Nucleolus

Nucleolar activity during larval development of Myrmeleon uniformis Navas, 1920 (Neuroptera, Myrmeleontidae)

C. A. Pacheco, Alevi, K. C. C., Silva, T. L., Azeredo-Oliveira, M. T. V., Ceron, C. R., and Kobayashi, M. K. H., Nucleolar activity during larval development of Myrmeleon uniformis Navas, 1920 (Neuroptera, Myrmeleontidae), vol. 13, pp. 5154-5158, 2014.

It has been reported in the literature that the Malpighian tubules of Neuroptera in the third instar undergo drastic histological changes, when they stop functioning in osmoregulation and start to secrete silk fibers for a cocoon. Therefore, to increase our knowledge about these cellular alterations that occur in the larvae of Neuroptera, we analyzed the cells that constitute the Malpighian tubules of each larval instar of the species Myrmeleon uniformis, with emphasis on nucleolar activity.

Nucleolar behavior during meiosis in four species of phyllostomid bats (Chiroptera, Mammalia)

M. R. Beguelini, Marchesin, S. R. C., Azeredo-Oliveira, M. T. V., and Morielle-Versute, E., Nucleolar behavior during meiosis in four species of phyllostomid bats (Chiroptera, Mammalia), vol. 10, pp. 552-565, 2011.

We analyzed the behavior of the nucleolus, nucleolar structures and nucleolus organizer regions (NORs) during meiotic di­vision in four species of phyllostomid bats that have different num­bers and locations of NORs. Nucleoli began disassembly at leptotene, and the subcomponents released from the nucleolus were dispersed in the nucleoplasm, associated with perichromosomal regions, or they remained associated with NORs throughout division. In Phyllostomus discolor, a delay in nucleolus disassembly was observed; it disas­sembled by the end of pachytene.

Chromosome number and cytogenetics of Euphorbia heterophylla L.

J. R. Aarestrup, Karam, D., and Fernandes, G. W., Chromosome number and cytogenetics of Euphorbia heterophylla L., vol. 7, pp. 217-222, 2008.

Euphorbia heterophylla L. (Euphorbiaceae) is a herbaceous species of great economic importance due to its invasive potential and consequent damage to agriculture and pasture land. For the first time, we provide information on its chromosome number, morphology, and behavior of mitotic chromosomes. Seeds were germinated and submitted to four treatments to obtain metaphases: 0.5% colchicine for 2 to 5 h, at ambient temperature; 0.5% colchicine for 16 to 24 h; 0.0029 M 8-hydroxyquinoline (8-HQ) for 2 to 5 h at ambient temperature, and 0.0029 M 8-HQ for 16 to 24 h at 4ºC.

Pattern of silver nitrate-staining during meiosis and spermiogenesis in testicular lobes of Antiteuchus tripterus (Heteroptera: Pentatomidae)

H. V. Souza, Castanhole, M. M. U., Bicudo, H. E. M. C., and Itoyama, M. M., Pattern of silver nitrate-staining during meiosis and spermiogenesis in testicular lobes of Antiteuchus tripterus (Heteroptera: Pentatomidae), vol. 7, pp. 196-206, 2008.

The pattern of silver nitrate (Ag)-staining differed among testicular lobes of Antiteuchus tripterus. In general, these differences are in regard to the number, size, shape, coloring intensity, and location of the stained bodies or masses, observed during meiosis and spermiogenesis. These characteristics were similar in lobes 1-3. Lobes 4-6, however, differed from each other and from lobes 1-3 as well.

Cytogenetic analysis in the spermatogenesis of Triatoma melanosoma (Reduviidae; Heteroptera)

V. B. Bardella, Azeredo-Oliveira, M. T. V., and Tartarotti, E., Cytogenetic analysis in the spermatogenesis of Triatoma melanosoma (Reduviidae; Heteroptera), vol. 7, pp. 326-335, 2008.

Triatomines are of great concern in public health because they are vectors of Chagas’ disease. This study presents an analysis of the species Triatoma melanosoma. The cytogenetic characteristics of triatomines include holocentric chromosomes, post-reductional meiosis in the sex chromosomes and nucleolar fragmentation in the meiotic cycle. The methodology utilized consisted of the techniques of lacto-acetic orcein staining and silver ion impregnation. The organs analyzed were adult testicles.

Meiosis, spermatogenesis and nucleolar behavior in the seminiferous tubules of Alydidae, Coreidae and Rhopalidae (Heteroptera) species

H. V. Souza, Souza, F. B., Maruyama, S. R. C., Castanhole, M. M. U., and Itoyama, M. M., Meiosis, spermatogenesis and nucleolar behavior in the seminiferous tubules of Alydidae, Coreidae and Rhopalidae (Heteroptera) species, vol. 8, pp. 1383-1396, 2009.

We studied the karyotype, spermatogenesis and nucleolar activity at spermatogenesis in five species of Heteropera: Hyalymenus sp and Neomegalotomus pallescens, Alydidae; Catorhintha guttula and Hypselonotus fulvus, Coreidae; and Niesthrea sidae, Rhopalidae. They showed a red (Alydidae) or orange (Coreidae and Rhopalidae) membrane covering the testes, which consisted of seven testicular lobes, except in N. pallescens, which had only five.

New evidence for nucleolar dominance in hybrids of Drosophila arizonae and Drosophila mulleri

C. I. Oliveira, Itoyama, M. M., and Bicudo, H. E. M. C., New evidence for nucleolar dominance in hybrids of Drosophila arizonae and Drosophila mulleri, vol. 5, pp. 632-637, 2006.

Drosophila mulleri (MU) and D. arizonae (AR) are cryptic species of the mulleri complex, mulleri subgroup, repleta group. Earlier cytogenetic studies revealed that these species have different regulatory mechanisms of nucleolar organizing activity. In these species, nucleolar organizing regions are found in both the X chromosome and the microchromosome. In the salivary glands of hybrids between MU females and AR males, there is an interspecific dominance of the regulatory system of the D.

Acid phosphatase activity distribution in salivary glands of triatomines (Heteroptera, Reduviidae, Triatominae)

A. C. B. Anhê, Lima-Oliveira, A. P. M., and Azeredo-Oliveira, M. T. V., Acid phosphatase activity distribution in salivary glands of triatomines (Heteroptera, Reduviidae, Triatominae), vol. 6, pp. 197-205, 2007.

Acid phosphatase activity (Gömori technique) in salivary gland cells was investigated in adult insects (males and females) of four species of triatomines: Triatoma infestans, Panstrongylus megistus, Rhodnius neglectus, and Rhodnius prolixus. Binucleated cells with bulky and polyploidy nuclei were detected, with acid phosphatase activity in the heterochromatin and nucleolus, which showed the most intense response.

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