کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2818762 1160090 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Retrotransposons, reverse transcriptase and the genesis of new genetic information
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی ژنتیک
پیش نمایش صفحه اول مقاله
Retrotransposons, reverse transcriptase and the genesis of new genetic information
چکیده انگلیسی

Spermatozoa of virtually all species can take up exogenous DNA or RNA molecules and internalize them into nuclei. A sperm endogenous reverse transcriptase activity can reverse-transcribe the internalized molecules in cDNA copies: exogenous RNA is reverse-transcribed in a one-step reaction, whereas DNA is first transcribed into RNA and subsequently reverse-transcribed. In either case, the newly synthesized cDNAs are delivered from sperm cells to oocytes at fertilization and are further propagated throughout embryogenesis and in tissues of adult animals. The reverse-transcribed sequences are underrepresented (below 1 copy/genome), mosaic distributed in tissues of adult individuals, transmitted in a non-Mendelian fashion from founders to F1 progeny, transcriptionally competent, variably expressed in different tissues and temporally transient, as they progressively disappear in aged animals. Based on these features, the reverse-transcribed sequences behave as extrachromosomal, biologically active retrogenes and induce novel phenotypic traits in animals. This RT-dependent mechanism, presumably originating from LINE-1 retroelements, generates transcriptionally competent retrogenes in sperm cells. These data strengthen the emerging view of a novel transgenerational genetics as the source of a continuous flow of novel epigenetic and phenotypic traits, independent from those associated to chromosomes. The distinctive features of this retrotransposon-based phenomenon share analogies with a recently discovered form of RNA-mediated inheritance, compatible with a Lamarckian-type adaptation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gene - Volume 448, Issue 2, 15 December 2009, Pages 180–186
نویسندگان
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