TY - JOUR
T1 - Otx1l, Otx2 and Irx1b establish and position the ZLI in the diencephalon
AU - Scholpp, Steffen
AU - Foucher, Isabelle
AU - Staudt, Nicole
AU - Peukert, Daniela
AU - Lumsden, Andrew
AU - Houart, Corinne
PY - 2007/9
Y1 - 2007/9
N2 - The thalamic complex is the major sensory relay station in the vertebrate brain and comprises three developmental subregions: the
prethalamus, the thalamus and an intervening boundary region – the zona limitans intrathalamica (ZLI). Shh signalling from the ZLI
confers regional identity of the flanking subregions of the ZLI, making it an important local signalling centre for regional
differentiation of the diencephalon. However, our understanding of the mechanisms responsible for positioning the ZLI along the
neural axis is poor. Here we show that, before ZLI formation, both Otx1l and Otx2 (collectively referred to as Otx1l/2) are expressed
in spatially restricted domains. Formation of both the ZLI and the Irx1b-positive thalamus require Otx1l/2; embryos impaired in
Otx1l/2 function fail to form these areas, and, instead,the adjacent pretectum and, to a lesser extent, the prethalamus expand into
the mis-specified area. Conditional expression of Otx2 in these morphant embryos cell-autonomously rescues the formation of the
ZLI at its correct location. Furthermore, absence of thalamic Irx1b expression, in the presence of normal Otx1l/2 function, leads to a
substantial caudal broadening of the ZLI by transformation of thalamic precursors. We therefore propose that the ZLI is induced
within the competence area established by Otx1l/2, and is posteriorly restricted by Irx1b.
AB - The thalamic complex is the major sensory relay station in the vertebrate brain and comprises three developmental subregions: the
prethalamus, the thalamus and an intervening boundary region – the zona limitans intrathalamica (ZLI). Shh signalling from the ZLI
confers regional identity of the flanking subregions of the ZLI, making it an important local signalling centre for regional
differentiation of the diencephalon. However, our understanding of the mechanisms responsible for positioning the ZLI along the
neural axis is poor. Here we show that, before ZLI formation, both Otx1l and Otx2 (collectively referred to as Otx1l/2) are expressed
in spatially restricted domains. Formation of both the ZLI and the Irx1b-positive thalamus require Otx1l/2; embryos impaired in
Otx1l/2 function fail to form these areas, and, instead,the adjacent pretectum and, to a lesser extent, the prethalamus expand into
the mis-specified area. Conditional expression of Otx2 in these morphant embryos cell-autonomously rescues the formation of the
ZLI at its correct location. Furthermore, absence of thalamic Irx1b expression, in the presence of normal Otx1l/2 function, leads to a
substantial caudal broadening of the ZLI by transformation of thalamic precursors. We therefore propose that the ZLI is induced
within the competence area established by Otx1l/2, and is posteriorly restricted by Irx1b.
U2 - 10.1242/dev.001461
DO - 10.1242/dev.001461
M3 - Article
SN - 1477-9129
VL - 134
SP - 3167
EP - 3176
JO - Development (Cambridge): for advances in developmental biology and stem cells
JF - Development (Cambridge): for advances in developmental biology and stem cells
IS - 17
ER -