Endocrine Mechanisms Regulating Post-Diapause Development in the Cabbage Armyworm, Mamestra brassicae
نویسندگان
چکیده
Diapause, a programmed developmental arrest at a specific stage, is common in insects and is regulated by hormones. It is well established that in pupal diapause, cessation of ecdysteroid secretion from the prothoracic glands (PGs) after pupal ecdysis leads to diapause initiation, while resumption of its secretion induces post-diapause development. However, what regulates the activity of the glands is poorly understood, especially for the glands of diapause-terminated pupae. In the present study, we investigate the mechanisms by which post-diapause development is regulated in the cabbage armyworm Mamestra brassicae. We demonstrate that the brain is necessary for the initiation of post-diapause development and that the factor in the brain responsible for the activation of the PGs is the prothoracicotropic hormone (PTTH). Further, through measuring the hemolymph PTTH titers by time-resolved fluoroimmunoassay, we show that PTTH is actually released into the hemolymph prior to the activation of the PGs. Although its peak titer is much lower than expected, this low concentration of PTTH is most likely still effective to activate the PGs of post-diapause pupae, because the responsiveness to PTTH of the glands at this stage is very high compared to that of nondiapause pupal PGs. These results strongly suggest that in M. brassicae, PTTH serves as a trigger to initiate pupa-adult development after diapause termination by stimulating the PGs to secrete ecdysteroid.
منابع مشابه
Melatonin in the Testis of the Cabbage Armyworm, Mamestra brassicae
Toshiaki Shimizu* and Naokuni Takeda Laboratory of Applied Entomology, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan Department of Biomedical Science, COSMO Research Institute, Gongendo, Satte, Saitama, 340-01, Japan Z. Naturforsch. 53c, 927-931 (1998); received May 14/June 12, 1998 Melatonin, Mamestra brassicae, Testis, HPLC-ECD, Metabolic Path...
متن کاملMyosuppressin is involved in the regulation of pupal diapause in the cabbage army moth Mamestra brassicae
Diapause, a programmed developmental arrest, is common in insects, enabling them to survive adverse seasons. It is well established that pupal diapause is regulated by ecdysteroids secreted by the prothoracic glands (PGs), with cessation of ecdysteroid secretion after pupal ecdysis leading to pupal diapause. A major factor regulating the gland activity is prothoracicotropic hormone (PTTH) secre...
متن کاملPhysical Map of the DNA of a Mamestra brassicae Nuclear Polyhedrosis Virus Variant Isolated from Spodoptera exigua
The D N A of a multiply-enveloped nuclear polyhedrosis virus (MNPV) of the cabbage moth Mamestra brassicae (Mb), isolated from the beet armyworm Spodoptera exigua, was analysed using restriction endonucleases SmaI, BamHI, BgllI and PstI. The size of the viral D N A was calculated to be about 152 kilobase pairs. Mapping of restriction sites on the D N A was accomplished by hybridization of 32 P-...
متن کاملProthoracicotropic Hormone Acts as a Neuroendocrine Switch between Pupal Diapause and Adult Development
Diapause is a programmed developmental arrest that has evolved in a wide variety of organisms and allows them survive unfavorable seasons. This developmental state is particularly common in insects. Based on circumstantial evidence, pupal diapause has been hypothesized to result from a cessation of prothoracicotropic hormone (PTTH) secretion from the brain. Here, we provide direct evidence for ...
متن کاملAnnual Migration of Cabbage Moth, Mamestra brassicae L. (Lepidoptera: Noctuidae), over the Sea in Northern China
The cabbage moth, Mamestra brassicae L. (Lepidoptera: Noctuidae), is a serious pest of vegetable crops throughout the world. In order to determine whether or not M. brassicae is a migrant, and if yes, what is the pattern of M. brassicae seasonal migration, a long-term study on M. brassicae from April to October in 2003-2014 was carried out by means of a searchlight trap on a small island locate...
متن کامل