Chin Chiang
Professor of Cell and Developmental Biol
Last active: 3/30/2020

Lkb1 regulates granule cell migration and cortical folding of the cerebellar cortex.

Ryan KE, Kim PS, Fleming JT, Brignola E, Cheng FY, Litingtung Y, Chiang C
Dev Biol. 2017 432 (1): 165-177

PMID: 28974424 · PMCID: PMC5694378 · DOI:10.1016/j.ydbio.2017.09.036

Cerebellar growth and foliation require the Hedgehog-driven proliferation of granule cell precursors (GCPs) in the external granule layer (EGL). However, that increased or extended GCP proliferation generally does not elicit ectopic folds suggests that additional determinants control cortical expansion and foliation during cerebellar development. Here, we find that genetic loss of the serine-threonine kinase Liver Kinase B1 (Lkb1) in GCPs increased cerebellar cortical size and foliation independent of changes in proliferation or Hedgehog signaling. This finding is unexpected given that Lkb1 has previously shown to be critical for Hedgehog pathway activation in cultured cells. Consistent with unchanged proliferation rate of GCPs, the cortical expansion of Lkb1 mutants is accompanied by thinning of the EGL. The plane of cell division, which has been implicated in diverse processes from epithelial surface expansions to gyrification of the human cortex, remains unchanged in the mutants when compared to wild-type controls. However, we find that Lkb1 mutants display delayed radial migration of post-mitotic GCPs that coincides with increased cortical size, suggesting that aberrant cell migration may contribute to the cortical expansion and increase foliation. Taken together, our results reveal an important role for Lkb1 in regulating cerebellar cortical size and foliation in a Hedgehog-independent manner.

Copyright © 2017 Elsevier Inc. All rights reserved.

MeSH Terms (13)

Animals Cell Differentiation Cell Division Cell Movement Cerebellar Cortex Cytoplasmic Granules Hedgehog Proteins Mice Nerve Tissue Proteins Neurons Organogenesis Protein-Serine-Threonine Kinases Signal Transduction

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