Translational Research Unit, Veterinary Teaching Hospital, Graduate School of Veterinary Medicine, Hokkaido University, Japan; One Health Research Center, Hokkaido University, Japan.
Department of Pediatrics, MD Anderson Cancer Center, Houston, Tx, USA.
Res Vet Sci. 2021 Oct;139:193-199. doi: 10.1016/j.rvsc.2021.07.024. Epub 2021 Jul 24.
Obesity and its associated comorbidities constitute a major and growing health problem worldwide not only involved with people but also dogs and cats. Although few genetic mutations have been associated with obesity in dogs, molecular mechanism remains to be clearly understood. Given the fact that DNA methylation leads to gene expression variability and has plasticity affected by metabolic phenotypes such as obesity in human, the objective of this study is to identify obesity-associated differentially methylated cytosine-phosphate-guanine (CpG) dinucleotide sites in dogs. With genome-wide DNA methylation analysis using next-generation sequencing for blood samples from fourteen Miniature dachshunds with body condition score (BCS) 4-5 and BCS ≥6, over 100,000 sites could be analysed to identify genomic locations of differentially methylated CpG sites. As a result, 191 differentially methylated CpG sites (89 CpG sites were hypermethylated in BCS ≥6 and 102 were hypermethylated in BCS 4-5) were identified. These sites included promoter regions of Kisspeptin receptor (KISS1R) and Calcyphosine 2 (CAPS2) genes which were subsequently validated by bisulfite-pyrosequencing for another set of 157 dog blood samples. KISS1R methylation levels were found to be higher in BCS ≥6 group than BCS 4-5 in senior (>84 months) dogs. Especially male dogs but not female dogs as well as uncastrated male dogs but not castrated male dogs showed this trend. DNA methylation of KISS1R gene will be useful for understanding of comprehensive epigenetic change in obese dogs.
肥胖及其相关的合并症不仅与人类有关，也与狗和猫有关，构成了一个全球范围内日益严重的重大健康问题。尽管已有少数基因突变与狗的肥胖有关，但分子机制仍有待明确。鉴于 DNA 甲基化导致基因表达的可变性，并且受代谢表型（如肥胖）的影响具有可塑性，本研究的目的是确定肥胖相关的犬科动物中差异甲基化的胞嘧啶-磷酸-鸟嘌呤（CpG）二核苷酸位点。对 14 只迷你腊肠犬的血液样本进行全基因组 DNA 甲基化分析，采用下一代测序技术，这些样本的体况评分（BCS）为 4-5 和 BCS≥6，分析了超过 100000 个位点，以确定差异甲基化 CpG 位点的基因组位置。结果鉴定出 191 个差异甲基化 CpG 位点（BCS≥6 中有 89 个 CpG 位点呈超甲基化，BCS 4-5 中有 102 个 CpG 位点呈超甲基化）。这些位点包括 Kisspeptin 受体（KISS1R）和 Calcyphosine 2（CAPS2）基因的启动子区域，随后在另一组 157 只犬的血液样本中通过亚硫酸氢盐-焦磷酸测序进行了验证。在>84 个月的老年犬中，BCS≥6 组的 KISS1R 甲基化水平高于 BCS 4-5 组。特别是雄性犬，而不是雌性犬，以及未去势的雄性犬，而不是去势的雄性犬，表现出这种趋势。KISS1R 基因的 DNA 甲基化将有助于理解肥胖犬的全面表观遗传变化。
