rDNA

Cytogenetic description of Ancistrus abilhoai (Siluriformes: Loricariidae) from Iguaçu River basin, southern Brazil

M. O. Ribeiro, Noleto, R. B., Lorscheider, C. A., Porto, F. E., Prizon, A. C., Zawadzki, C. H., Oliveira, L. C., and Castro, A. L. B. Portela, Cytogenetic description of Ancistrus abilhoai (Siluriformes: Loricariidae) from Iguaçu River basin, southern Brazil, vol. 14, pp. 4051-4057, 2015.

The Iguaçu River basin is a tributary to the upper Paraná River in southern Brazil, and is considered an important aquatic ecoregion that, although having few species of fish, 51-71% of these are apparently endemic. Ancistrus abilhoai is one of three recently described species for this basin and is currently considered endemic to the basin.

B chromosome prevalence and physical mapping of 18S rDNA and H4 histone sites in the grasshopper Xyleus discoideus angulatus (Romaleidae)

C. B. Machado, Neto, L. C. Silva, Loreto, V., and Souza, M. J., B chromosome prevalence and physical mapping of 18S rDNA and H4 histone sites in the grasshopper Xyleus discoideus angulatus (Romaleidae), vol. 13, pp. 7052-7060, 2014.

We sampled 11 natural populations of the grasshopper Xyleus discoideus angulatus in Northeastern Brazil to analyze B chromosome frequency and meiotic behavior. We observed a single large B chromosome, resembling the X chromosome, in 29 of the 402 specimens. Eight of the 11 populations had B chromosomes, with a rather broad geographical distribution, suggesting that this is an ancient polymorphism; significant differences were observed in B chromosome prevalence among the populations. Presence of the B chromosome was associated with increased frequency of macrospermatids.

Cloning and sequencing of the rDNA gene family of the water buffalo (Bubalus bubalis)

C. Y. Pang, Deng, T. X., Tang, D. S., Yang, C. Y., Jiang, H., Yang, B. Z., and Liang, X. W., Cloning and sequencing of the rDNA gene family of the water buffalo (Bubalus bubalis), vol. 11, pp. 2878-2883, 2012.

The rDNA genes coding for ribosomal RNA in animals are complicated repeat sequences with high GC content. We amplified water buffalo rDNA gene sequences with the long and accurate (LA) PCR method, using LA Taq DNA polymerase and GC buffer, based on bioinformatic analysis of related organisms. The rDNA genes were found to consist of 9016 nucleotides, including three rRNA genes and two internal transcribed spacers (ITS), which we named 18S rRNA, ITS1, 5.8S rRNA, ITS2 and 28S rRNA.

Molecular characterization of endophytes isolated from Saccharum spp based on esterase and ribosomal DNA (ITS1-5.8S-ITS2) analyses

A. C. Leme, Bevilaqua, M. R. R., Rhoden, S. A., Mangolin, C. A., Machado, M. F. P. S., and Pamphile, J. A., Molecular characterization of endophytes isolated from Saccharum spp based on esterase and ribosomal DNA (ITS1-5.8S-ITS2) analyses, vol. 12, pp. 4095-4105, 2013.

This study used esterases and ribosomal DNA (rDNA) markers to determine endophytic variability in order to better understand endophyte-host interactions. Polyacrylamide gel electrophoresis and esterase isoenzymes (EST; EC 3.1.1.3), with α-naphthyl acetate and β-naphthyl acetate as substrates, were used to assess relationships among endophytes. ITS1-5.8S-ITS2 sequencing data were used as rDNA markers. Thirty-two esterases were obtained from 37 isolates of Saccharum spp, which clustered into five endophyte groups.

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