Differential proteome analysis of mature and germinated embryos of Araucaria angustifolia

Araucaria angustifolia is an endangered Brazilian native conifer tree. The aim of the present work was to identify differentially expressed proteins between mature and germinated embryos of A. angustifolia, using one and two dimensional gel electrophoresis approaches followed by protein identification by tandem mass spectrometry. The identities of 32 differentially expressed protein spots from two dimensional gel maps were successfully determined, including proteins and enzymes involved in storage mobilization such as the vicilin-like storage protein and proteases. A label free approach, based on spectral counts, resulted in detection of 10 and 14 mature and germinated enriched proteins, respectively. Identified proteins were mainly related to energetic metabolism pathways, translational processes, oxidative stress regulation and cellular signaling. The integrated use of both strategies permitted a comprehensive protein expression overview of changes in germinated embryos in relation to matures, providing insights into the this process in a recalcitrant seed species. Applications of the data generated on the monitoring and control of in vitro somatic embryos were discussed.     

The value of endangered species in protected areas at risk: the case of the leatherback turtle in the Dominican Republic

Protected areas are considered essential elements for global biodiversity conservation. They may not necessarily result in an effective conservation of resources in developing countries due to lack of funding for management and enforcement. In addition, poor governance aligned with conflicts of economic interests related to their use can further threaten their integrity and persistence. In the Dominican Republic, the western beaches of the Jaragua National Park (JNP), a protected area which is also part of a UNESCO Biosphere Reserve, have been proposed for development using a mass-tourism model. One of the most charismatic species found in this area is the leatherback turtle (Dermochelys coriacea). In the present study, we assess hatching success, and factors affecting it, to determine the reproductive value across the area for the leatherback turtle. The main factors found driving hatching success at the study beaches are beach sector, incubation duration, date of lay and clutch size. Our results show that clutches in La Cueva (located in the buffer zone of the park) and Bahía de las Águilas (located inside the limits of the park) have an unusually high hatching success (~75 %) for this species, highlighting the importance of increasing protection efforts at these sites. We strongly recommend including La Cueva inside the limits of the JNP.     

Search engine processor: Filtering and organizing peptide spectrum matches

The search engine processor (SEPro) is a tool for filtering, organizing, sharing, and displaying peptide spectrum matches. It employs a novel three-tier Bayesian approach that uses layers of spectrum, peptide, and protein logic to lead the data to converge to a single list of reliable protein identifications. SEPro is integrated into the PatternLab for proteomics environment, where an arsenal of tools for analyzing shotgun proteomic data is provided. By using the semi-labeled decoy approach for benchmarking, we show that SEPro significantly outperforms a commercially available competitor.     

Saturnius minutus n. sp. and S. dimitrovi n. sp. (Digenea: Hemiuridae) from Mugil cephalus L. (Teleostei: Mugilidae), with a multivariate morphological analysis of the Mediterranean species of Saturnius Manter, 1969

Three species of the bunocotyline genus Saturnius Manter, 1969 are described from the stomach lining of mugilid fishes of the Mediterranean and Black Seas. Two of the species are new: S. minutus n. sp. occurs in Mugil cephalus off the Mediterranean coast of Spain; and S. dimitrovi n. sp., a parasite of M. cephalus off the Bulgarian Black Sea coast and the Spanish Mediterranean coast, was originally described as S. papernai by Dimitrov et al. (1998). In addition, S. papernai Overstreet, 1977 is redescribed from M. cephalus off the Spanish Mediterranean coast and from Liza aurata and L. saliens off the Bulgarian Black Sea coast. The three species are distinguished morphometrically using univariate and multivariate analyses. These results were verified using Linear Discriminant Analysis which correctly allocated all specimens to their species designations based on morphology (i.e. 100% successful classification rate) and assigned almost all specimens to the correct population (locality). The following variables were selected for optimal separation between samples: the length of the forebody, ventral sucker and posterior testis, the length and width of the posteriormost pseudosegment, and the width of the muscular flange at ventral sucker level.     

Diclidophora merlangi (Monogenea: Diclidophoridae) on Atlantic cod, Gadus morhua

Diclidophora merlangi (Kuhn, in Nordmann, 1832), as species specific to whiting, Merlangius merlangus (Linnaeus, 1758), is reported and described for the first time on the gills of Atlantic cod Gadus morhua (Linnaeus, 1758). Of the about 1,200 cod examined in this article, only 2 specimens of D. merlangi occurred on 2 fish, suggesting that they represented accidental infections. The 2 specimens showed specific traits of D. merlangi, but their size was considerably smaller than that of D. merlangi on whiting. Principal-component analyses showed that the morphology of the specimens on cod was more similar to that of D. merlangi than those of other congeneric species from the North Atlantic, additionally supporting their assignment to D. merlangi. Quantitative data documenting the potential reproductive consequences of D. merlangi occurring on cod is also provided. The testes and germaria of the specimens on cod were noticeably smaller than those of D. merlangi on whiting, but the number of testes was similar and spermatozoa were observed in the sperm duct. By contrast, the aspect and smaller size of the oocytes suggested that D. merlangi on cod could not produce viable ova, although 1 specimen exhibited an egg with normal sized and shaped capsule.     

Proteome analysis of cold acclimation in sunflower

Cold acclimation is the phenomenon in which plants are exposed to low, but nonfreezing, temperatures before exposure to drastic temperatures. To investigate how sunflower plants adjust their metabolism during cold treatment, a comparative proteomic approach, based on spectral counting data, was adopted to identify differentially expressed proteins in leaves of freezing susceptible (Hopi) and tolerant (PI 543006 and BSD-2-691) lines after cold acclimation. In total 718, 675, and 769 proteins were confidently identified by tandem mass spectrometry in Hopi, PI 543006, and BSD-2-691 sunflower lines. Tolerant lines PI 543006 and BSD-2-691 showed the highest number of differentially expressed proteins, as 43, 72, and 168 proteins changed their expression in Hopi, PI 543006, and BSD-2-691 sunflower lines, respectively, at 95% confidence. Cold-responsive proteins were mostly involved in metabolism, protein synthesis, energy, and defense processes in all sunflower lines studied. Hierarchical clustering of all differentially expressed proteins resulted in the characterization of 14 different patterns of expression across Hopi, PI 543006, and BSD-2-691 and indicated that tolerant lines showed different proteome responses to cold acclimation.     

Aggregation patterns of helminth populations in the introduced fish, Liza haematocheilus (Teleostei: Mugilidae): disentangling host–parasite relationships

A number of hypotheses exist to explain aggregated distributions, but they have seldom been used to investigate differences in parasite spatial distribution between native and introduced hosts. We applied two aggregation models, the negative binomial distribution and Taylor’s power law, to study the aggregation patterns of helminth populations from Liza haematocheilus across its native (Sea of Japan) and introduced (Sea of Azov) distribution ranges. In accordance with the enemy release hypothesis, we predicted that parasite populations in the introduced host range would be less aggregated than in the native host area, because aggregation is tightly constrained by abundance. Contrary to our expectation, aggregation of parasite populations was higher in the introduced host range. However, the analyses suggested that the effect of host introduction on parasite aggregation depends on whether parasite species, or higher level taxonomic groups, were acquired in or carried into the new area. The revealed similarity in the aggregation parameters of co-introduced monogeneans can be attributed to the repeatability and identity of the host–parasite systems. In contrast, the degree of aggregation differed markedly between regions for higher level taxa, which are represented by the native parasites in the Sea of Japan versus the acquired species in the Sea of Azov. We propose that the host species plays a crucial role in regulating infra-population sizes of acquired parasites due to the high rate of host-induced mortality. A large part of the introduced host population may remain uninfected due to their resistance to native naïve parasites. The core concept of our study is that the comparative analysis of aggregation patterns of parasites in communities and populations, and macroecological relationships, can provide a useful tool to reveal cryptic relationships in host–parasite systems of invasive hosts and their parasites.     

Biometric variability of Hadwenius tursionis (Marchi, 1873) (Digenea,Campulidae) from the intestine of the bottlenose dolphin Tursiops truncatus (Montagu, 1821)

The species discrimination in the family Campulidae is largely based on morphometric characters (absolute measurements and ratios). To assess the variability of this characters we have studied the campulid species Hadwenius tursionis from four Mediterranean bottlenose dolphins Tursiops truncatus from the Western Mediterranean. In H. tursionis most absolute measurements differed significantly across the infrapopulations, showing high coefficients of variation. Only egg dimensions appeared to be fairly conservative. Body ratios were less variable than absolute measurements, but growth patterns did vary significantly between the infrapopulations studied. None of the ratios previously used in relation to other species of the family Campulidae indicated either isometric or allometric growth in this case. Only the ratios concerning the size of the gonads and the shape of the gonads and suckers showed isometry. It is concluded that absolute measurements and ratios should be used with caution in relation to the separation of species of the family Campulidae unless their intrinsic variability can be established beforehand.     

Native and invasive hosts play different roles in host–parasite networks

Parasites are often key players in biological invasions since they can mediate the impact of host invasions or can themselves become invasive species. However, the nature and extent of parasite-mediated invasions are often difficult to delineate. Here, we used individual-based, weighted bipartite networks to study the roles (degrees of interactions of individuals in a modular network according to their within- and among-module connections) played by native and invasive host individuals to their parasite communities. We studied two phylogenetically and ecologically close fish species, Mugil cephalus s.l. and Planiliza haematocheilus (Teleostei: Mugilidae). Planiliza haematocheilus is native to the Sea of Japan and invasive in the Sea of Azov whereas, M. cephalus s.l. is native to both seas. Based on the common evolutionary history that drives native host–parasite networks, we hypothesised that 1) native networks have higher modularity than invaded ones; and 2) invasive hosts in the invaded area play a peripheral role to structure parasite communities. We analysed the whole parasite community and subsets based on transmission strategy and host specificity of the parasite species to establish whether modularity and host roles are related to these features in the native and invaded areas. All networks were found to be modular. However, modularity tended to be higher in networks of the native area rather than those of the invaded area. Host individuals of both fish species played similar roles in the native area, whereas invasive hosts played a peripheral role in the networks of the invaded area. We propose that long-term monitoring of the roles of invasive hosts in parasite communities can be a useful proxy for estimating the maturity of the establishment of the invasive hosts in an ecosystem.