16
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Variation of the interphase heterochromatin in Artemia (Crustacea, Anostraca) of the Americas is related to changes in nuclear size and ionic composition of hipersaline habitats Translated title: Variação da heterocromatina interfásica em Artemia (Crustacea, Anostraca) das Américas está relacionada a mudanças no tamanho nuclear e composição iônica em habitats hipersalinos

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Abstract The populations of Artemia (or brine shrimp) from the Americas exhibit a wide variation in the amount of interphase heterochromatin. There is interest in understanding how this variation affects different parameters, from the cellular to the organismal levels. This should help to clarify the ability of this organism to tolerate brine habitats regularly subject to strong abiotic changes. In this study, we assessed the amount of interphase heterochromatin per nucleus based on chromocenter number (N-CHR) and relative area of chromocenter (R-CHR) in two species of Artemia, A. franciscana (Kellog, 1906) (n=9 populations) and A. persimilis (Piccinelli and Prosdocimi, 1968) (n=3 populations), to investigate the effect on nuclear size (S-NUC). The relationship of the R-CHR parameter with the ionic composition (IC) of brine habitats was also analysed. Our results indicate a significant variation in the amount of heterochromatin both within and between species (ANOVA, p<0.001). The heterochromatin varied from 0.81 ± 1.17 to 12.58 ± 3.78 and from 0.19 ± 0.34% to 11.78 ± 3.71% across all populations, for N-CHR and R-CHR parameters, respectively. N-CHR showed less variation than R-CHR (variation index 15.5-fold vs. 62-fold). At least five populations showed a significant association (p<0.05) between R-CHR and S-NUC, either with negative (four populations, r= from -0.643 to -0.443), or positive (one population, r= 0.367) values.Within each species, there were no significant associations between both parameters (p>0.05). The R-CHR and IC parameters were associated significantly for the magnesium ion (r= 0.496, p<0.05) and also for the chloride, sodium and calcium ions (r = from -0.705 to -0.478, p<0.05). At species level, a significant association between both parameters was also found in A. franciscana populations, for the sulphate and calcium ions, in contrast to A. persimilis. These findings suggest that the amount of interphase heterochromatin modifies the nuclear size in Artemia. Our data also indicate that change in the amount of interphase heterochromatin is in line with the ionic composition of brines. This would be a species-specific phenomenon, whose occurrence may be involved in the ability of this organism to survive in these environments.

          Translated abstract

          Resumo As populações de Artemia (ou camarão de salinas) das Américas apresentam uma grande variação na quantidade de heterocromatina interfásica. Há interesse em compreender como esta variação afeta diferentes parâmetros, desde o nível celular até os organismos. Isso deve ajudar a esclarecer a capacidade destes organismos tolerarem habitats extremos de água hipersalinas, que normalmente são submetidos a fortes mudanças abióticas. Neste estudo, avaliou-se a quantidade heterocromatina interfásica por núcleo através do número de cromocentros (N-CHR) e a área relativa de cromocentros (R-CHR) em duas espécies de Artemia, A. franciscana (Kellog, 1906) (n=9 populações) e A. persimilis (Piccinelli e Prosdocimi, 1968) (n=3 populações), para investigar o seu efeito no tamanho nuclear (S-NUC). Também foi analisada a relação de R-CHR com a composição iónica (CI) dos habitats hipersalinos. Nossos resultados indicam uma variação significativa na quantidade de heterocromatina dentro e entre espécies (ANOVA, p<0,001). Em todas as populações, a heterocromatina variou de 0,81 ± 1,17 para 12,58 ± 3,78 e de 0,19 ± 0,34% para 11,78 ± 3,71% para os parâmetros R-CHR e N-CHR, respectivamente. N-CHR apresentou menor variação do que R-CHR (amplitude de variação de 15,5 vezes vs. 62 vezes). Pelo menos cinco populações apresentaram uma associação significativa (p<0,05) entre R-CHR e S-NUC, seja com valores negativos (quatro populações, r = -0,643 a -0,443) ou positivo (uma população, r = 0,367). Os parâmetros R-CHR e CI foram associados significativamente para o íon de magnésio (r = 0,496, p<0,05) e também para os íons cloreto, sódio e cálcio (r = -0,705 a -0,478, p<0,05). Ao nível de espécie, foi também encontrada uma associação significativa entre esses dois parâmetros em populações de A. franciscana para os íons de sulfato e de cálcio, em contraste com A. persimilis. Estes achados sugerem que a quantidade heterocromatina interfásica modifica o tamanho nuclear em Artemia. Os nossos dados também indicam que a mudança na quantidade de heterocromatina interfásica está associada com a composição iónica das salinas. Este seria um fenómeno específico da espécie, cuja ocorrência pode estar envolvida na capacidade deste organismo sobreviver em tais ambientes.

          Related collections

          Most cited references51

          • Record: found
          • Abstract: not found
          • Article: not found

          A graphic procedure in the geochemical interpretation of water-analyses

            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Arabidopsis CROWDED NUCLEI (CRWN) proteins are required for nuclear size control and heterochromatin organization

            Background Plant nuclei superficially resemble animal and fungal nuclei, but the machinery and processes that underlie nuclear organization in these eukaryotic lineages appear to be evolutionarily distinct. Among the candidates for nuclear architectural elements in plants are coiled-coil proteins in the NMCP (Nuclear Matrix Constituent Protein) family. Using genetic and cytological approaches, we dissect the function of the four NMCP family proteins in Arabidopsis encoded by the CRWN genes, which were originally named LINC (LITTLE NUCLEI). Results CRWN proteins are essential for viability as evidenced by the inability to recover mutants that have disruptions in all four CRWN genes. Mutants deficient in different combinations of the four CRWN paralogs exhibit altered nuclear organization, including reduced nuclear size, aberrant nuclear shape and abnormal spatial organization of constitutive heterochromatin. Our results demonstrate functional diversification among CRWN paralogs; CRWN1 plays the predominant role in control of nuclear size and shape followed by CRWN4. Proper chromocenter organization is most sensitive to the deficiency of CRWN4. The reduction in nuclear volume in crwn mutants in the absence of a commensurate reduction in endoreduplication levels leads to an increase in average nuclear DNA density. Conclusions Our findings indicate that CRWN proteins are important architectural components of plant nuclei that play diverse roles in both heterochromatin organization and the control of nuclear morphology.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Molecular melodies in high and low C.

              D Hartl (2000)
              For 50 years now, one of the enigmas of molecular evolution has been the C-value paradox, which refers to the often massive, counterintuitive and seemingly arbitrary differences in genome size observed among eukaryotic organisms. For example, the genome of the fruitfly Drosophila melanogaster is 180 megabases (Mb), whereas that of the European brown grasshopper Podisma pedestris is 18,000 Mb. The difference in genome size of a factor of 100 is difficult to explain in view of the apparently similar levels of evolutionary, developmental and behavioural complexity of these organisms.
                Bookmark

                Author and article information

                Contributors
                Role: ND
                Role: ND
                Journal
                bjb
                Brazilian Journal of Biology
                Braz. J. Biol.
                Instituto Internacional de Ecologia
                1678-4375
                2017
                : 0
                : 0
                Affiliations
                [1 ] Universidad de Los Lagos Chile
                Article
                S1519-69842017005101101
                10.1590/1519-6984.02516
                e9414ce4-2c7a-4020-8cfb-989a392e20a7

                This work is licensed under a Creative Commons Attribution 4.0 International License.

                History
                Product

                SciELO Brazil

                Self URI (journal page): http://www.scielo.br/scielo.php?script=sci_serial&pid=1519-6984&lng=en
                Categories
                BIOLOGY

                General life sciences
                Artemia,interphase heterochromatin,chromocenter,nuclear size,brine ionic composition,heterocromatina interfásica,cromocentro,tamanho nuclear,composição iónica

                Comments

                Comment on this article