RT Journal Article
SR Electronic
T1 Characterizing the diverse cells that associate with the developing commissures of the zebrafish forebrain
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.07.16.205153
DO 10.1101/2020.07.16.205153
A1 J. Schnabl
A1 M.P.H. Litz
A1 C. Schneider
A1 N. PenkoffLidbeck
A1 S. Bashiruddin
A1 M.S. Schwartz
A1 K. Alligood
A1 M.J.F. Barresi
YR 2020
UL http://biorxiv.org/content/early/2020/07/17/2020.07.16.205153.abstract
AB During embryonic development of bilateral organisms, neurons send axons across the midline at specific points to connect the two halves of the nervous system with a commissure. Little is known about the cells at the midline that facilitate this tightly regulated process. We exploit the con served process of vertebrate embryonic development in the zebrafish model system to elucidate the identity of cells at the midline that may facilitate postoptic (POC) and anterior commissure (AC) development. We have discovered that three differentgfap+ astroglial cell morphologies persist in contact with pathfinding axons throughout commissure formation. Similarly, olig2+ progenitor cells occupy delineated portions of the postoptic and anterior commissures. These early olig2+ progenitors demonstrate glial-like morphologies despite the lack of a myelination marker. Moreover, we conclude that both the gfap+ and olig2+progenitor cells give rise to neuronal populations in both the telencephalon and diencephalon. Interestingly, these varied cell populations showed significant developmental heterochrony between the telencephalon and diencephalon. Lastly, we also showed that fli1a+ mesenchymal cells migrate along the presumptive commissure regions before and during midline axon crossing. Furthermore, following commissure maturation, specific blood vessels formed at the midline of the POC and immediately ventral and parallel to the AC. This comprehensive account of the cellular populations that correlate with the timing and position of commissural axon pathfinding has supported the conceptual modeling and identification of the early forebrain architecture that may be necessary for proper commissure development.Competing Interest StatementThe authors have declared no competing interest.