evolution, structure and function of metazoan splicing factor PRPF39

In the yeast U1 snRNP the Prp39/Prp42 heterodimer is essential for early steps of spliceosome assembly. In metazoans no Prp42 ortholog exists, raising the question how the heterodimer is functionally substituted. Here we present the crystal structure of murine PRPF39, which forms a homodimer. Structure-guided point mutations disrupt dimer formation and inhibit splicing, manifesting the homodimer as functional unit. PRPF39 expression is controlled by NMD-inducing alternative splicing in mice and human, suggesting a role in adapting splicing efficiency to cell type specific requirements. A phylogenetic analysis reveals coevolution of shortened U1 snRNA and the absence of Prp42, which correlates with overall splicing complexity in different fungi. While current models correlate the diversity of spliceosomal proteins with splicing complexity, our study highlights a contrary case. We find that organisms with higher splicing complexity have substituted the Prp39/Prp42 heterodimer with a PRPF39 homodimer

Life-History and Behavior of the Diamondback Moth Plutella xylostella on Brassicaceae Cultivars over Multiple Generations

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a cosmopolitan pest that causes leaf-area reduction in Brassicaceae plants. DBM populations have significant genetic variability that manifests in different feeding preferences and reproductive behaviors across generations. We evaluated the influence of Brassicaceae cultivars on biological and behavioral parameters across 18 generations of DBM populations that were separated and held on three varieties of Brassicaceae: Brassica oleracea var. acephala (kale), Brassica oleracea var. italica (broccoli), and Brassica oleracea var. capitata (cabbage). P, F6, F12, and F18 generations were evaluated, and biological aspects of young adulthood and fertility parameters of adults held on each host plant were examined over multiple generations. Additionally, larvae and adults were subjected to dual-choice and multiple-choice (feeding and oviposition) between cultivars, over generations. The results indicated that larvae of P. xylostella consumed greater quantities of kale and broccoli cultivars, on average (4.05 cm2), than cabbage (2.7 cm2). The number of eggs per female in F18 generation was 1.95 and 2.17 times higher than those in the parental (P) generation, when reared on kale and cabbage. The population reared exclusively on kale had higher net population growth rate (R0), intrinsic rate (rm), finite rate (λ) and generation time (T) than that reared on broccoli and cabbage. Last generations evaluated, the larval stage reared on cabbage showed feeding preference (F18) and oviposition preference (F12 and F18) for cabbage. Thus, we note the existence of learning, characterized as pre-imaginal conditioning to cabbage cultivars, over various DBM generations

Classificação de cultivares de brássicas com relação à resistência à traça-das-crucíferas e à presença de glucosinolatos.

O objetivo deste trabalho foi avaliar o efeito de cultivares de repolho e de couve na biologia da traça-das-crucíferas; analisar a composição química das plantas, em relação aos glucosinolatos e aplicar a análise multivariada na classificação das cultivares. Foram utilizadas as cultivares: de repolho verde Chato-de-quintal e o híbrido Midori; de repolho roxo Roxo precoce e o híbrido Roxo TPC00682; e de couve-manteiga Geórgia (padrão de suscetibilidade) e Geórgia híbrido HS20. Foram avaliadas as características biológicas da praga: viabilidade e duração das fases larval e pupal, razão sexual, fecundidade das fêmeas, longevidade dos adultos e duração e viabilidade da fase de ovo, tendo-se calculado o potencial reprodutivo corrigido (PRC). Obtiveram-se as correlações entre os parâmetros pelo método de Pearson, e realizaram-se análises multivariadas de agrupamento e de componentes principais. Em cromatógrafo líquido, avaliaram-se a presença de sinigrina e de outros glucosinolatos nas plantas. A cultivar Geórgia e os híbridos HS20 e Roxo foram classificados como altamente suscetíveis; 'Roxo precoce' e 'Midori' como suscetíveis e, 'Chato-de-quintal' como moderadamente resistente à Plutella xylostella. As análises multivariadas proporcionam melhor classificação das cultivares, em razão do grau de resistência apresentado. Os materiais genéticos avaliados não apresentam a substância secundária sinigrina

Desempenho da remoção de nitrogênio em um reator Anammox híbrido combinando leito fluidizado e fixo.

Projeto/Plano de Ação: 04.10.00.01

Avaliação do efeito da substituição de meio sintético por efluente real no processo anammox.

Projeto/Plano de Ação: 03.11.91.200-03