Длинные диспергированные повторяющиеся элементы класса LINE1 (L1) представляют собой семейство ретротранспозонов, способных реплицироваться в геноме хозяина и интегрироваться в него. L1 внесли значительный вклад в эволюцию генома млекопитающих посредством перемещения в клетках зародышевого пути и в раннем эмбриогенезе, что привело к их широкой представленности в геномах высших млекопитающих. В организме человека L1 элементы составляют более 30 % генома. Исторически считалось, что ретротранспозиции элементов L1 происходят только во время гаметогенеза и опухолевых процессов, однако последние исследования показали, что L1 чрезвычайно активны у мышей, крыс и человека в клетках нейрональных предшественников. Было установлено, что клетки гиппокампа и некоторые другие регионы мозга могут иметь множественные соматические инсерции. Эти инсерции могут оказывать влияние на транскрипционную экспрессию нейронов, обуславливая уникальность транскриптомов отдельных нервных клеток.
Long interspersed nucleotide elements 1 LINE1 (L1) are retrotransposons, which can duplicate by a copy-and-paste genetic mechanism. L1 have significantly influenced mammalian genome evolution by retrotransposing in the germ-line cells or in early embryogenesis, which led to their wide representation in the genomes of higher mammals. The human L1 elements constitute over 30% of the genome. Historically, it was believed that L1 retrotransposition take place only during gametogenesis and neoplastic processes, but recent studies have found that L1 is highly active in the mouse, rat and human neural progenitor cells. It was established that cells of the hippocampus and other regions of brain can have multiple somatic insertion. These insertions can cause unique of the transcriptome of individual neurons by influence transcriptional expression neuronal cells.
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