Drotos Katherine H I, Zagoskin Maxim V, Kess Tony, Gregory T Ryan, Wyngaard Grace A
Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA.
Trends Genet. 2022 May;38(5):483-500. doi: 10.1016/j.tig.2022.02.003. Epub 2022 Feb 25.
Programmed elimination of DNA during development yields somatic cell nuclei with dramatically different DNA sequence and content relative to germline nuclei, profoundly influencing genome architecture and stability. Whole-genome sequencing has significantly expanded the list of taxa known to exhibit this trait and has revealed the identity of excised genes and transposable elements (TEs) in certain taxa. Here, we compare the diverse mechanisms employed by ciliates, nematodes, copepods, and lamprey to downsize their genomes during development and propose tests of hypotheses about the evolution and/or maintenance of this trait. We explore possible functional roles that programmed DNA elimination (PDE) could play in genomic defense (especially against TEs), regulation of development, sex determination, co-option, and modulating nucleotypic effects, which together argue for a place in the mainstream investigation of genome evolution.
发育过程中DNA的程序性消除产生了与生殖细胞核相比，DNA序列和含量差异巨大的体细胞核，这对基因组结构和稳定性产生了深远影响。全基因组测序显著扩充了已知具有这一特征的生物分类群列表，并揭示了某些分类群中被切除基因和转座元件（TEs）的身份。在此，我们比较了纤毛虫、线虫、桡足类动物和七鳃鳗在发育过程中用于缩减其基因组的多种机制，并提出了关于这一特征的进化和/或维持的假设检验。我们探讨了程序性DNA消除（PDE）在基因组防御（尤其是针对TEs）、发育调控、性别决定、功能获得以及调节核型效应中可能发挥的功能作用，这些共同表明其在基因组进化主流研究中应占有一席之地。
