Jr-Kai Yu

My research is focused on developmental mechanisms of the cephalochordate amphioxus. Amphioxus is a basal chordate and is the best available stand-in for the proximate invertebrate ancestor of the vertebrates. The body plans of amphioxus and vertebrates share chordate key features (e.g. dorsal nerve cord, notochord, segmented somites, and pharyngeal gill slits). However, vertebrates have additional characters not present in amphioxus- namely, a more elaborate head and forebrain, migratory neural crest, and neurogenic placodes. My goal in studying the developmental genetics of amphioxus is to elucidate the basic patterning mechanisms for the chordate body plan. Because of its important evolutionary position, comparative studies of amphioxus with vertebrates will also provide important insights to understand the origin of the patterning mechanisms that lead to the vertebrate body plan.

One of the specific questions I would like to address with amphioxus as a model system is the origin of neural crest. Arising at the neural plate border, vertebrate neural crest cells undergo an epithelial to mesenchymal transition (EMT) to become a migratory cell population that forms numerous differentiated cell types, including the craniofacial skeleton, much of the peripheral nervous system, and pigment cells of the skin. Evolution of the neural crest is a hallmark of vertebrates, responsible for many complex structures of the vertebrate head that are lacking in invertebrate chordates, like amphioxus. By comparing the genetic controls operating during development at the edges of the neural plate in embryos of amphioxus and traditional vertebrate models, we can start to pin-point which part of the gene regulatory network might have been changed over time.

cDNA database for the cephalochordate amphioxus Branchiostoma floridae


Selected Publications

1. J. K. S. Yu.*, in press, "The evolutionary origin of the vertebrate neural crest and its developmental gene regulatory network - insights from amphioxus", Zoology. ( SCI )
2. B. Bajoghli, N. Aghaallaei, I. Hess, I. Rode, N. Netuschil, B. H. Tay, B. Venkatesh, J. K. Yu, S. L. Kaltenbach, N. D. Holland, D. Diekhoff, C. Happe, M. Schorpp, T. Boehm, 2009, "Evolution of genetic networks underlying the emergence of thymopoiesis in vertebrates.", Cell, 138, 186-197. ( SCI )
3. S. L. Kaltenbach, J. K. Yu, N. D. Holland*, 2009, "The origin and migration of the earliest-developing sensory neurons in the peripheral nervous system of amphioxus", Evol. Dev., 11, 142-151. ( SCI )
4. J. K. Yu*, M. C. Wang, T. Shin-i, Y. Kohara, L. Z. Holland*, N. Satoh* and Y. Satou, 2008, "A cDNA resource for the cephalochordate amphioxus Branchiostoma floridae", Dev Genes Evol., 218, 723-727. ( SCI )
5. J. K. Yu, D. Meulemans, S. J. McKeown and M. Bronner-Fraser*, 2008, "Insights from the amphioxus genome on the origin of vertebrate neural crest", Genome Research, 18, 1127-1132. ( SCI )
6. N. H. Putnam, T. Butts, D. E. K. Ferrier, R. F. Furlong, U. Hellsten, T. Kawashima, M. Robinson-Rechavi, E. Shoguchi, A. Terry, J. K. Yu, È Benito-Gutiérrez, I. Dubchak, J. Garcia-Fernàndez, I. V. Grigoriev, A. C. Horton, P. J. D. Jong, J. Jurka, V. Kapitonov, Y. Kohara, Y. Kuroki, E. Lindquist, S. Lucas, K. Osoegawa, L. A. Pennacchio, A. A. Salamov, Y. Satou, T. Sauka-Spengler, J. Schmutz, T. Shin-I, A. Toyoda, J. J. Gibson-Brown, M. Bronner-Fraser, A. Fujiyama, L. Z. Holland, P. W. H. Holland, N. Satoh* and D. S. Rokhsar*, 2008, "The amphioxus genome and the evolution of the chordate karyotype", Nature, 453, 1064-1071. ( SCI )
7. L. Z. Holland*, R. Albalat, K. Azumi, È. Benito-Gutiérrez, M. J. Blow, M. Bronner-Fraser, F. Brunet, T. Butts, S. Candiani, L. J. Dishaw, D. E. K. Ferrier, J. Garcia-Fernàndez, J. J. Gibson-Brown, C. Gissi, A. Godzik, F. Hallböök, D. Hirose, K. Hosomichi, T. Ikuta, H. Inoko, M. Kasahara, J. Kasamatsu, T. Kawashima, A. Kimura, M. Kobayashi, Z. Kozmik, K. Kubokawa, V. Laudet, G. W. Litman, A. C. McHardy, D. Meulemans, M. Nonaka, R. P. Olinski, Z. Pancer, L. A. Pennacchio, M. Pestarino, J. P. Rast, I. Rigoutsos, M. Robinson-Rechavi, G. Roch, H. Saiga, Y. Sasakura, M. Satake, Y. Satou, M. Schubert, N. Sherwood, T. Shiina, N. Takatori, J. Tello, P. Vopalensky, S. Wada, A. Xu, Y. Ye, K. Yoshida, F. Yoshizaki, J. K. Yu, Q. Zhang, C. M. Zmasek, N. H. Putnam, D. S. Rokhsar, N. Satoh* and P. W. H. Holland*, 2008, "The amphioxus genome illuminates vertebrate origins and cephalochordate biology", Genome Research, 18, 1100-1111. ( SCI )
8. J. K. Yu, F. Mazet, Y. T. Chen, S. W. Huang, K. C. Jung and S. M*. Shimeld, 2008, "The Fox genes of Branchiostoma floridae", Dev. Genes Evol., 218, 629-638. ( SCI)
9. J. K. Yu, Y. Satou, N. D. Holland, T. Shin-I, Y. Kohara, N. Satoh, M. Bronner-Fraser and L. Z. Holland*, 2007, "Axial patterning in cephalochordates and the evolution of the organizer", Nature, 445, 613-617. ( SCI)
10. M. Schubert, J. K. Yu, N. D. Holland, V. Laudet, H. Escriva and L. Z. Holland*, 2005, "Retinoic acid-signaling acts via Hox1 to establish the posterior limit of the pharynx in the chordate amphioxus", Development, 132, 61-73. ( SCI )