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Abstract：
A goal of developmental genetics is to identify functional interactions that underlie phenotypes caused by mutations. We sought to identify functional interactors of Vsx2, which when mutated, disrupts early retinal development. We utilized the Vsx2 loss-of-function mouse, ocular retardation J (orJ), to assess interactions based on principles of positive and negative epistasis as applied to bulk transcriptome data. This was first tested in vivo with Mitf, a target of Vsx2 repression, and then to cultures of orJ retina treated with inhibitors of Retinoid-X Receptors (RXR) to target Rxrg, an up-regulated gene in the orJ retina, and gamma-Secretase, an enzyme required for Notch signaling, a key mediator of retinal proliferation and neurogenesis.
Whereas Mitf exhibited robust positive epistasis with Vsx2, it only partially accounts for the orJ phenotype, suggesting other functional interactors. RXR inhibition yielded minimal evidence for epistasis between Vsx2 and Rxrg. In contrast, gamma-Secretase inhibition caused hundreds of Vsx2-dependent genes associated with proliferation to deviate further from wild-type, providing evidence for convergent negative epistasis with Vsx2 in regulating tissue growth.
Combining in vivo and ex vivo testing with transcriptome analysis revealed quantitative and qualitative characteristics of functional interaction between Vsx2, Mitf, RXR, and gamma-Secretase activities.
Whereas Mitf exhibited robust positive epistasis with Vsx2, it only partially accounts for the orJ phenotype, suggesting other functional interactors. RXR inhibition yielded minimal evidence for epistasis between Vsx2 and Rxrg. In contrast, gamma-Secretase inhibition caused hundreds of Vsx2-dependent genes associated with proliferation to deviate further from wild-type, providing evidence for convergent negative epistasis with Vsx2 in regulating tissue growth.
Combining in vivo and ex vivo testing with transcriptome analysis revealed quantitative and qualitative characteristics of functional interaction between Vsx2, Mitf, RXR, and gamma-Secretase activities.
摘要：
背景：发育遗传学的一个目标是鉴定由突变引起的表型的功能相互作用。我们试图确定Vsx2的功能相互作用者，当突变时，破坏早期视网膜发育.我们使用了Vsx2功能丧失鼠标，眼发育迟滞J(orJ),根据应用于批量转录组数据的阳性和阴性上位性原则评估相互作用。这首先是用Mitf在体内测试的，Vsx2压制的目标，然后用视黄醇-X受体（RXR）抑制剂靶向Rxrg处理的orJ视网膜培养物，orJ视网膜中的一个上调基因,和γ-分泌酶,Notch信号所需的酶，视网膜增殖和神经发生的关键介质。
结果：尽管Mitf对Vsx2表现出强烈的阳性表达，但它仅部分解释了orJ表型，建议其他功能相互作用者。RXR抑制在Vsx2和Rxrg之间产生了最小的上位性证据。相比之下,γ-分泌酶抑制导致数百个与增殖相关的Vsx2依赖性基因进一步偏离野生型，为Vsx2在调节组织生长方面的趋同阴性上位提供证据。
结论：将体内和离体测试与转录组分析相结合，揭示了Vsx2，Mitf，RXR,和γ-分泌酶活性。
结果：尽管Mitf对Vsx2表现出强烈的阳性表达，但它仅部分解释了orJ表型，建议其他功能相互作用者。RXR抑制在Vsx2和Rxrg之间产生了最小的上位性证据。相比之下,γ-分泌酶抑制导致数百个与增殖相关的Vsx2依赖性基因进一步偏离野生型，为Vsx2在调节组织生长方面的趋同阴性上位提供证据。
结论：将体内和离体测试与转录组分析相结合，揭示了Vsx2，Mitf，RXR,和γ-分泌酶活性。
