Karine Frehner Kavalco

Publications

• 1.73

  Impact points

  Comparative cytogenetics and molecular phylogeography in the group astyanax altiparanae--Astyanax aff. bimaculatus (Teleostei, Characidae).

  K F Kavalco, R Pazza, K D O Brandão, C Garcia, L F Almeida-Toledo

  Cytogenetic and genome research. 03/2011; 134(2):108-19.

  The genus Astyanax comprises small characin fish of the neotropical region. The so-called 'yellow-tailed characins' compose one of the most widely distributed Astyanax groups. A. altiparanae and A. aff. bimaculatus, are evolutionarily closely related and commonly found in several Brazilian h... [more] The genus Astyanax comprises small characin fish of the neotropical region. The so-called 'yellow-tailed characins' compose one of the most widely distributed Astyanax groups. A. altiparanae and A. aff. bimaculatus, are evolutionarily closely related and commonly found in several Brazilian hydrographic basins. In the present work, chromosomal data of specimens of A. altiparanae and A. aff. bimaculatus from 4 hydrographic basins in the states of São Paulo (Upper Tietê, Paranapanema, Ribeira de Iguape) and Rio de Janeiro (Guapimirim) are shown. All the populations showed 50 chromosomes, with different karyotypic formula. Although only a single Ag-NOR bearing chromosome pair was observed, all populations possess multiple cistrons of 18S rDNA. FISH with the 5S rDNA probe showed single signals at the interstitial position of one metacentric chromosome pair. C-bands are distributed in the terminal and interstitial regions of several chromosomes. However, the As-51 satDNA are frugally located in a few chromosomes of fishes from Upper Tietê, Paranapanema and Guapimirim Rivers, being absent in individuals of A. aff. bimaculatus from Ribeira de Iguape River basin. Beside these 4 populations, molecular phylogeography studies were also performed in individuals from Middle and Lower Tietê River basin and from 2 additional collection sites in the Paranapanema and Ribeira de Iguape River basins. The phylogeographic analysis using 2 mtDNA regions (totalizing 1.314 bp of ND2 and ATPase6/8 genes) of 8 populations of the group of 'yellow-tailed characins' from 3 major hydrographic basins showed structuring of populations, suggesting a correlation between chromosomal (nuclear) and molecular (mitochondrial) data.

• Gene mapping of 18S and 5S rDNA genes in the karyotype of the three-spot gourami Trichogaster trichopterus (Perciformes, Osphronemidae).

  Rubens Pazza, Karine Frehner Kavalco, Pierre Rafael Penteado, Sydney Antonio Frehner Kavalco, Lurdes Foresti de Almeida-Toledo

  Zebrafish. 09/2009; 6(3):219-22.

  Ornamental fish culture is important as an economic activity and for biodiversity conservation as well. The species of the genus Trichogaster (Perciformes, Osphronemidae), popularly known as three-spot gourami, are among the several commercial species raised around the world. In the present work, ei... [more] Ornamental fish culture is important as an economic activity and for biodiversity conservation as well. The species of the genus Trichogaster (Perciformes, Osphronemidae), popularly known as three-spot gourami, are among the several commercial species raised around the world. In the present work, eight specimens of Thrichogaster trichopterus from aquarium trade facilities were analyzed. The karyotype was composed of 23 pairs of subtelo/acrocentric chromosomes. Fluorescent in situ hybridization allowed identifying the 18S ribosomal gene at telomeric region on long arms of the largest acrocentric pair. On the other hand, the 5S rRNA gene is located at a proximal region on a pair of medium-sized chromosomes. Such information is extremely useful in face of the risks of introduction and the development of ornamental fish trade, once many fish species can be identified only by genetic studies.
• 0.58

  Impact points

  Astyanax hastatus Myers, 1928 (Teleostei, Characidae): A new species complex within the genus Astyanax?

  Karine Frehner Kavalco, Karina de Oliveira Brandão, Rubens Pazza, Lurdes Foresti de Almeida-Toledo

  Genetics and molecular biology. 07/2009; 32(3):477-83.

  Four populations of Astyanax hastatus Myers 1928 from the Guapimirim River basin (Rio de Janeiro State) were analyzed and three distinct cytotypes identified. These cytotypes presented 2n = 50 chromosomes, with 4M+8SM+10ST+28A (Cytotype A), 8M+10SM+14ST+18A (Cytotype B), 6M+8SM+4ST+32A (Cytotype C) ... [more] Four populations of Astyanax hastatus Myers 1928 from the Guapimirim River basin (Rio de Janeiro State) were analyzed and three distinct cytotypes identified. These cytotypes presented 2n = 50 chromosomes, with 4M+8SM+10ST+28A (Cytotype A), 8M+10SM+14ST+18A (Cytotype B), 6M+8SM+4ST+32A (Cytotype C) and scanty heterochromatin, mainly located throughout pericentromeric regions of several chromosomal pairs. No homologies with the As-51 satellite DNA were observed in the three cytotypes, although all of them presented multiple 18S rDNA sites, as detected by both silver nitrate staining and FISH (fluorescent in situ hybridization). The application of the term "species complex" in Astyanax is discussed from a cytotaxonomic viewpoint.
• 2.09

  Impact points

  Astyanax bockmanni Vari and Castro, 2007: an ambiguous karyotype in the Astyanax genus.

  Karine Kavalco, Rubens Pazza, Lurdes de Almeida-Toledo

  Genetica. 10/2008;

  Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing co... [more] Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing conservative features. A. bockmanni shows 2n = 50 chromosomes, a karyotypic formula composed of 10 M + 12SM + 12ST + 16A and multiple Ag-NORs. Eight positive signals in subtelocentric/acrocentric chromosomes were identified by fluorescent in situ hybridization (FISH) with 18S rDNA probes. After FISH with 5S rDNA probes, four sites were detected, comprising the interstitial region of a metacentric pair and the terminal region on long arms of another metracentric pair. Little amounts of constitutive heterochromatin were observed, mainly distributed at distal region in two chromosomal pairs. Additionally, heterochromatin was also located close to the centromeres in some chromosomes. No positive signals were detected in the chromosomes of A. bockmanni by FISH with the As-51 satellite DNA probe. The studied species combines a set of characteristics previously identified in two different Astyanax groups. The chromosomal evolution in the genus Astyanax is discussed.
• 1.73

  Impact points

  Chromosome polymorphism in Astyanax fasciatus (Teleostei, Characidae). 2 - Chromosomal location of a satellite DNA.

  R Pazza, K Frehner Kavalco, L A C Bertollo

  Cytogenetic and genome research. 02/2008; 122(1):61-66.

  Studies about composition of repetitive sequences and their chromosomal location have been helpful to evolutionary studies in many distinct organisms. In order to keep on assessing the possible relationships among different cytotypes of Astyanax fasciatus (Teleostei, Characiformes) in the Mogi-Guaçu... [more] Studies about composition of repetitive sequences and their chromosomal location have been helpful to evolutionary studies in many distinct organisms. In order to keep on assessing the possible relationships among different cytotypes of Astyanax fasciatus (Teleostei, Characiformes) in the Mogi-Guaçu River (São Paulo State, Brazil), C-banding, chromomycin A(3) staining, and fluorescent in situ hybridization with a repetitive DNA sequence (As51) isolated from Astyanax scabripinnis were performed in the present work. The constitutive heterochromatin was distributed in terminal regions on long arms of submetacentric, subtelocentric, and acrocentric chromosomes and in the terminal region on short arms of a pair of submetacentric chromosomes in both standard cytotypes. This latter heterochromatic site was also GC-rich, as revealed by chromomycin A(3) staining, corresponding to the nucleolar organizer region (NOR), as shown by previous studies. The sites of the satellite As51 DNA were located in terminal regions on long arms of several chromosomes. Some variant karyotypic forms, which diverge from the two standard cytotypes, also presented distinctive chromosomes carrying As51 satellite DNA. It is possible that the standard 2n = 46 cytotype represents an invader population in the Mogi-Guaçu River able to interbreed with the resident standard 2n = 48 cytotype. Therefore, the variant karyotypes would be related to a possible viable offspring, where complementary chromosomal rearrangements could favor new locations of the satellite DNA analyzed.

• Molecular cytogenetics of blind mexican tetra and comments on the karyotypic characteristics of genus Astyanax (Teleostei, Characidae).

  Karine Frehner Kavalco, Lurdes Foresti de Almeida-Toledo

  Zebrafish. 02/2007; 4(2):103-11.

  Astyanax mexicanus is popularly known as the blind Mexican tetra or blind cave tetra and has been extensively studied regarding various aspects of its biology and genetics. Despite the identification of linkage maps of genes related to quantitative trait loci by many recent studies, only its diploid... [more] Astyanax mexicanus is popularly known as the blind Mexican tetra or blind cave tetra and has been extensively studied regarding various aspects of its biology and genetics. Despite the identification of linkage maps of genes related to quantitative trait loci by many recent studies, only its diploid number was known from a cytogenetical point of view. With the purpose of providing a base for comparative studies and for the elucidation of physical maps for the species, cytogenetical studies were performed in a group of 10 blind specimens from Mexico. All the individuals presented 2n = 50 chromosomes and a karyotypic formula composed of 8M + 18SM + 12ST + 12A. A few specimens presented one or two B microchromosomes of the acrocentric type. Although simple argyrophilic nucleolar organizer regions (Ag-NORs) were evidenced, fluorescence in situ hybridization (FISH) with an 18S rDNA probe evidenced eight sites, and six sites were observed with a 5S rDNA probe. Little constitutive heterochromatin was observed, mainly related with the Ag-NORs and located close to the centromeres, including those from the B microchromosomes. A few pericentromeric heterochromatin regions were mainly constituted by GC, including the one from the Ag-NOR. Very subtle markings were observed by FISH with an As-51 satellite DNA probe. The B microchromosome did not present ribosomal genes or satellite DNA. Chromosomal aspects of the genus Astyanax are discussed.
• 1.73

  Impact points

  Chromosome polymorphism in Astyanax fasciatus (Teleostei, Characidae). 1. Karyotype analysis, Ag-NORs and mapping of the 18S and 5S ribosomal genes in sympatric karyotypes and their possible hybrid forms.

  R Pazza, K F Kavalco, L A C Bertollo

  Cytogenetic and genome research. 02/2006; 112(3-4):313-9.

  Astyanax fasciatus may be characterized as a chromosomally diversified 'species' presenting distinct cytotypes, each with its specific variants. The sympatric and syntopic occurrence of different cytotypes reinforces the hypothesis in which A. fasciatus may represent a group of species curre... [more] Astyanax fasciatus may be characterized as a chromosomally diversified 'species' presenting distinct cytotypes, each with its specific variants. The sympatric and syntopic occurrence of different cytotypes reinforces the hypothesis in which A. fasciatus may represent a group of species currently placed under a single common designation. Specimens from three collection points spread along the Mogi-Guaçu River in southeast Brazil were examined in the present work: (1) near its headwaters (Ouro Fino--MG), (2) in the middle region of the river (Cachoeira de Emas, Pirassunun ga--SP) and (3) close to its confluence with the Pardo River (Barrinha--SP). The 2n = 48 chromosomes cytotype was found in all sampling points, while cytotype 2n = 46 was only encountered in Barrinha and Cachoeira de Emas. In the latter locality, cytotype 2n = 46 predominated; nevertheless, other karyotype forms with 2n = 45 and 47 chromosomes also occurred, besides a structural variant of cytotype 2n = 46. One specimen with 2n = 47 chromosomes was also found in Ouro Fino. The Ag-NOR analysis, as well as the location of the 18S and 5S ribosomal genes, were conserved in all cytotypes. The data indicate that the variant karyotypes are a consequence of interbreeding between the standard cytotypes (2n = 46 and 48) and/or its descendants. This suggests a karyotype plasticity for this species, where at least a few variant karyotypes would not have deleterious effects on their bearers.
• 2.09

  Impact points

  Molecular cytogenetics of Oligosarcus hepsetus (Teleostei, Characiformes) from two Brazilian locations.

  Karine F Kavalco, Rubens Pazza, Luiz A C Bertollo, Orlando Moreira-Filho

  Genetica. 06/2005; 124(1):85-91.

  Karyotype and cytogenetic markers of Oligosarcus hepsetus from two Brazilian locations in the Paraiba do Sul River Basin (Brazil) were investigated using differential staining techniques (C-banding, silver (Ag)- and chromomycin A3 (CMA3)-staining) and fluorescent in situ hybridization (FISH) using 1... [more] Karyotype and cytogenetic markers of Oligosarcus hepsetus from two Brazilian locations in the Paraiba do Sul River Basin (Brazil) were investigated using differential staining techniques (C-banding, silver (Ag)- and chromomycin A3 (CMA3)-staining) and fluorescent in situ hybridization (FISH) using 18 S rDNA and 5S rDNA probes. The diploid chromosome number was invariably 2n = 50 with 3 pairs of metacentric, 5 pairs of submetacentric, 8 pairs of subtelocentric and 9 pairs of acrocentric chromosomes. No heteromorphic sex chromosomes were observed. The nucleolar organizer regions (NORs) were detected in the short arms of the largest acrocentric pair using Ag-, CMA3- stainings and FISH with 18S rDNA probe, the latter showing also positive labeling in the short arms of a small acrocentric pair, not visualized by the former methods. FISH with 5S rDNA probe showed positive labeling in the two chromosome pairs. While the CMA3-staining exhibited GC-rich heterochromatin segments in two pairs of chromosomes, including those coincided with Ag-NORs, the DAPI staining did not reveal any signal, indicating the absence of AT-rich heterochromatin. FISH with an As-51 satellite DNA probe derived from the closely related Astyanax scabripinnis did not reveal any positive signal, demonstrating the absence of this class of DNA in the genome of the specimens under study.
• 4.12

  Impact points

  Karyotypic diversity and evolution of Loricariidae (Pisces, Siluriformes).

  K F Kavalco, R Pazza, L A C Bertollo, O Moreira-Filho

  Heredity. 03/2005; 94(2):180-6.

  We present cytogenetic analyses of four fish species, belonging to four Loricariidae subfamilies: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) with 2n=56 chromosomes, Hypostomus affinis (Hypostominae) with 2n=66 chromosomes and Upsilodus sp.... [more] We present cytogenetic analyses of four fish species, belonging to four Loricariidae subfamilies: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) with 2n=56 chromosomes, Hypostomus affinis (Hypostominae) with 2n=66 chromosomes and Upsilodus sp. (Upsilodinae), with 2n=96 chromosomes. In addition to karyotypes, data on the location of 18s rDNA sites are presented, derived from indirect (silver nitrate impregnation) and direct (FISH) methods. There is only one pair of nucleolar organizing regions (NORs) per species, except in H. affinis. Diversity and NOR macrokaryotypic evolution in the species analyzed are discussed in relation to the evolution of the Loricariidae as a whole. In addition, a revision of the cytogenetic data available for this family is presented.
• 1.73

  Impact points

  Gene mapping of 5S rDNA sites in eight fish species from the Paraíba do Sul river basin, Brazil.

  K F Kavalco, R Pazza, L A C Bertollo, O Moreira-Filho

  Cytogenetic and genome research. 02/2004; 106(1):107-10.

  The use of improved cytogenetic techniques such as fluorescent in situ hybridization (FISH) has offered important methodologies for cytotaxonomic and evolutionary studies. In particular, the mapping of 5S rDNA sites has proved to be an excellent marker in the study of different organisms and, more r... [more] The use of improved cytogenetic techniques such as fluorescent in situ hybridization (FISH) has offered important methodologies for cytotaxonomic and evolutionary studies. In particular, the mapping of 5S rDNA sites has proved to be an excellent marker in the study of different organisms and, more recently, in fish. In the present work, the FISH technique was used to map the 5S rDNA sites in the chromosomes of eight neotropical fish species from the Paraíba do Sul river basin, four of these belonging to the order Characiformes, family Characidae, genus Astyanax (A. scabripinnis, A. parahybae, A. giton and A. intermedius) and four to the order Siluriformes, family Loricariidae (Neoplecostomus microps, Harttia loricariformis, Hypostomus affinis and Upsilodus sp.). Karyotype evolution aspects of the analyzed groups are discussed.
• 0.87

  Impact points

  Heterochromatin characterization of four fish species of the family Loricariidae (Siluriformes).

  Karine Frehner Kavalco, Rubens Pazza, Luiz Antonio Carlos Bertollo, Orlando Moreira-Filho

  Hereditas. 02/2004; 141(3):237-42.

  The karyotypic structures and the composition and distribution of the heterochromatin in the karyotypes of four catfish species belonging to four Loricariidae subfamilies were analysed, namely: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) wi... [more] The karyotypic structures and the composition and distribution of the heterochromatin in the karyotypes of four catfish species belonging to four Loricariidae subfamilies were analysed, namely: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) with 2n=56 chromosomes, Hypostomus affinis (Hypostominae) with 2n=66 chromosomes and Upsilodus sp. (Upsilodinae) with 2n=96 chromosomes. The amount and composition of heterochromatin was quite unequal among the studied species, being copious and mainly GC-rich in Upsilodus sp. and scarce and balanced in H. loricariformis. All of the H. affinis heterochromatin is GC-rich and related with nucleolar organizing regions. N. microps show low quantity of interstitial and GC-rich heterochromatin, one of them being related with NORs. Trends in the macrokaryotypic diversification as well as in the distribution pattern of the heterochromatin are discussed.

• Chromosome polymorphism in Astyanax fasciatus (Teleostei, Characidae), Part 3: Analysis of the RAPD and ISSR molecular markers

  Rubens Pazza, Karine Frehner Kavalco, Sônia Maria Alves Pinto Prioli, Alberto José Prioli, Luiz Antonio Carlos Bertollo

  Biochemical Systematics and Ecology.

  The Randomly Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeats (ISSR) molecular markers were used to complement the study of chromosomal polymorphism in Astyanax fasciatus (Teleostei, Characidae) from the Mogi-Guaçu River (Southeastern Brazil), analyzed in three collection sites alo... [more] The Randomly Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeats (ISSR) molecular markers were used to complement the study of chromosomal polymorphism in Astyanax fasciatus (Teleostei, Characidae) from the Mogi-Guaçu River (Southeastern Brazil), analyzed in three collection sites along the river (Ouro Fino – MG, Cachoeira de Emas – SP and Barrinha – SP). Two cytotypes (or karyotypic types), denominated standard cytotypes, were previously characterized, one including 2n = 46 chromosomes and the other 2n = 48 chromosomes, where all the chromosomes of the complement form homologous pairs. Additionally, variant karyotypic forms with 2n = 45, 46 and 47 chromosomes were also detected, although with a lower frequency in relation to the standard cytotypes. RAPD turned out little informative in the analysis of the observed situation, indicating a high value of migrants per generation among the cytotypes. On the other hand, ISSR showed a small structure, especially among the standard cytotypes from the Barrinha region where the Nm was 0.4301 with a genetic identity of 0.6862 and genetic distance of 0.3765. However, the general results obtained do not discard the possibility of interbreeding between both standard cytotypes and/or their descendants as a source of chromosome variation. The association between the cytogenetic and molecular markers viabilized putative explanatory scenery for the origin and evolution of the forms seen in A. fasciatus.