Abstract: Objective To examine the effect of Ubc9 and SUMO pathway on neural crest cell development of chicken embryo. Methods 1) Chicken embryos were collected, In situ hybridization and Immunofluorescence were used to observe the expression of SUMO-conjugating enzyme—Ubc9 and early markers of neural crest. 2) In the control group, 5- mismatch Ubc9-control morpholino (5MM-Mo) were used to treat chick embryos; In the Ubc9-Mo group, sequence-specific Morpholinos(Mo) were used to reduce Ubc9 levels in chicken embryos, then the mRNA levels of neural crest markers(Snail2，Sox9 and FoxD3) were observed. Results 1) Ubc9 is coexpressed with Pax7 in neural crest precursors of the neural fold at 4、6 and 8 stage of early chicken embryos. 2) Compared to the control group,Ubc9-Mo treatment led to a reduce of mRNA level of neural crest markers, Snail2（P<0.05），Sox9 （P<0.01）and FoxD3（P<0.05）. Conclusion SUMO-conjugating enzyme, Ubc9 expression started at neural fold at 4、6 and 8 stage of early chicken embryo, Ubc9 and SUMO pathway are required for neural crest cell development of chicken embryo.

Key words: Chicken embryo, Neural crest cell, Ubc9, SUMO pathway