Xkr8 Modulates Bipolar Cell Number in the Mouse Retina
Xkr8 Modulates Bipolar Cell Number in the Mouse Retina
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DOI：
10.3389/fnins.2018.00876
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发表时间：
2018-12-03
影响因子：
4.3
通讯作者：
Reese, Benjamin E.
中科院分区：
文献类型：
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作者：
Kautzman, Amanda G.;Keeley, Patrick W.;Reese, Benjamin E.
本研究探讨了与小鼠视网膜双极细胞群体大小相关的第4染色体数量性状位点（QTL）。该基因座通过定量来自两种近交实验室品系C57 BL/6 J（B6/J）和A/J的一组重组近交（RI）小鼠品系的视杆双极细胞和2型视锥双极细胞的数量，并将每种细胞类型的细胞数量变化的比例映射到该共享基因座来鉴定。在那里，我们确定了候选基因X Kell血型前体相关家族成员8同源物（Xkr 8）。虽然Xkr 8在视网膜中没有记录的作用，但我们通过原位杂交在成熟视网膜中定位了稳健的表达，通过免疫标记确认了其发育存在，并使用qPCR显示其在B6/J和NJ菌株之间的出生后期间受到差异调节。来自整个RI菌株组的全眼mRNA的微阵列分析表明，Xkr 8表达与这两种类型的双极细胞中的每一种的数量显著负相关，并且Xkr 8表达在菌株间的变化映射了顺式eQTL，暗示了区分亲本基因组的调节变体。在发育过程中，Xkr 8质粒电穿孔导致视网膜中双极细胞的数量减少，而两个亲本菌株基因组中Xkr 8的序列分析鉴定了3' UTR中可能破坏mRNA稳定性的结构变体，以及启动子中产生转录因子结合位点的两个SNP。我们建议，Xkr 8，通过其参与介导的细胞死亡，在视网膜中的双极细胞数量的规格中发挥作用。
The present study interrogated a quantitative trait locus (QTL) on Chr 4 associated with the population sizes of two types of bipolar cell in the mouse retina. This locus was identified by quantifying the number of rod bipolar cells and Type 2 cone bipolar cells across a panel of recombinant inbred (RI) strains of mice derived from two inbred laboratory strains, C57BL/6J (B6/J) and A/J, and mapping a proportion of that variation in cell number, for each cell type, to this shared locus. There, we identified the candidate gene X Kell blood group precursor related family member 8 homolog (Xkr8). While Xkr8 has no documented role in the retina, we localize robust expression in the mature retina via in situ hybridization, confirm its developmental presence via immunolabeling, and show that it is differentially regulated during the postnatal period between the B6/J and NJ strains using qPCR. Microarray analysis, derived from whole eye mRNA from the entire RI strain set, demonstrates significant negative correlation of Xkr8 expression with the number of each of these two types of bipolar cells, and the variation in Xkr8 expression across the strains maps a cis-eQTL, implicating a regulatory variant discriminating the parental genomes. Xkr8 plasmid electroporation during development yielded a reduction in the number of bipolar cells in the retina, while sequence analysis of Xkr8 in the two parental strain genomes identified a structural variant in the 3' UTR that may disrupt mRNA stability, and two SNPs in the promoter that create transcription factor binding sites. We propose that Xkr8, via its participation in mediating cell death, plays a role in the specification of bipolar cell number in the retina.