Divergent evolution and purifying selection of the H (FUT1) gene in New World monkeys (Primates, Platyrrhini)

In the present study, the coding region of the H gene was sequenced and analyzed in fourteen genera of New World primates (Alouatta, Aotus, Ateles, Brachyteles, Cacajao, Callicebus, Callithrix, Cebus, Chiropotes, Lagothrix, Leontopithecus, Pithecia, Saguinus, and Saimiri), in order to investigate the evolution of the gene. The analyses revealed that this coding region contains 1,101 nucleotides, with the exception of Brachyteles, the callitrichines (Callithrix, Leontopithecus, and Saguinus) and one species of Callicebus (moloch), in which one codon was deleted. In the primates studied, the high GC content (63%), the nonrandom distribution of codons and the low evolution rate of the gene (0.513 substitutions/site/MA in the order Primates) suggest the action of a purifying type of selective pressure, confirmed by the Z-test. Our analyses did not identify mutations equivalent to those responsible for the H-deficient phenotypes found in humans, nor any other alteration that might explain the lack of expression of the gene in the erythrocytes of Neotropical monkeys. The phylogenetic trees obtained for the H gene and the distance matrix data suggest the occurrence of divergent evolution in the primates.

Karyotypic evolution of ribosomal sites in buffalo subspecies and their crossbreed

Domestic buffaloes are divided into two group based on cytogenetic characteristics and habitats: the “river buffaloes” with 2n = 50 and the “swamp buffaloes”, 2n = 48. Nevertheless, their hybrids are viable, fertile and identified by a 2n = 49. In order to have a better characterization of these different cytotypes of buffaloes, and considering that NOR-bearing chromosomes are involved in the rearrangements responsible for the karyotypic differences, we applied silver staining (Ag-NOR) and performed fluorescent in situ hybridization (FISH) experiments using 18S rDNA as probe. Metaphases were obtained through blood lymphocyte culture of 21 individuals, including river, swamp and hybrid cytotypes. Ag-NOR staining revealed active NORs on six chromosome pairs (3p, 4p, 6, 21, 23, 24) in the river buffaloes, whereas the swamp buffaloes presented only five NOR-bearing pairs (4p, 6, 20, 22, 23). The F1 crossbreed had 11 chromosomes with active NORs, indicating expression of both parental chromosomes. FISH analysis confirmed the numerical divergence identified with Ag-NOR. This result is explained by the loss of the NOR located on chromosome 4p in the river buffalo, which is involved in the tandem fusion with chromosome 9 in this subspecies. A comparison with the ancestral cattle karyotype suggests that the NOR found on the 3p of the river buffalo may have originated from a duplication of ribosomal genes, resulting in the formation of new NOR sites in this subspecies.

Estudo da estrutura molecular dos cromossomos supranuméricos em Moenkhausia sanctaefilomenae (Teleostei, Characiformes, Characidae)

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

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

Estrutura molecular e citogenética de cromossomos B em Astyanax paranae (Characiformes, Characidae)

Pós-graduação em Ciências Biológicas (Genética) - IBB

Pesquisa docluster de imuno evasão e tipagem molecular em Staphylococcus aureus meticilina-sensíveis (MSSA), osolados de maipladores de alimentos

Pós-graduação em Biologia Geral e Aplicada - IBB

Epidemiologia molecular das estirpes LaSota e São João do Meriti do vírus da Doença de Newcastle

Pós-graduação em Microbiologia Agropecuária - FCAV

Systematic and historical biogeography of the Bryconidae (Ostariophysi: Characiformes) suggesting a new rearrangement of its genera and an old origin of Mesoamerican ichthyofauna

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

Chromosome Evolution in Dendropsophini (Amphibia, Anura, Hylinae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The evolution of behavioural systems: a study of grooming in rodents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sperm evolution in the family Alestidae with comparative data for the genus Chalceus (Ostariophysi: Characiformes)

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

Molecular and phylogenetic characterization based on the complete genome of a virulent pathotype of Newcastle disease virus isolated in the 1970s in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Development and evolution of the gynoecium in Myrteae (Myrtaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)