FISH

Polymorphisms of the nucleolus organizing regions in Loricaria cataphracta (Siluriformes, Loricariidae) of the upper Paraguay River basin indicate an association with transposable elements

F. E. Porto, Gindri, B. S., Vieira, M. M. R., Borin, L. A., Portela-Castro, A. L. B., and Martins-Santos, I. C., “Polymorphisms of the nucleolus organizing regions in Loricaria cataphracta (Siluriformes, Loricariidae) of the upper Paraguay River basin indicate an association with transposable elements”, vol. 13, pp. 1627-1634, 2014.

A cytogenetic analysis of Loricaria cataphracta revealed a diploid number of 2n = 64 chromosomes, distributed as 12 metacentric + 8 submetacentric + 2 subtelocentric + 42 acrocentric, with a fundamental number of 86. Analysis of the nucleolus organizing region (NOR) using silver nitrate impregnation and fluorescence in situ hybridization (18S rDNA probe) techniques showed intra-population chromosomal polymorphism that could be classified into five different patterns (I to V), involving four pairs of chromosomes (8, 9, 12, and 13).

Differentiation and evolutionary relationships in Erythrinus erythrinus (Characiformes, Erythrinidae): occurrence and distribution of B chromosomes

N. F. Martins, Cioffi, M. B., Troy, W. P., Martinez, J. F., Moreira-Filho, O., and Bertollo, L. A. C., “Differentiation and evolutionary relationships in Erythrinus erythrinus (Characiformes, Erythrinidae): occurrence and distribution of B chromosomes”, vol. 13, pp. 7094-7101, 2014.

Erythrinus erythrinus, a Neotropical fish species of the Erythrinidae family, has a wide distribution in South America. Previous cytogenetic analysis showed that this species presents extensive karyotype diversity, with 4 karyomorphs (A-D) described herein. This study investigated the karyotypic structure of 2 new populations of E. erythrinus from the Brazilian Pantanal region, in order to improve the knowledge of the chromosomal diversity in this species.

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.

Chromosomal diversity in Hypostomus (Siluriformes, Loricariidae) with emphasis on physical mapping of 18S and 5S rDNA sites

J. B. Traldi, Blanco, D. R., Vicari, M. R., Martinez, J. F., Lui, R. L., Barros, A. V., Artoni, R. F., and Moreira-Filho, O., “Chromosomal diversity in Hypostomus (Siluriformes, Loricariidae) with emphasis on physical mapping of 18S and 5S rDNA sites”, vol. 12, pp. 463-471, 2013.

We examined chromosomes of three species of the genus Hypostomus, in order to contribute to the understanding of the karyotype evolution of this group. Specimens of H. ancistroides and H. nigromaculatus displayed differences in karyotype formulas, distribution and location of heterochromatin and nucleolus organizer regions when compared to other populations of the same species. We made the first cytogenetic characterization of H. tapijara, an endemic species in the Ribeira de Iguape River. These specimens had 2n = 66 chromosomes, while H.

Molecular taxonomy and evolutionary hypothesis concerning Astyanax fasciatus (Characiformes, Characidae) from Vila Velha State Park and Tibagi and Iguaçu Rivers

D. A. Matoso, da Silva, M., Artoni, R. F., and Torres, R. A., “Molecular taxonomy and evolutionary hypothesis concerning Astyanax fasciatus (Characiformes, Characidae) from Vila Velha State Park and Tibagi and Iguaçu Rivers”, vol. 12, pp. 631-638, 2013.

A species complex hypothesis involving Astyanax fasciatus from southern Brazil was tested using 12S mtDNA sequences. Phylogenetic inferences were performed with maximum likelihood, maximum parsimony and Bayesian as phylogenetic methods and Hemigrammus bleheri as the outgroup. Besides 11 sequences from A. fasciatus, the data set was comprised of other partial 12S sequences including material from Astyanax altiparanae (two sequences) and Astyanax sp (four sequences), both from the Iguaçu River. The hypothesis of an A.

Karyotype characterization reveals active 45S rDNA sites located on chromosome termini in Smilax rufescens (Smilacaceae)

D. Pizzaia, Oliveira, V. M., Martins, A. R., Appezzato-da-Glória, B., Forni-Martins, E., and Aguiar-Perecin, M. L. R., “Karyotype characterization reveals active 45S rDNA sites located on chromosome termini in Smilax rufescens (Smilacaceae)”, vol. 12, pp. 1303-1310, 2013.

The genus Smilax (Smilacaceae) includes species of medicinal interest; consequently, their identification is important for the control of raw material used in the manufacture of phytotherapeutic products. We investigated the karyotype of Smilax rufescens in order to look for patterns that would be useful for comparative studies of this genus. To accomplish this, we developed procedures to grow plants and optimize root pretreatment with mitotic fuse inhibitors to obtain metaphase spreads showing clear chromosome morphology.

Numerical aberrations of chromosome 17 and TP53 in brain metastases derived from breast cancer

D. S. Vasconcelos, da Silva, F. P. E., Quintana, L. G., Anselmo, N. P., Othman, M. A. K., Liehr, T., and de Oliveira, E. H. C., “Numerical aberrations of chromosome 17 and TP53 in brain metastases derived from breast cancer”, vol. 12, pp. 2594-2600, 2013.

Breast cancer is the second most common origin of brain metastases, after lung cancer, and represents 14-20% of all cases. Abnormalities of chromosome 17 are important molecular genetic events in human breast cancer, and several oncogenes and tumor suppressor genes are located on this chromosome. In about half of all human cancers, the tumor suppressor gene TP53, located at 17p13.1, is either lost or mutated.

Improvements in cytological preparations for fluorescent in situ hybridization in Passiflora

M. M. Souza, Urdampilleta, J. D., and Forni-Martins, E. R., “Improvements in cytological preparations for fluorescent in situ hybridization in Passiflora”, vol. 9, pp. 2148-2155, 2010.

Cytological preparations for the fluorescent in situ hybridization (FISH) technique require cytoplasm-free metaphases, with well-spread chromosomes, for the localization of DNA sequences and chromosome mapping. We tested various procedures for FISH analysis of Passiflora cacaoensis, P. gardneri and hybrid F1 progeny of P. gardneri x P. gibertii. Two treatments with four enzymes and three incubation times were compared. The material was treated with 1.0 M HCl before enzymatic digestion.

Primed in situ labeling for detecting single-copy genes

J. - L. Gao, Nie, Y., and Ding, X. - P., “Primed in situ labeling for detecting single-copy genes”, vol. 10, pp. 1884-1890, 2011.

In order to analyze male sterility caused by deletion of SRY and DAZ, we examined the accuracy and cost-effectiveness of a modified primed in situ labeling (PRINS) technique for detection of single-copy genes. Peripheral blood samples were collected from 50 healthy men; medium-term cultured lymphocytes from these samples were suspended in fixative solution and then spread on clean slides.

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