One thousand plant transcriptomes and the phylogenomics of green plants

Abstract: Green plants (Viridiplantae) include around 450,000–500,000 species1, 2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life

Anatomische Untersuchung der sternalen Gefäßversorgung und ihre klinische Relevanz bei tiefen sternalen Wundheilungsstörungen

Introduction: Deep sternal wound infections (DSWI) are a rare but devastating complication after median sternotomy. Minor perfusion in bone and soft tissue, especially after recruiting the internal mammary artery for bypass supports the development of wound infection and nonunion of the sternal bone. The aim of the study was the macroscopic and radiological presentation of the vascular system supplying the sternum, in particular the compensating blood supply routes in the event that the internal mammary artery is no longer available after use as a bypass vessel.Method: This anatomic study was carried out on the anterior chest wall of 7 specimens. The thorax plates of 7 specimens were analyzed macroscopically after microsurgical preparation. Different anatomic preparations were produced using different contrast or form-giving substances. Radiological analysis and three-dimensional reconstructions were performed to show alternative, collateral sternal vessel perfusion under estimation of the loss of the internal thoracic artery due to a bypass.Results: The length of the ITA (internal thoracic artery), measured from the beginning of the first rib to the division into the superior epigastric artery and musculophrenic artery, was an average of 16.3 cm. On average, 18.5 branches were delivered from each artery, 10 medially to the sternum supply, and 8 to the intercostal muscle. Conclusion: Our analysis gives an overview of the macroanatomic vessel system supplying the sternal bone, describing especially a common trunk deriving from the ITA and supplying multiple branches and playing an important role in building a collateral circulation of the sternum.For better evaluation, in vivo CT analysis with contrast media should be performed in patients prior to the operation and directly after the use of the double ITA to demonstrate the change in perfusion of the sternum.In the future, preconditioning of the sternum by coiling the deriving branches could become an option, although patient selection has to be improved and further analysis of the topic performed.Einleitung: Tiefe sternale Wundheilungsstörungen sind seltene, aber verheerende Komplikationen nach medianer Sternotomie. Die verminderte Durchblutung von Knochen und Weichgewebe, vor allem nach Verwendung der Arteria thoracica interna in der kardio-chirurgischen Bypass-Chirurgie, unterstützt die Entwicklung von Wundinfektion und ein Nicht-Verheilen des sternalen Knochens. Das Ziel dieser Studie war die makroskopische und radiologische Darstellung der das Sternum versorgenden Gefäße, sowie insbesondere des kollateralen Blutkreislaufes, für den Fall, dass die Arteria thoracica interna, nach Verwendung als Bypass-Gefäß, nicht mehr zu Verfügung steht.Methode: Diese anatomische Studie wurde an den Brustwandpräparaten von 7 Körperspendern durchgeführt. Das Thoraxschild dieser 7 Körperspender wurde nach mikrochirurgischer Präparation makroskopisch evaluiert und ausgewertet. Es erfolgte die Herstellung verschiedener anatomischer Präparate durch die Verwendung von entweder Kontrast- oder Form-stabilisierenden Substanzen. Radiologische Untersuchungen und dreidimensionale Rekonstruktionen wurden durchgeführt, um die alternative kollaterale Durchblutung des Sternums unter der Annahme, dass die Arteria thoracica interna als Bypass-Gefäß Verwendung fand, darzustellen.Ergebnisse: Die Länge der Arteria thoracica interna (ATI), gemessen von der ersten Rippe bis zu der Aufzweigung in die Arteria epigastrica superior und die Arteria musculophrenica, betrug durchschnittlich 16,3 cm. Von jeder Arterie konnten durchschnittlich 18,5 Abgänge identifiziert werden, 10 in das Sternum ziehende und 8 in die Interkostalmuskulatur gehende Arterien.Fazit: Diese Untersuchung gibt einen Überblick des makroanatomischen Gefäßsystems, welches für die Durchblutung des Sternums verantwortlich ist. Im Besonderen konnte bei den Gefäßabgängen der ATI ein sog. gemeinsamer Stamm, welcher sich im Verlauf in verschiedene Äste aufzweigt, dargestellt werden. Dieser spielt eine wichtige Rolle in der Ausbildung der kollateralen Durchblutung des Sternums.Zur weiteren Evaluation sollten bei kardiochirurgischen Patienten, bei welchen die Bypass-Rekonstruktion mittels bilateraler Verwendung der ATI durchgeführt wird, prä- und postoperative Angio-CT-Untersuchungen durchgeführt werden. Hierdurch kann die Veränderung der sternalen Durchblutungssituation direkt sichtbar gemacht werden.Die Präkonditionierung des Sternums durch Coiling der von der ATI abgehenden Äste und hierdurch initiierter frühzeitiger Kollateralisierung des Sternums könnte eine Verbesserung der Durchblutungssituation des sternalen Knochens erzeugen. Zuvor sollten allerdings weitere Untersuchungen zu diesem Thema durchgeführt werden

Human vagus nerve branching in the cervical region

Background: Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation. Materials and methods: Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides) in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections. Results: Cervical vagus nerve branching was observed in 29%of all cases (26% unilaterally, 3% bilaterally) and proven histologically in all cases. Right-sided branching (22%) was more common than left-sided branching (12%) and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79mm vs. 3.78mm) and cross-sections (7.24 mm2 vs. 5.28mm2). Discussion: Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation

Synthetic exendin-4 disrupts responding to reward predictive incentive cues in male rats

Synthetic exendin-4 (EX4, exenatide), is a GLP-1 receptor agonist used clinically to treat glycemia in Type-2 diabetes mellitus. EX4 also promotes weight loss and alters food reward-seeking behaviors in part due to activation of GLP-1 receptors in the mesolimbic dopamine system. Evidence suggests that GLP-1 receptor activity can directly attenuate cue-induced reward seeking. Here, we tested the effects of EX4 (0.6, 1.2, and 2.4 μg/kg, i.p.) on incentive cue (IC) responding, using a task where rats emit a nosepoke response during an intermittent reward-predictive IC to obtain a sucrose reward. EX4 dose-dependently attenuated responding to ICs and increased the latencies to respond to the IC and enter the sucrose reward cup. Moreover, EX4 dose-dependently decreased the total number of active port nosepokes for every cue presented. There was no effect of EX4 on the number of reward cup entries per reward earned, a related reward-seeking metric with similar locomotor demand. There was a dose-dependent interaction between the EX4 dose and session time on the responding to ICs and nosepoke response latency. The interaction indicated that effects of EX4 at the beginning and end of the session differed by the dose of EX4, suggesting dose-dependent pharmacokinetic effects. EX4 had no effect on free sucrose consumption behavior (i.e., total volume consumed, bout size, number of bouts) within the range of total sucrose volumes obtainable during the IC task (~3.5 ml). However, when rats were given unrestricted access for 1 h, where rats obtained much larger total volumes of sucrose (~30 ml), we observed some dose-dependent EX4 effects on drinking behavior, including decreases in total volume consumed. Together, these findings suggest that activation of the GLP-1 receptor modulates the incentive properties of cues attributed with motivational significance

X-rays obtained from the cervical spine of a 69 year-old male in the anterior-posterior (3a) and in the lateral projection (3b).

<p>Metal needles indicate the most cranial and caudal part of the vagus nerve that could be visualized with the surgical approach to the carotid triangle. d = dorsal, l = left, r = right, v = ventral; scale bar = 10 mm.</p

Statistical comparison of vagus nerve diameters and cross-sections (mean value ± standard deviation).

<p>Statistical comparison of vagus nerve diameters and cross-sections (mean value ± standard deviation).</p

Images taken during dissection of the cervical vagus nerve (CVN) in the carotid sheath.

<p>Fig. 1a shows a left-sided CVN without branching and Fig. 1c-d CVN with branches on the left side (1b) or on the right side (1c,d). Arrows indicate the branches. C = (common or internal) carotid artery, J = internal jugular vein, O = superior venter of the omohyoideus muscle; cd = caudal, cr = cranial, m = medial, l = lateral; scale bar = 15 mm (a,b), 12 mm (c,d).</p

Hematoxylin-eosin stained histology samples obtained from the vagus nerve (2a) and from a vagus nerve branch (2b) for evaluating the existence of nerve fibers.

<p>A = arterial branch from the inferior thyroid artery, E = epineurium; scale bar = 500 μm.</p