High levels of fluctuating asymmetry in isolated stickleback populations

Background Fluctuating asymmetry (FA), defined as small random deviations from the ideal bilateral symmetry, has been hypothesized to increase in response to both genetic and environmental stress experienced by a population. We compared levels of FA in 12 bilateral meristic traits (viz. lateral-line system neuromasts and lateral plates), and heterozygosity in 23 microsatellite loci, among four marine (high piscine predation risk) and four pond (zero piscine predation risk) populations of nine-spined sticklebacks (Pungitius pungitius). Results Pond sticklebacks had on average three times higher levels of FA than marine fish and this difference was highly significant. Heterozygosity in microsatellite markers was on average two times lower in pond (HE ≈ 0.3) than in marine (HE ≈ 0.6) populations, and levels of FA and heterozygosity were negatively correlated across populations. However, after controlling for habitat effect on heterozygosity, levels of FA and heterozygosity were uncorrelated. Conclusions The fact that levels of FA in traits likely to be important in the context of predator evasion were elevated in ponds compared to marine populations suggests that relaxed selection for homeostasis in ponds lacking predatory fish may be responsible for the observed habitat difference in levels of FA. This inference also aligns with the observation that the levels of genetic variability across the populations did not explain population differences in levels of FA after correcting for habitat effect. Hence, while differences in strength of selection, rather than in the degree of genetic stress could be argued to explain habitat differences in levels of FA, the hypothesis that increased FA in ponds is caused by genetic stress cannot be rejected.Peer reviewe

Chromatin modifier developmental pluripotency associated factor 4 (DPPA4) is a candidate gene for alcohol-induced developmental disorders

Peer reviewe

Exposure to specific tumour necrosis factor inhibitors and risk of demyelinating and inflammatory neuropathy in cohorts of patients with inflammatory arthritis : a collaborative observational study across five Nordic rheumatology registers

Funding Information: This work was supported by NordForsk and the Foundation for Research in Rheumatology (Foreum) and Vinnova. The research infrastructure was supported by funds from the Swedish Research Council, the Swedish Heart Lung Foundation and the Swedish Cancer Society, and funds from Region Stockholm-Karolinska Institutet (ALF). The Center for Treatment of Rheumatic and Musculoskeletal Diseases (REMEDY) (Norway) is funded as a Centre for Clinical Treatment Research by the Research Council of Norway (project 328657). Publisher Copyright: © 2023 Author(s) (or their employer(s)). Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Objective To compare incidences of neuroinflammatory events, including demyelinating disease (DML), inflammatory polyneuropathies (IPN) and multiple sclerosis (MS), in patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA; including psoriatic arthritis) starting a tumour necrosis factor inhibitor (TNFi), investigating whether monoclonal TNFi antibodies (other TNFis (oTNFis)) confer higher risk than etanercept. Methods This is an observational cohort study including patients from the five Nordic countries starting a TNFi in 2001-2020. Time to first neuroinflammatory event was identified through register linkages. We calculated crude incidence rates (cIR) per 1000 person-years and used multivariable-adjusted Cox regression to compare incidences of neuroinflammatory events overall and for DML, IPN and MS with oTNFi versus etanercept. We further examined individual TNFis and indications. Results 33 883 patients with RA and 28 772 patients with SpA were included, initiating 52 704 and 46 572 treatment courses, respectively. In RA, we observed 135 neuroinflammatory events (65% DML) with cIR of 0.38 with oTNFi and 0.34 with etanercept. The HR of oTNFi versus etanercept was 1.07 (95% CI 0.74 to 1.54) for any neuroinflammatory event, 0.79 (95% CI 0.51 to 1.22) for DML, 2.20 (95% CI 1.05 to 4.63) for IPN and 0.73 (95% CI 0.34 to 1.56) for MS. In SpA, we observed 179 events (78% DML) with cIR of 0.68 with oTNFi and 0.65 with etanercept. The HR for any neuroinflammatory event, DML, IPN and MS was 1.06 (95% CI 0.75 to 1.50), 1.01 (95% CI 0.68 to 1.50), 1.28 (95% CI 0.61 to 2.69) and 0.94 (95% CI0.53 to 1.69), respectively. Conclusion The cIRs of neuroinflammatory events are higher in SpA than in RA, but the choice of specific TNFi does not seem to play an important role in the risk of neuroinflammatory events.Peer reviewe

Real-World Six- and Twelve-Month Drug Retention, Remission, and Response Rates of Secukinumab in 2,017 Patients With Psoriatic Arthritis in Thirteen European Countries

Objective There is a lack of real-life studies on interleukin-17 (IL-17) inhibition in psoriatic arthritis (PsA). We assessed real-life 6- and 12-month effectiveness (i.e., retention, remission, low disease activity [LDA], and response rates) of the IL-17 inhibitor secukinumab in PsA patients overall and across 1) number of prior biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs), 2) years since diagnosis, and 3) European registries. Methods Thirteen quality registries in rheumatology participating in the European Spondyloarthritis Research Collaboration Network provided longitudinal, observational data collected as part of routine care for secondary use. Data were pooled and analyzed with Kaplan-Meier plots, log rank tests, Cox regression, and multiple linear and logistic regression analyses. Results A total of 2,017 PsA patients started treatment with secukinumab between 2015 and 2018. Overall secukinumab retention rates were 86% and 76% after 6 and 12 months, respectively. Crude (LUNDEX adjusted) 6-month remission/LDA (LDA including remission) rates for the 28-joint Disease Activity Index for Psoriatic Arthritis, the Disease Activity Score in 28 joints using the C-reactive protein level, and the Simplified Disease Activity Index (SDAI) were 13%/46% (11%/39%), 36%/55% (30%/46%), and 13%/56% (11%/47%), and 12-month rates were 11%/46% (7%/31%), 39%/56% (26%/38%), and 16%/62% (10%/41%), respectively. Clinical Disease Activity Index remission/LDA rates were similar to the SDAI rates. Six-month American College of Rheumatology 20%/50%/70% improvement criteria responses were 34%/19%/11% (29%/16%/9%); 12-month rates were 37%/21%/11% (24%/14%/7%). Secukinumab effectiveness was significantly better for b/tsDMARD-naive patients, similar across time since diagnosis (4 years), and varied significantly across the European registries. Conclusion In this large real-world study on secukinumab treatment in PsA, 6- and 12-month effectiveness was comparable to that in previous observational studies of tumor necrosis factor inhibitors. Retention, remission, LDA, and response rates were significantly better for b/tsDMARD-naive patients, were independent of time since diagnosis, and varied significantly across the European countries.Peer reviewe

Fgfr1 regulates patterning of the pharyngeal region

Development of the pharyngeal region depends on the interaction and integration of different cell populations, including surface ectoderm, foregut endoderm, paraxial mesoderm, and neural crest. Mice homozygous for a hypomorphic allele of Fgfr1 have craniofacial defects, some of which appeared to result from a failure in the early development of the second branchial arch. A stream of neural crest cells was found to originate from the rhombomere 4 region and migrate toward the second branchial arch in the mutants. Neural crest cells mostly failed to enter the second arch, however, but accumulated in a region proximal to it. Both rescue of the hypomorphic Fgfr1 allele and inactivation of a conditional Fgfr1 allele specifically in neural crest cells indicated that Fgfr1 regulates the entry of neural crest cells into the second branchial arch non-cell-autonomously. Gene expression in the pharyngeal ectoderm overlying the developing second branchial arch was affected in the hypomorphic Fgfr1 mutants at a stage prior to neural crest entry. Our results indicate that Fgfr1 patterns the pharyngeal region to create a permissive environment for neural crest cell migration

Data from: Brain plasticity over the metamorphic boundary: carry-over effect of larval environment on froglet brain development

Brain development shows high plasticity in response to environmental heterogeneity. However, it is unknown how environmental variation during development may affect brain architecture across life history switch points in species with complex life cycles. Previously, we showed that predation and competition affect brain development in common frog (Rana temporaria) tadpoles. Here, we studied if larval environment had carry-over effects in brains of metamorphs. Tadpoles grown at high density had large optic tecta at metamorphosis, while tadpoles grown under predation risk had small diencephala. We found that larval density had a carry-over effect on froglet optic tectum size, while the effect of larval predation risk had vanished by metamorphosis. We discuss the possibility that the observed changes may be adaptive, reflecting the needs of an organism in given environmental and developmental contexts

metamorph brains

Experimental treatments included low and high larval density, crossed with the presence and absence of a caged predator. 100 tadpoles from each of the 12 clutches were pooled into a bucket and allocated to each tank (high density = 50 tadpoles/tank; low density = 10 tadpoles/tank). In tanks with the predator treatments, one dragonfly larva (Aeshna sp.) was placed in a cylindrical cage (diameter 8 cm; height 21 cm) made of transparent plastic film with a double net bottom (mesh size 1.5 mm) and hung 6 cm over the tank bottom. This allowed tadpoles to receive both visual and chemical cues from the predator, while the predator was unable to actually prey on tadpoles. In the no-predator treatment, the cage was left empty. During the experiment, tadpoles relied on the initial resources provided (leaves, rabbit pellets), as well as subsequent algal growth. Each treatment combination was replicated eight times, resulting in a total of 32 experimental units. 143 metamorphs (four to five per tank) were used for analyses. Formalin fixed metamorphs were weighed with a digital balance. After dissection, dorsal and right lateral views of brains were photographed with a digital camera connected to a dissecting microscope. We could only measure two dimensions for each brain part (length and width of telencephalon, diencephalon and optic tectum, and height and width of medulla oblongata) because some of the borders of the brain parts could not be identified accurately. Measurements were taken from digital photographs using tpsDig 1.37 software, and were defined as the greatest distance enclosed by the given structure in the given direction. All brains were photographed and measured three times. Repeatability of different brain measurements was high (R = 0.71 – 0.96 [mean = 0.86])

FGFR1 is independently required in both developing mid- and hindbrain for sustained response to isthmic signals

Fibroblast growth factors (FGFs) are signaling molecules of the isthmic organizer, which regulates development of the midbrain and cerebellum. Tissue-specific inactivation of one of the FGF receptor (FGFR) genes, Fgfr1, in the midbrain and rhombomere 1 of the hindbrain of mouse embryos results in deletion of the inferior colliculi in the posterior midbrain and vermis of the cerebellum. Analyses of both midbrain–hindbrain and midbrain-specific Fgfr1 mutants suggest that after establishment of the isthmic organizer, FGFR1 is needed for continued response to the isthmic signals, and that it has direct functions on both sides of the organizer. In addition, FGFR1 appears to modify cell adhesion properties critical for maintaining a coherent organizing center. This may be achieved by regulating expression of specific cell-adhesion molecules at the midbrain–hindbrain border

Metamorphs body weight

143 metamorphs (four to five per tank) were used for analyses. Formalin fixed metamorphs were weighed with a digital balance