Sha Ky, Fire Andrew
Carnegie Institution of Washington, Department of Embryology, Baltimore, Maryland 21210, USA.
Genetics. 2005 Aug;170(4):1633-52. doi: 10.1534/genetics.104.040303. Epub 2005 Jun 8.
We have observed a gamete-of-origin imprinting effect in C. elegans using a set of GFP reporter transgenes. From a single progenitor line carrying an extrachromosomal unc-54::gfp transgene array, we generated three independent autosomal integrations of the unc-54::gfp transgene. The progenitor line, two of its three integrated derivatives, and a nonrelated unc-119:gfp transgene exhibit an imprinting effect: single-generation transmission of these transgenes through the male germline results in approximately 1.5- to 2.0-fold greater expression than transmission through the female germline. There is a detectable resetting of the imprint after passage through the opposite germline for a single generation, indicating that the imprinted status of the transgenes is reversible. In cases where the transgene is maintained in either the oocyte lineage or sperm lineage for multiple, consecutive generations, a full reset requires passage through the opposite germline for several generations. Taken together, our results indicate that C. elegans has the ability to imprint chromosomes and that differences in the cell and/or molecular biology of oogenesis and spermatogenesis are manifest in an imprint that can persist in both somatic and germline gene expression for multiple generations.
我们使用一组绿色荧光蛋白（GFP）报告转基因在秀丽隐杆线虫中观察到了配子起源印记效应。从携带一个游离型unc-54::gfp转基因阵列的单个祖代品系中，我们产生了unc-54::gfp转基因的三个独立常染色体整合。祖代品系、其三个整合衍生物中的两个，以及一个不相关的unc-119::gfp转基因表现出印记效应：这些转基因通过雄性生殖系的单代传递导致的表达比通过雌性生殖系传递高约1.5至2.0倍。在通过相反生殖系单代传递后，印记有可检测到的重置，这表明转基因的印记状态是可逆的。在转基因在卵母细胞谱系或精子谱系中连续多代维持的情况下，完全重置需要通过相反生殖系几代。综上所述，我们的结果表明秀丽隐杆线虫有能力对染色体进行印记，并且卵子发生和精子发生在细胞和/或分子生物学上的差异体现在一种印记中，这种印记可以在体细胞和生殖系基因表达中持续多代。
