Missense Mutations in the Human Nanophthalmos Gene TMEM98 Cause Retinal Defects in the Mouse
Missense Mutations in the Human Nanophthalmos Gene TMEM98 Cause Retinal Defects in the Mouse
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DOI：
10.1101/513846
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
S. Cross;Lisa McKie;M. Keighren;K. West;C. Thaung;T. Davey;D. Soares;L. Sánchez-Pulido;I. Jackson-I
中科院分区：
文献类型：
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作者：
S. Cross;Lisa McKie;M. Keighren;K. West;C. Thaung;T. Davey;D. Soares;L. Sánchez-Pulido;I. Jackson-I
我们以前发现一种显性突变Rwhs，导致视网膜上出现白色斑点并伴有视网膜皱褶。在这里，我们确定突变基因是Tmem 98。在人类中，orthopathy基因的突变会导致小眼球。我们在小鼠中模拟了这些突变，并表征了这些和Rwhs的突变眼表型。方法通过基因定位和测序鉴定Tmem 98基因Rwhs突变为错义突变。通过CRISPR-Cas9在小鼠基因中产生人TMEM 98 nanophthalmos错义突变。通过间接检眼镜检查眼睛，并使用视网膜照相机对视网膜成像。视网膜电图检查视网膜功能。采用组织学、免疫组织化学和电镜技术对成人眼进行研究。结果Tmem 98的I135 T突变导致显性Rwhs表型，纯合子时围产期致死。TMEM 98的两个显性错义突变A193 P和H196 P与人类小眼球相关。在小鼠中，这些突变单独或彼此组合引起类似于Rwhs表型的隐性视网膜缺陷，但不引起小眼球。视网膜电图检查显示，视网膜皱褶不影响视网膜功能。免疫组织化学和电子显微镜检查显示，在褶皱内有组织紊乱的外节材料积聚，巨噬细胞已浸润到这些区域。结论：人类nanophthalmos基因TMEM 98的小鼠直向同源物突变不会导致小眼睛。相反，存在光感受器的层状结构的局部破坏。
PURPOSE We previously found a dominant mutation, Rwhs, causing white spots on the retina accompanied by retinal folds. Here we identify the mutant gene to be Tmem98. In humans, mutations in the orthologous gene cause nanophthalmos. We modelled these mutations in mice and characterised the mutant eye phenotypes of these and Rwhs. METHODS The Rwhs mutation was identified to be a missense mutation in Tmem98 by genetic mapping and sequencing. The human TMEM98 nanophthalmos missense mutations were made in the mouse gene by CRISPR-Cas9. Eyes were examined by indirect ophthalmoscopy and the retinas imaged using a retinal camera. Electroretinography was used to study retinal function. Histology, immunohistochemistry and electron microscopy techniques were used to study adult eyes. RESULTS An I135T mutation of Tmem98 causes the dominant Rwhs phenotype and is perinatally lethal when homozygous. Two dominant missense mutations of TMEM98, A193P and H196P are associated with human nanophthalmos. In the mouse these mutations cause recessive retinal defects similar to the Rwhs phenotype, either alone or in combination with each other, but do not cause nanophthalmos. The retinal folds did not affect retinal function as assessed by electroretinography. Within the folds there was accumulation of disorganised outer segment material as demonstrated by immunohistochemistry and electron microscopy, and macrophages had infiltrated into these regions. CONCLUSIONS Mutations in the mouse orthologue of the human nanophthalmos gene TMEM98 do not result in small eyes. Rather, there is localised disruption of the laminar structure of the photoreceptors.