Historical microbiology: revival and phylogenetic analysis of the luminous bacterial cultures of M . W . B eijerinck

Luminous bacteria isolated by M artinus W . B eijerinck were sealed in glass ampoules in 1924 and 1925 and stored under the names P hotobacterium phosphoreum and ‘ P hotobacterium splendidum ’. To determine if the stored cultures were viable and to assess their evolutionary relationship with currently recognized bacteria, portions of the ampoule contents were inoculated into culture medium. Growth and luminescence were evident after 13 days of incubation, indicating the presence of viable cells after more than 80 years of storage. The B eijerinck strains are apparently the oldest bacterial cultures to be revived from storage. Multi‐locus sequence analysis, based on the 16S rRNA , gapA , gyrB , pyrH , recA , luxA , and luxB genes, revealed that the B eijerinck strains are distant from the type strains of P . phosphoreum , ATCC 11040 T , and V ibrio splendidus , ATCC 33125 T , and instead form an evolutionarily distinct clade of V ibrio . Newly isolated strains from coastal seawater in N orway, F rance, U ruguay, M exico, and J apan grouped with the B eijerinck strains, indicating a global distribution for this new clade, designated as the beijerinckii clade. Strains of the beijerinckii clade exhibited little sequence variation for the seven genes and approximately 6300 nucleotides examined despite the geographic distances and the more than 80 years separating their isolation. Gram‐negative bacteria therefore can survive for many decades in liquid storage, and in nature, they do not necessarily diverge rapidly over time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88047/1/fem1177.pd

Viviparity Stimulates Diversification in an Order of Fish

International audienceSpecies richness is distributed unevenly across the tree of life and this may be influenced by the evolution of novel phenotypes that promote diversification. Viviparity has originated B150 times in vertebrates and is considered to be an adaptation to highly variable environments. Likewise, possessing an annual life cycle is common in plants and insects, where it enables the colonization of seasonal environments, but rare in vertebrates. The extent to which these reproductive life-history traits have enhanced diversification and their relative importance in the process remains unknown. We show that convergent evolution of viviparity causes bursts of diversification in fish. We built a phylogenetic tree for Cyprino-dontiformes, an order in which both annualism and viviparity have arisen, and reveal that while both traits have evolved multiple times, only viviparity played a major role in shaping the patterns of diversity. These results demonstrate that changes in reproductive life-history strategy can stimulate diversification

Digital Orthopaedics: A Glimpse Into the Future in the Midst of a Pandemic.

BackgroundThe response to COVID-19 catalyzed the adoption and integration of digital health tools into the health care delivery model for musculoskeletal patients. The change, suspension, or relaxation of Medicare and federal guidelines enabled the rapid implementation of these technologies. The expansion of payment models for virtual care facilitated its rapid adoption. The authors aim to provide several examples of digital health solutions utilized to manage orthopedic patients during the pandemic and discuss what features of these technologies are likely to continue to provide value to patients and clinicians following its resolution.ConclusionThe widespread adoption of new technologies enabling providers to care for patients remotely has the potential to permanently change the expectations of all stakeholders about the way care is provided in orthopedics. The new era of Digital Orthopaedics will see a gradual and nondisruptive integration of technologies that support the patient's journey through the successful management of their musculoskeletal disease

Phylogenetic analysis of host–symbiont specificity and codivergence in bioluminescent symbioses

Several groups of marine fishes and squids form mutualistic bioluminescent symbioses with luminous bacteria. The dependence of the animal on its symbiont for light production, the animal's specialized anatomical adaptations for harboring bacteria and controlling light emission, and the host family bacterial species specificity characteristic of these associations suggest that bioluminescent symbioses are tightly coupled associations that might involve coevolutionary interactions. Consistent with this possibility, evidence of parallel cladogenesis has been reported for squid–bacterial associations. However, genetic adaptations in the bacteria necessary for and specific to symbiosis have not been identified, and unlike obligate endosymbiotic associations in which the bacteria are transferred vertically, bacterially bioluminescent hosts acquire their light-organ symbionts from the environment with each new host generation. These contrasting observations led us to test the hypotheses of species specificity and codivergence in bioluminescent symbioses, using an extensive sampling of naturally formed associations. Thirty-five species of fish in seven teleost families (Chlorophthalmidae, Macrouridae, Moridae, Trachichthyidae, Monocentridae, Acropomatidae, Leiognathidae) and their light-organ bacteria were examined. Phylogenetic analysis of a taxonomically broad sampling of associations was based on mitochondrial 16S rRNA and cytochrome oxidase I gene sequences for the fish and on recA , gyrB and luxA sequences for bacteria isolated from the light organs of these specimens. In a fine-scale test focused on Leiognathidae, phylogenetic analysis was based also on histone H3 subunit and 28S rRNA gene sequences for the fish and on gyrB , luxA , luxB , luxF and luxE sequences for the bacteria. Deep divergences were revealed among the fishes, and clear resolution was obtained between clades of the bacteria. In several associations, bacterial species identities contradicted strict host family bacterial species specificity. Furthermore, the fish and bacterial phylogenies exhibited no meaningful topological congruence; evolutionary divergence of host fishes was not matched by a similar pattern of diversification in the symbiotic bacteria. Re-analysis of data reported for squids and their luminous bacteria also revealed no convincing evidence of codivergence. These results refute the hypothesis of strict host family bacterial species specificity and the hypothesis of codivergence in bioluminescent symbioses. © The Willi Hennig Society 2007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73754/1/j.1096-0031.2007.00157.x.pd

IDENTIFICATION OF TOUCHDOWN AND TOE-OFF IN TURF-SPORT SPECIFIC MOVEMENTS USING KINEMATIC DATA

The accurate determination of touchdown and toe-off during the stance phase in human locomotion is important for further motion analysis. The aim of this study was to evaluate the accuracy of using kinematic data to detect these events and therefore ground contact time of movements on artificial turf. Seven athletes performed five different turf-sport specific movements in which a single contact was made on a force plate (1000 Hz), while kinematic data of six markers were recorded (CODA, 400 Hz). A force threshold (20N) was set to determine the events of the touchdown and toe-off for the kinetic data. Comparison was made between the kinetic and kinematic derived event times. The errors between the kinetic and kinematic data ranged from 1.6 to 3.4% for the acceleration, hurdle hop and a turn with change of direction of 135°. It was concluded that kinematic data can accurately determine touchdown and toe-off events for certain movements on artificial turf

Analysis of myotube-motoneuron interaction within an in vitro 3D collagen-based model of skeletal muscle

In seeking to further our understanding of skeletal muscle physiology and function in both healthy and diseased tissues, there is a strong need to develop in vitro culture systems that better represent the in vivo condition. This project is aimed at developing an innervated 3D in vitro model of skeletal muscle. It is hoped that the incorporation of primary motoneurons into a 3D model of skeletal muscle established in our lab will promote myofibre development towards an adult phenotype and improve the biomimicity of the system. Furthermore, the formation of neuromuscular junctions (NMJ) within a 3D in vitro setting should allow for testing of the effects of neuromuscular agents in culture, thereby reducing the need for in vivo experimentation. Here we present data characterising the development and maturation of this 3D co-culture system in comparison to conventional 2D cultures and discuss the implications for the future of skeletal muscle tissue culture techniques

Mapping the root systems of individual trees in a natural community using genotyping-by-sequencing

•The architecture of root systems is an important driver of plant fitness, competition and ecosystem processes. However, the methodological difficulty of mapping roots hampers the study of these processes. Existing approaches to match individual plants to belowground samples are low throughput and species specific. Here, we developed a scalable sequencing-based method to map the root systems of individual trees across multiple species. We successfully applied it to a tropical dry forest community in the Brazilian Caatinga containing 14 species. • We sequenced all 42 individual shrubs and trees in a 14 × 14 m plot using double-digest restriction site-associated sequencing (ddRADseq). We identified species-specific markers and individual-specific haplotypes from the data. We matched these markers to the ddRADseq data from 100 mixed root samples from across the centre (10 × 10 m) of the plot at four different depths using a newly developed R package. • We identified individual root samples for all species and all but one individual. There was a strong significant correlation between belowground and aboveground size measurements, and we also detected significant species-level root-depth preference for two species. • The method is more scalable and less labour intensive than the current techniques and is broadly applicable to ecology, forestry and agricultural biology

Establishment of a 3D engineered skeletal muscle-motoneuron co-culture using fibrin-cast gels

The successful in vitro engineering of complex tissues such as skeletal muscle would be of great benefit in the fields of tissue engineering and regenerative medicine, muscle physiology and neuromuscular research. A number of in vitro engineered models of skeletal muscle have been described that demonstrate many structural, biochemical and physiological similarities to in vivo muscle. As yet, however, there is no truly biomimetic in vitro model of skeletal muscle. An important aspect of in vivo muscle development and maintenance is the presence of a neuronal input via neuromuscular junctions (NMJs). Here we have increased the complexity of existing muscle models by introducing primary motoneurons with the aim of engineering a functional neuronal input in an established in vitro skeletal muscle model