Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa no ha, Kashiwa City, Chiba #277-8562, Japan; Research Fellow of Japan Society for the Promotion of Science (JSPS), Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan.
Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa no ha, Kashiwa City, Chiba #277-8562, Japan.
Gen Comp Endocrinol. 2019 Sep 1;280:185-191. doi: 10.1016/j.ygcen.2019.05.001. Epub 2019 May 2.
Myosuppressin is one of essential peptides controlling biological processes including feeding behavior. Here we identified and characterized the cDNAs that encode myosuppressin precursor and its receptor in the two-spotted cricket Gryllus bimaculatus. The presence of the mature peptide (Grybi-MS) was confirmed by direct measurement of adult brain. RT-PCR revealed the tissue distribution of these transcripts; myosuppressin is expressed predominantly in the brain and central nervous system, whereas its receptor is ubiquitously expressed in the cricket body. To address the function of Grybi-MS, we performed several bioassays to test concerning feeding behavior and digestive function upon exposure to Grybi-MS. Administration of synthetic Grybi-MS resulted in increased feeding motivation, accompanied by an increase in food intake. Meanwhile, the hemolymph lipid and carbohydrate titers were both elevated after Grybi-MS injection. As the intestinal contraction is significantly inhibited by the exposure to Grybi-MS, the upregulating feeding index might be complicated in the cricket body. The current data indicate that Grybi-MS modulates feeding behavior to control the physiological processes in the cricket.
肌抑制素是控制包括摄食行为在内的生物过程的必需肽之一。在这里，我们鉴定并描述了双斑蟋蟀 Gryllus bimaculatus 中肌抑制素前体及其受体的 cDNA。通过直接测量成年大脑证实了成熟肽（Grybi-MS）的存在。RT-PCR 揭示了这些转录本的组织分布；肌抑制素主要在大脑和中枢神经系统中表达，而其受体在蟋蟀体内广泛表达。为了研究 Grybi-MS 的功能，我们进行了几项生物测定，以测试接触 Grybi-MS 后对摄食行为和消化功能的影响。合成 Grybi-MS 的给药导致摄食动机增加，伴随着食物摄入量的增加。同时，注射 Grybi-MS 后血液中的脂质和碳水化合物含量均升高。由于肠道收缩受到 Grybi-MS 的暴露显著抑制，因此在蟋蟀体内，上调的摄食指数可能很复杂。目前的数据表明，Grybi-MS 调节摄食行为以控制蟋蟀的生理过程。
