Comparison of wild-type and Mfsd2a KO eye cups

Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the omega-3 fatty acid docosahexaenote (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier (BRB) or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine symporter expressed at the BRB. Microarrays were used to determine difference in gene expression between wild-type and Mfsd2a KO eye cups. RNA was extracted from eye cups from postnatal day 13 wild-type and Mfsd2a KO mice. Equal amounts of RNA from 6 wild-type eye cups were pooled for the wild-type sample, or 6 Mfsd2a KO eye cups were pooled for the Mfsd2a KO sample. Microarray profiling was done on pooled samples with a RIN cut-off of 7.0 using Mouse 430 2.0 arrays (Affymetrix).

视杆细胞外节中的光感受器膜盘高度富集视觉色素视紫红质与ω-3脂肪酸二十二碳六烯酸（docosahexaenoic acid, DHA）。眼部可通过血液获取DHA，但目前尚未发现能够介导DHA跨越血-视网膜屏障（blood-retinal barrier, BRB）或视网膜色素上皮细胞的转运蛋白。Mfsd2a是新近被鉴定的钠依赖性溶血磷脂胆碱同向转运蛋白，表达于血-视网膜屏障处。本研究通过微阵列技术检测野生型与Mfsd2a基因敲除（knockout, KO）小鼠眼杯的基因表达差异：实验提取出生后第13天的野生型及Mfsd2a KO小鼠眼杯的总RNA，将6只野生型小鼠眼杯的等量RNA混合作为野生型样本，6只Mfsd2a KO小鼠眼杯的RNA混合作为敲除组样本；随后采用Affymetrix小鼠基因组430 2.0芯片对上述混合样本进行微阵列表达谱分析，实验设定RNA完整性数（RNA Integrity Number, RIN）阈值为7.0。