Distribution of constitutive heterochromatin in two species of triatomines: Triatoma lenti Sherlock and Serafim (1967) and Triatoma sherlocki Papa, Jurberg, Carcavallo, Cerqueira & Barata (2002)

Triatoma lenti and Triatoma sherlocki are hemipterans that belong to the brasiliensis subcomplex. In triatomines, the constitutive heterochromatin pattern is species-specific and allows, in many cases, for the grouping of species. Thus, we cytogenetically analyzed T. sherlocki and T. lenti using C-banding, and we compared the results with previous ones obtained in other species of the brasiliensis subcomplex. Both species were found to have a male diploid chromosome number of 22 chromosomes (2n = 20A. +. XY) with heterochromatic blocks at one or both chromosomal ends of all autosomal pairs. During early meiotic prophase, they showed a large heteropycnotic chromocenter constituted by the association of both sex chromosomes plus two autosomal pairs and many heterochromatic blocks dispersed inside the nucleus. All of these cytogenetic characteristics are similar to those observed in other species of brasiliensis subcomplex, results which confirm the grouping of T. sherlocki and T. lenti within this subcomplex. However, we emphasize the importance of other approaches, such as molecular analysis, to confirm the placement of T. lenti within the brasiliensis subcomplex. © 2012 Elsevier B.V.

Cytogenetic description of the Amazonian brown brocket Mazama nemorivaga (Artiodactyla, Cervidae)

The Amazonian brown brocket Mazama nemorivaga (Cuvier, 1817) is a small to medium-sized deer from the Amazon rainforest and ecotones. The first karyotype described was 2n=67 to 69 + 2-7 B and FN= 69-72, in which all chromosomes were acrocentric and the X chromosome was the only submetacentric chromosome. However, important aspects of the species chromosome evolution were not resolved because of the lack of information on chromosome banding. The G-banding pattern of M. nemorivaga karyotype showedthe presence of an XX/XY1Y2 sex chromosome system as a product of an X-autosome tandem fusion, which results in a basic 2n=68, FN=70 in females and 2n= 69, FN=70 in males. The fact that this karyotype only differs from that of Capreolus capreolus pygargus (Pallas, 1771; 2n=70, FN=72+B) by X-autosome tandem fusion may corroborate the basal condition of M. nemorivaga and its proximity to the ancestral karyotype of the American Odocoileini. A derived karyotype 2n=67, XY1Y2, FN=70 + 3B from the Brazilianstate of Mato Grosso (the western Amazon) may be evidence of differentiation between western and eastern populations. © Bruno Ferreto Fiorillo et al.

Meiotic pairing of B chromosomes, multiple sexual system, and Robertsonian fusion in the red brocket deer Mazama americana (Mammalia, Cervidae)

Deer species of the genus Mazama show significant inter and intraspecific chromosomal variation due to the occurrence of rearrangements and B chromosomes. Given that carriers of aneuploidies and structural rearrangements often show anomalous chromosome pairings, we here performed a synaptonemal complex analysis to study chromosome pairing behavior in a red brocket deer (Mazama americana) individual that is heterozygous for a Robertsonian translocation, is a B chromosome carrier, and has a multiple sex chromosome system (XY1Y2). The synaptonemal complex in spermatocytes showed normal chromosome pairings for all chromosomes, including the autosomal and sex trivalents. The electromicrographs showed homology among B chromosomes since they formed bivalents, but they also appeared as univalents, indicating their anomalous behavior and non-Mendelian segregation. Thus, synaptonemal complex analysis is a useful tool to evaluate the role of B chromosomes and rearrangements during meiosis on the intraspecific chromosomal variation that is observed in the majority of Mazama species. © FUNPEC-RP.

Chromosomal characteristics of a Brazilian whip spider (Amblypygi) and evolutionary relationships with other arachnid orders

We analyzed mitotic and meiotic cells of a Brazilian amblypygid, Heterophrynus longicornis, using conventional and molecular cytogenetic techniques (Giemsa staining, C-banding, Ag-NOR, and FISH with rDNA probe). This is the first study that focuses solely on amblypygid chromosomes; it was undertaken to add data on cytogenetic knowledge of this group and contribute to the understanding of chromosome evolution in the Arachnida. We found 2n = 66 for male and female individuals, monocentric chromosomes, and absence of morphologically differentiated sex chromosomes. C-banding showed heterochromatin in the pericentromeric region of most chromosomes. Mitotic and meiotic nuclei submitted to silver impregnation and FISH revealed, respectively, Ag-NORs and ribosomal genes in the terminal region of two chromosome pairs. Most chromosome features that we observed in H. longicornis are shared with species of other arachnid orders; however, the absence of morphologically differentiated sex chromosomes in amblypygid contrasts with the remarkable variety of sex chromosome systems recorded for the Araneae. Consequently, we conclude that analysis of species of the Tetrapulmonata clade is useful for understanding the trends of sex chromosome evolution in this arachnid group. © FUNPEC-RP.

Evolução cromossômica em aranhas caranguejeiras (Mygalomorphae) e Haploginas Basais (Araneomorphae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evolução cromossômica em Cassidinae sensu lato (Coleoptera, Polyphaga, Chrysomelidae)

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Estudo da microarquitetura óssea, do estado nutricional e de fatores farmacológicos na síndrome de Turner

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Espermatogênese e comportamento nucleolar em machos de Heteoptera aquáticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo morfológico dos testículos com ênfase na análise da espermatogênese e ultraestrutura de espécies aquáticas de Heteroptera

Pós-graduação em Genética - IBILCE

Identificação dos cromossomos de Mazama gouazoubira (Artiodactyla; Cervidae) envolvidos em rearranjos induzidos pela doxorrubicina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Citogenética molecular e caracterização cromossômica no gênero Eigenmannia (Teleostei, Gymnotiformes, Sternopygidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudos citogenéticos em raias do gênero Patamotrygon (Chondrichthyes: Myliobatiformes: Potamotrygonidae) na bacia superior do rio Paraná

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relacionamento filogenético entre espécies pertencentes às famílias Belostomatidae, Gelastocoridae, Gerridae, Notonectidae, Veliidae (Hemiptera: Heteroptera) e Cercopidae (Hemiptera:Auchenorrhyncha)

Pós-graduação em Genética - IBILCE

Análise dos cromossomos sexuais de Characidium (Characiformes, Crenuchidae) por microdissecção e pintura cromossômica

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Estudos citogenéticos no genêro Characidium (Teleostei, Characiformes, Chrenuchidae), com análise estrutural e molecular do sistema ZZ-ZW de cromossomos sexuais

Pós-graduação em Ciências Biológicas (Zoologia) - IBB