TY - JOUR TI - Domestic chickens activate a piRNA defense against avian leukosis virus AU - Sun, Yu Huining AU - Xie, Li Huitong AU - Zhuo, Xiaoyu AU - Chen, Qiang AU - Ghoneim, Dalia AU - Zhang, Bin AU - Jagne, Jarra AU - Yang, Chengbo AU - Li, Xin Zhiguo A2 - Goff, Stephen P VL - 6 PY - 2017 DA - 2017/04/06 SP - e24695 C1 - eLife 2017;6:e24695 DO - 10.7554/eLife.24695 UR - https://doi.org/10.7554/eLife.24695 AB - PIWI-interacting RNAs (piRNAs) protect the germ line by targeting transposable elements (TEs) through the base-pair complementarity. We do not know how piRNAs co-evolve with TEs in chickens. Here we reported that all active TEs in the chicken germ line are targeted by piRNAs, and as TEs lose their activity, the corresponding piRNAs erode away. We observed de novo piRNA birth as host responds to a recent retroviral invasion. Avian leukosis virus (ALV) has endogenized prior to chicken domestication, remains infectious, and threatens poultry industry. Domestic fowl produce piRNAs targeting ALV from one ALV provirus that was known to render its host ALV resistant. This proviral locus does not produce piRNAs in undomesticated wild chickens. Our findings uncover rapid piRNA evolution reflecting contemporary TE activity, identify a new piRNA acquisition modality by activating a pre-existing genomic locus, and extend piRNA defense roles to include the period when endogenous retroviruses are still infectious. KW - piRNA KW - endogenous retrovirus KW - PIWI KW - transposable element KW - White Leghorn KW - Red Jungle Fowl JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -