Spermatogenesis and karyotypes of three species of water striders (Gerridae, Heteroptera).

Although they are of economic importance, there have been few cytogenetic studies of the Gerridae (Heteroptera) in Brazil. We examined spermatogenesis (meiosis and spermiogenesis) and nucleolar behavior in three species of the family Gerridae. Brachymetra albinerva and Halobatopsis platensis were found to have a chromosome complement of 2n = 25 (24A + X0) and Cylindrostethus palmaris 2n = 29 (28A + X0) chromosomes. Fifteen individuals of these species were collected from the reservoir of São José do Rio Preto, SP, using screens and were transported in pots containing water to the laboratory, where cytogenetic preparations were made. The polyploidy nuclei are formed by several heteropyknotic regions; cells in meiotic prophase have a heteropyknotic region that is probably the sex chromosome, and the chromosomes from chiasmata. The spermatids are rounded and have a heteropyknotic region at the periphery of the nucleus; the sperm head is small, with a long tail. Silver impregnation of meiotic cells showed one or more disorganized bodies around the perichromosomal sheath. The round spermatids had two bodies next to each other, but these were elongated; one of the bodies remained in the head and the other migrated to the initial part of the tail at the end of spermagenesis, when the staining was no longer evident. The meiotic cells appear during spermatogenesis and have very similar silver-impregnation patterns in different species of Heteroptera.

Latin-American Society Of Forensic Genetics (SLAGF) results of the Interlaboratory Quality Control Exercise 2010-2011

Latin-American Society of Forensic Genetics (SLAGF) Interlaboratory Quality Control Exercise (2010-2011) included the analysis of three bloodstain samples in FTA Classic Card (three persons, biologically unrelated) and one theoretical exercise. There were 56 participating laboratories from 13 Latin-American countries that belong to society, were reported 70 STRs, including autosomal and sex chromosome markers with consensus in 53 STRs with a rate in reporting errors of 2.3%. Fifty-six laboratories reported results in theoretical exercise with mistakes in calculation of IP for each marker. It is necessary to hold meetings to discuss the results of this exercise to reach conclusions and recommendations on all aspects of DNA forensics analysis and paternity test, to improve results and quality in the results of each laboratory. © 2011 Elsevier B.V.

Characterization and genome organization of a repetitive element associated with the nucleolus organizer region in leporinuselongatus (anostomidae: Characiformes)

Chromosome mapping and studies of the genomic organization of repetitive DNA sequences provide valuable insights that enhance our evolutionary and structural understanding of these sequences, as well as identifying chromosomal rearrangements and sex determination. This study investigated the occurrence and organization of repetitive DNA sequences in Leporinus elongatus using restriction enzyme digestion and the mapping of sequences by chromosomal fluorescence in situ hybridization (FISH). A 378-bp fragment with a 54.2% GC content was isolated after digestion with the SmaI restriction enzyme. BLASTN search found no similarity with previously described sequences, so this repetitive sequence was named LeSmaI. FISH experiments were conducted using L. elongatus and other Anostomidae species, i.e. L. macrocephalus,L. obtusidens, L. striatus, L. lacustris, L. friderici, Schizodon borellii, S. isognathus, and Abramites hypselonotus which detected signals that were unique to male and female L. elongatus individuals. Double-FISH using LeSmaI and 18S rDNA showed that LeSmaI was located in a nucleolus organizer region (NOR) in the male and female metaphases of L. elongatus. This report also discusses the role of repetitive DNA associated with NORs in the diversification of Anostomidae species karyotypes. Copyright © 2012 S. Karger AG, Basel.

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.

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

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

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

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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)

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)

Isolamentos e caracterização de DETs(Differentially Expressed Transcripts) em espécies de peixes: Leporinus macrocephalus(Characiformes) e Danio rerio (Cypriniformes)

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

Contribuições a elucidação da estrutura, origem e evolução de neo-sistemas cromossômicos de determinação sexual em gafanhotos utilizando como modelo espécies dos gêneros Chlorus, Dichromatos e Eurotettix (Melanoplinae; Acrididae)

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

Citotaxonomia dos triatomíneos: a citogenética como ferramenta no estudo do complexo Triatoma brasiliensis e do subcomplexo Brasiliensis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Population differentiation and speciation in the genus Characidium (Characiformes: Crenuchidae): effects of reproductive and chromosomal barriers

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genetic differentiation among distinct karyomorphs of the wolf fish Hoplias malabaricus species complex (Characiformes, Erythrinidae) and report of unusual hybridization with natural triploidy

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

Karyotype diversity and patterns of chromosomal evolution in Eigenmannia (Teleostei, Gymnotiformes, Sternopygidae)

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

Distribution of constitutive heterochromatin in Triatoma melanocephala (Hemiptera, Triatominae)

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