基因組銘印

基因銘印(英語:Genomic imprinting)又譯遗传印记遺傳銘印genetic imprinting或基因印记是一種不遵从孟德尔定律表观遺傳學現象,指只有來自特定親代的等位基因得以表达。此現象已知可見於昆蟲哺乳动物開花植物[1][2]

在一般二倍體生物的體細胞中擁有分别来自两个亲本的兩份基因組,通常這兩份基因組中的等位基因都能表現。但少數(小於1%)的基因會受到銘印的影響,使其中一份基因失去作用,称之为沉默,只表达等位基因中的一者。例如一種製造類胰島素的生長因子IGF-2英语Insulin-like growth factor 2的基因,只有來自父親的等位基因能夠表現。有研究表明,基因印记在胚胎发生的过程中至关重要。[3]

机制

基因銘印通常是由基因的表观遗传修饰导致的,多见于CpG位点甲基化(在胞嘧啶上添加甲基),有沉默基因的作用,甲基化的等位基因表达是受抑制的,而活性等位基因是未被甲基化的。[4][5]人类的基因印记是在配子(精子、卵细胞)生成的时候被重置、决定的。[6]

參見

外部連結

参考文献

  1. ^ Ohnishi, Takayuki; Sekine, Daisuke; Kinoshita, Tetsu. Chapter One - Genomic Imprinting in Plants: What Makes the Functions of Paternal and Maternal Genes Different in Endosperm Formation?. Yamamoto, Daisuke (编). Advances in Genetics. Epigenetic Shaping of Sociosexual Interactions 86. Academic Press. 2014-01-01: 1–25. doi:10.1016/b978-0-12-800222-3.00001-2. 
  2. ^ Deshpande, Sharvari; Nair, Sweta; Balasinor, N. H. Chapter 2 - Genomic imprinting. Tollefsbol, Trygve (编). Epigenetics and Reproductive Health. Translational Epigenetics 21. Academic Press. 2021-01-01: 27–46 [2024-01-15]. doi:10.1016/b978-0-12-819753-0.00002-7. (原始内容存档于2021-06-01). 
  3. ^ Tucci, Valter; Isles, Anthony R.; Kelsey, Gavin; Ferguson-Smith, Anne C.; Tucci, Valter; Bartolomei, Marisa S.; Benvenisty, Nissim; Bourc’his, Déborah; Charalambous, Marika; Dulac, Catherine; Feil, Robert. Genomic Imprinting and Physiological Processes in Mammals. Cell. 2019-02, 176 (5). ISSN 0092-8674. doi:10.1016/j.cell.2019.01.043. 
  4. ^ Li, Xia. 5 - Uniparental disomy and imprinting disorders. Li, Xia (编). Cases in Laboratory Genetics and Genomics (LGG) Practice. Academic Press. 2023-01-01: 65–81. ISBN 978-0-323-99622-8. doi:10.1016/b978-0-323-99622-8.00031-9. 
  5. ^ Falls, J. Greg; Pulford, David J.; Wylie, Andrew A.; Jirtle, Randy L. Genomic Imprinting: Implications for Human Disease. The American Journal of Pathology. 1999-03-01, 154 (3) [2023-11-10]. ISSN 0002-9440. PMC 1866410 . PMID 10079240. doi:10.1016/S0002-9440(10)65309-6. (原始内容存档于2023-11-10) (英语). 
  6. ^ Li, Yufeng; Sasaki, Hiroyuki. Genomic imprinting in mammals: its life cycle, molecular mechanisms and reprogramming. Cell Research. 2011-03, 21 (3) [2024-01-15]. ISSN 1748-7838. PMC 3193417 . PMID 21283132. doi:10.1038/cr.2011.15. (原始内容存档于2024-04-12) (英语).