The centriole adjunct of insects: Need to update the definition
| Autor: | Romano Dallai, David Mercati, Pietro Lupetti, Francesco Paoli |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Axoneme Male Centriole Spermiogenesis Biology 010603 evolutionary biology 01 natural sciences Electron Hemiptera 03 medical and health sciences Microscopy Electron Transmission Accessory bodies Centriole adjunct Insect centriole Microtubule organizing center (MTOC) Pericentriolar material (PCM) Animals Centrioles Centrosome Microtubule-Organizing Center Sperm Tail Spermatids Spermatogenesis Biological Evolution Cell Biology Developmental Biology Microtubule Basal body Transmission Pericentriolar material Microscopy urogenital system Microtubule organizing center General Medicine Cell biology 030104 developmental biology |
| Popis: | The ancestral eukaryotes presumably had an MTOC (microtubule organizing center) which late gave origin to the centriole and the flagellar axoneme. The centrosome of insect early spermatids is in general composed of two components: a single centriole and a cloud of electron-dense pericentriolar material (PCM). During spermiogenesis, the centriole changes its structure and gives rise to a flagellar axoneme, while the proteins of PCM, gamma tubulin in particular, are involved in the production of microtubules for the elongation and shaping of spermatid components. At the end of spermiogenesis, in many insects, additional material is deposited beneath the nucleus to form the centriole adjunct (ca). This material can also extend along the flagellum in two accessory bodies (ab) flanking the axoneme. Among Homoptera Sternorrhyncha, a progressive modification of their sperm flagella until complete disappearance has been verified. In the Archaeococcidae Matsucoccus feytaudi, however, a motile sperm flagellum-like structure is formed by an MTOC activity. This finding gives support to the hypothesis that an evolutionary reversal has occurred in the group and that the cell, when a non-functional centriole is present, activates an ancestral structure, an MTOC, to form a polarized motile bundle of microtubules restoring sperm motility. The presence and extension of the centriole adjunct in the different insect orders is also enlisted. |
| Databáze: | OpenAIRE |
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