Concurrent Exposure of Bottlenose Dolphins (Tursiops truncatus) to Multiple Algal Toxins in Sarasota Bay, Florida, USA

Sentinel species such as bottlenose dolphins (Tursiops truncatus) can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA), the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs) of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX) produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA). Over a ten-year study period (2000–2009) we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009) with 36% of all animals testing positive for brevetoxin (n = 118) and 53% positive for DA (n = 83) with several individuals (14%) testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001) and eosinophil (p<0.001) counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health

Gibberellin Acts through Jasmonate to Control the Expression of MYB21, MYB24, and MYB57 to Promote Stamen Filament Growth in Arabidopsis

Precise coordination between stamen and pistil development is essential to make a fertile flower. Mutations impairing stamen filament elongation, pollen maturation, or anther dehiscence will cause male sterility. Deficiency in plant hormone gibberellin (GA) causes male sterility due to accumulation of DELLA proteins, and GA triggers DELLA degradation to promote stamen development. Deficiency in plant hormone jasmonate (JA) also causes male sterility. However, little is known about the relationship between GA and JA in controlling stamen development. Here, we show that MYB21, MYB24, and MYB57 are GA-dependent stamen-enriched genes. Loss-of-function of two DELLAs RGA and RGL2 restores the expression of these three MYB genes together with restoration of stamen filament growth in GA-deficient plants. Genetic analysis showed that the myb21-t1 myb24-t1 myb57-t1 triple mutant confers a short stamen phenotype leading to male sterility. Further genetic and molecular studies demonstrate that GA suppresses DELLAs to mobilize the expression of the key JA biosynthesis gene DAD1, and this is consistent with the observation that the JA content in the young flower buds of the GA-deficient quadruple mutant ga1-3 gai-t6 rga-t2 rgl1-1 is much lower than that in the WT. We conclude that GA promotes JA biosynthesis to control the expression of MYB21, MYB24, and MYB57. Therefore, we have established a hierarchical relationship between GA and JA in that modulation of JA pathway by GA is one of the prerequisites for GA to regulate the normal stamen development in Arabidopsis

Utilização da biofotogrametria para a avaliação da flexibilidade de tronco

INTRODUÇÃO: a ginástica rítmica (GR) é uma modalidade de ginástica que requer alto grau de flexibilidade, em virtude dos movimentos complexos que são requeridos. OBJETIVO: esta pesquisa objetivou comparar o teste de sentar e alcançar (TSA) e a técnica de biofotogrametria como indicadores de flexibilidade de tronco, em praticantes iniciantes de GR. METODOLOGIA: a amostra contou com 60 meninas (de cinco a 11 anos de idade) de um universo de 110, todas matriculadas em um centro de iniciação esportiva no estado do Paraná. A coleta de dados foi realizada no mês de novembro do ano de 2009. Para a comparação TSA com a biofotogrametria, foram traçados os ângulos de flexão da pelve (WP), flexão da coluna lombar (WC) e flexão do total do tronco (WT). RESULTADOS: o resultado médio atingido pelas participantes na escala do TSA foi de 27,75cm. Encontrou-se forte correlação do ângulo WT com o TSA. Por ser uma composição de WC e WP, o WT possibilita uma visualização global da distância do tronco até os membros inferiores quando ocorre a flexão durante o teste. Por isso, as correlações entre os ângulos são boas e significativas. CONCLUSÃO: uma vez que o TSA apresenta alguns fatores intervenientes que podem mascarar o seu resultado, a biofotogrametria é discutida como um teste que permite observar, através de imagens fotográficas e cálculos angulares, dados fidedignos para a mensuração de flexibilidade e compensações musculares não identificadas normalmente