Explore the vast range of titles available.

Background Vasopressin/oxytocin (VP/OT)-type neuropeptides are well known for their roles as regulators of diuresis, reproductive physiology and social behaviour. However, our knowledge of their functions is largely based on findings from studies on vertebrates and selected protostomian invertebrates. Little is known about the roles of VP/OT-type neuropeptides in deuterostomian invertebrates, which are more closely related to vertebrates than protostomes. Results Here, we have identified and functionally characterised a VP/OT-type signalling system comprising the neuropeptide asterotocin and its cognate G-protein coupled receptor in the starfish (sea star) Asterias rubens , a deuterostomian invertebrate belonging to the phylum Echinodermata. Analysis of the distribution of asterotocin and the asterotocin receptor in A. rubens using mRNA in situ hybridisation and immunohistochemistry revealed expression in the central nervous system (radial nerve cords and circumoral nerve ring), the digestive system (including the cardiac stomach) and the body wall and associated appendages. Informed by the anatomy of asterotocin signalling, in vitro pharmacological experiments revealed that asterotocin acts as a muscle relaxant in starfish, contrasting with the myotropic actions of VP/OT-type neuropeptides in vertebrates. Furthermore, in vivo injection of asterotocin had a striking effect on starfish behaviour—triggering fictive feeding where eversion of the cardiac stomach and changes in body posture resemble the unusual extra-oral feeding behaviour of starfish. Conclusions We provide a comprehensive characterisation of VP/OT-type signalling in an echinoderm, including a detailed anatomical analysis of the expression of both the VP/OT-type neuropeptide asterotocin and its cognate receptor. Our discovery that asterotocin triggers fictive feeding in starfish provides important new evidence of an evolutionarily ancient role of VP/OT-type neuropeptides as regulators of feeding in animals.

Sulfakinin (SK)/cholecystokinin (CCK)-type neuropeptides regulate feeding and digestion in protostomes (e.g. insects) and chordates. Here, we characterised SK/CCK-type signalling for the first time in a non-chordate deuterostome – the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArSK/CCK1, ArSK/CCK2) derived from the precursor protein ArSK/CCKP act as ligands for an SK/CCK-type receptor (ArSK/CCKR) and these peptides/proteins are expressed in the nervous system, digestive system, tube feet, and body wall. Furthermore, ArSK/CCK1 and ArSK/CCK2 cause dose-dependent contraction of cardiac stomach, tube foot, and apical muscle preparations in vitro, and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens . Thus, an evolutionarily ancient role of SK/CCK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm.

Neuropeptides derived from larger precursor proteins are secreted as signalling molecules by neurons and regulate diverse physiological and behavioural processes in animals. Recently, we reported the discovery of ArCRZ (HNTFTMGGQNRWKAG-NH 2 ) and ArLQ (EEKTRFPKFMRW-NH 2 )—novel neuropeptides in the starfish Asterias rubens that are orthologs of arthropod corazonins and molluscan luqins, respectively. However, our efforts to generate antibodies to ArCRZ and ArLQ have been unsuccessful, precluding immunohistochemical analysis of their expression. Here, we investigated an alternative experimental approach for neuropeptide immunohistochemistry by generating antibodies to peptides corresponding to the C-terminal region of the precursor proteins. As proof of principle, we generated antibodies to the C-terminal region of the precursor of the vasopressin/oxytocin-type neuropeptide asterotocin and show that these reveal immunostaining in A. rubens that is very similar to that observed with asterotocin antibodies. Furthermore, antibodies to the C-terminal region of the ArCRZ precursor (ArCRZP) and the ArLQ precursor (ArLQP) produced patterns of immunostaining consistent, respectively, with the distribution of ArCRZP and ArLQP transcripts revealed by mRNA in situ hybridisation. Detailed immunohistochemical analysis revealed widespread expression of ArCRZP and ArLQP in A. rubens , including the central nervous system, digestive system and the body wall and its associated appendages (e.g. tube feet), providing a neuroanatomical framework for investigation and interpretation of the pharmacological actions of ArCRZ and ArLQ in A. rubens . Furthermore, our findings provide a basis for use of antibodies to the C-terminal region of neuropeptide precursor proteins in other species where the production of antibodies to the bioactive neuropeptides is unsuccessful.

Somatostatin (SS) and allatostatin-C (ASTC) are inhibitory neuropeptides in chordates and protostomes, respectively, which hitherto were identified as orthologs. However, echinoderms have two SS/ASTC-type neuropeptides (SS1 and SS2), and here, our analysis of sequence data indicates that SS1 is an ortholog of ASTC and SS2 is an ortholog of SS. The occurrence of both SS-type and ASTC-type neuropeptides in echinoderms provides a unique context to compare their physiological roles. Investigation of the expression and actions of the ASTC-type neuropeptide ArSS1 in the starfish Asterias rubens revealed that it causes muscle contraction (myoexcitation), contrasting with myoinhibitory effects of the SS-type neuropeptide ArSS2. Our findings suggest that SS-type and ASTC-type neuropeptides are paralogous and originated by gene duplication in a common ancestor of the Bilateria, with only one type being retained in chordates (SS) and protostomes (ASTC) but with both types being retained in echinoderms. Loss of ASTC-type and SS-type neuropeptides in chordates and protostomes, respectively, may have been due to their functional redundancy as inhibitory regulators of physiological processes. Conversely, the retention of both neuropeptide types in echinoderms may be a consequence of the evolution of a myoexcitatory role for ASTC-type neuropeptides mediated by as yet unknown signaling mechanisms.

Abstract Cholecystokinin (CCK) / sulfakinin (SK)-type neuropeptides regulate feeding and digestion in chordates and protostomes (e.g. insects). Here we characterised CCK/SK-type signalling for the first time in a non-chordate deuterostome - the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArCCK1, ArCCK2) derived from the precursor protein ArCCKP act as ligands for a CCK/SK-type receptor (ArCCKR) and are expressed in the nervous system, digestive system, tube feet and body wall. Furthermore, ArCCK1 and ArCCK2 cause dose-dependent contraction of cardiac stomach, tube foot and body wall apical muscle preparations in vitro and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens. Thus, an evolutionarily ancient role of CCK/SK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm. Competing Interest Statement The authors have declared no competing interest. Footnotes * E-mail addresses: Ana. B. Tinoco: a.b.tinoco{at}qmul.ac.uk, Antón Barreiro-Iglesias: anton.barreiro{at}usc.es, Luis Alfonso Yañez-Guerra: L.Yanez-Guerra{at}exeter.ac.uk, Jérôme Delroisse: Jerome.delroisse{at}umons.ac.be, Ya Zhang: yazhang94{at}gmail.com, Elizabeth F. Gunner: elizabethis{at}sky.com, Cleidiane Zampronio: c.g.zampronio{at}warwick.ac.uk, Michaela Egertová: m.egertova{at}qmul.ac.uk, Alexandra M. Jones: alex.jones{at}warwick.ac.uk

Traumatic meningeal enhancement (TME) is a novel biomarker observed on post-contrast fluid-attenuated inversion recovery (FLAIR) in patients who undergo contrast-enhanced magnetic resonance imaging (MRI) after suspected traumatic brain injury (TBI). TME may be seen on acute MRI despite the absence of other trauma-related intracranial findings. In this study we compare conspicuity of TME on FLAIR post-contrast and T1 weighted imaging (T1WI) post-contrast, and investigate if TME is best detected by FLAIR post-contrast or T1WI post-contrast sequences. Subjects selected for analysis enrolled in the parent study (NCT01132937) in 2016 and underwent contrast-enhanced MRI within 48 hours of suspected TBI. Two blinded readers reviewed pairs of pre- and post-contrast T1WI and FLAIR images for presence or absence of TME. Discordant pairs between the two blinded readers were reviewed by a third reader. Cohen’s kappa coefficient was used to calculate agreement. Twenty-five subjects (15 males, 10 females; median age 48 (Q1:35-Q3:62; IQR: 27)) were included. The blinded readers had high agreement for presence of TME on FLAIR (Kappa of 0.90), but had no agreement for presence of TME on T1WI (Kappa of -0.24). The FLAIR and T1WI scans were compared among all three readers and 62% of the cases positive on FLAIR could be seen on T1WI. However, 38% of the cases who were read positive on FLAIR for TME were read negative for TME on T1WI. Conspicuity of TME is higher on post-contrast FLAIR MRI than on post-contrast T1WI. TME as seen on post-contrast FLAIR MRI can aid in the identification of patients with TBI.

Morphological trait matching between species affects resource partitioning in mutualistic systems. Yet, the determinants of spatial variation in trait matching remain largely unaddressed. Here, we generate a hypothesis that is based on the geographical distributions of species morphologies. To illustrate our hypothesis, as a study system we use hummingbirds in the tropical Andes. Hummingbirds with specialized morphologies (i.e., long or curved bills) may forage on flowers that are inaccessible to hummingbirds with generalized bill morphologies (i.e., small-to-medium-sized bills with no curvature), yet the vast majority of hummingbirds have generalized bill morphologies. Thus, we propose that trait matching across space is determined by the distribution of morphological specialists. In the Andes, we observe the richness of specialized hummingbird morphotypes to peak at high and low elevations. Therefore, we hypothesize that trait matching should be most influential in predicting pairwise interactions at high and low elevations. We illustrate our hypothesis by field observations along an elevational gradient in Podocarpus National Park (Ecuador). Using Bayesian hierarchical modeling of interaction frequencies in combination with network analyzes, we found that hummingbirds at high and low elevations contributed to resource partitioning by foraging on morphologically close-matching flowers. Moreover, at high and low elevations, hummingbirds with specialized morphologies showed a stronger tendency to visit close-matching flowers than morphological nonspecialists did. In contrast, at mid-elevations, hummingbirds were not attracted to morphologically close-matching flowers. These results suggest that the spatial distribution of specialized morphotypes determines trait matching and the partitioning of interactions within hummingbird–plant communities.

Across the world, millions of couples get married each year. One of the strongest predictors of whether partners will remain in their relationship is their reported satisfaction. Marital satisfaction is commonly found to be a key predictor of both individual and relational well-being. Despite its importance in predicting relationship longevity, there are relatively few empirical research studies examining predictors of marital satisfaction outside of a Western context. To address this gap in the literature and complete the existing knowledge about global predictors of marital satisfaction, we used an open-access database of self-reported assessments of self-reported marital satisfaction with data from 7178 participants representing 33 different countries. The results showed that sex, age, religiosity, economic status, education, and cultural values were related, to various extents, to marital satisfaction across cultures. However, marriage duration, number of children, and gross domestic product (GDP) were not found to be predictors of marital satisfaction for countries represented in this sample. While 96% of the variance of marital satisfaction was attributed to individual factors, only 4% was associated with countries. Together, the results show that individual differences have a larger influence on marital satisfaction compared to the country of origin. Findings are discussed in terms of the advantages of conducting studies on large cross-cultural samples.

Aim: Species interaction networks are known to vary in structure over large spatial scales. We investigated the hypothesis that environmental factors affect interaction network structure by influencing the functional diversity of ecological communities. Notably, we expect more functionally diverse communities to form interaction networks with a higher degree of niche partitioning. Location: Americas. Time period: Current. Major taxa studied: Hummingbirds and their nectar plants. Methods: We used a large dataset comprising 74 quantitative plant–hummingbird interaction networks distributed across the Americas, along with morphological trait data for 158 hummingbird species. First, we used a model selection approach to evaluate associations between the environment (climate, topography and insularity), species richness and hummingbird functional diversity as predictors of network structure (niche partitioning, i.e., complementary specialization and modularity). Second, we used structural equation models (SEMs) to ask whether environmental predictors and species richness affect network structure directly and/or indirectly through their influence on hummingbird functional diversity. For a subset of 28 networks, we additionally evaluated whether plant functional diversity was associated with hummingbird functional diversity and network structure. Results: Precipitation, insularity and plant richness, together with hummingbird functional diversity (specifically, functional dispersion), were consistently strong predictors of niche partitioning in plant–hummingbird networks. Moreover, SEMs showed that environmental predictors and plant richness affected network structure both directly and indirectly through their effects on hummingbird functional diversity. Plant functional diversity, however, was unrelated to hummingbird functional diversity and network structure. Main conclusions: We reveal the importance of hummingbird functional diversity for niche partitioning in plant–hummingbird interaction networks. The lack of support for similar effects for plant functional diversity potentially indicates that consumer functional diversity might be more important for structuring interaction networks than resource functional diversity. Changes in pollinator functional diversity are therefore likely to alter the structure of interaction networks and associated ecosystem functions.

Background: Nance–Horan syndrome (NHS) is a rare, frequently underdiagnosed, X-linked disease caused by mutations in the NHS gene. In males, it causes bilateral dense pediatric cataracts, dental anomalies, and facial dysmorphisms. Females traditionally have a more subtle phenotype with discrete lens opacities as an isolated feature. The objective of this case report is to describe a novel variant in NHS, as well as to discuss genotype–phenotype correlations. Methods: Whole-exome sequencing was performed in 3 affected individuals (2 males and 1 female) with pediatric cataracts from the same family, as well as in 2 unaffected members from the same family. Ophthalmological and clinical genetic evaluations were conducted. Results: The likely pathogenic variant c.3333del (p.Phe1111Leufs*9) was found in all affected individuals, as well as in one unaffected female family member. Our family was initially diagnosed with isolated hereditary cataracts, but only after the sequencing results was the phenotype revealed, with the systemic features being identified. Conclusions: This reinforces the importance of genetic testing of bilateral familial pediatric cataracts, especially since systemic features such as dental anomalies and intellectual disability may take years before they develop. Not only did genetic testing help to identify extraocular features, but it also made possible accurate family counseling essential in all pediatric cataract cases.