To know ourselves /

"July 1996."

Human genome report card.

Description based on: March 1993; title from cover.

Validação de espécies de Centropomus (Centropomidae, Perciformes) do litoral do Rio Grande do Norte através de caracterização citogenética e molecular

The Centropomidae family consists of three genera, Centropomus, Lates and Psammoperca. Centropomus is the most diverse group, with six Centropomus species occur in the Western Atlantic Ocean C. poeyi Chávez, 1961, C. parallelus Poey, 1860, C. mexicanus Bocourt, 1868, C. pectinatus Poey, 1860 and C. ensiferus Poey, 1860. Some of these species are considered cryptic, because of its morphological traits showed low resolution for identification purposes. Despite showing great interest as a natural resource and fish culture, aspects of their diversity and karyotypic patterns are poorly understood. In this work morphological identification and comparison of mitochondrial 16S gene sequence were used to identify the species of the genus Centropomus occurring in Rio Grande do Norte, northeastern Brazil. Two sepecies were identified, C. undecimalis and C. mexicanus, which had the chromosomal aspects analyzed, through Classical cytogenetic method analyzes (conventional staining, C-banding, Ag-NORs), fluorochrome staining AT- and GC-specific, replication bands by incorporating of the base analog 5-Bromo-2’-deoxyuridine (5-BrdU), in situ chromosomal mapping of (TTAGGG)n sequences and in situ chromosome mapping 18S and 5S rRNA genes. Both species show 2n=48 acrocentric chromosomes, with ribosomal sites (Ag-NOR/18S rDNA/ Mitramycin+) in second chromosomal pair, in telomeric position on the long arm in C. mexicanus and interstitial in C. undecimalis. The nuclear organization pair (pair 2) shown a resolutive cytotaxonomic marker for these two species. The generated data reveal a lower species diversity than previously believed, suggesting that greater attention should be paid in taxonomic identification of the species, in view of optimize commercial actions exploitation, biological conservation and cultivation.

Abnormalities on 1q and 7q are associated with poor outcome in sporadic Burkitt's lymphoma. A cytogenetic and comparative genomic hybridization study.

Comparative genomic hybridization (CGH) studies have demonstrated a high incidence of chromosomal imbalances in non-Hodgkin's lymphoma. However, the information on the genomic imbalances in Burkitt's Lymphoma (BL) is scanty. Conventional cytogenetics was performed in 34 cases, and long-distance PCR for t(8;14) was performed in 18 cases. A total of 170 changes were present with a median of four changes per case (range 1-22). Gains of chromosomal material (143) were more frequent than amplifications (5) or losses (22). The most frequent aberrations were gains on chromosomes 12q (26%), Xq (22%), 22q (20%), 20q (17%) and 9q (15%). Losses predominantly involved chromosomes 13q (17%) and 4q (9%). High-level amplifications were present in the regions 1q23-31 (three cases), 6p12-p25 and 8p22-p23. Upon comparing BL vs Burkitt's cell leukemia (BCL), the latter had more changes (mean 4.3 +/- 2.2) than BL (mean 2.7 +/- 3.2). In addition, BCL cases showed more frequently gains on 8q, 9q, 14q, 20q, and 20q, 9q, 8q and 14q, as well as losses on 13q and 4q. Concerning outcome, the presence of abnormalities on 1q (ascertained either by cytogenetics or by CGH), and imbalances on 7q (P=0.01) were associated with a short survival.

A study of rat chromosome 8 by congenics : Mapping and dissecting quantitative trait loci into opposite blood pressure effects

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

"Refined mapping of a quantitative trait locus on chromosome 1 responsible for mouse embryonic death"

Recurrent spontaneous abortion (RSA) is defined as the loss of three or more consecutive pregnancies during the first trimester of embryonic intrauterine development. This kind of human infertility is frequent among the general population since it affects 1 to 5% of women. In half of the cases the etiology remains unelucidated. In the present study, we used interspecific recombinant congenic mouse strains (IRCS) in the aim to identify genes responsible for embryonic lethality. Applying a cartographic approach using a genotype/phenotype association, we identified a minimal QTL region, of about 6 Mb on chromosome 1, responsible for a high rate of embryonic death (,30%). Genetic analysis suggests that the observed phenotype is linked to uterine dysfunction. Transcriptomic analysis of the uterine tissue revealed a preferential deregulation of genes of this region compared to the rest of the genome. Some genes from the QTL region are associated with VEGF signaling, mTOR signaling and ubiquitine/proteasome-protein degradation pathways. This work may contribute to elucidate the molecular basis of a multifactorial and complex human disorder as RSA.

Refined mapping of a quantitative trait locus on chromosome 1 responsible for mouse embryonic death

Recurrent spontaneous abortion (RSA) is defined as the loss of three or more consecutive pregnancies during the first trimester of embryonic intrauterine development. This kind of human infertility is frequent among the general population since it affects 1 to 5% of women. In half of the cases the etiology remains unelucidated. In the present study, we used interspecific recombinant congenic mouse strains (IRCS) in the aim to identify genes responsible for embryonic lethality. Applying a cartographic approach using a genotype/phenotype association, we identified a minimal QTL region, of about 6 Mb on chromosome 1, responsible for a high rate of embryonic death (similar to 30%). Genetic analysis suggests that the observed phenotype is linked to uterine dysfunction. Transcriptomic analysis of the uterine tissue revealed a preferential deregulation of genes of this region compared to the rest of the genome. Some genes from the QTL region are associated with VEGF signaling, mTOR signaling and ubiquitine/proteasome-protein degradation pathways. This work may contribute to elucidate the molecular basis of a multifactorial and complex human disorder as RSA.

Cytogenetic mapping of the W chromosome in the genus Leporinus (Teleostei, Anostomidae) using a highly repetitive DNA sequence

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

Chromosomal mapping of repetitive DNAs in the beetle Dichotomius geminatus provides the first evidence for an association of 5S rRNA and histone H3 genes in insects, and repetitive DNA similarity between the B chromosome and A complement

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

Chromosomal mapping of rDNAs and H3 histone sequences in the grasshopper rhammatocerus brasiliensis (acrididae, gomphocerinae): extensive chromosomal dispersion and co-localization of 5S rDNA/H3 histone clusters in the A complement and B chromosome

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 7 and comparative mapping to the cattle and human genomes

A preliminary radiation hybrid (RH) map containing 50 loci on chromosome 7 of the domestic river buffalo Bubalus bubalis (BBU; 2n = 50) was constructed based on a comparative mapping approach. The RH map of BBU7 includes thirty-seven gene markers and thirteen microsatellites. All loci have been previously assigned to Bos taurus (BTA) chromosome BTA6, which is known for its association with several economically important milk production traits in cattle. The map consists of two linkage groups spanning a total length of 627.9 cR(5,000). Comparative analysis of the BBU7 RH 5,000 map with BTA6 in cattle gave new evidence for strong similarity between the two chromosomes over their entire length and exposed minor differences in locus order. Comparison of the BBU7 RH 5,000 map with the Homo sapiens (HSA) genome revealed similarity with a large chromosome segment of HSA4. Comparative analysis of loci in both species revealed more variability than previously known in gene order and several chromosome rearrangements including centromere relocation. The data obtained in our study define the evolutionarily conserved segment on BBU7 and HSA4 to be between 3.5 megabases (Mb) and 115.8 Mb in the HSA4 (genome build 36) DNA sequence. Copyright (c) 2008 S. Karger AG, Basel.