Cyclin D2 Is Critical for Intermediate Progenitor Cell Proliferation in the Embryonic Cortex

• DOI: 10.1523/jneurosci.2284-09.2009
• Publication Date: 2009-07-29T17:27:56Z
• Authors: Sara B. Glickstein; Julie A. Monaghan; Hajira B. Koeller; Tiffanie K. Jones; M. Elizabeth Ross
• Keywords: Progenitor

Expression of cyclins D1 (cD1) and D2 (cD2) in ventricular zone subventricular (SVZ), respectively, suggests that a switch to cD2 could be requisite step the generation cortical intermediate progenitor cells (IPCs). However, direct evidence is lacking. Here, cD1 or was seen colabel subsets Pax6-expressing radial glial (RGCs), whereas only colabeled with Tbr2. Loss IPCs −/− embryonic cortex analysis expression patterns mutant embryos lacking Tbr2 indicate used as progenitors transition from RGCs important for expansion IPC pool. This further supported by laminar thinning, microcephaly, selective reduction SVZ population cortex. Cell cycle dynamics between day 14–16 knock-out lines showed preserved parameters mutants induced expression, but absence not compensated cD1. associated reduced proliferation enhanced cell exit progenitors, indicating crucial role support divisions. In addition, cD2, cD1, affected both G 1 -phase also S-phase duration, implicating importance these phases division cycles expand That predominant D-cyclin expressed human at 19–20 weeks gestation indicated evolutionary larger mammals whom expansive divisions are thought enable larger, convoluted, cerebral cortices.