UV RESISTANCE LOCUS 8-Mediated UV-B Response Is Required Alongside CRYPTOCHROME 1 for Plant Survival in Sunlight under Field Conditions

As sessile, photoautotrophic organisms, plants are subjected to fluctuating sunlight that includes potentially detrimental ultraviolet-B (UV-B) radiation. Experiments under controlled conditions have shown that the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8) controls acclimation and tolerance to UV-B in Arabidopsis thaliana; however, its long-term impact on plant fitness under naturally fluctuating environments remain poorly understood. Here, we quantified the survival and reproduction of different Arabidopsis mutant genotypes under diverse field and laboratory conditions. We found that uvr8 mutants produced more fruits than wild type when grown in growth chambers under artificial low-UV-B conditions but not under natural field conditions, indicating a fitness cost in the absence of UV-B stress. Importantly, independent double mutants of UVR8 and the blue light photoreceptor gene CRYPTOCHROME 1 (CRY1) in two genetic backgrounds showed a drastic reduction in fitness in the field. Experiments with UV-B attenuation in the field and with supplemental UV-B in growth chambers demonstrated that UV-B caused the cry1 uvr8 conditional lethal phenotype. Using RNA-seq data of field-grown single and double mutants, we explicitly identified genes showing significant statistical interaction of UVR8 and CRY1 mutations in the presence of UV-B in the field. They were enriched in Gene Ontology categories related to oxidative stress, photoprotection and DNA damage repair in addition to UV-B response. Our study demonstrates the functional importance of the UVR8-mediated response across life stages in natura, which is partially redundant with that of cry1. Moreover, these data provide an integral picture of gene expression associated with plant responses under field conditions.

Finding the most suitable puncture site for intraosseous access in term and preterm neonates: an ultrasound-based anatomical pilot study

The purpose of this prospective ultrasound-based pilot study was to identify the most suitable tibial puncture site for intraosseous (IO) access in term and preterm neonates, describe tibial dimensions at this site, and provide anatomical landmarks for rapid localization. We measured the tibial dimensions and distances to anatomical landmarks at puncture sites A (proximal: 10 mm distal to the tibial tuberosity; distal: 10 mm proximal to the malleolus medialis) and B (chosen by palpation of the pediatrician), in 40 newborns in four weight groups (< 1000 g; 1000-2000 g, 2000-3000 g, and 3000-4000 g). Sites were rejected if they fell short of the assumed safety distance to the tibial growth plate of 10 mm. If both A and B were rejected, puncture site C was determined sonographically at the maximum tibial diameter while maintaining the safety distance. Puncture site A violated the safety distance in 53% and 85% (proximally and distally, respectively) and puncture site B in 38% and 33%. In newborns weighing 3000-4000 g, at median (IQR), the most suitable puncture site at the proximal tibia was 13.0 mm (12.0-15.8) distal to the tuberosity and 6.0 mm (4.0-8.0) medial to the anterior rim of the tibia. The median (IQR) diameters at this site were 8.3 mm (7.9-9.1) (transverse) and 9.2 mm (8.9-9.8) (anterior-posterior). The diameters increased significantly with increasing weight.  Conclusion: This study adds concise, practical information on the implementation of IO access in neonatal patients: the tibial dimensions in newborns in four different weight groups and initial data on anatomical landmarks to easily locate the IO puncture site. The results may help implement IO access in newborns more safely. What is Known: • Intraosseous access is a feasible option for emergency administration of vital drugs and fluids in newborns undergoing resuscitation when an umbilical venous catheter is impossible to place. • Severe complications of IO access due to malpositioned IO needles have been reported in neonates. What is New: • This study reports the most suitable tibial puncture sites for IO access and the tibial dimensions, in newborns of four weight groups. • The results can help to implement safe IO access in newborns.

Neonatal simulation training decreases the incidence of chest compressions in term newborns

AIM OF THE STUDY

To determine the effectiveness of a multidimensional neonatal simulation-based medical education training programme on direct and indirect patient outcome parameters.

METHODS

This was a retrospective analytical study with a historical control group in a level II neonatal care unit (1,700 births per year). A multidimensional interdisciplinary training programme on neonatal resuscitation was implemented in 2015; pre-training (2012-2014) and post-training (2015-2019) eras were compared in terms of mortality (direct outcome) and the received intervention level immediately after birth (indirect outcome). Intervention levels were defined as follows: A) short-term non-invasive ventilation, B) prolonged non-invasive ventilation (>5 inflation breaths), C) chest compressions.

RESULTS

Of 13,950 neonates born during the study period, 826 full-term newborns received one of the three intervention levels for adaptation after birth. A total of 284 (34.4%) patients received short-term non-invasive ventilation (A), 477 (57.8%) had prolonged ventilation (B), and 65 (7.9%) chest compressions (C), respectively. Comparing the pre- and post-training eras, there was no significant reduction in mortality, and no significant changes were found in groups A or B. However, the risk for chest compressions (group C) decreased significantly from 0.91% in the pre-training era to 0.20% in the post-training era (p < 0.001).

CONCLUSION

Although there was no significant effect on neonatal mortality, regular interdisciplinary simulation training decreased the number of administered chest compressions immediately after birth. Further studies are needed to test indirect outcome-related parameters, such as frequency of chest compressions as a measure of effectiveness and impact of medical training.

Efficient Detection of Novel Nuclear Markers for Brassicaceae by Transcriptome Sequencing

The lack of DNA sequence information for most non-model organisms impairs the design of primers that are universally applicable for the study of molecular polymorphisms in nuclear markers. Next-generation sequencing (NGS) techniques nowadays provide a powerful approach to overcome this limitation. We present a flexible and inexpensive method to identify large numbers of nuclear primer pairs that amplify in most Brassicaceae species. We first obtained and mapped NGS transcriptome sequencing reads from two of the distantly related Brassicaceae species, Cardamine hirsuta and Arabis alpina, onto the Arabidopsis thaliana reference genome, and then identified short conserved sequence motifs among the three species bioinformatically. From these, primer pairs to amplify coding regions (nuclear protein coding loci, NPCL) and exon-primed intron-crossing sequences (EPIC) were developed. We identified 2,334 universally applicable primer pairs, targeting 1,164 genes, which provide a large pool of markers as readily usable genomic resource that will help addressing novel questions in the Brassicaceae family. Testing a subset of the newly designed nuclear primer pairs revealed that a great majority yielded a single amplicon in all of the 30 investigated Brassicaceae taxa. Sequence analysis and phylogenetic reconstruction with a subset of these markers on different levels of phylogenetic divergence in the mustard family were compared with previous studies. The results corroborate the usefulness of the newly developed primer pairs, e.g., for phylogenetic analyses or population genetic studies. Thus, our method provides a cost-effective approach for designing nuclear loci across a broad range of taxa and is compatible with current NGS technologies.

Molecular phylogenetics of New Caledonian Diospyros (Ebenaceae) using plastid and nuclear markers

To clarify phylogenetic relationships among New Caledonian species of Diospyros, sequences of four plastid markers (atpB, rbcL, trnK-matK and trnS-trnG) and two low-copy nuclear markers (ncpGS and PHYA) were analysed. New Caledonian Diospyros species fall into three clades, two of which have only a few members (1 or 5 species); the third has 21 closely related species for which relationships among species have been mostly unresolved in a previous study. Although species of the third group (NC clade III) are morphologically distinct and largely occupy different habitats, they exhibit little molecular variability. Diospyros vieillardii is sister to the rest of the NC clade III, followed by D. umbrosa and D. flavocarpa, which are sister to the rest of this clade. Species from coastal habitats of western Grande Terre (D. cherrieri and D. veillonii) and some found on coralline substrates (D. calciphila and D. inexplorata) form two well-supported subgroups. The species of NC clade III have significantly larger genomes than found in diploid species of Diospyros from other parts of the world, but they all appear to be diploids. By applying a molecular clock, we infer that the ancestor of the NC clade III arrived in New Caledonia around 9 million years ago. The oldest species are around 7 million years old and the youngest ones probably much less than 1 million years.