Selection maintains a nonadaptive floral polyphenism.

Adaptive phenotypic plasticity evolves in response to the contrasting selection pressures that arise when organisms face environmental heterogeneity. Despite its importance for understanding how organisms successfully cope with environmental change, adaptive plasticity is often assumed but rarely demonstrated. We study here the adaptive nature of the extreme seasonal within-individual floral polyphenism exhibited by the crucifer Moricandia arvensis, a Mediterranean species that produces two different types of flowers depending on the season of the year. During spring, this species has large, cross-shaped, lilac flowers, while during summer, it develops small, rounded, white flowers. Although floral polyphenism was associated with increased plant fitness, selection moved floral traits away from their local optimum values during the harsh summer. This result strongly suggests that floral polyphenism is not adaptive in M. arvensis. The main factor selecting against floral polyphenism was pollinators, as they select for the same floral morph in all environments. Despite not being adaptive, floral polyphenism occurs throughout the entire distribution range of M. arvensis and has probably been present since the origin of the species. To solve this paradox, we explored the factors causing floral polyphenism, finding that floral polyphenism was triggered by summer flowering. Summer flowering was beneficial because it led to extra seed production and was favored by adaptive plasticity in leaf functional traits. Taken together, our study reveals a complex scenario in which nonadaptive floral polyphenism has been indirectly maintained over M. arvensis evolutionary history by selection operating to favor summer flowering. Our study provides thus strong evidence that nonadaptive plasticity may evolve as a byproduct of colonizing stressful environments.

Implementation of the Versius robotic surgical system for thoracic surgery: first clinical evaluation of feasibility and performance.

OBJECTIVES: The aim of this study is to demonstrate the ability of the Versius surgical system to successfully and safely complete a range of thoracic procedures aligned with Stage 2a (Development) of the Idea, Development, Exploration, Assessment and Long-term follow-up framework for surgical innovation. METHODS: This prospective study included the first 30 consecutive patients who underwent robotic surgery with Versius by 2 surgeons without prior robotic experience between 1 April 2023 and 30 December 2023 [25 lung resections (wedge, segmentectomy and lobectomy) and 5 thymectomies]. There were no specific predetermined selection criteria for each case. The primary outcome was safe completion of the procedure without unplanned conversion. Secondary outcomes included intraoperative and postoperative complications, intraoperative device-related outcomes and pathology results. RESULTS: Twenty-eight (93.3%) cases were completed without conversion. Both conversions were to thoracoscopy, one due to a 'console alarm' and the other due to pulmonary artery bleeding. In lung resections, median console time was 103 (90-129) min. Five (20%) patients experienced postoperative complications, most frequent was persistent air leak (16%). Median length-of-stay was 3 (2-4) days. Neither readmissions nor mortality was observed. In thymectomies, no intraoperative or postoperative complications, readmissions, reinterventions or mortality were observed. Median console time was 77 (75-89) min and median length of stay was 1 (1-1) day. CONCLUSIONS: This phase 2a IDEAL-D study confirms lung resections and thymectomies are feasible with the use of Versius system, laying the foundation for larger phase 2b and 3 clinical studies within the IDEAL-D framework.

Prevalence of Dry Eye Disease in Laser-Assisted In Situ Keratomileusis Candidates.

OBJECTIVE: To evaluate the prevalence of dry eye disease (DED) in laser-assisted in situ keratomileusis (LASIK) candidates. METHODS: A chart review of consecutive LASIK candidates who underwent full ocular surface work-up was performed, including ocular surface disease index (OSDI), noninvasive tests (noninvasive tear breakup time [ni-TBUT], tear meniscus height, lipid layer thickness, and meibography), and invasive tests (Schirmer test I, fluorescein TBUT, corneal staining, and meibomian gland [MG] expressibility). The prevalence of DED was calculated according to the Dry Eye Workshop II (DEWS II), and Japanese and Asia Dry Eye Society (JDES/ADES) criteria. RESULTS: In total, 135 patients (270 eyes) were evaluated. The mean age was 32.6±8.3 years, and 62.9% were women (n=85); 19 patients (15.4%) wore contact lenses, and 31 patients (23.8%) used artificial tears. The mean OSDI was 18.2±16.9, which was abnormal in 54.1% (n=62). Inferior lid MG dropout was the sign with the highest percentage of abnormal results (61.5%; n=83). There were no differences between men and women in any test except for ni-TBUT (6.3±0.3 and 7.2±0.2, respectively; P=0.002). Dry eye disease prevalence was 25.9% and 53.3%, according to JDES/ADES and DEWS II criteria, respectively. The only significant risk factor for DED was artificial tear use for both DEWS II (odds ratio [OR]=3.5, confidence interval [CI] [1.35-9.39]) and JDES/ADES (OR=2.58, CI [1.03-6.48]). CONCLUSIONS: This study found a high prevalence of DED and abnormalities in LASIK candidates and highlights the importance of ocular surface evaluation before photorefractive surgery.

The stringent response regulates the poly-ß-hydroxybutyrate (PHB) synthesis in Azotobacter vinelandii.

The stringent response exerted by (p)ppGpp and RNA-polymerase binding protein DksA regulates gene expression in diverse bacterial species. To control gene expression (p)ppGpp, synthesized by enzymes RelA and SpoT, interacts with two sites within the RNA polymerase; site 1, located in the interphase between subunits ß' and ω (rpoZ), and site 2 located in the secondary channel that is dependent on DksA protein. In Escherichia coli, inactivation of dksA results in a reduced sigma factor RpoS expression. In Azotobacter vinelandii the synthesis of polyhydroxybutyrate (PHB) is under RpoS regulation. In this study, we found that the inactivation of relA or dksA, but not rpoZ, resulted in a negative effect on PHB synthesis. We also found that the dksA, but not the relA mutation reduced both rpoS transcription and RpoS protein levels, implying that (p)ppGpp and DksA control PHB synthesis through different mechanisms. Interestingly, despite expressing rpoS from a constitutive promoter in the dksA mutant, PHB synthesis was not restored to wild type levels. A transcriptomic analysis in the dksA mutant, revealed downregulation of genes encoding enzymes needed for the synthesis of acetyl-CoA, the precursor substrate for PHB synthesis. Together, these data indicate that DksA is required for optimal expression of RpoS which in turn activates transcription of genes for PHB synthesis. Additionally, DksA is required for optimal transcription of genes responsible for the synthesis of precursors for PHB synthesis.

Hydrogel Augmentation of the Lumbar Intervertebral Disc: An Early Feasibility Study of a Treatment for Discogenic Low Back Pain.

PURPOSE: To assess the safety and effectiveness of intradiscal hydrogel in patients with chronic low back pain (CLBP) due to degenerative disc disease (DDD) refractory to conventional medical management. MATERIALS AND METHODS: Twenty patients aged 22-69 years with numerical rating scale (NRS) pain of ≥4 were enrolled. All patients with CLBP resulting from DDD confirmed by imaging and discography received injections of hydrogel (Hydrafil Intervertebral Disc Augmentation; ReGelTec, Baltimore, Maryland) at 1 or 2 lumbar levels (29 levels treated) from August to December 2020. The primary safety end point was freedom from serious adverse events (SAEs). The primary performance end point was successful gel delivery into the desired disc. Patients were also assessed on the NRS as well as the Oswestry disability index (ODI). RESULTS: Nineteen patients were followed up at a mean of 131 days, and 1 patient was lost to follow-up. Preliminary results showed significant reductions in median NRS back pain from 7 (range 4-10) to 1 (range 0-8) (P <.0001) and median ODI scores from 54 (range 22-58) to 2 (range 0-58) (P <.0001) at 6 months of follow-up. There were 5 SAEs, and 4 of the 2 were determined to be associated with treatment. CONCLUSIONS: This early feasibility study showed that the hydrogel implant was safe with no persistently symptomatic SAEs, and demonstrated effectiveness with significant reduction in pain and improvement in function when used to treat painful DDD and CLBP.

Inheritance pattern of tetraploids pummelo, mandarin, and their interspecific hybrid sour orange is highly influenced by their phylogenomic structure.

Citrus polyploidy is associated with a wide range of morphological, genetic, and physiological changes that are often advantageous for breeding. Citrus triploid hybrids are very interesting as new seedless varieties. However, tetraploid rootstocks promote adaptation to different abiotic stresses and promote resilience. Triploid and tetraploid hybrids can be obtained through sexual hybridizations using tetraploid parents (2x × 4x, 4x × 2x, or 4x × 4x), but more knowledge is needed about the inheritance pattern of tetraploid parents to optimize the efficiency of triploid varieties and tetraploid rootstock breeding strategies. In this work, we have analyzed the inheritance pattern of three tetraploid genotypes: 'Chandler' pummelo (Citrus maxima) and 'Cleopatra' mandarin (Citrus reticulata), which represent two clear examples of autotetraploid plants constituted by the genome of a single species, and the 'Sevillano' sour orange, which is an allotetraploid interspecific hybrid between C. maxima and C. reticulata. Polymorphic simple sequence repeat (SSR) and single-nucleotide polymorphism (SNP) markers were used to estimate parental heterozygosity restitution, and allele frequencies for centromeric loci were used to calculate the preferential pairing rate related to the proportion of disomic and tetrasomic segregation. The tetraploid pummelo and mandarin displayed tetrasomic segregation. Sour orange evidenced a clear intermediate inheritance for five of the nine chromosomes (1, 2, 5, 7, and 8), a slight tendency toward tetrasomic inheritance on chromosome 3, and intermediate inheritance with a tendency toward disomy for chromosomes 4, 6, and 9. These results indicate that the interspecific versus intraspecific phylogenomic origin affects preferential pairing and, therefore, the inheritance patterns. Despite its high level of heterozygosity, the important preferential chromosome pairing observed in sour orange results in a limited diversity of the genotypic variability of its diploid gametes, and consequently, a large part of the genetic value of the original diploid sour orange is transferred to the tetraploid progenies.

The role of phenotypic plasticity in shaping ecological networks.

Plasticity-mediated changes in interaction dynamics and structure may scale up and affect the ecological network in which the plastic species are embedded. Despite their potential relevance for understanding the effects of plasticity on ecological communities, these effects have seldom been analysed. We argue here that, by boosting the magnitude of intra-individual phenotypic variation, plasticity may have three possible direct effects on the interactions that the plastic species maintains with other species in the community: may expand the interaction niche, may cause a shift from one interaction niche to another or may even cause the colonization of a new niche. The combined action of these three factors can scale to the community level and eventually expresses itself as a modification in the topology and functionality of the entire ecological network. We propose that this causal pathway can be more widespread than previously thought and may explain how interaction niches evolve quickly in response to rapid changes in environmental conditions. The implication of this idea is not solely eco-evolutionary but may also help to understand how ecological interactions rewire and evolve in response to global change.

Aislamiento enzimático de protoplastos a partir del mesófilo de vitroplantas de Gynerium sagittatum Aubl. Beauv. cv. "Criolla"

Gynerium sagittatum es una gramínea ampliamente utilizada en la costa Caribe colombiana como fuente de fibra natural para la elaboración de artesanías, particularmente por la comunidad Zenú. En la presente investigación se evaluó el efecto de diferentes concentraciones de enzimas: celulasa y macerozima a diferentes tiempos de incubación y sus interacciones en el aislamiento de protoplastos. Los protoplastos se obtuvieron del mesófilo foliar de vitroplantas de G. sagittatum expuesto a combinaciones enzimáticas de celulasa (1.5 y 2.0%), con macerozima (0.3, 0.6 y 0.9%), durante 3, 6 y 9 horas de incubación, para un total de 18 tratamientos con 5 réplicas cada uno. Los mayores números de protoplastos aislados correspondieron a T18 (2.0% celulasa, 0.9% macerozima), T12 (2.0% de celulasa, 0.3% macerozima), T3 (1.5% de celulasa, 0.3% de macerozima) y T6 (1.5% de celulasa, 0.6% de macerozima) por 9 horas de incubación cada uno, con valores de 88.625, 83.000, 75.000 y 53.375 protoplastos/mL respectivamente. El tiempo de incubación fue significativo en el aislamiento de los protoplastos (p<0.05). Las predicciones entre factores mostraron que una interacción de 2.0% de celulasa y 0.9% de macerozima permite obtener 44.302 protoplastos/mL, mientras que las interaciciones tiempo de incubación-celulasa y tiempo de incubación-macerozima mostraron que es posible obtener 72.073 y 71.212 protoplastos/mL con 2.0% de celulasa y 0.9% macerozima por 9 horas de incubación cada una respectivamente. Los resultados indican que la aplicación de estas enzimas permite obtener cantidades considerables de protoplastos de G. sagittatum a partir de explantes cultivados in vitro.

Gynerium sagittatum is a graminaceous plant widely used in the Caribbean coast of Colombia as a natural fiber source for the elaboration of handicrafts, particularly by the Zenú community. In the present investigation, the effect of different concentrations of cellulase and macerozyme enzymes at different incubation times and their interaction in the isolation of protoplasts was evaluated. Protoplasts were obtained from leaf mesophyll of G. sagittatum vitroplants exposed to enzymatic combinations of cellulase (1.5 and 2.0%), with macerozyme (0.3, 0.6 and 0.9%), for 3, 6 and 9 hours of incubation, for a total of 18 treatments with 5 replicates each. The highest numbers of isolated protoplasts corresponded to T18 (2.0% cellulase, 0.9% macerozyme), T12 (2.0% cellulase, 0.3% macerozyme), T3 (1.5% cellulase, 0.3% macerozyme) and T6 (1.5% cellulase, 0.6% macerozyme); at 9 hours incubation. The protoplast number for these treatments were: 88.625, 83.000, 75.000 and 53.375 protoplasts/mL respectively. Incubation time was significant in the isolation of protoplasts (p<0.05). The predictions between the factors showed that with an interaction of 2.0% cellulase and 0.9% macerozyme it is possible to obtain 44.302 protoplasts/mL, likewise, the incubation time-cellulase and incubation time-macerozyme interactions showed that it is possible to obtain 72.073 and 71.212 protoplasts/mL with 2.0% cellulase and 0.9% macerozyme for 9 hours of incubation respectively. The results indicate that the use of these enzymes and time, allows the isolation of of protoplasts from G. sagittatum in vitro plants.

Genotyping by Sequencing for SNP-Based Linkage Analysis and the Development of KASPar Markers for Male Sterility and Polyembryony in Citrus.

Polyembryony and male sterility (MS) are essential characters for citrus breeding. MS, coupled with parthenocarpy, allows for addressing the diversification of diploid seedless mandarin varieties, and nucleocytoplasmic MS is the most prevalent system. Polyembryony limits the use of seed parents in scion breeding programs, and the recovery of monoembryonic hybrids to be used as female parents is a crucial pre-breeding component. The objectives of this work were the identification of SNPs closely linked with the genes implied in these traits for marker-assisted selection. Genotyping by sequencing was used to genotype 61 diploid hybrids from an F1 progeny recovered from crossing 'Kiyomi' and 'Murcott' tangors. A total of 6444 segregating markers were identified and used to establish the two parental genetic maps. They consisted of 1374 and 697 markers encompassing 1416.287 and 1339.735 cM for 'Kiyomi' and 'Murcott', respectively. Phenotyping for MS and polyembryony was performed. The genotype-trait association study identified a genomic region on LG8 which was significantly associated with MS, and a genomic region on LG1 which was significantly associated with polyembryony. Annotation of the identified region for MS revealed 19 candidate genes. One SNP KASPar marker was developed and fully validated for each trait.