The historical biogeography of Pteroglossus aracaris (Aves, Piciformes, Ramphastidae) based on Bayesian analysis of mitochondrial DNA sequences

Most Neotropical birds, including Pteroglossus aracaris, do not have an adequate fossil record to be used as time constraints in molecular dating. Hence, the evolutionary timeframe of the avian biota can only be inferred using alternative time constraints. We applied a Bayesian relaxed clock approach to propose an alternative interpretation for the historical biogeography of Pteroglossus based on mitochondrial DNA sequences, using different combinations of outgroups and time constraints obtained from outgroup fossils, vicariant barriers and molecular time estimates. The results indicated that outgroup choice has little effect on the Bayesian posterior distribution of divergence times within Pteroglossus, that geological and molecular time constraints seem equally suitable to estimate the Bayesian posterior distribution of divergence times for Pteroglossus, and that the fossil record alone overestimates divergence times within the fossil-lacking ingroup. The Bayesian estimates of divergence times suggest that the radiation of Pteroglossus occurred from the Late Miocene to the Pliocene (three times older than estimated by the ôstandardõ mitochondrial rate of 2% sequence divergence per million years), likely triggered by Andean uplift, multiple episodes of marine transgressions in South America, and formation of present-day river basins. The time estimates are in agreement with other Neotropical taxa with similar geographic distributions.

Diversification of Ramphastinae (Aves, Ramphastidae) prior to the Cretaceous/Tertiary boundary as shown by molecular clock of mtDNA sequences

Partial cytochrome b and 12S rDNA mitochondrial DNA sequences of eight representatives of the Ramphastidae family were analyzed. We applied the linearized tree method to identify sequences evolving at similar rates and estimated the divergence times among some of the taxa analyzed. After excluding Ramphastos tucanus and Capito dayi from our data set, the remaining taxa presented a constant rate of DNA substitution, and branch lengths could be re-estimated with a clock constraint using the maximum likelihood method. Branch lengths were calibrated assuming that Galliformes and Piciformes split around 100 million years ago (mya). Our results indicate that Ramphastinae, and probably Capitoninae, diverged from other Piciformes in the Late Cretaceous (82 mya), suggesting that Piciformes is another avian order that survived the mass extinction event occurred 65 mya at the Cretaceous/Tertiary (K/T) boundary. The divergence times estimated within the Ramphastinae genera cover the period from the Middle Eocene (around 47 mya) through the Late Miocene (9.5 mya). Our estimate of divergence time is coincidental with the split of the African and the South American continents and other intense geologic activities and modifications of the areas which correspond to the current Neotropics. These events might have influenced the diversification of Ramphastinae in South America.

DNA fingerprinting in the rare black-fronted piping guan Pipile jacutinga (Cracidae, Aves)

Brazilian Cracidae are threatened by heavy environmental degradation and hunting. The Black-fronted piping-guan (Pipile jacutinga) used to inhabit the Atlantic coastal highland forests. Now it occurs in limited forest areas where it is rarely seen. Interative management, including captive breeding, might be an important action for its survival. We present data on DNA fingerprinting using Jeffreys' human minisatlelite probes 33.6 and 33.15. Our results show that this technique is useful for estimating the genetic variability of natural populations and may help to maintain the genetic variability of captive bred individuals of this species. A linkage analysis of the fingerprint profiles in a family with 7 chicks was performed (to estimate the number of independently segregating loci detected in this species) and at least 16 highly polymorphic independent loci were identified for each probe.

Hipertermia materna como provavel fator tetarogenico / Maternal hipertemy like provable factor tetarogenic

Estudos experimentais em animais tem demonstrado que a hipertermia no primeiro terco da gestacao induz a erros no fechamento do tubo neural e disrupcao do desenvolvimento do macico facial. Na especie humana o mesmo espectro malformativo tem sido relatado em neonatos cujas maes tem historico positivo de hipertermia no inicio da gestacao. Diferentes fatores podem ser responsaveis pela hipertermia materna: doencas infecciosas, banhos de sauna e banhos de imersao prolongados e muito quentes. O proposito estudado neste trabalho apresenta labio leporino bilateral e palato fendido, microftalmia, coloboma de iris, apendices auriculares bilaterais, pavilhao auditivo de implantacao anomala, lesao isodensa supra-selar e historico gestacional de febre alta no inicio da gravidez.Estas caracteristicas sao interpretadas como disrupcao do desenvolvimento da linha media da face, dos primeiros e segundo arcos branquiais, e heteropatias neuronias, compativeis com o diagnostico de disrupcao do desenvolvimento por hipertermia materna. A febre alta materna foi causada provavelmente pelo Dengue .

Macrossomia, macrocrania e incoordenaçäo motora da infância: síndrome de sotos (McKusick 11755); Estudo de 7 casos e revisäo de aspectos clínicos de 198 casos publicados / Macrosomia, macrocrania and motor disordes in childhood: sotos syndrome (McKusick 11755), report of 7 cases and review of clinical aspects of 198 report cases

Crianças com síndrome de Sotos apresentam aceleraçäo do crescimento, macrocrania, padröes acromegalóides e dificuldades iniciais no desenvolvimento neuropsicomotor. A delineaçäo da síndrome e o diagnóstico diferencial estäo baseados na avaliaçäo das características clínicas e no histórico evolutivo desses pacientes. Sete pacientes com síndrome de Sotos säo descritos, bem como revistas as características clínicas presentes em 198 pacientes da literatura. As dificuldades motoras presentes durante a primeira infância nos pacientes com síndrome de Sotos säo responsáveis pelo mau desempenho destas crianças nos testes de QI. A estimulaçäo especializada deve ser encorajada para ajustar os afetados a superarem suas dificuldades iniciais

In vitro cytogenetic effects of cannabidiol on human lymphocyte cultures

Investigou-se o efeito in vitro do canabidiol (CBD) sobre o índice mitótico e a frequência de células com aberraçöes cromossômicas numéricas e/ou estruturais, em culturas de linfócitos humanos. Em uma primeira fase o CBD foi dissolvido em álcool etílico absoluto (0,01 ml/ml de meio) nas concentraçöes de 0,001, 0,01 0,1, e 10,0 microng de CBD/ml de meio e, na segunda fase, o etanol foi evaporado antes de ser adicionado o meio de cultura. O efeito clastogênico do CBD foi maior quando associado ao álcool. A açäo do etanol foi predominantemente anti-mitogênica enquanto o CBD teve efeito mais nítido sobre a produçäo de células com aberraçöes cromossômicas. Após a evaporaçäo do etanol, a proporçäo de células com aberraçöes cromossômicas estruturais manteve uma relaçäo aproximadamente crescente com o aumento da taxa de CBD