Navegando por Autor "CARNEIRO, Jeferson Costa"

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Filogenia e história biogeográfica do grupo Callicebus moloch (Primates, Pitheciidae)
(Universidade Federal do Pará, 2015-01-29) CARNEIRO, Jeferson Costa; SILVA JÚNIOR, José de Sousa e; http://lattes.cnpq.br/4998536658557008; SCHNEIDER, Horacio; http://lattes.cnpq.br/3621033429800270
Callicebus is a genus of Neotropical primate of the family Pitheciidae. Thirty-two species are currently recognized. They are classified in two subgenera, Torquatus and Callicebus, and five species groups: C. torquatus, C. moloch, C. cupreus, C. donacophilus and C. personatus. The arrangement of subgenera and groups is based on morphology and geographic distributions. The first section, we is introduction to the taxonomy of Callicebus. In the second section, I present an article for submission to the jounrla Primates concerning the chapter presence or absence of a molecular region known as an Alu element. An Alu element is a transposon in the genome of primates Because of this particular characteristic of Alu insertion, I discovered that the C. moloch and C. cupreus groups are closely related and that C. torquatus is the basal group in the genus. In the third section , from a multilocus approach I investigated the phylogenetic relationships of the C. moloch group and the time of diversification between the species, in order to test the hypothesis of formation of the Amazon River basin during the Plio-Pleistocene. Our results support the hypothesis of origin of Amazonian rivers in the last 3 Ma. However, not all diversification events in Callicebus can be explained by the theory of rivers. the results also indicate that the different species groups are derived from a radiation in the Amazonian region at different times during the upper Miocene. The phylogenetic analysis identified a number of potentioal taxa that a number of taxa which the current knowledge of species diversity in Callicebus is underestimated, and that recently diversified species are taxonomically neglected.
Acesso aberto (Open Access)
Genetic variation in native and farmed populations of Tambaqui (Colossoma macropomum) in the Brazilian Amazon: regional discrepancies in farming systems
(2013) AGUIAR, Jonas da Paz; SCHNEIDER, Horacio; GOMES, Maria de Fátima; CARNEIRO, Jeferson Costa; SILVA, Simoni Santos da; RODRIGUES, Luis Reginaldo Ribeiro; SAMPAIO, Maria Iracilda da Cunha
The tambaqui, Colossoma macropomum, is the most popular fish species used for aquaculture in Brazil but there is no study comparing genetic variation among native and farmed populations of this species. In the present study, we analyzed DNA sequences of the mitochondrial DNA to evaluate the genetic diversity among two wild populations, a fry-producing breeding stock, and a sample of fish farm stocks, all from the region of Santarém, in the west of the Brazilian state of Pará. Similar levels of genetic diversity were found in all the samples and surprisingly the breeding stock showed expressive representation of the genetic diversity registered on wild populations. These results contrast considerably with those of the previous study of farmed stocks in the states of Amapá, Pará, Piauí, and Rondônia, which recorded only two haplotypes, indicating a long history of endogamy in the breeding stocks used to produce fry. The results of the two studies show two distinct scenarios of tambaqui farming in the Amazon basin, which must be better evaluated in order to guarantee the successful expansion of this activity in the region, and the rest of Brazil, given that the tambaqui and its hybrids are now farmed throughout the country.
Acesso aberto (Open Access)
Molecular data highlight hybridization in squirrel monkeys (Saimiri, Cebidae)
(Universidade Federal do Pará, 2016-12) CARNEIRO, Jeferson Costa; RODRIGUES FILHO, Luis Fernando da Silva; SCHNEIDER, Horacio; SAMPAIO, Maria Iracilda da Cunha
Hybridization has been reported increasingly frequently in recent years, fueling the debate on its role in the evolutionary history of species. Some studies have shown that hybridization is very common in captive New World primates, and hybrid offspring have phenotypes and physiological responses distinct from those of the "pure" parents, due to gene introgression. Here we used the TA15 Alu insertion to investigate hybridization in the genus Saimiri. Our results indicate the hybridization of Saimiri boliviensis peruviensis with S. sciureus macrodon, and S. b. boliviensis with S. ustus. Unexpectedly, some hybrids of both S. boliviensis peruviensis and S. b. boliviensis were homozygous for the absence of the insertion, which indicates that the hybrids were fertile.