylated PER proteins were observed by ZT12 suggesting that degradation of PER proteins might be attenuated. Nonetheless, we observed that c155-gal4;;spartin1 flies manifested~24 h periodalbeit with no expression of spartin. On the contrary, (17)Da-gal4;spartin1 flies manifested~26.7 h period with strong expression of spartin. These results indicated that there is no correlation between long circadian period and the status of spartinexpression. We further discoveredthat the 1st chromosome of spartin1 flies contributed to the long circadian period of these flies. Thus, to elucidate the precise mechanism for the regulation of circadian period in spartin1 flies, further studies to clone the potential mutation(s) on the 1st chromosome will be necessary.

Author dc:creator

• 이, 은아

Contributors dc:contributor

• 김, 은영
• 대학원 의생명과학과
• 201124380

• 초파리
• 생체시계
• period
• timeless
• 유전성연축성대마비
• Troyer syndrome
• SPARTIN
• Drosophila
• Circadian Clock
• Hereditary Spastic Paraplegias (HSPs)

Language dc:language

ko

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000015074
000000015074

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/8609