Schulman A H, Kalendar R
Plant Breeding Biotechnology, MTT Agrifood Research, Jokioinen, Finland.
Cytogenet Genome Res. 2005;110(1-4):598-605. doi: 10.1159/000084993.
Cellular genes comprise at most 5% of the barley genome; the rest is occupied primarily by retrotransposons. Retrotransposons move intracellularly by a replicative mechanism similar to that of retroviruses. We describe the major classes of retrotransposons in barley, including the two nonautonomous groups that were recently identified, and detail the evidence supporting our current understanding of their life cycle. Data from analyses of long contiguous segments of the barley genome, as well as surveys of the prevalence of full-length retrotransposons and their solo LTR derivatives in the genus Hordeum, indicate that integration and recombinational loss of retrotransposons are major factors shaping the genome. The sequence conservation and integrative capacity of barley retrotransposons have made them excellent sources for development of molecular marker systems.
细胞基因在大麦基因组中所占比例至多为5%；其余部分主要由逆转座子占据。逆转座子通过一种类似于逆转录病毒的复制机制在细胞内移动。我们描述了大麦中逆转座子的主要类别，包括最近鉴定出的两个非自主类群，并详细阐述了支持我们目前对其生命周期理解的证据。来自大麦基因组长连续片段分析的数据，以及对大麦属中全长逆转座子及其单独长末端重复序列衍生物的流行情况的调查表明，逆转座子的整合和重组丢失是塑造基因组的主要因素。大麦逆转座子的序列保守性和整合能力使其成为开发分子标记系统的优良来源。
