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| Author(s): |
Fernanda Fernandez Madeira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São José do Rio Preto. 2017-03-14. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto |
| Defense date: | 2017-03-02 |
| Advisor: | Maria Tercília Vilela Azeredo Oliveira; Patrícia Simone Leite Vilamaior |
| Abstract | |
Triatomines are hematophagous insects of great importance for public health, since they are considered as the main form of transmission of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. Besides the epidemiological importance, these insects stand out in cellular studies, as they present some peculiarities, such as holocentric chromosomes, inverted meiosis for sex chromosomes and nucleolar persistence during meiosis. The phenomenon of nucleolar persistence is defined by the presence of the nucleolus or nucleolar corpuscles during all phases of meiosis. So far, this phenomenon has been described for 24 triatomine species of the genus Triatoma, Rhodnius and Panstrongylus. However, only the presence of this nuclear structure in all phases of meiosis does not guarantee its transcriptional activity. So, the objective of the present study was to describe the nucleologenesis in new species of at least seven new genera (Cavernicola, Psammolestes, Dipetalogaster, Eratyrus, Meccus, Mepraia, Nesotriatoma), in order to analyze if nucleolar persistence is a synapomorphy of the subfamily Triatominae. Besides that, this work had the purpose to evaluate the nucleolar activity during the meiosis of the species Triatoma infestans, Rhodnius montenegrensis and Panstrongylus megistus, by means of the cytochemical technique Acridine Orange, with the objective of characterizing, based on the presence of RNA, if there is transcriptional activity in the persistent nucleolar material. All 59 species analyzed, distributed in seven genera, presented nucleolar persistence during meiosis, thus corroborating that this phenomenon is a synapomorphy of the subfamily Triatominae. By means of the fluorochrome Acridine Orange, the persistent nucleolus has been found to be transcriptionally active. Thus, it was evident, for the first time, that the nucleolus is present in the spermatogenesis of all triatomines and that this material is transcriptionally active, supporting the relationship between nucleolar persistence during the meiosis of these insects and the formation of the organelle chromatoid body. (AU) | |
| FAPESP's process: | 15/14762-5 - Is there transcriptional activity during nucleolar persistence in the meiosis of triatomines? |
| Grantee: | Fernanda Fernandez Madeira |
| Support Opportunities: | Scholarships in Brazil - Master |