Phenotypic Diversity Caused by Differential Expression of SFTPC-Cre-Transgenic Alleles
Phenotypic Diversity Caused by Differential Expression of SFTPC-Cre-Transgenic Alleles
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DOI：
10.1165/rcmb.2019-0416ma
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发表时间：
2020-06-01
影响因子：
6.4
通讯作者：
Alder, Jonathan K.
中科院分区：
文献类型：
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作者：
Jiang, Mao;Roth, Mark G.;Alder, Jonathan K.
肺泡II型上皮细胞(AEC2s)在肺上皮细胞的功能和维持中起着重要作用。利用人SFTPC启动子驱动Cre重组酶的表达，已经建立了几种转基因小鼠来研究这些细胞在体内的功能。这些转基因等位基因的确切活性还没有被研究过，以前的报告表明，它们的活性可能取决于育种策略。我们用基本端粒封端蛋白TRF2的条件等位基因与两个不同的SFTPC-Cre转基因菌株培育小鼠，并观察到相反的表型(100%致死率与100%存活率)。我们鉴定了这两个转基因株系中Cre重组酶的活性，发现不同的表型是由两个转基因基因在胚胎中表达的差异所驱动的，可能是由于位置效应或转基因构建体的差异。我们还测试了SFTPC-Cre活性是否依赖于母系或父系遗传。当父系遗传时，两个SFTPC-Cre等位基因产生的后代都具有结构性报告活性，这与Cre等位基因的遗传无关，表明Cre重组酶在减数分裂前就在雄性种系中表达。睾丸免疫组织化学分析显示精子发生过程中有报告活性。对小鼠和人类睾丸单细胞RNA测序数据的分析表明，SFTPC在人类精子发生过程中独特表达，表明在这些结构中使用人类启动子对男性生殖系活动负责。我们的数据强调了仔细分析转基因等位基因活性的重要性，并确定了对小鼠泛上皮靶向有用的SFTPC-Cre等位基因。
Type II alveolar epithelial cells (AEC2s) play an essential role in the function and maintenance of the pulmonary epithelium. Several transgenic mice have been developed to study the function of these cells in vivo by using the human SFTPC promoter to drive expression of Cre recombinase. The precise activity of each of these transgenic alleles has not been studied, and previous reports suggest that their activity can depend on breeding strategies. We bred mice with a conditional allele of the essential telomere capping protein TRF2 with two different SFTPC-Cre-transgenic strains and observed opposite phenotypes (100% lethality vs. 100% viability). We characterized the Cre recombinase activity in these two transgenic lines and found that the contrasting phenotypes were driven by difference in embryonic expression of the two transgenes, likely due to position effects or differences in the transgenic constructs. We also tested if SFTPC-Cre activity was dependent on maternal or paternal inheritance. When paternally inherited, both SFTPC-Cre alleles produced offspring with constitutive reporter activity independent of the inheritance of the Cre allele, suggesting that Cre recombinase was expressed in the male germline before meiosis. Immunohistochemical analysis of the testis showed reporter activity during spermatogenesis. Analysis of single-cell RNA sequencing data from murine and human testis demonstrated SFTPC expression uniquely during human spermatogenesis, suggesting that use of the human promoter in these constructs is responsible for male germline activity. Our data highlight the importance of careful analysis of transgenic allele activity and identify an SFTPC-Cre allele that is useful for panepithelial targeting in the mouse.