Candida zeylanoides as a new yeast model for lipid metabolism studies: effect of nitrogen sources on fatty acid accumulation

Lipid homeostasis is well-known in oleaginous yeasts, but there are few non-oleaginous yeast models apart from Saccharomyces cerevisiae. We are proposing the non-oleaginous yeast Candida zeylanoides QU 33 as model. The aim of this study was to investigate the influence of the carbon/nitrogen ratio and the type of nitrogen source upon oil accumulation by this yeast grown on shake flask cultures. The maximum biomass was obtained in yeast extract (2.39?±?0.19 g/l), followed by peptone (2.24?±?0.05 g/l), while the highest content of microbial oil (0.35?±?0.01 g/l) and the maximum lipid yield (15.63 %) were achieved with peptone. Oleic acid was the predominant cellular fatty acid in all culture media (>32.23 %), followed by linoleic (>15.79 %) and palmitic acids (>13.47 %). The highest lipid yield using glucose and peptone was obtained at the C/N ratio of 200:1.     

Antiprotozoal activity of Brazilian plant extracts from isoquinoline alkaloid-producing families

Leishmaniasis and Chagas disease afflict the poorest countries in the world. The Brazilian flora represents a rich source for the screening of potential antiparasitic compounds. In this work, we tested the total alkaloid and ethanol extracts of nine different plants from Brazilian families which produce isoquinoline alkaloids, to determine their in vitro antiparasitic effect against L. chagasi and T. cruzi parasites. Promastigotes of L. chagasi were shown to be susceptible only to the total alkaloid extracts of A. crassiflora (EC50 value = 24.89 microg/ml), A. coriacea (EC50 value = 41.60 microg/ml), C. ovalifolia (EC50 value = 63.88 microg/ml) and G. australis (EC50 value = 37.88 microg/ml). Except for the G. australis total alkaloids, all the three extracts presented a considerable activity when tested against intracellular amastigotes. The most effective alkaloid extracts were those from A. crassiflora and C. ovalifolia, which reduced the number of infected macrophages at 25 microg/ml by 86.1% and 89.8%, respectively. Among the 18 tested extracts, 16 showed anti-Trypanosoma activity. Eight extracts (A. crassiflora, A. coriacea, C. ovalifolia, D. furfuracea, D. lanceolata, S. guianensis, X. emarginata and G. australis) were the most effective against the trypomastigotes, killing approximately 100% of the parasites at the maximal concentration of 100 microg/ml. Cytotoxicity against mammalian cells was evaluated for all extracts, but potential ones showed little or no cytotoxicity and a considerable antiparasitic effect, including D. furfuracea, D. lanceolata, G. australis, S. guianensis and X. emarginata. Plants are a rich source of natural compounds, and a powerful tool for the development of new arsenals for the therapy of protozoan diseases.     

Expression of fibroblast growth factor 10 and cognate receptors in the developing bovine ovary

In the mammalian ovary, FGF10 is expressed in oocytes and theca cells and is a candidate for paracrine signaling to the developing granulosa cells. To gain insight into the participation of FGF10 in the regulation of fetal folliculogenesis, we assessed mRNA expression patterns of FGF10 and its receptors, FGFR1B and FGFR2B, in relation to fetal follicle dynamics and localized FGF10 protein in bovine fetal ovaries at different ages. Primordial, primary, secondary, and antral follicles were first observed on Days 75, 90, 150, and 210 of gestation, respectively. The levels of GDF9 and BMP15 mRNA, markers for primordial and primary follicles, respectively, increased during fetal ovary development in a consistent manner with fetal follicle dynamics. CYP17A1 mRNA abundance increased from Day 60 to Day 75 and then from Day 120 to Day 150, coinciding with the appearance of secondary follicles. FGF10 mRNA abundance increased from Day 90, and this increase was temporally associated with increases in FGFR1B mRNA abundance and in the population of primary follicles. In contrast, FGFR2B mRNA expression was highest on Day 60 and decreased thereafter. FGF10 protein was localized to oogonia and oocytes and surrounding granulosa cells at all fetal ages. The present data suggest a role for FGF10 in the control of fetal folliculogenesis in cattle.     

Seasonal variation of sound production in the Lusitanian toadfish Halobatrachus didactylus

Seasonal variation of sound production, which includes boatwhistles, grunts, croaks and double croaks, was studied in the Lusitanian toadfish Halobatrachus didactylus . Boatwhistles were emitted during the mating season in contrast with the other sound types, which were emitted all year round.     

Complete genome sequencing of sixteen Francisella noatunensis subsp. orientalis isolates: A genomic approach for molecular characterization and spread dynamics of this clonal population

Francisella noatunensis subsp. orientalis (FNO) is an important emerging pathogen associated with disease outbreaks in farm-raised Nile tilapia. FNO genetic diversity using PCR-based typing, no intra-species discrimination was achieved among isolates/strains from different countries, thus demonstrating a clonal behaviour pattern. In this study, we aimed to evaluate the population structure of FNO isolates by comparing whole-genome sequencing data. The analysis of recombination showed that Brazilian isolates group formed a clonal population; whereas other lineages are also supported by this analysis for isolates from foreign countries. The whole-genome multilocus sequence typing (wgMLST) analysis showed varying numbers of dissimilar alleles, suggesting that the Brazilian clonal population are in expansion. Each Brazilian isolate could be identified as a single node by high-resolution gene-by-gene approach, presenting slight genetic differences associated to mutational events. The common ancestry node suggests a single entry into the country before 2012, and the rapid dissemination of this infectious agent may be linked to market sales of infected fingerlings.     

Cretaceous and Eocene fossils of the rare extant genus Synneuron Lundstrom (Diptera: Canthyloscledidae): evidence of a true Pangean clade

The first two fossil species of the canthyloscelid genus Synneuron are described based on compression wings. Synneuron eomontana sp. nov. is described from the Middle Eocene Coal Creek Member of the Kishenehn Formation, in the USA, and Synneuron jelli sp. nov. is described from the Lower Cretaceous Koonwarra Fossil Bed of the Korumburra Group, in Australia. The wings are illustrated and compared to the extant species of the genus, to species of the three other recent genera of Canthyloscelidae and to an anisopodid. A phylogenetic analysis of the relationships between the species of Synneuron was performed. The Eocene fossil S. eomontana appears as sister of the pair of recent Holarctic species of the genus, while the Australian Cretaceous species S. jelli is sister of the clade with the species of Synneuron of the northern hemisphere. The sister group of Synneuron is the canthyloscelid clade (Hyperoscelis + Canthyloscelis), for which a middle Jurassic fossil is known. At the early Cretaceous, Gondwana was already separated from Laurasia and the disjunction between the species of Synneuron in Australia and the northern hemisphere clade of the genus suggest a true pangeic origin for the genus. The biology of the canthyloscelid larvae is shaped by its trophic specialization—xylosaprophagous. This suggests that the transition from the Pangean Jurassic gymnosperm-dominated forests to the late Cretaceous angiosperm-dominated forests may be related to the low recent diversity of Synneuron or of the canthyloscelids in the world—and maybe to the extinction of the genus in the southern hemisphere. This major turnover of the vegetation type along the Cretaceous may be also somehow related to the complete extinction of other groups of flies strictly associated with gymnosperms, as may be the case of the lower brachyceran family Zhangsolvidae. This speculation needs additional corroboration from other groups, that will become available with the combination of systematics, paleontology and biogeographical information of different early Cretaceous clades.