Function of Pax1 and Pax9 in the sclerotome of medaka fish.
We examined the expression and functions of Pax1 and Pax9 in a teleost fish, the medaka Oryzias latipes. While Pax1 and Pax9 show distinct expression in the sclerotome in amniotes, we could not detect the differential expression of Pax1 and Pax9 in the developing sclerotome of the medaka. Furthermore, unlike the mouse, in which Pax1 is essential for development of the vertebral body, and where the neural arch is formed independent of either Pax1 or Pax9, our morpholino knockdown experiments revealed that both Pax1 and Pax9 are indispensable for the development of the vertebral body and neural arch. Therefore, we conclude that after gene duplication, Pax1 and Pax9 subfunctionalize their roles in the sclerotome independently in teleosts and amniotes. In Stage-30 embryo, Pax9 was strongly expressed in the posterior mesoderm, as was also observed for mouse Pax9. Since this expression was not detected for Pax1 in the mouse or fish, this new expression in the posterior mesoderm likely evolved in Pax9 of ancestral vertebrates after gene duplication. Two-month-old fish injected with Pax9 morpholino oligonucleotide showed abnormal morphology in the tail hypural skeletal element, which may have been related to this expression.
Mise
Takeshi
T
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
Iijima
Minoru
M
Inohaya
Keiji
K
Kudo
Akira
A
Wada
Hiroshi
H
D000818:Animals; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D009990:Oryzias / Q000196:embryology* / Q000378:metabolism; D051764:PAX9 Transcription Factor / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051761:Paired Box Transcription Factors / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D019170:Somites / Q000196:embryology / Q000378:metabolism; D013131:Spine / Q000196:embryology
D016376:Oligonucleotides, Antisense; D051764:PAX9 Transcription Factor; D051761:Paired Box Transcription Factors; C070835:PAX1 transcription factor