College of Livestock Husbandry and Veterinary Engineering, Henan Agricultural University, No. 15 Longzi Lake University Campus, Zhengzhou, 450046, P.R. China.
Sci Rep. 2020 Feb 19;10(1):2972. doi: 10.1038/s41598-020-59703-y.
Mitochondrial heterogeneity is the presence of two or more types of mitochondrial (mt)DNA in the same individual/tissue/cell. It is closely related to animal health and disease. ND2 is a protein-coding gene in mtDNA, which participates in mitochondrial respiratory chain and oxidative phosphorylation. In previous studies, we observed that the mt.A5703T and mt.T5727G sites in the ND2 gene were the heteroplasmic variation sites. We used pyrophosphate sequencing technology to examine chicken mt.A5703T and mt.T5727G heteroplasmic sites in the ND2 gene, in different tissues and at different development stages in chickens. We also investigated whether nutritional factors could affect the mt.A5703T and mt.T5727G heteroplasmy. Our results showed that chicken mt.A5703T and mt.T5727G heteroplasmy had clear spatio-temporal specificities, which varied between tissues/development stages. The mtDNA heterogeneity was relatively stable upon nutrition intervention, 30% dietary energy restriction (from 18 to 48 days old) and different types of dietary fats (at 5% concentration, from 1 to 42 days old) did not change the breast muscle heteroplasmy of broilers at the mt.A5703T and mt.T5727G sites. In addition, multiple potential heteroplasmic sites were detected by clone sequencing in the ND2 region, which potentially reflected abundant heteroplasmy in the chicken mitochondrial genome. These results provide an important reference for further research on heteroplasmy in chicken mitochondria.
线粒体异质性是指同一个体/组织/细胞中存在两种或多种类型的线粒体（mt）DNA。它与动物健康和疾病密切相关。ND2 是 mtDNA 中的一个蛋白编码基因，参与线粒体呼吸链和氧化磷酸化。在之前的研究中，我们观察到 ND2 基因中的 mt.A5703T 和 mt.T5727G 位点是异质体变异位点。我们使用焦磷酸测序技术检测了鸡 ND2 基因中 mt.A5703T 和 mt.T5727G 异质体位点，在不同组织和不同发育阶段的鸡中。我们还研究了营养因素是否会影响 mt.A5703T 和 mt.T5727G 的异质体。我们的研究结果表明，鸡 mt.A5703T 和 mt.T5727G 异质体具有明显的时空特异性，在组织/发育阶段之间存在差异。在营养干预下，mtDNA 异质性相对稳定，30%的膳食能量限制（从 18 天到 48 天）和不同类型的膳食脂肪（5%浓度，从 1 天到 42 天）没有改变胸肌在 mt.A5703T 和 mt.T5727G 位点的异质体。此外，在 ND2 区域通过克隆测序检测到多个潜在的异质体位点，这可能反映了鸡线粒体基因组中丰富的异质体。这些结果为进一步研究鸡线粒体异质体提供了重要参考。
