IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cellular basis of the embryonic rat pineal gland.
Autor/es:
M.P. IBAÑEZ RODRÍGUEZ; S. NOCTOR; E. MUÑOZ
Lugar:
Mendoza
Reunión:
Congreso; LASC2013-XII Latin American Symposium on Chronobiology; 2013
Resumen:
The pineal gland (PG) begins as an evagination of the diencephalic roof at E15 and becomes a solid organ at the end of gestation. In this study we characterized the major cellular and morphological events that take place in the developing PG from E15 to E21, by examining the expression patterns of Pax6, vimentin (vim), GFAP, Iba-1 and the mitotic marker pSer10-histone H3 (pH3). Pax6 was expressed in pinealocyte precursors throughout PG development, with the highest nuclear levels at earlier stages. A few pH3-positive cells were present in the apical region of the stratified neuroepithelium from E15 to E17, but they were more abundant and randomly expressed in later phases. Interestingly, these mitotic cells showed low Pax6 expression. The embryonic PG expressed vim but not GFAP. In the PG recess, vim-positive cells presented a radial morphology. In more advanced stages, especially at E18 and E19, cells double positive for both Pax6 and vim were observed in rosette-like arrangements. At E20 and E21, high levels of vim expression were confined to a few randomly distributed cells. Iba1-positive microglial cells, possibly derived from choroid plexus and meninges, invaded the PG from E15 onwards. In brief, the PG evolves from Pax6- and vim-positive precursor cells capable of adopting different morphologies throughout development to give rise the main cell type, the pinealocytes, and a subpopulation of interstitial cells that are also present in the adult PG. We speculate that microglia modulate PG morphogenesis and are a key player in the immunological functions recently attributed to the PG.