Dab1 contributes differently to the morphogenesis of the hippocampal subdivisions

Abstract

The hippocampal formation (HF) is morphologically and functionally distinguishable into the subdivisions, such as the dentate gyrus (DG), subiculum, and Ammon's horn. The Ammon's horn is further divided into the CA (Cornu Ammonis)1, CA2, and CA3. The Reelin-Dab1 signal is essential for the morphogenesis of the mammalian brain. In the neocortex of Reelin-Dab1 signal mutants the laminar pattern of the neurons is disrupted along the radial axis. Morphological abnormalities in the HF of the Reelin-Dab1 mutants were known, but how these abnormalities appear during development had not been extensively studied. We examined the morphology of the well-developed Dab1 deficient HF by staining with a silver impregnation method in this report, and found that disruption of lamination in the CA1, CA3, and DG was different. Abnormalities observed in the development of Dab1 deficient CA1 were similar to those reported in the neocortical development, while Dab1 deficient CA3 neuronal progenitors radially spreaded beyond presumptive pyramidal layer. The intermediate progenitor cells ectopically located in the Dab1 deficient DG, but neurogenesis was normal in the CA1 and CA3. These observations suggest that the morphogenesis in these HF subdivisions employs different developmental mechanisms involving Dab1 function.

Multiple types of genomic variation contribute to adaptive traits in the mustelid subfamily Guloninae

“…We also detected PSGs (DAB1, OPA1 and CTNS) linked to cognition, brain development and vision (Blume et al 2017;Del Dotto et al 2018;Browning et al 2019). Several PSGs (BNIPL, IL18BP, CRNN) were associated with the immune system; (Im et al 2002;Xie et al 2004;Nelson et al 2008) while three others (ANAPC7, RNF212B, IZUMO3) are involved in reproduction processes (Grayson and Civetta 2012;Reynolds et al 2013;Wild et al 2018) and USB1 and CLCN4 have a role in basal cell cycle processes (Picollo and Pusch 2005;Nomura et al 2018).…”

HeterozygousDab1Null Mutation Disrupts Neocortical and Hippocampal Development

“…Homozygous null mutation of the Dab1 gene causes severe migration failure both in the cerebral neocortex and hippocampus ( Howell et al, 1997 ; Yoneshima et al, 1997 ; Franco et al, 2011 ; Blume et al, 2017 ). However, half reduction of Dab1 gene expression did not cause migration failure in the cerebral neocortex, and impaired only late-born pyramidal neuron migration in the caudal hippocampus.…”

Tsukushi is essential for proper maintenance and terminal differentiation of mouse hippocampal neural stem cells

“…For example, expression of Nuclear factor one X (NFIX) by neuronal progenitor cells has been reported to regulate the differentiation of the progenitor cells and ultimately influence the hippocampal morphogenesis (Heng et al, ). A downstream component of RELN signaling pathway, Disabled‐1 (Dab1) has been found to have a critical role for the morphogenesis of hippocampal subdivisions (Blume et al, ). Ubiquitin‐specific protease 9X (USP9X), a deubiquitylating protein has also been reported to play an important role for hippocampal development, as USP9X‐deletion results in severe morphological abnormalities (Oishi et al, ).…”