Testing for local adaptation in brown trout using reciprocal transplants.

ABSTRACT: BACKGROUND: Local adaptation can drive the divergence of populations but identification of the traits under selection remains a major challenge in evolutionary biology. Reciprocal transplant experiments are ideal tests of local adaptation, yet rarely used for higher vertebrates because of the mobility and potential invasiveness of non-native organisms. Here, we reciprocally transplanted 2500 brown trout (Salmo trutta) embryos from five populations to investigate local adaptation in early life history traits. Embryos were bred in a full-factorial design and raised in natural riverbeds until emergence. Customized egg capsules were used to simulate the natural redd environment and allowed tracking the fate of every individual until retrieval. We predicted that 1) within sites, native populations would outperform non-natives, and 2) across sites, populations would show higher performance at 'home' compared to 'away' sites. RESULTS: There was no evidence for local adaptation but we found large differences in survival and hatching rates between sites, indicative of considerable variation in habitat quality. Survival was generally high across all populations (55% +/- 3%), but ranged from 4% to 89% between sites. Average hatching rate was 25% +/- 3% across populations ranging from 0% to 62% between sites. CONCLUSION: This study provides rare empirical data on variation in early life history traits in a population network of a salmonid, and large-scale breeding and transplantation experiments like ours provide powerful tests for local adaptation. Despite the recently reported genetic and morphological differences between the populations in our study area, local adaptation at the embryo level is small, non-existent, or confined to ecological conditions that our experiment could not capture.

Stimulation by leptin of 3H GDP binding to brown adipose tissue of fasted but not fed rats.

OBJECTIVES: To assess the effects of intracerebroventricular (i.c.v.) leptin administration on rats fed ad libitum or fasted on 3H GDP binding to brown adipose tissue (BAT). SUBJECTS: Groups of 5-6 ten-week-old male Wistar rats. EXPERIMENTAL DESIGN: An i.c.v. cannula was inserted and unilateral denervation of interscapular brown adipose tissue (BAT) was performed 5 d before each study. Thereafter, leptin was infused i.c.v. during 72 h while rats were fed ad libitum or fasted. Vehicle-infused, pair-fed or fasted rats were used as controls. MEASUREMENTS: 3H GDP binding to innervated and denervated BAT mitochondria. RESULTS: 3H GDP binding to innervated or denervated BAT of rats fed ab libitum compared to vehicle-infused, pair-fed rats was not increased by i.c.v. leptin. 3H GDP binding was lower in fasted than in fed rats, and the difference was larger in innervated than denervated BAT. I.c.v. leptin increased 3H GDP binding by 30% in innervated, and by 51% in denervated BAT (P < 0.05) in fasted rats. CONCLUSIONS: I.c.v. leptin does not increase 3H GDP binding to BAT of rats fed ad libitum compared to pair-fed (food-restricted) rats. In contrast, i.c.v. leptin produces a mild stimulation of 3H GDP binding to BAT of fasted rats. This effect is not mediated by the sympathetic nervous system, because it is observed in both innervated and denervated BAT. These results are compatible with the concept that, in fasting rats, the decrease in leptin secretion contributes to the reduction in 3H GDP binding to BAT mitochondria.

Características biológicas e comportamentais de Neodohrniphora elongata Brown (Diptera, Phoridae), um parasitóide da saúva Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae)

Foram investigadas as características da biologia e comportamento do forídeo Neodohrniphora elongata Brown, 2001 em relação às operárias do hospedeiro Atta sexdens rubropilosa Forel, 1908. Vinte e quatro fêmeas de N. elongata coletadas no campo foram liberadas, uma por vez, em uma cuba de observação interposta entre um ninho de A. sexdens rubropilosa e uma arena de forrageamento. As moscas realizaram de quatro a cinco vezes mais investidas sem sucesso contra as formigas do que ataques efetivos, quando elas ovipositaram na cabeça das operárias. Houve ataques em 426 operárias e desenvolvimento da larva do parasitóide na cápsula cefálica de 63,8% delas, sendo que emergiram 218 moscas. N. elongata ovipositou nas maiores operárias, ou seja, naquelas com largura da cápsula cefálica de 2,9 ± 0,4 mm, o que parece ser importante para o desenvolvimento do parasitóide, pois o fracasso na formação de pupas ou a não emergência do adulto ocorreram principalmente em formigas com largura da cápsula inferior a 2,9 mm. As moscas que emergiram em laboratório tiveram maior longevidade quando alimentadas com solução de mel 10% do que com solução de mel 50% ou somente água destilada. As fêmeas que emergiram no laboratório exibiram os mesmos comportamentos de voo e ataque das fêmeas do campo, mas não foi possível obter parasitóides de segunda geração. Estudos adicionais devem ser realizados para investigar a adequação de fontes naturais de carboidratos e proteínas sobre a longevidade e reprodução de N. elongata, visando à multiplicação deste e de outros forídeos de saúvas em laboratório.

Use of artificial substrates of different colors for oviposition by the brown stink bug Euschistus heros (Hemiptera, Pentatomidae)

Aiming to contribute to a rearing methodology for the brown stink bug, Euschistus heros, in the laboratory, we evaluated oviposition on artificial substrates of different colors. During six days, oviposition was evaluated daily, by counting the total number of eggs, number of clutches, and eggs/clutch. Females laid 12,463 eggs, in 1,677 clutches, resulting in an average of 7.28 ± 0.44 eggs/clutch. Black, brown, and green felt had the most eggs and clutches. The results demonstrated that many colors are suitable as oviposition substrate for E. heros, providing information for the mass rearing of this insect.

The brown lacewings (Neuroptera, Hemerobiidae) of northwestern Turkey with new records, their spatio-temporal distribution and harbouring plants

The brown lacewings (Neuroptera, Hemerobiidae) of northwestern Turkey with new records, their spatio-temporal distribution and harbouring plants. The occurrence and spatio-temporal distribution of brown lacewing species (Neuroptera, Hemerobiidae) in Bursa province, northwestern Turkey, was investigated during 1999-2011. A total of 852 brown lacewing specimens of 20 species, including the genera of Hemerobius, Megalomus, Micromus, Sympherobius, and Wesmaelius were collected. Of these, 12 species were new records for northwestern Turkey while Sympherobius klapaleki is a new record for the Neuroptera fauna of Turkey. The most widespread species were Hemerobius handschini and Sympherobius pygmaeus with percent dominance values of 42.00 and 15.96%, respectively. Wesmaelius subnebulosus was the earliest emerging hemerobiid species and had the longest flight activity lasting from March to October. The species of southern origin characterized by the Mediterranean elements constituted 55% of the hemerobiid fauna and prevailed over the species of northern origin that belong to the Siberian centres. The total number of hemerobiid species reached a peak in July with captures of 15 species per month. There were 11, 13, 18 and 5 hemerobiid species occurring at altitudes between 1-500, 501-1000, 1001-1500 and 1500-2000 m, respectively. In addition, plant species harbouring hemerobiids are given for each species, and their association with the hemerobiid fauna is discussed.

Temperature-induced sex reversal is not responsible for sex-ratio distortions in grayling Thymallus thymallus or brown trout Salmo trutta.

On the basis of the experiments carried out over various years, it was concluded that (1) grayling Thymallus thymallus and brown trout Salmo trutta are resistant to temperature-induced sex reversal at ecologically relevant temperatures, (2) environmental sex reversal is unlikely to cause the persistent sex ratio distortion observed in at least one of the study populations and (3) sex-specific tolerance of temperature-related stress may be the cause of distorted sex ratios in populations of T. thymallus or S. trutta.

The red island and the seven dwarfs: body size reduction in Cheirogaleidae

AimSmall body size in Madagascar's dwarf and mouse lemurs (Cheirogaleidae) is generally viewed as primitive. We investigated the evolution of body size in this family and in its sister-taxon, the Lepilemuridae, from phylogenetic, ontogenetic and adaptive perspectives. LocationMadagascar. MethodsWe used a phylogenetic method to reconstruct the evolution of body size in lemurs, and allometric regression models of gestation periods and static and growth allometries in Cheirogaleidae and Lepilemuridae to test the hypothesis that dwarfing occurred as a result of truncated ontogeny (progenesis). We also examined adaptive hypotheses relating body size to environmental variability, life history, seasonality of reproduction, hypothermy (use of torpor), and a diet rich in plant exudates. ResultsOur results indicated that cheirogaleids experienced at least four independent events of body size reduction from an ancestor as large as living Lepilemuridae, by means of progenesis. Our interpretation is supported by the paedomorphic appearance and parallel ontogenetic trajectories of the dwarf taxa, as well as their very short gestation periods and increased fecundity. Lepilemur species that occupy more predictable environments are significantly larger than those occupying unpredictable habitats. Main conclusionsCheirogaleidae appear to be paedomorphic dwarfs, a consequence of progenesis, probably as an adaptation to high environmental unpredictability. Although the capacity to use hypothermy is related to small body size, this advantage is unlikely to have driven dwarfing in cheirogaleids. We propose that gummmivory/exudativory co-evolved with body size reduction in this clade, probably from a folivorous ancestor. Their small size is derived, and their suitability as models for the ancestral primate' is therefore dubious.

Ultrastructural and morphometrical analyses of the brown adipocyte nucleus in a hibernating dormouse.

The fine morphology, size, and perichromatin granule frequency were analysed in brown adipocyte nuclei from hibernating, arousing, and euthermic dormice, Muscardinus avellanarius. Unusual nuclear structural constituents such as nuclear amorphous bodies, coiled body-like constituents and bundles of nucleoplasmic filaments were described as typical of hibernating nuclei. Morphometrical findings showed significant difference in total nuclear and nucleolar size in the three physiological conditions investigated as well as decreasing frequency of perichromatin granules in nuclei of hibernating to arousing to euthermic animals. A possible involvement of these granules in the intranuclear transport or storage of pre-mRNA is discussed in the context of other experimental evidence.

Plac8 is an inducer of C/EBPβ required for brown fat differentiation, thermoregulation, and control of body weight.

Brown adipocytes oxidize fatty acids to produce heat in response to cold or to excessive energy intake; stimulation of brown fat development and function may thus counteract obesity. Brown adipogenesis requires activation of the transcription factor C/EBPβ and recruitment of the zinc finger protein Prdm16, but upstream inducers of these proteins are incompletely defined. Here, we show that genetic inactivation of Plac8, a gene encoding an evolutionarily conserved protein, induces cold intolerance, and late-onset obesity, as well as abnormal morphology and impaired function of brown adipocytes. Using brown preadipocyte lines we show that Plac8 is required for brown fat differentiation, that its overexpression induces C/EBPβ and Prdm16, and that upon induction of differentiation Plac8 associates with C/EBPβ and binds to the C/EBPβ promoter to induce its transcription. Thus, Plac8 is a critical upstream regulator of brown fat differentiation and function that acts, at least in part, by inducing C/EBPβ expression.

Cyclooxygenase-2 controls energy homeostasis in mice by de novo recruitment of brown adipocytes.

Obesity results from chronic energy surplus and excess lipid storage in white adipose tissue (WAT). In contrast, brown adipose tissue (BAT) efficiently burns lipids through adaptive thermogenesis. Studying mouse models, we show that cyclooxygenase (COX)-2, a rate-limiting enzyme in prostaglandin (PG) synthesis, is a downstream effector of beta-adrenergic signaling in WAT and is required for the induction of BAT in WAT depots. PG shifted the differentiation of defined mesenchymal progenitors toward a brown adipocyte phenotype. Overexpression of COX-2 in WAT induced de novo BAT recruitment in WAT, increased systemic energy expenditure, and protected mice against high-fat diet-induced obesity. Thus, COX-2 appears integral to de novo BAT recruitment, which suggests that the PG pathway regulates systemic energy homeostasis.

Wheat yield and physical properties of a brown latosol under no-tillage in south-central Paraná

Soil management influences the chemical and physical properties of soil. Chemical conditions have been thoroughly studied, while the role of soil physical conditions regarding crop yield has been neglected. This study aimed to analyze the wheat yield and its relationship with physical properties of an Oxisol under no-tillage (NT). The study was carried out between 2010 and 2011, in Reserva do Iguaçu, State of Paraná, Brazil, on the Campo Bonito farm, after 25 years of NT management. Based on harvest maps of barley (2006), wheat (2007) and maize (2009) of a plot (150 ha), zones with higher and lower yield potential (Z1 and Z2, respectively) were identified. Sampling grids with 16 units (50 x 50 m) and three sampling points per unit were established. The wheat grain yield (GY) and water infiltration capacity (WIC) were evaluated in 2010. Soil samples with disturbed and undisturbed structure were collected from the 0.00-0.10 and 0.10-0.20 m layers. The former were used to determine soil organic carbon (Corg) levels and the latter to determine soil bulk density (BD), total porosity (TP), macroporosity (Mac), and microporosity (Mic). Soil penetration resistance (PR) and water content (SWC) were also evaluated. The wheat GY of the whole plot was close to the regional average and the yield between the zones differed significantly, i.e. 22 % higher in Z1 than in Z2. No significant variation in Mic was observed between zones, but Z1 had higher Corg levels, SWC, TP and Mac and lower BD than Z2 in both soil layers, as well as a lower PR than Z2 in the 0.00-0.10 m layer. Therefore, soil physical conditions were more restrictive in Z2, in agreement with wheat yield and zone yield potential defined a priori, based on the harvest maps. Soil WIC in Z1 was significantly higher (30 %) than in Z2, in agreement with the results of TP and Mac which were also higher in Z1 in both soil layers. The correlation analysis of data of the two layers showed a positive relationship between wheat GY and the soil properties TP, SWC and WIC.