Expression of embryonic tau protein isoforms persist during adult neurogenesis in the hippocampus.
Tau is a microtubule-associated protein with a developmentally regulated expression of multiple isoforms. The neonatal isoform is devoid of two amino terminal inserts and contains only three instead of four microtubule-binding repeats (0N/3R-tau). We investigated the temporal expression pattern of 0N-tau and 3R-tau in the rat hippocampus. After the decline of 0N- and 3R-tau immunoreactivity during the postnatal development both isoforms remain highly expressed in a few cells residing beneath the granule cell layer. Coexpression of the polysialylated neuronal cell adhesion molecule, doublecortin, and incorporated bromodeoxyuridine showed that these cells are proliferating progenitor cells. In contrast mature granule cells express the adult tau protein isoform containing one aminoterminal insert domain (1N-tau). Therefore a shift in tau isoform expression takes place during adult neurogenesis, which might be related to migration, differentiation, and integration in the granule cell layer. A model for studying shifts in tau isoform expression in a defined subset of neurons might help to understand the etiology of tauopathies, when isoform composition is crucial for neurodegeneration, as in Pick's disease or FTDP-17.
Bullmann
Torsten
T
Department of Neuroanatomy, Paul-Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany.
de Silva
Rohan
R
Holzer
Max
M
Mori
Hiroshi
H
Arendt
Thomas
T
D000818:Animals; D000831:Animals, Newborn; D000963:Antimetabolites; D015415:Biomarkers; D001973:Bromodeoxyuridine; D064026:Calbindins; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D004622:Embryo, Mammalian / Q000378:metabolism*; D005091:Exons / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000254:growth & development* / Q000378:metabolism*; D007536:Isomerism; D008297:Male; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D039842:Neural Cell Adhesion Molecule L1 / Q000096:biosynthesis; D009457:Neuroglia / Q000378:metabolism; D009479:Neuropeptides / Q000096:biosynthesis; D011247:Pregnancy; D051381:Rats; D011920:Rats, Inbred WF; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis; D012794:Sialic Acids / Q000096:biosynthesis; D016875:tau Proteins / Q000096:biosynthesis*
D000963:Antimetabolites; D015415:Biomarkers; D064026:Calbindins; C000714848:Dcx protein, rat; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D039842:Neural Cell Adhesion Molecule L1; D009479:Neuropeptides; D064030:S100 Calcium Binding Protein G; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule; D016875:tau Proteins; D001973:Bromodeoxyuridine