Developmental Biology
Developmental Biology
11th Edition
ISBN: 9781605354705
Author: Scott F. Gilbert, Michael J. F. Barresi
Publisher: Sinauer Associates is an imprint of Oxford University Press
bartleby

Concept explainers

bartleby

Videos

Question
Book Icon
Chapter 21, Problem 1DQ
Summary Introduction

To review:

The control of diseases such as malaria by altering insect metamorphosis.

Introduction:

Malaria is one of the most widespread vector-borne diseases common in tropical and subtropical areas of the world, including regions in Africa, Asia, and America. Malaria is caused by the protozoan parasites, belonging to the genus Plasmodium, residing in some female mosquitoes of the genus Anopheles.

Expert Solution & Answer
Check Mark

Explanation of Solution

Hormonal control is essential for coordination and regulation of many aspects of the developmental process in many organisms. Insect molting and metamorphosis are controlled by two effector hormones: the steroid 20-hydroxyecdysone (20E) and the lipid juvenile hormone (JH). 20E has been characterized as the principal molting hormone in insects (Gilbert et al., 2002), which initiates and coordinates each molt (larva-to-larva, larva-to-pupa, pupa-to-adult) and regulates the gene expression changes that occur during metamorphosis. Molting and metamorphosis are initiated by a rise in the titer of the ecdysteroids. Upon initiation of the endocrine signaling, 20E binds to the ecdysone receptor (EcR), a member of the nuclear hormone receptor superfamily, which heterodimerizes with another nuclear receptor. The regulation of insect metamorphosis is controlled by the juvenile hormone (JH), ecdysone, and active hormone 20E. 20E and JH together cause molts forming next larval instar. The low concentration of JH, the 20E-induced molt produces pupa instead of larva. When 20E acts in the absence of JH, the imaginal discs differentiate and the molt gives rise to an adult (imago).

In Lepidoptera, there is one or more small peaks of ecdysteroids in the absence of JH following attainment of a critical weight that initiate metamorphic events such as wandering behavior. Then a high peak of ecdysteroids in the presence of JH initiates pupation. In numerous studies, precise fluctuations of ecdysteroid titers in last instar larval and in pupal stages of Ae. Aegypti have been determined. Many studies attempted to correlate ecdysteroid levels to gene expression profiles to measure ecdysteroid fluctuations in our system. Expression of ecdysone receptors, transcription factors and other ecdysone-regulated genes was compared with the timing of ecdysteroid peaks.

Conclusion

The future research focuses on the specific function(s) of ecdysone receptors and ecdysone regulated transcription factors during mosquito development to control malaria.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Nursing #2Help me with this question Explain  the impact digital technology has had on assistive devices for people with physical challenges.?
Nursing questions Whatbenefit can community involvement in development provide?
Question Completion Status: You feel that a gecko (lizard) would be the perfect, low-maintenance, pandemic pet. After doing your research on its needs, you go out and buy a gecko. It turns out, your favourite part of having the gecko is watching her chase and eat her crickets. As you learned a lot this semester in your Biology labs, you pay particular attention to how she watches her crickets and then runs after them. You also notice that she moves much faster when she's been sitting on her heating rock and then gets fed. Explain the following: a. How her legs being to the side of her body (vs under as in mammals) dictates how she walks. b. What she does with her tail as she moves her body c. How many chambers are in its heart d. How its circulation differs with respect to gas content based on the number of chambers e. Whether they are ectotherms or endotherms f. What its heart starts doing with the temperature increase g. Why its heart does what you described in (f) above (This is a…

Chapter 21 Solutions

Developmental Biology

Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Understanding Nutrition (MindTap Course List)
Health & Nutrition
ISBN:9781337392693
Author:Eleanor Noss Whitney, Sharon Rady Rolfes
Publisher:Cengage Learning
Chapter 7 - Human Movement Science; Author: Dr. Jeff Williams;https://www.youtube.com/watch?v=LlqElkn4PA4;License: Standard youtube license