Aquaporin10 is a pseudogene in cattle and their relatives.
Aquaporin10 is a pseudogene in cattle and their relatives.
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DOI：
10.1016/j.bbrep.2015.03.009
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发表时间：
2015-05
影响因子：
2.7
通讯作者：
Ishibashi K
中科院分区：
文献类型：
--
作者：
Tanaka Y;Morishita Y;Ishibashi K
虽然AQP10主要在人的胃肠道表达，但其生理作用尚不清楚。事实上，我们之前报道过小鼠AQP10是一个假基因。AQP10在其他动物中也有可能是假基因。在基因组数据库中搜索AQP10同源基因，并对每个候选假基因的基因组DNA进行测序以确认其突变。RT-PCR检测AQP10在人AQP10高表达的小肠组织中的表达。一些哺乳动物的基因组数据库中有AQP10基因外显子的插入和缺失，包括牛(Bos Taurus)、绵羊(Ovis Aries)和山羊(Capra Hircus)。在牛AQP10基因中，外显子1和外显子5的缺失分别导致移码或提前终止，基因组DNA的直接外显子测序证实了这一点。在RT-PCR实验中，外显子1/2和外显子4/5的聚合酶链式反应未能在十二指肠和空肠中检测到AQP10基因的条带。绵羊和山羊的基因组DNA中也证实了类似的AQP10基因突变。虽然这些动物来自猪的祖先，但猪(Sus Scrofa)AQP10基因的外显子是完整的，没有突变。因此，AQP10基因可能在大约6500万年前，当牛从猪的祖先进化而来时，已经变成了假基因。反胃动物的AQP10可能已经失去了作用，这可能是由于其他水甘油多孔蛋白的过度表达所致。主要在胃肠道表达的AQP10在奶牛体内已转为假基因。其他反刍动物如绵羊和山羊也存在AQP10假基因。在猪体内发现的AQP10可能表明AQP10在6500万年前转变为假基因。
Although AQP10 is mainly expressed in the human GI tract, its physiological role is unclear. In fact, we previously reported that mouse AQP10 is a pseudogene. It is possible that AQP10 is also a pseudogene in other animals. Genome databases were searched for AQP10 orthologs and the genomic DNA of each candidate pseudogene was sequenced to confirm its mutations. The expression of the AQP10 mRNA was examined by RT-PCR in the small intestine where human AQP10 is highly expressed. The genomic database of some mammals had insertions and deletions in the exons of the AQP10 gene, including cattle (Bos taurus), sheep (Ovis aries) and goats (Capra hircus). In the bovine AQP10 gene, exon 1 and 5 had deletions resulting in a frame-shift or a premature termination, respectively, which were confirmed by the direct exon sequencing of the genomic DNA. In the RT-PCR experiments, the PCR primer sets for exon 1/2 and exon 4/5 failed to detect the bands for AQP10 mRNA in the duodenum and jejunum. Similar AQP10 gene mutations were also confirmed in the genomic DNA from sheep and goats. Although these animals were derived from porcine ancestors, the exons of the swine (Sus scrofa) AQP10 gene were complete without mutations. Therefore, AQP10 gene might have turned to a pseudogene around 65 million years before when cattle evolved from porcine ancestors. AQP10 of ruminantia which regurgitate and rechew their food may have lost its role possibly due to the redundant expression of other aquaglyceroporins. AQP10, mainly expressed in the GI tract, has turned to a pseudogene in the cow. The other ruminantia such as sheep and goat also have the AQP10 pseudogene. The presence of authentic AQP10 in the pig may indicate that AQP10 turned to a pseudogene 65 million years ago.