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SUMMARY:Maternal mRNA regulation by the piRNA pathway in the Drosophila em
 bryo\,  from degradation to stabilization
DTSTART:20160901T150000
DTEND:20160901T160000
DTSTAMP:20260408T105140Z
UID:c12f765ca8f672eb0616e5ef91b5b79802f3b5e6c64c68a817d88568
CATEGORIES:Conferences - Seminars
DESCRIPTION:Jeremy DUFOURT\nPiwi-interacting RNAs (piRNAs) and PIWI protei
 ns play a crucial role in germ cells and germline stem cells\, by repressi
 ng transposable elements and regulating gene expression. In particular\, r
 ecent data have demonstrated the implication of the piRNA pathway in post-
 transcriptional gene regulation in germ cells. In Drosophila\, piRNAs prod
 uced in the female germline are loaded maternally into the embryo\, bound 
 mostly to the PIWI protein Aubergine (Aub). piRNA-loaded Aub is present bo
 th in the somatic part of the embryo and at higher levels in the posterior
  germ plasm\, a specialized cytoplasm where germ cells are specified. In t
 he embryo\, Aub targets maternal mRNAs through incomplete base-pairing wit
 h piRNAs and can induce their destabilization by either direct cleavage or
  the recruitment the CCR4-NOT deadenylation complex. Aub-dependent unstabl
 e mRNAs encode germ cell determinants\, which are degraded in the somatic 
 part of the embryo\, while they are stabilized and translated in the germ 
 plasm to participate in germ cell development. This raises the question of
  the role of piRNAs and Aub in the stabilization of these germ cell mRNAs 
 in the germ plasm. Using nanos mRNA that encodes a conserved germline dete
 rminant\, we show that piRNAs and Aub play an active role in the protectio
 n of germ cell mRNAs in the germ plasm. We identify Wispy\, the germline-s
 pecific non-canonical poly(A) polymerase as directly interacting with Aub 
 and colocalizing with Aub in the germ plasm. We propose that Aub acts by d
 irectly recruiting Wispy to germ cell mRNAs\, leading to their polyadenyla
 tion and stabilization in the germ plasm. These results reveal an unexpect
 ed role of piRNAs in mRNA localization and stabilization and identify Aub 
 and piRNAs as key players in orchestrating embryonic patterning through tw
 o opposite functions: somatic decay and germline stabilization of germ cel
 l mRNAs.
LOCATION:AI 1153 https://plan.epfl.ch/?room==AI%201153
STATUS:CONFIRMED
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