Genomic Organization Under Different Environmental Conditions: Hoplosternum Littorale as a Model
| Autor: | Eliana Feldberg, Fabricio Beggiato Baccaro, Carlos Henrique Schneider, Francijara Araújo da Silva, Natália Dayane Moura Carvalho, Maria Claudia Gross |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Zoology Mitosis Genomics Biology 010603 evolutionary biology 01 natural sciences complex mixtures DNA Ribosomal Epigenesis Genetic 03 medical and health sciences Rivers RNA Ribosomal 18S Animals Repeated sequence Ribosomal DNA Catfishes Ecosystem Genomic organization Genetics fungi technology industry and agriculture RNA Ribosomal 5S Chromosome Mapping Original Articles equipment and supplies biology.organism_classification 030104 developmental biology Micronucleus test bacteria Animal Science and Zoology Ploidy Hoplosternum littorale Developmental Biology |
| Popis: | The Amazon has abundant rivers, streams, and floodplains in both polluted and nonpolluted environments, which show great adaptability. Thus, the goal of this study was to map repetitive DNA sequences in both mitotic chromosomes and erythrocyte micronuclei of tamoatás from polluted and nonpolluted environments and to assess the possible genotoxic effects of these environments. Individuals were collected in Manaus, Amazonas (AM), and submitted to classical and molecular cytogenetic techniques, as well as to a blood micronucleus test. Diploid number equal to 60 chromosomes are present in all individuals, with 18S ribosomal DNA sites present in one chromosome pair and no interstitial telomeric sites on chromosomes. The micronucleus test showed no significant differences in pairwise comparisons between environments or collection sites, but the Rex3 retroelement was dispersed on the chromosomes of individuals from unpolluted environments and compartmentalized in individuals from polluted environments. Divergent numbers of 5S rDNA sites are present in individuals from unpolluted and polluted environments. The mapping of repetitive sequences revealed that micronuclei have different compositions both intra- and interindividually that suggests different regions are lost in the formation of micronuclei, and no single fragile region undergoes breaks, although repetitive DNA elements are involved in this process. |
| Databáze: | OpenAIRE |
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