The functional repertoire contained within the native microbiota of the model nematode Caenorhabditis elegans

The microbiota is generally assumed to have a substantial influence on the biology of multicellular organisms. The exact functional contributions of the microbes are often unclear and cannot be inferred easily from 16S rRNA genotyping, which is commonly used for taxonomic characterization of bacterial associates. In order to bridge this knowledge gap, we here analyzed the metabolic competences of the native microbiota of the model nematode Caenorhabditis elegans. We integrated whole-genome sequences of 77 bacterial microbiota members with metabolic modeling and experimental characterization of bacterial physiology. We found that, as a community, the microbiota can synthesize all essential nutrients for C. elegans. Both metabolic models and experimental analyses revealed that nutrient context can influence how bacteria interact within the microbiota. We identified key bacterial traits that are likely to influence the microbe’s ability to colonize C. elegans (i.e., the ability of bacteria for pyruvate fermentation to acetoin) and affect nematode fitness (i.e., bacterial competence for hydroxyproline degradation). Considering that the microbiota is usually neglected in C. elegans research, the resource presented here will help our understanding of this nematode’s biology in a more natural context. Our integrative approach moreover provides a novel, general framework to characterize microbiota-mediated functions

Convergent Evolution in Aquatic Tetrapods: Insights from an Exceptional Fossil Mosasaur

Mosasaurs (family Mosasauridae) are a diverse group of secondarily aquatic lizards that radiated into marine environments during the Late Cretaceous (98–65 million years ago). For the most part, they have been considered to be simple anguilliform swimmers – i.e., their propulsive force was generated by means of lateral undulations incorporating the greater part of the body – with unremarkable, dorsoventrally narrow tails and long, lizard-like bodies. Convergence with the specialized fusiform body shape and inferred carangiform locomotory style (in which only a portion of the posterior body participates in the thrust-producing flexure) of ichthyosaurs and metriorhynchid crocodyliform reptiles, along with cetaceans, has so far only been recognized in Plotosaurus, the most highly derived member of the Mosasauridae. Here we report on an exceptionally complete specimen (LACM 128319) of the moderately derived genus Platecarpus that preserves soft tissues and anatomical details (e.g., large portions of integument, a partial body outline, putative skin color markings, a downturned tail, branching bronchial tubes, and probable visceral traces) to an extent that has never been seen previously in any mosasaur. Our study demonstrates that a streamlined body plan and crescent-shaped caudal fin were already well established in Platecarpus, a taxon that preceded Plotosaurus by 20 million years. These new data expand our understanding of convergent evolution among marine reptiles, and provide insights into their evolution's tempo and mode

Testosterone in men with hypogonadism and transgender males: a systematic review comparing three different preparations

Testosterone therapy is the cornerstone in the care of men with hypogonadism and transgender males. Gel and intramuscular injections are most frequently used and are registered and included in the international guidelines. The specific preparation should be selected according to the patient's preference, cost, availability, and formulation-specific properties. As the majority of men with hypogonadism and transgender males require lifelong treatment with testosterone, it is important to utilize a regimen that is effective, safe, inexpensive, and convenient to use with optimal mimicking of the physiological situation. This systematic review reviews current literature on differences between the three most used testosterone preparations in adult men with hypogonadism and transgender males. Although it appeared hardly any comparative studies have been carried out, there are indications of differences between the preparations, for example, on the stability of testosterone levels, hematocrit, bone mineral density, and patient satisfaction. However, there are no studies on the effects of testosterone replacement on endpoints such as cardiovascular disease in relation to hematocrit or osteoporotic fractures in relation to bone mineral density. The effect of testosterone therapy on health-related quality of life is strongly underexposed in the reviewed studies, while this is a highly relevant outcome measure from a patient perspective. In conclusion, current recommendations on testosterone treatment appear to be based on data primarily from non-randomized clinical studies and observational studies. The availability of reliable comparative data between the different preparations will assist in the process of individual decision-making to choose the most suitable formula

Testosterone in men with hypogonadism and transgender males: a systematic review comparing three different preparations

Testosterone therapy is the cornerstone in the care of men with hypogonadism and transgender males. Gel and intramuscular injections are most frequently used and are registered and included in the international guidelines. The specific preparation should be selected according to the patient's preference, cost, availability, and formulation-specific properties. As the majority of men with hypogonadism and transgender males require lifelong treatment with testosterone, it is important to utilize a regimen that is effective, safe, inexpensive, and convenient to use with optimal mimicking of the physiological situation. This systematic review reviews current literature on differences between the three most used testosterone preparations in adult men with hypogonadism and transgender males. Although it appeared hardly any comparative studies have been carried out, there are indications of differences between the preparations, for example, on the stability of testosterone levels, hematocrit, bone mineral density, and patient satisfaction. However, there are no studies on the effects of testosterone replacement on endpoints such as cardiovascular disease in relation to hematocrit or osteoporotic fractures in relation to bone mineral density. The effect of testosterone therapy on health-related quality of life is strongly underexposed in the reviewed studies, while this is a highly relevant outcome measure from a patient perspective. In conclusion, current recommendations on testosterone treatment appear to be based on data primarily from non-randomized clinical studies and observational studies. The availability of reliable comparative data between the different preparations will assist in the process of individual decision-making to choose the most suitable formula.Metabolic health: pathophysiological trajectories and therap

Pathologic-anatomic and morphometric examinations on the heart in feral cockatoos Pathologisch-anatomische und morphometrische untersuchungen am herzen von wildlebenden kakadus

Objective: To evaluate the heart of free-living psittacine birds macroscopically and morphologically, and to compare the results to findings published for psittacine birds living in captivity to obtain information on the influence of bird keeping in a human environment on the psittacine heart. Material and methods: In total, 84 wild-living cockatoos were examined, including 50 sulphur-crested cockatoos (Cacatua galerita), 31 galahs (Eolophus roseicapilla) and three long-billed corellas (Cacatua tenuirostris). The birds were euthanized because of a local cockatoo control program in Australia, and were examined pathologically within 8 hours of euthanasia. A macroscopic necropsy was performed, and the heart was assessed morphologically. Furthermore, a histological organ screening was conducted. Results: The birds demonstrated good body condition and excellent muscle condition. Except for some paleness of the heart muscle, none of the animals showed any pathological alteration of the heart or large vessels. The mean heart mass was 8.7 g for the sulphur-crested cockatoos, 5.3 g for the galahs and 8.6 g for the long-billed corellas. Independent of the species examined, a highly significant correlation was found between the heart and body masses (r = 0.91; p < 0.001), which was also confirmed as significant within the sulphur-crested cockatoo (r = 0.59; p < 0.001) and galah groups (r = 0.52; p = 0.003). This correlation can be used to calculate the expected heart mass based on the body mass, using the formula: heart mass (g) = 2.9 + 0.01 x body mass (g). In comparison to reports on Australian parakeets, the relative thickness of the heart muscle wall of the left ventricle found in this study was greater. Conclusion: In comparison to psittacine birds kept in captivity, wild-living cockatoos have good body condition and rarely suffer from macroscopically detectable diseases of the heart or large vessels. The cardiac fitness level is superior in comparison to that found in healthy appearing psittacine birds kept in captivity. Clinical relevance: The results can serve as a basis for the assessment of the heart in psittacine birds, because in contrast to earlier reports, the heart of healthy psittacine birds not previously exposed to any human influence could be assessed

Detection and subcellular localization of two Sym plasmid-dependent proteins of Rhizobium leguminosarum biovar viciae.

The previously described Sym plasmid-dependent 24-kilodalton rhi protein of Rhizobium leguminosarum biovar viciae was localized in the cytosol fraction. Another Sym plasmid-dependent protein of 50 kilodaltons is secreted into the growth medium, and its expression is dependent on both the nodD gene and a nod gene inducer

Bacteriocin small of fast-growing rhizobia is chloroform soluble and is not required for effective nodulation.

Small bacteriocin is a low-molecular-weight bacteriocin which is common in fast-growing rhizobia. As its activity could not be detected in chloroform-sterilized culture supernatants (P.R. Hirsch, J. Gen. Microbiol. 113:219-228, 1979), the bacteriocin could not be purified in order to study its mechanism of action. We report here that small is soluble in chloroform, an observation which led to effective and simple (partial) purification. Other properties of small are its low molecular weight, which is estimated to be between 700 and 1,500, its resistance to proteolytic enzymes, pectinase, and lysozyme, and its heat stability at pH 5.5 but not at pH 7.0. Its bactericidal action on exponentially growing sensitive cells was not detected until 11 h after its addition. The bactericidal action was preceded by inhibition of cell division. To determine whether small activity is required for nodulation or nitrogen fixation, a transposon Tn5-induced small-negative mutant was isolated. The observation that this strain formed normal, acetylene-reducing root nodules showed that small production is not a prerequisite for the formation of effective nodules