Effect of metamorphic hormones on gene expression, Biology

Effect of Metamorphic Hormones on Gene Expression

Effect of metamorphic hormones on gene expression in moulting and metamorphosing insects, the first report of a particular hormone being capable to influence specific gene loci, control their transcription and lastly influence cell differentiation was reported in the 1960s by Clever and Karlson on the basis of their studies on Dipteran larva Chironomus. These findings were based upon experiments in which Clever injected minute quantities of ecdysone into the larva and take place within fifteen minutes, hormone induced puffings (swellings) at specific regions of a specific chromosome. Clever also studied patterns of puffing in polytene chromosomes at various larval developmental stages. He extra established that puffing of specific chromosomal bands takes place at specific times in usual course of development and follows a fixed sequence whereby certain bands puff at one stage to synthesize RNA and regress at a later stage. For instance he injected ecdysone into an intermoult larva in which puffing of a band 1-19A was known to be particularly active, and observed that in 10- 15 minutes, puff 1-19,A regressed, band 1-18C started to puff, followed by puffing of band IV-2B. This puffing sequence was exactly identical to the sequence that occurs just before moulting, a time at which the insect spontaneously releases ecdysone into the hemolymph Figure diaplys similar findings in Drosophila as observed by Becker, 1959.


1291_Effect of metamorphic hormones on gene expression.png

Figure: Puffs appearing and disappearing during the third larval instar and the prepupal stage at the base of chromosome arm 111 L of Drosophila melanogaster salivary glands. Numbers indicate hours before or after pupanum formation. After H. Becker, Chromosome. 10-654 (1959).

 

 

Posted Date: 1/31/2013 12:10:13 AM | Location : United States







Related Discussions:- Effect of metamorphic hormones on gene expression, Assignment Help, Ask Question on Effect of metamorphic hormones on gene expression, Get Answer, Expert's Help, Effect of metamorphic hormones on gene expression Discussions

Write discussion on Effect of metamorphic hormones on gene expression
Your posts are moderated
Related Questions

Explain Saquinavir Saquinavir (SQV, Fortovase, Invirase) - When administered as a single protease inhibitor, a soft-gel preparation (Fortovase) with improved bioavailability an

How is synthesis of soluble proteins taking equatorial part on the surface of lens? Synthesis of soluble proteins taking equatorial part on the surface of lens as follows: 1

What is factor VIII? What is the genetic disease in which this factor is absent? Factor VIII has the function of activating factor X that in its turn is essential for the trans

Q. Indications for Surgery of mitral regurgitation? Surgery is indicated in all symptomatic patients (class II and above) with severe mitral regurgitation and normal or decreas

Method for fractionation of subcellular organelles In order to study the composition and the metabolic role of the various subcellular organelles in a cell, it becomes necessar

Is it possible to perform investigation of natural paternity, maternity or brotherhood and sisterhood using the ABO blood typing? By using the ABO blood typing it is possible o

Sucrose is a non-reducing Sugar while Maltose and Lactose are reducing due to the presence of free Aldehydic Functional Group in them. In SUgar the Aldehydic Group of both Glucose

Which one of the following statements is correct with respect to AIDS? 1. The HIV can be transmitted through eating food together with an infected person 2. Drug addicts are

Q. What do you mean by hydraulic modelling? Modelling is neither new nor relevant to hydraulic engineering only. It is practiced in the field of hydraulic machinery for testing