1. Dorsal-ventral patterning of the neural tube 

Vertebrate neural tube is patterned along the dorsal-ventral axis through the interplay of a group of signaling molecules and transcription factors. We have characterized several factors involved in dorsal-ventral neural patterning in Xenopus, including Nkx6, Islet1, Dbx2, etc. We have also isolated one ubiquitin ligase that is specifically expressed in the ventral neural tube both in Xenopus and mouse. We are currently studying its role in neural development and screening for its target molecules. 

2. Mechanisms of neural crest development 

Neural crest is a multipotent cell population originates at the border between the neural plate and epidermis in vertebrates. Later these cells migrate to various places throughout the body and give rise to various tissues. The induction, specification, migration and differentiation of the NC cells are tightly regulated by a multistep gene regulatory network. Using Xenopus as a model animal, we are studying the roles of Nkx6.3 and reduced folate carrier in neural crest development. Our current data suggest that Nkx6.3 regulates neural crest induction through regulating Wnt signaling pathway while Xenopus reduce folate carrier is involved in the epigenetic regulation of neural crest gene expression. 

The molecular mechanisms of neural patterning and how these mechanisms evolve during vertebrate origin are the focuses of our lab. We use the amphibian Xenopus and the cephalochordate amphioxus as our model animals.

1. Xu HB#, Li YX#, Li Y, Otecko NO, Zhang YP, Mao B*, Wu DD*. (2018) Origin of new genes after zygotic genome activation in vertebrate. J Mol Cell Biol. 10:139-146.

2.      Sun J#, Wang X#, Shi Y, Li J, Li C, Shi Z, Chen Y, Mao B*. (2018) EphA7 regulates claudin6 and pronephros development in Xenopus，BiochemBiophys Res Commun. 495:1580–1587.

3.      Ma P^#,*, Ren B#, Yang X#, Sun B, Liu X, Kong Q, Li C, Mao B*, (2017) ZC4H2 stabilizes Smads to enhance BMP signalling, which is involved in neural development in Xenopus. Open Biol. 7: 170122.

4.      Liu X#, Xia Y#, Tang J, Ma L, Li C, Ma P*, Mao B*.（2017）Dual roles of Akirin2 during Xenopus neural development. J Biol Chem. 292:5676-5684.

5.      Wang X, Sun J, Li C, Mao B*. (2016）. EphA7 modulates apical constriction of hindbrain neuroepithelium during neurulation in Xenopus. BiochemBiophys Res Commun. 479:759-765.

6.      Liu X, Yang X, Li Y., Zhao S, Li C, Ma P*, & Mao B*. (2016). Trip12 is an E3 ubiquitin ligase for USP7/HAUSP involved in the DNA damage response.  FEBS Lett. 590:4213-4222.

7.      Yang X#, Li J#, Zeng W, Li C, Mao B* (2016). Elongator Protein 3 (Elp3) stabilizes Snail1 and regulates neural crest migration in Xenopus. Sci. Rep. 6, 26238.

8.      Yang KY, Chen Y, Zhang Z, Ng PK, Zhou WJ, Zhang Y, Liu M, Chen J, Mao B*, Tsui SK*. （2016）Transcriptome analysis of different developmental stages of amphioxus reveals dynamic changes of distinct classes of genes during development. Sci Rep.6, 23195.

9.      Jiang S, Du J, Kong Q, Li C, Li Y, Sun H, Pu J*, Mao B*. (2015) A group of ent-Kauranediterpenoids inhibit hedgehog signaling and induce cilia elongation. PLoSONE 10: e0139830.

10. Sun J, Wang X, Li C, Mao B*. （2015）Xenopus Claudin-6 is required for embryonic pronephros morphogenesis and terminal differentiation. BiochemBiophys Res Commun. 462:178-83.

11. Zhang Z, Shi Y, Zhao S, Li J, Li C, Mao B*. (2014) Xenopus Nkx6.3 is a neural plate border specifier required for neural crest development. PLoS ONE，9: e115165.

12. Ma P, Yang X, Kong Q, Li C, Yang S, Li Y, Mao B*. (2014) The ubiquitin ligase RNF220 enhances canonical Wnt signaling through USP7 mediated deubiquitination of β-catenin. Mol. Cell. Biol., 34:4355-4366.

13. Ma P, Xia Y, Ma L, Zhao S*, Mao B*. (2013) Xenopus Nkx6.1 and Nkx6.2 are required for mid-hindbrain boundary development.Dev Genes Evol. 223:253-259.

14. Chen Y, Ding Y, Zhang Z, Wang W, Chen J, Naoto Ueno, Mao B*. (2011). Evolution of vertebrate central nervous system is accompanied by novel expression changes of duplicate genes. J. Genet. Genomics, 38:577-584.

15. Li J, Shi Y, Sun J, Zhang Y, Mao B*. (2011), Xenopus reduced folate carrier regulates neural crest development epigenetically, PLoS ONE 6(11): e27198.