# HORMONAL REGULATION OF THE INSECT EPIDERMIS

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 1990 · $175,525

## Abstract

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.

## Key facts

- **NIH application ID:** 3125189
- **Project number:** 5R01AI012459-15
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **SAM.gov UEI:** HD1WMN6945W6
- **Principal Investigator:** LYNN M RIDDIFORD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $175,525
- **Award type:** 5
- **Project period:** 1979-01-01 → 1991-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3125189

## Citation

> US National Institutes of Health, RePORTER application 3125189, HORMONAL REGULATION OF THE INSECT EPIDERMIS (5R01AI012459-15). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3125189. Licensed CC0.

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