Evolution and genetic architecture of sex-limited polymorphism in cuckoos.

Sex-limited polymorphism has evolved in many species including our own. Yet, we lack a detailed understanding of the underlying genetic variation and evolutionary processes at work. The brood parasitic common cuckoo (Cuculus canorus) is a prime example of female-limited color polymorphism, where adult males are monochromatic gray and females exhibit either gray or rufous plumage. This polymorphism has been hypothesized to be governed by negative frequency-dependent selection whereby the rarer female morph is protected against harassment by males or from mobbing by parasitized host species. Here, we show that female plumage dichromatism maps to the female-restricted genome. We further demonstrate that, consistent with balancing selection, ancestry of the rufous phenotype is shared with the likewise female dichromatic sister species, the oriental cuckoo (Cuculus optatus). This study shows that sex-specific polymorphism in trait variation can be resolved by genetic variation residing on a sex-limited chromosome and be maintained across species boundaries.

Inhibiting cholinergic signalling in the cerebellar interpositus nucleus impairs motor behaviour.

The role of neuromodulators in the cerebellum is not well understood. In particular, the behavioural significance of the cholinergic system in the cerebellum is unknown. To investigate the importance of cerebellar cholinergic signalling in behaviour, we infused acetylcholine receptor antagonists, scopolamine and mecamylamine, bilaterally into the rat cerebellum (centred on interpositus nucleus) and observed the motor effects through a battery of behavioural tests. These tests included unrewarded behaviour during open field exploration and a horizontal ladder walking task and reward-based beam walking and pellet reaching tasks. Infusion of a mix of the antagonists did not impair motor learning in the horizontal ladder walking or the reaching task but reduced spontaneous movement during open field exploration, impaired coordination during beam walking and ladder walking, led to fewer reaches in the pellet reaching task, slowed goal-directed reaching behaviour and reduced reward pellet consumption in a free access to food task. Infusion of the muscarinic antagonist scopolamine on its own resulted in deficits in motor performance and a reduction in the number of reward pellets consumed in the free access to food task. By contrast, infusion of the nicotinic antagonist mecamylamine on its own had no significant effect on any task, except beam walking traversal time, which was reduced. Together, these data suggest that acetylcholine in the cerebellar interpositus nucleus is important for the execution and coordination of voluntary movements mainly via muscarinic receptor signalling, especially in relation to reward-related behaviour.

Cerebellar Prediction and Feeding Behaviour.

Given the importance of the cerebellum in controlling movements, it might be expected that its main role in eating would be the control of motor elements such as chewing and swallowing. Whilst such functions are clearly important, there is more to eating than these actions, and more to the cerebellum than motor control. This review will present evidence that the cerebellum contributes to homeostatic, motor, rewarding and affective aspects of food consumption.Prediction and feedback underlie many elements of eating, as food consumption is influenced by expectation. For example, circadian clocks cause hunger in anticipation of a meal, and food consumption causes feedback signals which induce satiety. Similarly, the sight and smell of food generate an expectation of what that food will taste like, and its actual taste will generate an internal reward value which will be compared to that expectation. Cerebellar learning is widely thought to involve feed-forward predictions to compare expected outcomes to sensory feedback. We therefore propose that the overarching role of the cerebellum in eating is to respond to prediction errors arising across the homeostatic, motor, cognitive, and affective domains.

A mechanism for red coloration in vertebrates.

Red coloration is a salient feature of the natural world. Many vertebrates produce red color by converting dietary yellow carotenoids into red ketocarotenoids via an unknown mechanism. Here, we show that two enzymes, cytochrome P450 2J19 (CYP2J19) and 3-hydroxybutyrate dehydrogenase 1-like (BDH1L), are sufficient to catalyze this conversion. In birds, both enzymes are expressed at the sites of ketocarotenoid biosynthesis (feather follicles and red cone photoreceptors), and genetic evidence implicates these enzymes in yellow/red color variation in feathers. In fish, the homologs of CYP2J19 and BDH1L are required for ketocarotenoid production, and we show that these enzymes are sufficient to produce ketocarotenoids in cell culture and when ectopically expressed in fish skin. Finally, we demonstrate that the red-cone-enriched tetratricopeptide repeat protein 39B (TTC39B) enhances ketocarotenoid production when co-expressed with CYP2J19 and BDH1L. The discovery of this mechanism of ketocarotenoid biosynthesis has major implications for understanding the evolution of color diversity in vertebrates.

Molecular parallelisms between pigmentation in the avian iris and the integument of ectothermic vertebrates.

Birds exhibit striking variation in eye color that arises from interactions between specialized pigment cells named chromatophores. The types of chromatophores present in the avian iris are lacking from the integument of birds or mammals, but are remarkably similar to those found in the skin of ectothermic vertebrates. To investigate molecular mechanisms associated with eye coloration in birds, we took advantage of a Mendelian mutation found in domestic pigeons that alters the deposition of yellow pterin pigments in the iris. Using a combination of genome-wide association analysis and linkage information in pedigrees, we mapped variation in eye coloration in pigeons to a small genomic region of ~8.5kb. This interval contained a single gene, SLC2A11B, which has been previously implicated in skin pigmentation and chromatophore differentiation in fish. Loss of yellow pigmentation is likely caused by a point mutation that introduces a premature STOP codon and leads to lower expression of SLC2A11B through nonsense-mediated mRNA decay. There were no substantial changes in overall gene expression profiles between both iris types as well as in genes directly associated with pterin metabolism and/or chromatophore differentiation. Our findings demonstrate that SLC2A11B is required for the expression of pterin-based pigmentation in the avian iris. They further highlight common molecular mechanisms underlying the production of coloration in the iris of birds and skin of ectothermic vertebrates.

Dopamine and serotonin mediate the impact of stress on cleaner fish cooperative behavior.

Stress is known to modulate behavioral responses and rapid decision-making processes, especially under challenging contexts which often occur in social and cooperative interactions. Here, we evaluated the effects of acute stress on cooperative behavior of the Indo-Pacific cleaner wrasse (Labroides dimidiatus) and the implications of pre-treatment with monoaminergic compounds: the selective serotonin reuptake inhibitor - fluoxetine, the 5-HT1A receptor antagonist - WAY-100,635, the D1 receptor agonist - SKF-38393, and the D1 receptor antagonist - SCH-23390. We demonstrated that stress decreased the predisposal to interact and increased cortisol levels in cleaners, which are alleviated by fluoxetine and the dopaminergic D1 antagonist. Overall, our findings highlight the crucial influence of stress on cooperative behavior.

Experimental evidence for a role of dopamine in avian personality traits.

There is increasing interest in the genetic and physiological bases of behavioural differences among individuals, namely animal personality. One particular dopamine (DA) receptor gene (the dopamine receptor D4 gene) has been used as candidate gene to explain personality differences, but with mixed results. Here, we used an alternative approach, exogenously manipulating the dopaminergic system and testing for effects on personality assays in a social bird species, the common waxbill (Estrilda astrild). We treated birds with agonists and antagonists for DA receptors of both D1 and D2 receptor pathways (the latter includes the D4 receptor) and found that short-term manipulation of DA signalling had an immediate effect on personality-related behaviours. In an assay of social responses (mirror test), manipulation of D2 receptor pathways reduced time spent looking at the social stimulus (mirror image). Blocking D2 receptors reduced motor activity in this social assay, while treatment with a D2 receptor agonist augmented activity in this social assay but reduced activity in a non-social behavioural assay. Also, in the non-social assay, treatment with the D1 receptor antagonist markedly increased time spent at the feeder. These results show distinct and context-specific effects of the dopaminergic pathways on waxbill personality traits. Our results also suggest that experimental manipulation of DA signalling can disrupt a behavioural correlation (more active individuals being less attentive to mirror image) that is habitually observed as part of a behavioural syndrome in waxbills. We discuss our results in the context of animal personality, and the role of the DA system in reward and social behaviour.

A non-coding region near Follistatin controls head colour polymorphism in the Gouldian finch.

Discrete colour morphs coexisting within a single population are common in nature. In a broad range of organisms, sympatric colour morphs often display major differences in other traits, including morphology, physiology or behaviour. Despite the repeated occurrence of this phenomenon, our understanding of the genetics that underlie multi-trait differences and the factors that promote the long-term maintenance of phenotypic variability within a freely interbreeding population are incomplete. Here, we investigated the genetic basis of red and black head colour in the Gouldian finch (Erythrura gouldiae), a classic polymorphic system in which naturally occurring colour morphs also display differences in aggressivity and reproductive success. We show that the candidate locus is a small (approx. 70 kb) non-coding region mapping to the Z chromosome near the Follistatin (FST) gene. Unlike recent findings in other systems where phenotypic morphs are explained by large inversions containing hundreds of genes (so-called supergenes), we did not identify any structural rearrangements between the two haplotypes using linked-read sequencing technology. Nucleotide divergence between the red and black alleles was high when compared to the remainder of the Z chromosome, consistent with their maintenance as balanced polymorphisms over several million years. Our results illustrate how pleiotropic phenotypes can arise from simple genetic variation, probably regulatory in nature.

Signalling with a cryptic trait: the regularity of barred plumage in common waxbills.

Sexual signals often compromise camouflage because of their conspicuousness. Pigmentation patterns, on the contrary, aid in camouflage. It was hypothesized that a particular type of pattern-barred plumage in birds, whereby pigmented bars extend across feathers-could simultaneously signal individual quality, because disruptions of these patterns should be perceptually salient at close range and help assess plumage condition. Here we show that common waxbills (Estrilda astrild), which have extensive barred plumage, have more regular patterns as adults than as juveniles, and that adult males have more regular patterns than females. Both these differences are indicative of sexual signalling in species with conventional sex roles. More regular barred plumage was related to better body condition in adult males. Colour ornamentation traits were also related to aspects of quality, either the same as barred plumage (body condition) or a different one (good feather development), supporting both the 'redundant message' and the 'multiple message' hypotheses for the coexistence of multiple sexual signals. Although receiver responses to the regularity of barred plumage were not studied here, research on other species has shown that barred plumage can mediate social interactions. We conclude that using barred plumage as a signal of quality helps circumvent the functional compromise between camouflage and communication.

Contrast enhanced ultrasound and magnetic resonance imaging in hepatocellular carcinoma diagnosis.

BACKGROUND: The new developments in imaging technology, including contrast enhanced ultrasound (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI), allow a better diagnosis of both malignant and benign liver lesions. MATERIAL AND METHODS: A retrospective trial of 126 patients was conducted in the Gastroenterology and Imaging Departments of the University of Medicine and Pharmacy Craiova, Romania. CEUS and MRI were the imaging techniques used for diagnosis of focal liver lesions (FLL), especially for hepatocellular carcinoma (HCC). Histopathology was used only in 15 cases. For each method of investigation we calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV), positive and negative likelihood ratio (+LR, -LR), accuracy and we compared the ROC curves. Statistical analysis also included the Chi-square and Kappa tests. RESULTS: Seventy six cases were diagnosed as HCC, with average size of 5.2±3.3 cm in diameter. The sensitivity and specificity were 71.4% and 95.6% for CEUS and 91.4%, 98.9% respectively, for MRI. When comparing the ROC curves, we found a higher area under curve for MRI (0.952) then for CEUS (0.835) (p=0.005), and 95% confidence interval of 0.0343 to 0.199. No statistically significant difference in diagnosis of FLL was found between CEUS and MRI (p > 0.05) and the agreement between the two imaging techniques was good (k = 0.78). CONCLUSIONS: CEUS can be used as the first step in the diagnosis of liver lesions, but MRI remains the gold standard diagnostic method for liver tumors.

[Multiple evanescent white dot syndrome and multiple sclerosis]. / Syndrome des taches blanches évanescentes et sclérose en plaques.

PURPOSE: To describe a patient who fulfilled the criteria for both clinically definite multiple evanescent white dot syndrome (MEWDS) and multiple sclerosis. METHODS: We performed a complete ophthalmologic and neurological examination in a 30-year-old woman who was referred to our department for blurred vision in her left eye (LE) with photopsia. RESULTS: Following a complete ophthalmologic examination, the patient was diagnosed with MEWDS and coincident multiple sclerosis. She underwent therapy with intravenous methylprednisolone (1000 mg/day) for three days, followed by oral prednisone (1 mg/kg per day) for 15 days. Most of the symptoms and signs apparently regressed within one month, despite a still abnormal OCT macular scan, probably due to atrophic post-inflammatory changes in the outer and photoreceptor layers (rods and cones). CONCLUSION: This report, showing the clinical features of MEWDS associated with multiple sclerosis, strongly suggests common neuropathological and inflammatory mechanisms between MS and white dot syndromes.

[Binge eating disorder in a population of morbid obese candidates to bariatric surgery at the Oswaldo Cruz University Hospital in Recife, PE]. / Transtorno da compulsão alimentar periódica em uma população de obesos mórbidos candidatos a cirurgia bariátrica do Hospital Universitário Oswaldo Cruz, em Recife--PE.

OBJECTIVES: To analyze the frequency of binge eating disorder (BED) and of the main psychiatric disorders associated with morbid obesity in individuals on the waiting list for bariatric surgery. METHOD: Cross sectional study. Interviews with patients from the Surgery for Obesity Program of Oswaldo Cruz University Hospital were conducted evaluating socio-demographic profile, quality of life (SF-36 scale), BED (Binge Eating Scale BES) and psychiatric disorders (M.I.N.I./DSM-IV). RESULTS: 67 out of 400 patients enrolled in the program were interviewed (16.8%). The BMI varied from 36.1 to 81.8 kg/m(2) (average 48.5 +/- 8.8). All have associated diseases, the most frequent being systemic arterial hypertension, sleeping disorders and osteopathies. The most frequent psychiatric disorders were: 47.8% generalized anxiety disorder, 29.9% major depressive disorder, single episode, 34.3% recurrent major depressive disorder. In this group 56.7% showed BED (25.4% moderate and 31.3% severe) and the worse scores in all the domains of quality of life (SF-36 scale). CONCLUSIONS: High prevalence of BED. The compulsive eaters showed a higher number of obesity treatments, higher prevalence of actual major depression, and the worse scores in all the domains of the SF-36 scale. Considering the ample range of psychopathology associated with BED and the greater probability of jeopardizing the surgery results it is very important to improve the detection of these disorders in order to provide adequate treatment.

Transtorno da compulsão alimentar periódica em uma população de obesos mórbidos candidatos a cirurgia bariátrica do Hospital Universitário Oswaldo Cruz, em Recife - PE / Binge eating disorder in a population of morbid obese candidates to bariatric surgery at the Oswaldo Cruz University Hospital in Recife, PE / Binge eating disorder in a population of morbid obese candidates to bariatric surgery at the Oswaldo Cruz University Hospital in Recife, PE

OBJETIVOS: Avaliar a freqüência de transtorno da compulsão alimentar periódica (TCAP) e dos principais transtornos psiquiátricos associados à obesidade mórbida em indivíduos à espera de cirurgia bariátrica. MÉTODOS: Estudo de corte transversal. Foram entrevistados pacientes do programa de cirurgia da obesidade do Hospital Universitário Oswaldo Cruz e avaliados o perfil sócio-demográfico, a qualidade de vida (escala SF-36), o TCAP (Binge Eating Scale ­ BES) e os transtornos psiquiátricos (Mini International Neuropsychiatry Interview ­ M.I.N.I./DSM-IV). RESULTADOS: Dos 400 pacientes inscritos no programa, 67 (16,8 por cento) foram entrevistados. O IMC variou de 36,1 a 81,8 kg/m² (média 48,5 ± 8,8). Todos os entrevistados apresentavam doenças associadas, sendo a HAS, os distúrbios do sono e as osteopatias as mais freqüentes. Os transtornos psiquiátricos mais freqüentes foram: 47,8 por cento transtorno de ansiedade generalizada; 29,9 por cento depressão atual e 34,3 por cento depressão no passado. Verificou-se TCAP em 56,7 por cento dos pacientes (25,4 por cento TCAP moderado e 31,3 por cento, grave) e esses apresentaram os piores escores em todos os domínios de qualidade de vida da escala SF-36. CONCLUSÕES: Constatou-se elevada prevalência de TCAP. Grupo com TCAP apresentou maior número de tratamentos realizados com objetivo de perder peso, elevada prevalência de depressão maior no momento da avaliação, piores escores em todos os domínios da escala de qualidade de vida SF-36. Visto que os portadores de TCAP apresentam vasta psicopatologia e maior probabilidade de comprometimento nos resultados da cirurgia, deve-se aprimorar a detecção desses distúrbios a fim de proporcionar-lhes o tratamento adequado.

OBJECTIVES: To analyze the frequency of binge eating disorder (BED) and of the main psychiatric disorders associated with morbid obesity in individuals on the waiting list for bariatric surgery. METHOD: Cross sectional study. Interviews with patients from the Surgery for Obesity Program of Oswaldo Cruz University Hospital were conducted evaluating socio-demographic profile, quality of life (SF-36 scale), BED (Binge Eating Scale ­ BES) and psychiatric disorders (M.I.N.I./DSM-IV). RESULTS: 67 out of 400 patients enrolled in the program were interviewed (16.8 percent). The BMI varied from 36.1 to 81.8 kg/m² (average 48.5 ± 8.8). All have associated diseases, the most frequent being systemic arterial hypertension, sleeping disorders and osteopathies. The most frequent psychiatric disorders were: 47.8 percent generalized anxiety disorder, 29.9 percent major depressive disorder, single episode, 34.3 percent recurrent major depressive disorder. In this group 56.7 percent showed BED (25.4 percent moderate and 31.3 percent severe) and the worse scores in all the domains of quality of life (SF-36 scale). CONCLUSIONS: High prevalence of BED. The compulsive eaters showed a higher number of obesity treatments, higher prevalence of actual major depression, and the worse scores in all the domains of the SF-36 scale. Considering the ample range of psychopathology associated with BED and the greater probability of jeopardizing the surgery results it is very important to improve the detection of these disorders in order to provide adequate treatment.