Gene expression changes in testes from Abcg8 knockout mice compared to wild-type mice or to Abcg8 knockout mice where plant sterol entry was blocked by ezetimibe

Abcg8 knockout mice, fed chow, are infertile. These mice also are susceptible to absorption and retention of xenosterols contained in the diet. Ezetimibe, a blocker of dieary sterol entry, can reverse the fertility in Abcg8 knockout mice. In order to identify if the xenosterols resulted in disruption of a specific set of genes in the testes, we compared wild-type testes, Abcg8 knockout testes, or testes from Abcg8 knockout mice fed chow supplemented with 0.005% ezetimibe. To identify genes of interest, we reasoned that any causative gene expression changes seen in Abcg8 knockout mice fed chow, resulting in xenosterol exposure and accumulation, leading to infertilty, would be reveresed back to a pattern seen in the wild-type mice, when Abcg8 knockout mice are raised on chow containing ezetimibe (which prevents xenosterol absorption in the intestine). The target of this drug, Npc1l1, is not expressed in the testes. Testes from wild-type mice, Abcg8 knockout mice, and Abcg8 knockout mice fed chow supplemented with ezetimibe were analyzed.喂食普通饲料的Abcg8基因敲除小鼠（Abcg8 knockout mice）表现为不育表型，同时易于吸收并潴留膳食来源的外源性甾醇（xenosterols）。依泽替米贝（Ezetimibe）作为一种膳食甾醇摄取阻滞剂，可恢复Abcg8基因敲除小鼠的生育能力。为明确外源性甾醇是否会干扰睾丸内特定基因集合的表达谱，本研究对三组睾丸样本开展对比分析：野生型小鼠睾丸、Abcg8基因敲除小鼠睾丸，以及喂食添加0.005%依泽替米贝的普通饲料的Abcg8基因敲除小鼠睾丸。为筛选目标基因，本研究提出如下推论：若喂食普通饲料的Abcg8基因敲除小鼠因暴露并蓄积外源性甾醇而出现致因性基因表达异常，则当该类小鼠喂食添加依泽替米贝的普通饲料（可阻断肠道对外源性甾醇的吸收）时，上述基因表达模式将恢复至野生型小鼠的状态。该药物的作用靶点NPC1L1基因（Npc1l1）在睾丸组织中无表达。最终，本研究完成了对上述三组小鼠睾丸样本的分析。