The insect epidermis which produces the overlying cuticle (exoskeleton) performs its various roles in a precisely coordinated manner regulated by the hormonal milieu. Moreover, the epidermal cell in many insects undergoes a sequential polymorphism controlled by the two hormones, 20 hydroxyecdysone (20HE) and juvenile hormone (JH). Therefore, to prove more deeply into the nature and control of these processes, we propose to continue our studies on the epidermis of the tobacco hornworm, Manduca sexta, as a model system.
Our specific aims are: to isolate the insecticyanin gene from the Manduca genomic clone library and use it as a representative larval gene to study the regulation of its synthesis by 20HE and JH during the molt cycle and its permanent turnoff at metamorphosis; to study the hormonal control of larval cuticular melanization and associated epidermal pigmentation with special reference to the synthesis and activities of the enzymes involved; to analyze the sequential nature of pupal cuticle deposition in vivo and in vitro, both cytologically and biochemically (in terms of changing protein patterns), the elucidate the role of ecdysteroids in its regulation utilizing the in vitro culture system; to analyze the substrates and enzymes involved in pre-ecdysial pupal tanning and the control of this process by ecdysteroids; to explore the biochemistry of the secretion of the dermal (Verson's) gland and its endocrine regulation as the basis for a possible model system for a study of the morphogenetic action of JH. The information gained in these studies can be readily applied to other insects such as vectors of disease whose epidermis is not soreadily available and utilized in devising insect control methods related to either cuticle synthesis, sclerotization, and waterproofing or to the hormonal control of these processes. Moreover, the information gained about the cellular and molecular basis of the morphogenetic action of 20HE and JH will contribute to a better understanding of a fundamental problem in developmental biology, i.e. how is a cell committed to a particular differentiative pathway.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI012459-10
Application #
3125185
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1979-01-01
Project End
1986-12-31
Budget Start
1985-01-01
Budget End
1985-12-31
Support Year
10
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Arts and Sciences
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Bayer, Cynthia; Zhou, Xiaofeng; Zhou, Baohua et al. (2003) Evolution of the Drosophila broad locus: the Manduca sexta broad Z4 isoform has biological activity in Drosophila. Dev Genes Evol 213:471-6
Weller, J; Sun, G C; Zhou, B et al. (2001) Isolation and developmental expression of two nuclear receptors, MHR4 and betaFTZ-F1, in the tobacco hornworm, Manduca sexta. Insect Biochem Mol Biol 31:827-37
Zhou, B; Hiruma, K; Shinoda, T et al. (1998) Juvenile hormone prevents ecdysteroid-induced expression of broad complex RNAs in the epidermis of the tobacco hornworm, Manduca sexta. Dev Biol 203:233-44
Zhou, B; Hiruma, K; Jindra, M et al. (1998) Regulation of the transcription factor E75 by 20-hydroxyecdysone and juvenile hormone in the epidermis of the tobacco hornworm, Manduca sexta, during larval molting and metamorphosis. Dev Biol 193:127-38
Lan, Q; Wu, Z; Riddiford, L M (1997) Regulation of the ecdysone receptor, USP, E75 and MHR3 mRNAs by 20-hydroxyecdysone in the GV1 cell line of the tobacco hornworm, Manduca sexta. Insect Mol Biol 6:3-10
Jindra, M; Huang, J Y; Malone, F et al. (1997) Identification and mRNA developmental profiles of two ultraspiracle isoforms in the epidermis and wings of Manduca sexta. Insect Mol Biol 6:41-53
Rebers, J E; Niu, J; Riddiford, L M (1997) Structure and spatial expression of the Manduca sexta MSCP14.6 cuticle gene. Insect Biochem Mol Biol 27:229-40
Lan, Q; Riddiford, L M (1997) DNA transfection in the ecdysteroid-responsive GV1 cell line from the tobacco hornworm, Manduca sexta. In Vitro Cell Dev Biol Anim 33:615-21
Riddiford, L M (1996) Juvenile hormone: the status of its ""status quo"" action. Arch Insect Biochem Physiol 32:271-86
Jindra, M; Malone, F; Hiruma, K et al. (1996) Developmental profiles and ecdysteroid regulation of the mRNAs for two ecdysone receptor isoforms in the epidermis and wings of the tobacco hornworm, Manduca sexta. Dev Biol 180:258-72

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