Genetics and Molecular Biology Laboratory, Department of Zoology, University of Dhaka, Dhaka-1000, Bangladesh.
Microrna. 2020;9(4):283-288. doi: 10.2174/2211536609666200204113403.
Learning and memory are basic aspects of neurogenetics as most of the neurological disorders start with dementia or memory loss. Several genes associated with memory formation have been discovered. MicroRNA genes, miR-1000 and miR-375, were reported to be associated with neural integration and glucose homeostasis in some insects and vertebrates. However, the neuronal function of these genes is yet to be established in D. melanogaster.
The possible role of miR-1000 and miR-375 in learning and memory formation in this fly has been explored in the present study.
Both types of appetitive and aversive olfactory conditional learning were tested in the miR- 1000 and miR-375 knockout (KO) strains and compared with the wild one. Five days old third instar larvae were trained by allowing them to be associated with an odor with reward (fructose) or punishment (salt). Then, the larvae were tested to calculate their preferences to the odor they were trained with. Learning Index (LI) values and larval locomotion speed were calculated for all strains.
Knockout strain of miR-1000 showed significant deficiency in both appetitive and aversive memory formation whereas miR-375 KO strain showed a significantly lower response only in appetitive one.
The results of the present study indicate an important role of miR-1000 and miR-375 genes in forming short-term memory in D. melanogaster.
学习和记忆是神经遗传学的基本方面，因为大多数神经紊乱疾病都始于痴呆或记忆丧失。已经发现了一些与记忆形成相关的基因。在一些昆虫和脊椎动物中，miR-1000 和 miR-375 等 microRNA 基因与神经整合和葡萄糖稳态有关。然而，这些基因在黑腹果蝇中的神经元功能尚未确定。
本研究探索了 miR-1000 和 miR-375 在果蝇学习和记忆形成中的可能作用。
在 miR-1000 和 miR-375 敲除（KO）菌株中测试了这两种类型的味觉和厌恶嗅觉条件学习，并与野生型进行了比较。通过让 5 天大的三龄幼虫与有奖励（果糖）或惩罚（盐）的气味相关联来进行训练。然后，测试幼虫以计算它们对所训练气味的偏好。为所有菌株计算学习指数（LI）值和幼虫的运动速度。
miR-1000 的敲除菌株在味觉和厌恶记忆形成方面都表现出明显的缺陷，而 miR-375 KO 菌株仅在味觉记忆形成方面表现出明显较低的反应。
本研究结果表明，miR-1000 和 miR-375 基因在黑腹果蝇短期记忆形成中起着重要作用。
