Bonetti Monica, Rodriguez-Martinez Virginia, Paardekooper Overman Jeroen, Overvoorde John, van Eekelen Mark, Jopling Chris, Hertog Jeroen den
Hubrecht Institute-Koninklijke Nederlandse Akademie van Wetenschappen and University Medical Center Utrecht, Utrecht, The Netherlands.
Hubrecht Institute-Koninklijke Nederlandse Akademie van Wetenschappen and University Medical Center Utrecht, Utrecht, The Netherlands; Institute of Biology, Leiden, Leiden, The Netherlands.
PLoS One. 2014 Apr 15;9(4):e94884. doi: 10.1371/journal.pone.0094884. eCollection 2014.
The PTPN11 (protein-tyrosine phosphatase, non-receptor type 11) gene encodes SHP2, a cytoplasmic PTP that is essential for vertebrate development. Mutations in PTPN11 are associated with Noonan and LEOPARD syndrome. Human patients with these autosomal dominant disorders display various symptoms, including short stature, craniofacial defects and heart abnormalities. We have used the zebrafish as a model to investigate the role of Shp2 in embryonic development. The zebrafish genome encodes two ptpn11 genes, ptpn11a and ptpn11b. Here, we report that ptpn11a is expressed constitutively and ptpn11b expression is strongly upregulated during development. In addition, the products of both ptpn11 genes, Shp2a and Shp2b, are functional. Target-selected inactivation of ptpn11a and ptpn11b revealed that double homozygous mutants are embryonic lethal at 5-6 days post fertilization (dpf). Ptpn11a-/-ptpn11b-/- embryos showed pleiotropic defects from 4 dpf onwards, including reduced body axis extension and craniofacial defects, which was accompanied by low levels of phosphorylated Erk at 5 dpf. Interestingly, defects in homozygous ptpn11a-/- mutants overlapped with defects in the double mutants albeit they were milder, whereas ptpn11b-/- single mutants did not show detectable developmental defects and were viable and fertile. Ptpn11a-/-ptpn11b-/- mutants were rescued by expression of exogenous ptpn11a and ptpn11b alike, indicating functional redundance of Shp2a and Shp2b. The ptpn11 mutants provide a good basis for further unravelling of the function of Shp2 in vertebrate development.
PTPN11（蛋白酪氨酸磷酸酶，非受体11型）基因编码SHP2，一种对脊椎动物发育至关重要的细胞质蛋白酪氨酸磷酸酶。PTPN11中的突变与努南综合征和豹皮综合征相关。患有这些常染色体显性疾病的人类患者表现出各种症状，包括身材矮小、颅面缺陷和心脏异常。我们以斑马鱼为模型来研究Shp2在胚胎发育中的作用。斑马鱼基因组编码两个ptpn11基因，ptpn11a和ptpn11b。在此，我们报告ptpn11a组成性表达，而ptpn11b的表达在发育过程中强烈上调。此外，两个ptpn11基因的产物Shp2a和Shp2b都具有功能。对ptpn11a和ptpn11b进行靶向选择失活显示，双纯合突变体在受精后5 - 6天（dpf）胚胎致死。Ptpn11a-/-ptpn11b-/-胚胎从4 dpf起就表现出多效性缺陷，包括体轴延伸减少和颅面缺陷，同时在5 dpf时磷酸化Erk水平较低。有趣的是，纯合ptpn11a-/-突变体的缺陷与双突变体的缺陷重叠，尽管程度较轻，而ptpn11b-/-单突变体未表现出可检测到的发育缺陷，并且存活且可育。通过表达外源性ptpn11a和ptpn11b均可挽救Ptpn11a-/-ptpn11b-/-突变体，这表明Shp2a和Shp2b具有功能冗余性。ptpn11突变体为进一步阐明Shp2在脊椎动物发育中的功能提供了良好基础。
