Retrotransposons, reverse transcriptase and the genesis of new genetic information

Sciamanna, Ilaria; Vitullo, Patrizia; Curatolo, A; Spadafora, Corrado

doi:10.1016/j.gene.2009.07.011

Cited by 50 publications

(48 citation statements)

References 72 publications

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“…Telomerase is also a kind of RTase; however, the function of RTase very low levels by exhibiting a rare group of MSCs subpopulations (49). The level of telomerase activity was is dissimilar to telomerase in the cells (38). Even though the function of nontelomeric RTase has not been fully undetected in the somatic cells such as fibroblasts; however, the telomerase activity was detected in the adult demonstrated, nontelomeric RTase coding genes were…”

Section: Dfscs and Mscs Interestingly Total Pulp Cells From Telomermentioning

confidence: 90%

“…The isolated clumps of three types of cells were digested by incubating in D-PBS containing 1 mg/ml from one position in the genome to another by replacement through RNA intermediates in the eukaryotic gecollagenase type I at 37°C with gentle agitation for 30 min. After washing, the clumps of cells were neutralized nome (38,42). Although obvious functions of these by adding 10% fetal bovine serum (FBS), and followed EDTA, and the cells were incubated with a fluorescein isothiocyanate (FITC)-conjugated primary antibodies on by centrifugation at 500 × g for 5 min.…”

Section: Materials and Methods Destruction Each Cell Division In Normentioning

confidence: 99%

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Comparative Analysis of Telomere Length, Telomerase and Reverse Transcriptase Activity in Human Dental Stem Cells

et al. 2011

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Stem cells from dental tissues have been isolated and established for tooth regenerative applications. However, basic characterization on their biological properties still needs to be investigated before employing them for effective clinical trials. In this study, we compared the telomere length, relative telomerase activity (RTA), and relative reverse transcriptase activity (RRA) as well as the surface antigen profile and mesenchymal differentiation ability in human dental papilla stem cells (DPaSCs), dental pulp stem cells (DPuSCs), and dental follicle stem cells (DFSCs) with mesenchymal stem cells (MSCs) derived from bone marrow. Dental stem cells (DSCs) were strongly positive for cell surface markers, such as CD44 and CD90. However, slightly lower expression of CD105 was observed in DPaSCs and DPuSCs compared to DFSCs and MSCs. Following specific induction, DPaSCs, DFSCs, and MSCs were successfully differentiated into adipocytes and osteocytes. However, DPuSCS, in particular, were able to differentiate into adipocytes but failed to induce into osteogenic differentiation. Further, all DSCs, MSCs, and MRC-5 fibroblasts as control were investigated for telomere length by nonradioactive chemiluminescent assay, RTA by relative-quantitative telomerase repeat amplification protocol (RQ-TRAP), and RRA by PCR-based assay. Mean telomere lengths in DPaSCs, DPuSCs, DFSCs, and MSCs was ϳ11 kb, and the values did not differ significantly (p < 0.05) among the cells analyzed. RTA levels in DPaSCs were significantly (p < 0.05) higher than in MSCs, DPuSCs, DFSCs, and MRC-5 fibroblasts and among DSCs, DFSCs showed a significantly (p < 0.05) lower RTA. Moreover, RRA levels were significantly (p < 0.05) higher in DPaSCs, DPuSCs, and MSCs than in DFSCs. Based on these observations, we conclude that among DSCs, DPaSCs possessed ideal characteristics on telomere length, telomerase activity and reverse transcriptase (RTase) activity, and may serve as suitable alternative candidates for regenerative medicine.

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Section: Dfscs and Mscs Interestingly Total Pulp Cells From Telomermentioning

confidence: 90%

Section: Materials and Methods Destruction Each Cell Division In Normentioning

confidence: 99%

Comparative Analysis of Telomere Length, Telomerase and Reverse Transcriptase Activity in Human Dental Stem Cells

et al. 2011

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“…With this innovation competence quasispecies-consortia (qs-c) transfer this adaptive principle also to all forms of cellular life. The defective parts of infectious genetic parasites represent an abundance of appropriate tools for cellular needs, documented in the variety of non-coding RNAs which are essential actors in all stages of cellular life such as transcription, translation, repair, recombination and immune functions [60][61][62][63][64][65] .…”

Section: Evolutionary Genetic Invention Is Not the Results Of Replicatmentioning

confidence: 99%

Pragmatic turn in biology: From biological molecules to genetic content operators

Witzany¹

2014

WJBC

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Core tip: Meaning in natural languages/codes and communication is context dependent. In contrast, artificial formalizable (algorithm based) languages employ a "universal" syntax in order to determine meaning independent of the contextual circumstances. It is empirically evident that no natural language speaks itself as no natural code codes itself. It always requires living agents that share a competence to generate and interpret these natural codes. Therefore I suppose that changes in the genetic code, which are of evolutionary relevance, are rather the result of fine-tuned processes by a large network of mobile genetic elements, persistent viruses, its defectives and other genetic parasites that alter DNA sequences. In this respect DNA remains as ecosphere habitat for social interacting RNA inhabitants. This represents a pragmatic turn in biology from syntax centered molecular biology to pragmatics centered agents interactions. AbstractErwin Schrödinger's question "What is life?" received the answer for decades of "physics + chemistry". The concepts of Alain Turing and John von Neumann introduced a third term: "information". This led to the understanding of nucleic acid sequences as a natural code. Manfred Eigen adapted the concept of Hammings "sequence space". Similar to Hilbert space, in which every ontological entity could be defined by an unequivocal point in a mathematical axiomatic system, in the abstract "sequence space" concept each point represents a unique syntactic structure and the value of their separation represents their dissimilarity. In this concept molecular features of the genetic code evolve by means of self-organisation of matter. Biological selection determines the fittest types among varieties of replication errors of quasi-species. The quasi-species concept dominated evolution theory for many decades. In contrast to this, recent empirical data on the evolution of DNA and its forerunners, the RNA-world and viruses indicate cooperative agent-based interactions. Group behaviour of quasi-species consortia constitute de novo and arrange available genetic content for adaptational purposes within real-life contexts that determine epigenetic markings. This review focuses on some fundamental changes in biology, discarding its traditional status as a subdiscipline of physics and chemistry. Witzany G. Pragmatic turn in biology the new paradigm that information is physically embodied in DNA sequences of four different types [1] . In contrast to the years before 1953, the question of "information" now became central: the components of DNA are simple chemicals, but the biological complexity that can be generated by the information of different sequences is revolutionary. The fundamental concept that integrated this new biological "information" with matter and energy was enshrined in the universal Turing machine and von Neumann's self-reproducing machines [2][3][4] . Consequently it follows that biology is physics with computation [5] . This was the core paradigm of molecular biology for almost the n...

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“…These processes involve incubating sperm with high levels of a transfecting DNA (or RNA) that is then delivered to the egg at fertilization and can affect offspring phenotype accordingly but without altering genotype. SMGT and SMRGT, as reviewed by Smith and Spadafora (2005) and more recently by Sciamanna et al (2009), involves the processing of the transforming sequence as an extra-nuclear episomal element that rarely (but occasionally) integrates into the genome. As the process relies on incubating sperm beforehand with the transforming construct, the phenomena suggest that spermatozoa have an innate ability to absorb and process nucleic acids.…”

Section: The Incoming Sperm's Impact On the Oocytementioning

confidence: 99%

“…Absorbed DNA is thought to be processed through an RNA intermediate that leads to a heritable episomal cDNA presence .The unexpected presence of DNA and RNA dependent polymerase activities in mature murine sperm was originally described in mature human spermatozoa and semen back in the 1970s (Witkin and Bendich 1977). It is the activity of an operational reverse transcriptase in mature spermatozoa that is thought to be an essential component of the SMGT/SMRGT (henceforth referred to as simply SMRGT) mechanism (Sciamanna et al , 2009.…”

Section: The Incoming Sperm's Impact On the Oocytementioning

confidence: 99%

Confrontation, Consolidation, and Recognition: The Oocyte’s Perspective on the Incoming Sperm

Miller

2015

Cold Spring Harb Perspect Med

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From the oocyte's perspective, the incoming sperm poses a significant challenge. Despite (usually) arising from a male of the same species, the sperm is a "foreign" body that may carry with it additional, undesirable factors such as transposable elements (mainly retroposons) into the egg. These factors can arise either during spermatogenesis or while the sperm is moving through the epididymis or the female genital tract. Furthermore, in addition to the paternal genome, the sperm also carries its own complex repertoire of RNAs into the egg that includes mRNAs, lncRNAs, and sncRNAs. Last, the paternal genome itself is efficiently packaged into a protamine (nucleo-toroid) and histone (nucleosome)-based chromatin scaffold within which much of the RNA is embedded. Taken together, the sperm delivers a far more complex package to the egg than was originally thought. Understanding this complexity, at both the compositional and structural level, depends largely on investigating sperm chromatin from both the genomic (DNA packaging) and epigenomic (RNA carriage and extant histone modifications) perspectives. Why this complexity has arisen and its likely purpose requires us to look more closely at what happens in the oocyte when the sperm gains entry and the processes that then take place preparing the paternal (and maternal) genomes for syngamy.

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Retrotransposons, reverse transcriptase and the genesis of new genetic information

Cited by 50 publications

References 72 publications

Comparative Analysis of Telomere Length, Telomerase and Reverse Transcriptase Activity in Human Dental Stem Cells

Comparative Analysis of Telomere Length, Telomerase and Reverse Transcriptase Activity in Human Dental Stem Cells

Pragmatic turn in biology: From biological molecules to genetic content operators

Confrontation, Consolidation, and Recognition: The Oocyte’s Perspective on the Incoming Sperm

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