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
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Q. What are few examples of cnidarians? In which environments can these animals be found? Hydra, Jellyfish, sea anemones and corals are good examples. All of them are aquatic,

You may have heard in the news currently that a new species of frog was discovered within a rainforest. You objective are to isolate genomic DNA and construct an expression libr

Define Procedure for Measurement of pH? To ensure reliability of the pH readings, you should first calibrate the pH meter. You should adjust the pH meter so that the readings a

explain the role of photophosphorylation and chemiosmosis in photosynthesis

If 40% gene pool is heterozygous then what percentage should be homozygous?

Is there anything I can do to keep my brain healthy in older age? It is increasingly clear that how we live our lives on a daily basis strongly influences how well our brain ag

Define protein requirements of children up to age of 2 years? Infants and children up to age of 2 years should consume about 40% energy from fat (i.e. 40 en%). Fat is an import

what is the crystallization of a virus? what is the importance of this process?

OBSESSIVE COMPULSIVE DISORDER (OCD): OCD is another common neurotic disorder seen in the hospital.  Definition  Obsessive Compulsive Disorder is  the disorder characte