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Genetic determinants of acute hypoxic ventilation: patterns of inheritance in mice.

Acutely lowering ambient O(2) tension increases ventilation in many mammalian species, including humans and mice. Inheritance patterns among kinships and between mouse strains suggest that a robust genetic influence determines individual hypoxic ventilatory responses (HVR). Here, we tested specific genetic hypotheses to describe the inheritance patterns of HVR phenotypes among two inbred mouse strains and their segregant and nonsegregant progeny. Using whole body plethysmography, we assessed the magnitude and pattern of ventilation in C3H/HeJ (C3) and C57BL/6J (B6) progenitor strains at baseline and during acute (3-5 min) hypoxic [mild hypercapnic hypoxia, inspired O(2) fraction (FI(O(2))) = 0.10] and normoxic (mild hypercapnic normoxia, FI(O(2)) = 0.21) inspirate challenges in mild hypercapnia (inspired CO(2) fraction = 0.03). First- and second-filial generations and two backcross progeny were also studied to assess response distributions of HVR phenotypes relative to the parental strains. Although the minute ventilation (VE) during hypoxia was comparable between the parental strains, breathing frequency (f) and tidal volume were significantly different; C3 mice demonstrated a slow, deep HVR relative to a rapid, shallow phenotype of B6 mice. The HVR profile in B6C3F(1)/J mice suggested that this offspring class represented a third phenotype, distinguishable from the parental strains. The distribution of HVR among backcross and intercross offspring suggested that the inheritance patterns for f and VE during mild hypercapnic hypoxia are consistent with models that incorporate two genetic determinants. These results further suggest that the quantitative genetic expression of alleles derived from C3 and B6 parental strains interact to significantly attenuate individual HVR in the first- and second-filial generations. In conclusion, the genetic control of HVR in this model was shown to exhibit a relatively simple genetic basis in terms of respiratory timing characteristics.

Acute Disease↗

An Integrative Morphological and Genomic Analysis With a Refined Fluorescence In Situ Hybridization (FISH) Threshold and Novel Kinase Fusions in a Large Asian Cohort of Spitzoid Neoplasms.

Differentiating atypical Spitz tumors (ASTs) from true Spitz melanomas (SMs) and conventional melanomas with spitzoid features (MSFs) remains a formidable diagnostic challenge. Because current molecular epidemiological data are overwhelmingly derived from Caucasian cohorts, the genomic landscape of Asian populations remains largely unexplored. To elucidate the molecular progression landscape and refine the diagnostic criteria, we performed a comprehensive multimodal analysis-integrating histomorphology, immunohistochemistry, multiprobe fluorescence in situ hybridization (FISH), and targeted RNA/DNA-based next-generation sequencing (NGS)-on a cohort of 140 spitzoid neoplasms. This cohort, comprising 126 ASTs, 8 SMs, and 6 MSFs, represents the largest Asian cohort to date. Malignant phenotype strongly correlated with lesional asymmetry, deep atypical mitoses, a sheet-like growth pattern, diffuse preferentially expressed antigen of melanoma positivity, and significant loss of p16 expression (64.3% in SM/MSF vs 9.5% in ASTs; P < .0001). Building upon the established melanoma FISH criteria, we optimized a prognostic threshold of &#x2265;2 FISH abnormalities specifically tailored for spitzoid neoplasms. We demonstrated that isolated single chromosomal aberrations (particularly MYB loss) are relatively stable events that are frequent in indolent ASTs, whereas our refined &#x2265;2 threshold yielded 100% sensitivity and 92.5% specificity for predicting regional lymph node metastasis/local recurrence. Molecularly, NGS identified mutually exclusive initiating driver alterations (comprising kinase fusions and HRAS mutations) in 89.9% of true Spitz neoplasms, a remarkably high prevalence suggesting a distinct genetic background in Asian populations. We also characterized 5 entirely novel kinase fusions (ZNF24::ROS1, PCBP1::ROS1, NUMA1::RET, CBWD1::ALK, and TPR::NTRK1). Furthermore, NGS definitively segregated true Spitz neoplasms from morphological mimics (MSF), which lacked fusions and were driven by canonical genomic alterations of the conventional melanoma pathway. Integrating these genomic landscapes validated a stepwise progression model. Although isolated kinase fusions drove indolent ASTs, malignant SM invariably harbored concurrent pathogenic secondary alterations, demonstrating a profound reliance on CDKN2A/B, TP53, and CDK4 aberrations. Ultimately, we propose an integrated diagnostic algorithm combining morphological evaluation, the refined FISH threshold, and comprehensive NGS profiling, providing a precise, evidence-based framework for pathway classification and clinical management of spitzoid neoplasms.

fluorescence in situ hybridization↗

Type I bone morphogenetic protein receptors are expressed on cerebellar granular neurons and a constitutively active form of the type IA receptor induces cerebellar abnormalities.

Cerebellar granular neurons are the most abundant neuronal type in the CNS. Their number and experimental accessibility have made these neurons a valuable model for investigating mechanisms of cell proliferation and differentiation in the CNS. Proliferation of granular neurons is regulated, at least in part, by the secreted protein Sonic Hedgehog, whereas induction and differentiation both appear to be controlled by bone morphogenetic protein (BMP) signaling. Given the role of BMPs in granular cell differentiation, we postulated that BMP receptors (BMPRs) would be expressed on cerebellar granular neurons and that signaling through these receptors is required for normal differentiation. We found that both BMPRIA and BMPRIB are expressed on granular neuron precursors and on mature granular neurons in the developing cerebellum. To determine if these receptors are sufficient for granular cell induction and/or differentiation in vivo, we introduced a constitutively active BMPRIA construct into the developing cerebellum. The resulting cerebelli showed a simplified folial pattern and ectopic collections of small cells located deep in the cerebellar white matter. Phenotypic analysis demonstrated that the ectopic cells are granular neurons. From these data we suggest that signaling through the type I BMPRs occurs during normal cerebellar development and ectopic activation of this pathway affects normal granular neuron development. Furthermore, the similarity of the cerebellar anomalies arising from perturbed BMPR signaling to human cerebellar malformations suggests that dysregulation of BMP signaling may play a pathogenic role in some human cerebellar abnormalities.

Amino Acid Substitution↗

Lipopolysaccharides in bacterial membranes act like cholesterol in eukaryotic plasma membranes in providing protection against melittin-induced bilayer lysis.

Melittin is a small, cationic peptide that, like many other antimicrobial peptides, lyses cell membranes by acting on their lipid bilayers. However, the sensitivity to antimicrobial peptides varies among cell types. We have performed direct binding and vesicle leakage experiments to determine the sensitivity to melittin of bilayers composed of various physiologically relevant lipids, in particular, key components of eukaryotic membranes (cholesterol) and bacterial outer membranes (lipopolysaccharide or LPS). Melittin binds to bilayers composed of both zwitterionic and negatively charged phospholipids, as well as to the highly charged LPS bilayers. The magnitude of the free energy of binding (deltaG degrees ) increases with increasing bilayer charge density; deltaG degrees = -7.6 kcal/mol for phosphatidylcholine (PC) bilayers and -8.9 to -11.0 kcal/mol for negatively charged bilayers containing phosphatidylserine (PS), phospholipids with covalently attached polyethylene glycol (PEG-lipids), or LPS. Comparisons of these data show that binding is not markedly affected by the steric barrier produced by the PEG in PEG-lipids or by the polysaccharide core of LPS. The addition of equimolar cholesterol to PC bilayers reduces the level of binding (deltaG degrees = -6.4 kcal/mol) and reduces the extent of melittin-induced leakage by 20-fold. LPS and 1:1 PC/cholesterol bilayers have similar high resistance to melittin-induced leakage, indicating that cholesterol in eukaryotic plasma membranes and LPS in Gram-negative bacteria provide strong protection against the lytic effects of melittin. We argue that this resistance is due at least in part to the similar tight packing of the lipid acyl chains in PC/cholesterol and LPS bilayers. The addition of bacterial phospholipids to LPS bilayers increases their sensitivity to melittin, helping to explain the higher sensitivity of deep rough bacteria compared to smooth phenotypes.

Amino Acid Sequence↗

Deep soil layers show the most pronounced genetic variation in wheat root length.

Wheat is one of the most important cereals worldwide, yet significant gaps remain in our understanding of genetic variability in root traits, especially those associated with deeper rooting that support resource acquisition in challenging environments. Root traits are typically controlled by many genes with small effects and often display low heritability. Our aim was to develop a statistical approach to analyse root variation across soil depth and to determine where genetic differences in root intensity are most detectable. An experiment was conducted at the RadiMax semi-field facility, which is designed to measure deep root systems. Five years of phenotypic data recorded each June produced observations from 1500 rows. Each row captured root intensity across the soil profile from 0.6 m to 2.6 m, enabling detailed analysis of vertical root distribution. Across the five years, 513 winter wheat cultivars were grown in the facility, and among those 409 were genotyped with SNP chips. Depth-resolved regression models with random coefficients were used to quantify genetic and non-genetic variation in root intensity across soil depths, while accounting for spatial variation between rows. Random variation within rows was found to be constant across depths. The models showed that genetic variance for cumulative root intensity increased substantially below 1.1 m, with the deepest layers exhibiting the largest differences between wheat lines. Narrow-sense heritability of point measurements peaked at approximately 1.5 m ([Formula: see text]).

Genetic variability↗

Laser and intense pulsed light therapy for the esthetic treatment of lower extremity veins.

The role of lasers and intense pulsed light sources has gained increasing popularity over the last decade. Major advances associated with improved results are the main reasons associated with this increasing popularity. These advances include epidermal cooling technologies, variable spot sizes and pulse durations as well as the ability to deliver high-energy fluences. These advances have allowed the delivery of sufficient energy to cause uniform pan-endothelial necrosis without affecting epidermal structures causing adverse sequelae such as post-inflammatory hyperpigmentation and epidermal surface irregularities. The advent of extended-pulse longer-wavelength technologies such as the 1064 Neodymium : Yttrium Aluminum Garnet (Nd : YAG) laser have allowed the treatment of individuals with darker phenotypic skin types as well as deep blue reticular veins up to 3mm in diameter in a monomodal fashion. Combined approaches of sclerotherapy plus laser treatments performed at the same treatment session may produce synergistic results in selected individuals.

Humans↗

Genetic analysis of violacein biosynthesis by Chromobacterium violaceum.

Chromobacterium violaceum presents a distinctive phenotypic characteristic, the production of a deep violet pigment named violacein. Although the physiological function of this pigment is not well understood, the sequencing of the genome of this bacterium has given some insight into the mechanisms and control of violacein production. It was found that erythrose-4-phosphate (E4P), a precursor to aromatic amino acid biosynthesis, is produced by the non-oxidative portion of the hexose monophosphate pathway, since it lacks 6-phosphogluconate dehydrogenase. All genes leading from E4P plus phosphoenolpyruvate to tryptophan are present in the genome. Nevertheless, these genes are not organized in an operon, as in E. coli, indicating that other mechanisms are involved in expression. The sequencing data also indicated the presence and organization of an operon for violacein biosynthesis. Three of the four gene products of this operon presented similarity with nucleotide-dependent monooxygenases and one with a limiting enzyme polyketide synthase. As previously suggested, genes encoding proteins involved in quorum sensing control by N-hexanoyl-homoserine-lactone, an autoinducer signal molecule, are present in the bacterial genome. These data should help guide strategies to increase violacein biosynthesis, a potentially useful molecule.

Carboxylic Ester Hydrolases↗

Laser treatment of leg veins.

The role of lasers and intense pulsed light sources has gained increasing popularity in the management of both cosmetic telangiectasias and medically significant symptomatic varicose vein disease. These advances include endovascular technologies, novel cooling technologies, variable spot sizes and pulse durations, as well as the ability to deliver high-energy fluences. These advances have allowed the delivery of sufficient energy allowing more efficient pan-endothelial necrosis without affecting epidermal structures, and yielding a lower complication profile such as post-inflammatory hyperpigmentation and epidermal surface irregularities. The advent of extended-pulse, longer wavelength technologies such as the 1064 Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser have allowed the treatment of individuals with darker skin phenotypes, as well as treatment of deep blue reticular veins up to 3 mm in diameter in a monomodal fashion. Combined approaches of sclerotherapy plus laser treatments performed during the same treatment session may produce synergistic results in selected individuals.

Anesthesia, Local↗

[Aspergillus fumigatus: from saprophytism to virulence. Phenotypic and genotypic biodiversity].

During the last two decades, deep changes have arised in aspergillosis. Thus, this fungal infection mainly due Aspergillus fumigatus is becoming a serious public health-hazard in the growing population of immunocompromised patients. From literature and their own experience, the authors present a synthesis of phenomenons promoting this evolution: the host predisposing factors, environment and potential contamination sources, then the fungus itself. Genetic research developed into the disease-causing organism could be of major interest in epidemiology of aspergillosis and to identify new targets of prophylaxis.

Aspergillosis↗

Phosphoglycerides of Trichophyton terrestre and one phenotype selected from the Apollo 16 microbial ecology evaluation device.

Total lipid extracted from wild-type Trichophyton terrestre CDC-X285 was found to be 2.0 percent of the dry cell weight. The total lipid contained the following phospholipid components identified by silicic acid-impregnated thin-layer and paper chromatography: phosphatidyl inositol, phosphatidyl choline, phosphatidyl serine, and phosphatidic acid. The total lipid extracted from the phenotype T. terrestre 7048-1 isolated from the Apollo 16 Microbial Ecology Evaluation Device (MEED) was found to vary according to the time at which the phospholipids were extracted. The Trichophyton phenotype was selected from a cuvette housed in the MEED exposed to specific space parameters including ultraviolet light of known wavelengths and energy levels in deep space. The phospholipid components, identified in the phenotype were phosphatidyl ethanolamine and cardiolipin. The major lipid fraction was composed of digalactosyl diglyceride and monogalactosyl diglyceride. An unusual lipid was detected in the phenotype, which appeared to be sterol glycoside.

Cardiolipins↗

The PAI-1 gene 4G/5G polymorphism and deep vein thrombosis in patients with inherited thrombophilia.

Genetic and acquired factors may influence phenotypic expression of inherited thrombophilia. Hypofibrinolysis due to excess PAI-1 can be found in patients with deep vein thrombosis (DVT) and 4G/5G polymorphism of the PAI-1 gene may modulate the inhibitor's synthesis. In 149 patients with inherited thrombophilia, the possible thrombotic contribution of both 4G/5G polymorphism and PAI-1 plasma levels was evaluated. Sixty-seven patients with idiopathic DVT and 98 normal subjects were also studied. By comparison with controls, a significantly higher prevalence of 4G/4G genotype was seen in idiopathic DVT and in thrombophilia patients, although in this latter group the difference only remained significant in cases symptomatic for thrombosis (p = 0.01). The 4G/4G genotype was associated with a greater risk of thrombosis both in symptomatic thrombophilia patients (OR 2.85, 95% CI 1.26-6.46) and in idiopathic DVT patients (OR 3.1, 95% CI 1.26-7.59). The greater frequency of 4G allele in symptomatic thrombophilia patients with respect to controls was statistically significant (p = 0.04). Compared to healthy subjects, PAI-1:Ag levels were higher in symptomatic thrombophilia patients and related to the 4G/5G polymorphism, with significantly higher values in the 4G/4G carriers. In conclusion, PAI-1 4G/5G polymorphism may influence PAI-1 expression and thrombotic risk in patients with inherited thrombophilia.

Adolescent↗

Association of smooth muscle cell phenotypic modulation with extracellular matrix alterations during neointima formation in rabbit vein grafts.

PURPOSE: To clarify the mechanisms of structural changes underlying vein graft stenosis that limits efficacy of bypass grafting operation, we examined the accumulation and distribution of various extracellular matrix (ECM) components during neointima formation in rabbit vein grafts and analyzed their correlation with proliferation and phenotypic modulation of smooth muscle cells (SMCs). METHODS AND RESULTS: An autologous external jugular vein graft was transplanted into the carotid artery in 25 rabbits. After the restoration of blood flow, the graft was markedly dilated. Medial SMCs in the graft appeared to be injured, and they began to proliferate at day 4 and subsequently migrated and formed the neointima at day 7. The neointima observed at days 7 and 14 contained ECM components, including type I collagen, heparan sulfate, and chondroitin sulfate, and the intimal SMCs were phenotypically modulated from the differentiated-type (SM2-positive and SM embryonic-negative) to the dedifferentiated-type (SM2-negative and SM embryonic-positive) as determined with immunostainings for myosin heavy chain isoforms. The intimal SMC proliferation was maximal at 2 weeks and then decreased rapidly. However, the neointima continued to thicken thereafter throughout the 6-month period of the experiment, and ECM accumulation, such as type I collagen and decorin, a small dermatan sulfate proteoglycan, was a prominent feature observed in the hypocellular region of the deep intima from 2 months after the transplantation. The phenotype of the intimal SMCs gradually returned to the differentiated-type from the deep intima after 2 months, but a small number of the intimal SMCs remained in the dedifferentiated phenotype even at 6 months after the operation. CONCLUSION: The neointima in the vein graft was formed initially by means of migration and proliferation of the phenotypically modulated, dedifferentiated-type SMCs and continued to thicken by means of sustained ECM accumulation, including type I collagen and decorin, in association with the prolonged presence of the dedifferentiated-type SMCs. These chronologic features in cell kinetics and ECM accumulation may contribute to the frequent occurrence of graft wall thickening that occurs in the vein grafts.

Animals↗

Targeted inactivation of myogenic factor genes reveals their role during mouse myogenesis: a review.

The role of the four myogenic regulating genes Myf-5, myogenin, MyoD, and MRF4 (herculin, Myf-6) during mouse embryogenesis has been investigated by targeted gene inactivation. Null mutations for the MyoD gene generate no skeletal muscle phenotype due to a compensatory activation of the Myf-5 gene. Mice carrying a homozygous Myf-5 mutation exert considerably delayed myotome formation with unexpected consequences. While skeletal myogenesis in these mutant mice resumes normally at the onset of MyoD expression, a skeletal defect of the ribs persists. Apparently, Myf-5 and MyoD individually are not absolutely essential for skeletal muscle development, most likely because they have overlapping or redundant functions. In fact, double mutants lacking both, MyoD and Myf-5, fail to develop skeletal musculature and the muscle forming regions seem to be devoid of myoblasts. Homozygous inactivation of the myogenin gene leads to drastically reduced myofiber formation. These mice accumulate apparently normal numbers of myoblasts which are arrested in their terminal differentiation program. Myf-6 null mutant mice exhibit drastically reduced expression of Myf-5 for reasons presently unknown. The phenotype is very similar to Myf-5 mutants with an additional reduction of deep back muscles and minor alterations in sarcomeric protein isoforms. Based on the phenotypes obtained from these various gene "knock-out" mice, we now begin to understand the regulatory network and the homostatic relationship of genes which are critically involved in myogenesis of vertebrates.

Animals↗

E-cadherin is required for gastrulation cell movements in zebrafish.

E-cadherin is a member of the classical cadherin family and is known to be involved in cell-cell adhesion and the adhesion-dependent morphogenesis of various tissues. We isolated a zebrafish mutant (cdh1(rk3)) that has a mutation in the e-cadherin/cdh1 gene. The mutation rk3 is a hypomorphic allele, and the homozygous mutant embryos displayed variable phenotypes in gastrulation and tissue morphogenesis. The most severely affected embryos displayed epiboly delay, decreased convergence and extension movements, and the dissociation of cells from the embryos, resulting in early embryonic lethality. The less severely affected embryos survived through the pharyngula stage and showed flattened anterior neural tissue, abnormal positioning and morphology of the hatching gland, scattered trigeminal ganglia, and aberrant axon bundles from the trigeminal ganglia. Maternal-zygotic cdh1(rk3) embryos displayed epiboly arrest during gastrulation, in which the enveloping layer (EVL) and the yolk syncytial layer but not the deep cells (DC) completed epiboly. A similar phenotype was observed in embryos that received antisense morpholino oligonucleotides (cdh1MO) against E-cadherin, and in zebrafish epiboly mutants. Complementation analysis with the zebrafish epiboly mutant weg suggested that cdh1(rk3) is allelic to half baked/weg. Immunohistochemistry with an anti-beta-catenin antibody and electron microscopy revealed that adhesion between the DCs and the EVL was mostly disrupted but the adhesion between DCs was relatively unaffected in the MZcdh1(rk3) mutant and cdh1 morphant embryos. These data suggest that E-cadherin-mediated cell adhesion between the DC and EVL plays a role in the epiboly movement in zebrafish.

Alleles↗

Phenotypic effects of the weaver gene are evident in the embryonic cerebellum but not in the ventral midbrain.

Degeneration of neurons in two structures, the cerebellum and the dopaminergic neurons in the ventral midbrain, is a well characterized action of the weaver gene. In order to see whether the gene has effects prenatally, both the cerebellum and the ventral midbrain were examined in mouse embryos genotyped for the weaver gene (wv, Girk2) on day E19. Anatomically matched sections of the midline cerebellar vermis were quantitatively analyzed 2 h after the dams were given a single injection of [3H]thymidine. A gene-dose effect was seen in the retardation of fissure development. This was more pronounced in homozygotes (wv/wv) and less so in heterozygotes (wv/+) when compared with wild type controls (+/+). Quantitative measures of the following features showed stepwise differences between genotypes so that the wv/wv are most affected and wv/+ are somewhat affected compared with +/+: surface length of the midline vermis, area of the entire midline vermis and the external germinal layer (egl), total number of cells in the egl, [3H]thymidine-labeled and -unlabeled egl cells, cells in the Purkinje cell layer, cells in the region of the deep nuclei, [3H]thymidine-labeled cells in the Purkinje cell layer (presumptive proliferating Bergmann glia), and [3H]thymidine-labeled cells in the region of the deep nuclei. In contrast to the obvious phenotypic effects of wv in the embryonic cerebellum, qualitative immunocytochemical examination of tyrosine hydroxylase staining in the ventral midbrains of the same embryos showed that the position and density of the presumptive dopaminergic neurons was similar in all genotypes.

Animals↗

Recent developments in the thermophilic microbiology of deep-sea hydrothermal vents.

The diversity of thermophilic prokaryotes inhabiting deep-sea hot vents was actively studied over the last two decades. The ever growing interest is reflected in the exponentially increasing number of novel thermophilic genera described. The goal of this paper is to survey the progress in this field made in the years 2000-2005. In this period, representatives of several new taxa of hyperthermophilic archaea were obtained from deep-sea environments. Two of these isolates had phenotypic features new for this group of organisms: the presence of an outer cell membrane (the genus Ignicoccus) and the ability to grow anaerobically with acetate and ferric iron (the genus Geoglobus). Also, our knowledge on the diversity of thermophilic bacteria from deep-sea thermal environments extended significantly. The new bacterial isolates represented diverse bacterial divisions: the phylum Aquificae, the subclass Epsilonproteobacteria, the order Thermotogales, the families Thermodesulfobacteriaceae, Deferribacteraceae, and Thermaceae, and a novel bacterial phylum represented by the genus Caldithrix. Most of these isolates are obligate or facultative lithotrophs, oxidizing molecular hydrogen in the course of different types of anaerobic respiration or microaerobic growth. The existence and significant ecological role of some of new bacterial thermophilic isolates was initially established by molecular methods.

Anaerobiosis↗

Polymorphonuclear leukocyte integrins in deep venous thrombosis.

The polymorphonuclear leukocytes (PMN) have a role in the pathophysiology of deep venous thrombosis (DVT). We examined the phenotypical expression of PMN beta(2M)-integrins (CD ll a, CDll b, CD 11c) in a group of 19 subjects with leg DVT. PMN cells were incubated with fluorescent monoclonal antibodies against CD11a, CD11b, CD11c, and the evaluation was made by flow cytofluorimetry. The same integrins were determined after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). In DVT subjects, at baseline, the phenotypical expression of CD11b was decreased and that of CD11c increased when compared with normal controls. In normal subjects PMN activation with PMA and fMLP led to a constant increase of all PMN adhesion molecules, while in DVT subjects the CDl l a did not show any change. These data might have therapeutical applications, especially with the aim of preventing post-thrombotic deterioration of vein function.

Female↗

Is there a "migratory syndrome" common to all migrant birds?

Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory syndrome," a tightly integrated, old group of adaptive traits that enables birds to commit themselves to highly organized seasonal migrations, is assessed. A list of problems faced by migratory birds is listed first and the traits that migratory birds have evolved to deal with these problems are discussed. The usefulness of comparative approaches to investigate which traits are unique to migrants is then discussed. A provisional conclusion that, perhaps apart from a capacity for night-time compass orientation, there is little evidence for deeply rooted coadapted trait complexes that could make up such a migratory syndrome, is suggested. Detailed analyses of the genetic and physiological architecture of potential adaptations to migration, combined with a comparative approach to further identify the phylogenetic levels at which different adaptive traits for migration have evolved, are recommended.

Adaptation, Physiological↗