-
LesMardis
Mardisde
del’IAB
l’IAB
Les
Mardi 14 septembre 2010
Tuesday 30 June 2015
Benjamin Loppin
Centre de Génétique et de Physiologie Moléculaire et
Cellulaire, Lyon
IAB Conference room 11 am
Removing protamines from the fertilizing sperm nucleus
in Drosophila
In Drosophila and mammals, histones are massively replaced with sperm specific
DNA packaging proteins, such as protamines, during the differentiation of
spermatids. Protamines are responsible for the extreme compaction of sperm DNA.
At fertilization, protamines are rapidly removed from the fertilizing sperm nucleus
and immediately replaced with maternally provided histones. Although it is well
established that the HIRA/H3.3 nucleosome assembly pathway is crucial for
paternal chromatin assembly in both Drosophila and mouse, little is known about the
mechanism of protamine removal at fertilization. We have recently characterized a
Drosophila maternal thioredoxin that is specifically required for the removal of
sperm protamines. I will present evidence that this protein is targeted to the sperm
nucleus to reduce protamine disulfide bonds that lock sperm chromatin into its
compacted state.
Invited by Thierry Buchou
Rond Point de La Chantourne, 38700 La Tronche (tram line B, stop: Grand Sablon)
The seminar is followed by discussions and exchanges with the speaker and a sandwich buffet is offered.
http://www-iab.ujf-grenoble.fr