@article{4726d084a1ba4f1892988609e2013367,
title = "Distal spinal nerve development and divergence of avian groups",
abstract = "The avian transition from long to short, distally fused tails during the Mesozoic ushered in the Pygostylian group, which includes modern birds. The avian tail embodies a bipartite anatomy, with the proximal separate caudal vertebrae region, and the distal pygostyle, formed by vertebral fusion. This study investigates developmental features of the two tail domains in different bird groups, and analyzes them in reference to evolutionary origins. We first defined the early developmental boundary between the two tail halves in the chicken, then followed major developmental structures from early embryo to post-hatching stages. Differences between regions were observed in sclerotome anterior/posterior polarity and peripheral nervous system development, and these were consistent in other neognathous birds. However, in the paleognathous emu, the neognathous pattern was not observed, such that spinal nerve development extends through the pygostyle region. Disparities between the neognaths and paleognaths studied were also reflected in the morphology of their pygostyles. The ancestral long-tailed spinal nerve configuration was hypothesized from brown anole and alligator, which unexpectedly more resembles the neognathous birds. This study shows that tail anatomy is not universal in avians, and suggests several possible scenarios regarding bird evolution, including an independent paleognathous long-tailed ancestor.",
author = "Rashid, {Dana J.} and Roger Bradley and Bailleul, {Alida M.} and Kevin Surya and Woodward, {Holly N.} and Ping Wu and Wu, {Yun Hsin (Becky)} and Menke, {Douglas B.} and Minchey, {Sergio G.} and Ben Parrott and Bock, {Samantha L.} and Christa Merzdorf and Emma Narotzky and Nathan Burke and Horner, {John R.} and Chapman, {Susan C.}",
note = "Funding Information: We sincerely thank Don Collins at the Montana Emu Ranch and Lorca Smetana in Bozeman, MT for their contributions of emu and rock dove specimens for this study. In addition, we are indebted to Maria Jerome at the core histology facility at MSU for her histology expertise (funded by National Institutes of Health IDeA Program COBRE Grant GM110732). We offer our sincere thanks to Kimball Garrett at the Los Angeles County Museum of Natural History for his curation and photography of museum specimens. Our gratitude is also due to Ruth Elsey at the Rockefeller Wildlife Refuge for providing fertilized alligator eggs. For discussions of this work we extend our appreciation to Cheng-Ming Chuong at the University of Southern California and Dr. Bob Narotzky in Bozeman, MT. We would also like to thank Stephen Rigsby and DENTSPLY R&D for providing access to microscopy equipment. To the Maori people, we are thankful for access to the two kiwi specimens. For access to Museum of the Rockies specimens, we thank Amy Atwater. Primary funding was provided by private donations from Gerry Ohrstrom and George Lucas, for which we are deeply grateful. This work was also supported financially by an MSU Faculty of Excellence grant to D. Rashid, and by NIH/NIDCD under award number R01DC009236 and by a subaward, SC TRMIH P20COBRE GM121342, to S. Chapman. Additional support came from NSF award #1827647 to D. Menke. Support for K. Surya was granted through the INBRE undergraduate program at Montana State University (NIH/NIGMS award number P20GM103474), as well as a Student Research Grant from the Montana Academy of Sciences. Publisher Copyright: {\textcopyright} 2020, The Author(s).",
year = "2020",
month = dec,
day = "1",
doi = "10.1038/s41598-020-63264-5",
language = "English",
volume = "10",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",
}