This takes place via interaction with a complex known as the ribosome, which binds the mRNA and converts its genetic information into protein via the process of translation. So, following its transcription from DNA in the nucleus, mRNA is transported out of the nucleus to the cytoplasm, and possibly to a specific subcellular location depending on the mRNA, where it can be deciphered by the cell. The central dogma of genetics has been that DNA is transcribed into RNA that is then translated into protein-the “business” end of the process.
Based on measurements, we propose a mechanism for chromosome dynamics in mitosis and meiosis, which involves three individual processes: (i) aggregation of chromatin subdomains into a chromosome filament, (ii) condensation in length, which involves a progressive increase in diameter and (iii) separation of chromatids.Joseph Jankovic MD, in Bradley and Daroff's Neurology in Clinical Practice, 2022 DNA to RNA to Protein No indication was found for helical winding of chromosomes either in mitosis or in meiosis. Although chromosome architecture in early prophase of meiosis seems similar to mitosis in principle, there is no equivalent stage during transition to metaphase I when chromosomes condense to a much higher degree and show a characteristic “smooth” surface. The basic structural components of mitotic chromosomes of rye are “parallel fibers” and “chromomeres” which become highly compacted in metaphase. In contrast, in meiosis I, condensation of chromosomes in length and diameter is a sigmoidal process with a retardation in zygotene and pachytene and an acceleration from diplotene to diakinesis. Mitotic chromosomes condense in a linear fashion, shorten in length and increase moderately in diameter.
Structural investigation and morphometry of meiotic chromosomes by scanning electron microscopy (in comparison to light microscopy) of all stages of condensation of meiosis I + II show remarkable differences during chromosome condensation in mitosis and meiosis I of rye (Secale cereale) with respect to initiation, mode and degree of condensation.
0 kommentar(er)
