. Drosophila females homozygous for loss-of-function mutations in the gene auber
ID: 145110 • Letter: #
Question
. Drosophila females homozygous for loss-of-function mutations in the gene aubergine are sterile. RNA-Seq experiments show that in the ovaries of these females, the levels of RNAs for many kinds of transposable elements are more than 10× higher than in wild-type ovaries. The aubergine gene encodes a Piwi-family protein.
a. Why do you think these females are sterile?
b. Piwi proteins interact with piRNAs that are transcribed from piRNA gene clusters. Given that the levels of many kinds of TEs are elevated in mutant ovaries, what kinds of DNA sequences do you think are located in these clusters?
c. Many investigators think of piRNAs as a kind of defensive mechanism that protects organisms from the effects of new transposable elements that might be introduced into genomes, for example from other species. Explain.
d. In what way might piRNA systems be beneficial to transposable elements?
Explanation / Answer
Ans a. These females are sterile due to the loss of function mutations of aubergine resulting in truncated proteins. Aub protein is highly expressed in ovaries and testes, it plays a major role in the development of gonads and ensuring stability.
Ans b. Fragments cDNA would be observed in such clusters. It leads to the premature stopping of the codon.
Ans c. piRNAs implement epigenetic control by alteration of DNA methylation, chromatic modifications and non coding the RNAs would result in the maintenance of cell homeostatsis and proper cell development thus eliminating uncontrolled growth of cells.
Ans d. piRNAs functions as a master regulator in the repression of Transposal elements. The piRNAs repress the target mRNAs by a ping pong cycle, thus resulting in the proper control and regulation.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.