62 research outputs found
Captive breeding of European freshwater mussels as aconservation tool: A review
1. Freshwater mussels are declining throughout their range. Their importantecological functions along with insufficient levels of natural recruitment haveprompted captive breeding for population augmentation and questions about the usefulness and applicability of such measures. 2. This article reviews the current state of captive breeding and rearing programmes for freshwater mussels in Europe. It considers the various species, strategies, andtechniques of propagation, as well as the different levels of effort requiredaccording to rearing method, highlighting the key factors of success. 3. Within the last 30 years, 46 breeding activities in 16 European countries have been reported, mainly of Margaritifera margaritifera and Unio crassus. Some facilities propagate species that are in a very critical situation, such as Pseudunio auricularius, Unio mancus, and Unio ravoisieri, or multiple species concurrently. Insome streams, the number of released captive-bred mussels already exceeds the size of the remaining natural population. 4. Rearing efforts range from highly intensive laboratory incubation to lowerintensity methods using in-river mussel cages or silos. Most breeding efforts are funded by national and EU LIFE(+) grants, are well documented, and consider the genetic integrity of the propagated mussels. Limited long-term funding perspectives, the availability of experienced staff, water quality, and feeding/survival during early life stages are seen as the most important challenges. 5. Successful captive breeding programmes need to be combined with restoration ofthe habitats into which the mussels are released. This work will benefit from anevidence-based approach, knowledge exchange among facilities, and an overall breeding strategy comprising multiple countries and conservation units. aquaculture, captive breeding, conservation translocation, freshwater mussel culturing, Margaritifera margaritifera, propagation, reintroduction, Unio crassusCaptive breeding of European freshwater mussels as aconservation tool: A reviewpublishedVersio
Religion in the making: the Lived Ancient Religion approach
For the past five years (2012–2017), the Max Weber Center of Erfurt University has hosted a project on ‘Lived Ancient Religion: Questioning “cults” and “polis religion”’, financed by the European Research Council and embedded in the research group on
‘Religious individualisation in historical perspective’ (see Fuchs and Rüpke. [2015. “Religious Individualisation in Historical Perspective.” Religion 45 (3): 323–329. doi:10.1080/0048721X.2015.1041795]). It was designed to supplement existing accounts of the religious history of the Mediterranean area at the time of the long Roman Empire, accounts traditionally centred upon public or civic institutions. The new model focuses on the interaction of individuals with a variety of religious specialists and traditions, taking the form of material culture, spaces and text. It emphasises religious experience, embodiment and ‘culture in interaction’. On the basis of research into the history of religion of the Roman Empire, this co-authored article sets out to offer new tools for research into religion by formulating three major perspectives, namely religious agency, instantiated religion and narrated religion. We have tried to illustrate their potential value by means of 13 short case studies deriving from different geographical areas of the central and eastern Mediterranean area, and almost all relating to the period 150 BCE to 300 CE. These short descriptions are summarising research pursued by the members of the team of authors, published or to be published in extended form elsewhere, as indicated by the references
Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil
Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition
Characteristics of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) rRNA genes of Apis mellifera (Insecta: Hymenoptera): structure, organization, and retrotransposable elements
As an accompanying manuscript to the release of the honey bee genome, we report the entire sequence of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) ribosomal RNA (rRNA)-encoding gene sequences (rDNA) and related internally and externally transcribed spacer regions of Apis mellifera (Insecta: Hymenoptera: Apocrita). Additionally, we predict secondary structures for the mature rRNA molecules based on comparative sequence analyses with other arthropod taxa and reference to recently published crystal structures of the ribosome. In general, the structures of honey bee rRNAs are in agreement with previously predicted rRNA models from other arthropods in core regions of the rRNA, with little additional expansion in non-conserved regions. Our multiple sequence alignments are made available on several public databases and provide a preliminary establishment of a global structural model of all rRNAs from the insects. Additionally, we provide conserved stretches of sequences flanking the rDNA cistrons that comprise the externally transcribed spacer regions (ETS) and part of the intergenic spacer region (IGS), including several repetitive motifs. Finally, we report the occurrence of retrotransposition in the nuclear large subunit rDNA, as R2 elements are present in the usual insertion points found in other arthropods. Interestingly, functional R1 elements usually present in the genomes of insects were not detected in the honey bee rRNA genes. The reverse transcriptase products of the R2 elements are deduced from their putative open reading frames and structurally aligned with those from another hymenopteran insect, the jewel wasp Nasonia (Pteromalidae). Stretches of conserved amino acids shared between Apis and Nasonia are illustrated and serve as potential sites for primer design, as target amplicons within these R2 elements may serve as novel phylogenetic markers for Hymenoptera. Given the impending completion of the sequencing of the Nasonia genome, we expect our report eventually to shed light on the evolution of the hymenopteran genome within higher insects, particularly regarding the relative maintenance of conserved rDNA genes, related variable spacer regions and retrotransposable elements
Genetic analysis of two female-sterile loci affecting eggshell integrity and embryonic pattern formation in Drosophila melanogaster.
Abstract
We have analyzed female-sterile mutations at the X-linked loci fs(1)Nas and fs(1)ph which show allele-specific effects on egg shell structure and embryonic pattern formation. The majority of mutant alleles at both loci lead to a collapsed egg phenotype. The maternal effect lethal phenotype is characterized by cuticle defects resembling those found in three autosomal mutants of the terminal class. We have analyzed the complementation behavior of various heteroallelic combinations at both loci and show that one such combination at the fs(1)Nas locus is capable of restoring normal fertility. We have investigated possible interactions between fs(1)Nas and fs(1)ph and also between the terminal allele of fs(1)Nas and various maternal effect mutations altering the anteroposterior polarity of embryos. We have isolated one new allele of fs(1)Nas which combines the locus-typical phenotypic features with novel cuticle phenotypes. Our results suggest that the products of fs(1)Nas and fs(1)ph are required for the stability of the vitelline membrane and are also involved in a morphogenetic pathway necessary for the correct differentiation of the terminal regions of the embryo. Possible mechanisms to account for the association of these two functions are discussed.</jats:p
Increase of calnexin gene dosage boosts the secretion of heterologous proteins by Hansenula polymorpha
The type I membrane protein calnexin is a conserved key component of the quality control mechanism in the endoplasmic reticulum. It functions as a molecular chaperone that monitors the folding state of nascent polypeptides entering the endoplasmic reticulum. Calnexin also behaves as a lectin, as its chaperoning activity involves binding of oligosaccharide moieties present on newly imported glycoproteins. We isolated the calnexin gene (HpCNE1) from the methylotrophic yeast Hansenula polymorpha, and used HpCNE1 expression plasmids for supertransformation of H. polymorpha strains secreting target proteins of biotechnological interest. The elevated dosage of HpCNE1 enhanced secretion of the four proteins tested: three glycoproteins and one unglycosylated product. Secretion of bacterial alginate epimerase AlgE1 was increased threefold on average, and secretion of both human interferon-γ and fungal consensus phytase twofold. With phytase and AlgE1 this improvement was all the more remarkable, as the secretion level was already high in the original strains (g L(−1) range). The same approach improved secretion of human serum albumin, which lacks N-linked glycans, about twofold. Glycosylation of the pro-MFα1 leader may account for the effect of calnexin in this case. Our results argue that cooverexpression of calnexin can serve as a generally applicable tool for enhancing the secretion of all types of heterologous protein by H. polymorpha
Germline and somatic vitelline proteins colocalize in aggregates in the follicular epithelium of Drosophila
- …
