ABSTRACT
In domestic goats, the polled intersex syndrome (PIS) refers to XX female-to-male sex reversal associated with the absence of horn growth (polled). The causal variant was previously reported as a 11.7 kb deletion at approximately 129 Mb on chromosome 1 that affects the transcription of both FOXL2 and several long non-coding RNAs. In the meantime the presence of different versions of the PIS deletion was postulated and trials to establish genetic testing with the existing molecular genetic information failed. Therefore, we revisited this variant by long-read whole-genome sequencing of two genetically female (XX) goats, a PIS-affected and a horned control. This revealed the presence of a more complex structural variant consisting of a deletion with a total length of 10 159 bp and an inversely inserted approximately 480 kb-sized duplicated segment of a region located approximately 21 Mb further downstream on chromosome 1 containing two genes, KCNJ15 and ERG. Publicly available short-read whole-genome sequencing data, Sanger sequencing of the breakpoints and FISH using BAC clones corresponding to both involved genome regions confirmed this structural variant. A diagnostic PCR was developed for simultaneous genotyping of carriers for this variant and determination of their genetic sex. We showed that the variant allele was present in all 334 genotyped polled goats of diverse breeds and that all analyzed 15 PIS-affected XX goats were homozygous. Our findings enable for the first time a precise genetic diagnosis for polledness and PIS in goats and add a further genomic feature to the complexity of the PIS phenomenon.
Subject(s)
Disorders of Sex Development/veterinary , Goat Diseases/genetics , Sex Determination Processes , Animals , Disorders of Sex Development/genetics , Female , Genetic Testing/veterinary , Goats , Whole Genome SequencingABSTRACT
STUDY QUESTION: What are the consequences of radioactive iodine (RAI) therapy for testicular function? SUMMARY ANSWER: A single activity of 3.7 GBq RAI for differentiated thyroid carcinoma (DTC) treatment in young men transiently altered Sertoli cell function and induced sperm chromosomal abnormalities. WHAT IS KNOWN ALREADY: Few studies, mainly retrospective, have reported the potential impacts of RAI on endocrine and exocrine testicular function. STUDY DESIGN, SIZE, DURATION: A longitudinal prospective multi-center study on testicular function performed in DTC patients before a single 131I ablative activity of 3.7 GBq (V0) and at 3 months (V3) and 13 months (V13) after treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: Forty male patients, aged 18-55 years, with DTC participated. Hormonal analysis included FSH, LH, testosterone and inhibin B serum levels at V0, V3 and V13. Furthermore, sperm parameters, DNA fragmentation and sperm chromosomal abnormalities were evaluated at each time points. The differences in all parameters, between V0-V3, V0-V13 and V3-V13, were analyzed, using a Wilcoxon test. MAIN RESULTS AND THE ROLE OF CHANCE: Prior to RAI administration, all patients had normal gonadal function. At V3, a statistically significant increase in FSH levels and a decrease in inhibin B levels were observed and sperm concentration, as well as the percentage of morphologically normal spermatozoa, were significantly decreased (P < 0.0001). These modifications were transient as both sperm concentration and normal morphology rate returned to baseline values at V13. However, at this later time point, FSH and inhibin B levels were still impacted by RAI administration but remained in the normal range. Although no DNA fragmentation was observed at V3 nor V13, our study revealed a statistically significant increase in the number of sperm chromosomal abnormalities both at V3 (P < 0.001) and V13 (P = 0.01). LIMITATIONS, REASONS FOR CAUTION: Among the 40 patients included in the study, only 24 had all the parameters available at all visits. WIDER IMPLICATIONS OF THE FINDINGS: Prospective studies with longer term follow up would be helpful to determine whether the chromosome abnormalities persist. These studies would be required before sperm banking should be suggested for all patients. However, sperm preservation for DTC patients who require cumulative radioiodine activities higher than 3.7 GBq should be proposed. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Programme Hospitalier de Recherche Clinique, AP-HP (No. P040419). The authors report no conflict of interest in this work. TRIAL REGISTRATION NUMBER: NCT01150318.
Subject(s)
Carcinoma/radiotherapy , Infertility, Male/etiology , Iodine Radioisotopes/adverse effects , Radiation Dosage , Radiation Injuries/etiology , Testis/radiation effects , Thyroid Neoplasms/radiotherapy , Adolescent , Adult , Biomarkers/blood , Carcinoma/pathology , Cell Differentiation , Chromosome Aberrations , DNA Fragmentation , France , Hormones/blood , Humans , Infertility, Male/blood , Infertility, Male/genetics , Infertility, Male/pathology , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Radiation Injuries/blood , Radiation Injuries/genetics , Radiation Injuries/pathology , Radiotherapy, Adjuvant/adverse effects , Risk Assessment , Risk Factors , Spermatozoa/pathology , Spermatozoa/radiation effects , Testis/metabolism , Testis/pathology , Thyroid Neoplasms/pathology , Time Factors , Treatment Outcome , Young AdultABSTRACT
Spatial deficits are frequent after brain damage, particularly right hemisphere stroke. Visual judgments of line orientation (LINE) are often impaired after right parietal lesions. Perception of line orientation is an important visuoperceptual component of visuoconstructive capacities. Yet, little is known about modulating factors in LINE and effective treatments are rare for this disorder. Studies in patients with spatial neglect show that horizontal random dot motion (RDM) significantly modulates horizontal spatial disorders, both transiently and permanently after treatment. In the current study, we investigated whether rotational RDM modulates judgements in an oblique LINE task in 20 patients with right-hemispheric first ever stroke (10 of them with a disorder in LINE and 10 without such a disorder), and 10 healthy, age-matched subjects. Subjects were tested under three experimental conditions: (1) with a static background of small white dots, (2) with slow clockwise or (3) counterclockwise circular RDM of these background stimuli, while they performed the LINE task. In the baseline condition with static background, the impaired patient group showed a significant counterclockwise tilt. Clockwise rotating RDM normalized this deficit transiently but completely, while counterclockwise rotating RDM slightly aggravated it, though not significantly. Tilts in the LINE task were significantly correlated with left visuospatial neglect. Similar but much smaller effects were obtained in the spatially unimpaired patients and the normal controls. These results show that rotational RDM modulates deficits of line orientation in patients with right-sided stroke, possibly by influencing higher spatial representations devoted to the perception of oblique lines.
Subject(s)
Functional Laterality , Motion Perception , Perceptual Disorders/psychology , Space Perception , Stroke/psychology , Adult , Aged , Analysis of Variance , Brain/diagnostic imaging , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Perceptual Disorders/diagnostic imaging , Perceptual Disorders/etiology , Photic Stimulation/methods , Rotation , Stroke/complications , Stroke/diagnostic imagingABSTRACT
Studies in healthy individuals indicate a significant influence of rotating visual motion on judgments of the subjective visual vertical (SVV). Moreover, sensory stimulation manoeuvres like horizontal coherent dot movement significantly modulate horizontal spatial deficits in patients with rightsided stroke. Here, we investigated whether rotational coherent dot movement (RCDM) modulates spatial orientation deficits of the SVV in the roll plane in right hemispheric stroke. We tested the perceptual judgment of the SVV in 20 patients with right-hemispheric, first ever stroke (10 of them with a disorder of the SVV and 10 without a disorder), and 10 healthy, age-matched subjects under three experimental conditions: (1) with a static background of small white dots, (2) with slow clockwise or (3) counterclockwise circular RCDM of these background stimuli. In the baseline condition with static background, the impaired patient group showed a counterclockwise tilt of the SVV. Clockwise RCDM normalized this deficit completely, while with counterclockwise RCDM a slight aggravation was observed. Similar but quantitatively much smaller effects were obtained in the SVV-unimpaired patients and the healthy individuals. These results demonstrate a strong modulatory effect of RCDM on the SVV in patients with a tilt of the SVV due to right-sided stroke. RCDM thus appears to influence higher spatial representations devoted to visuospatial perception of the SVV. Possible mechanisms as well as clinical implications for therapy of visuospatial disorientation (self-orientation in space) after stroke are discussed.
Subject(s)
Functional Laterality , Motion Perception , Perceptual Disorders/psychology , Space Perception , Stroke/psychology , Adult , Aged , Brain/diagnostic imaging , Female , Humans , Judgment , Male , Middle Aged , Neuropsychological Tests , Perceptual Disorders/diagnostic imaging , Perceptual Disorders/etiology , Perceptual Disorders/therapy , Photic Stimulation/methods , Rotation , Stroke/complications , Stroke/diagnostic imaging , Stroke/therapyABSTRACT
Cage-chiral tetra-tert-butyl-P5-deltacyclene is accessible as a pair of highly enriched enantiomers and . The only secondary phosphorus atom P1 of the cage can be selectively oxidized by reaction with t-BuOOH. The P1-oxo species and , allow the direct determination of their ee values. Oxidation occurs with the complete retention of the optical activity of the compounds. The chiroptical properties of and are strongly dominated by their cage chirality, the oxygen atom does not contribute significantly. Elemental sulfur and selenium oxidize P5 with high preference to yield P5-thio- and P5-seleno-P5-deltacyclenes and of the intact cages again. Longer reaction time and more than stoichiometric amounts of selenium, leads to tri-seleno-P5-tetracycloundecane , a partially opened oxidized rearrangement product. The ligand properties of racemic were determined. Diphosphetane phosphorus atom P2 of is the active donor center to bind a Cr(CO)5 fragment, but a tautomerization of takes place if [(benzene)RuCl2]2 is added. A hydrogen atom migrates from P1 to the oxygen atom to form a phosphinous acid ligand. The lone pair of P1 is regenerated and acts as the active ligand function of the cage in this case. As for , the base n-BuLi induces an efficient cage rearrangement reaction of , where P1 and the neighboring carbon atom C4 containing its t-Bu substituent change places. C4 moves to its new position without breaking the bond with P5, this way forming the novel P1-oxo-P5-norsnoutene cage in a highly diastereoselective process.
ABSTRACT
BACKGROUND AND OBJECTIVES: When the National Socialists (NS) came to power in 1933, the German health care system was reorganized according to the principles of eugenics. Neuropsychiatric patients were victims of compulsory sterilisation and "euthanasia". As the Saar territory did not become part of the German Reich until the 1 March 1935, it is of special interest how quickly and completely NS health care policies were implemented. METHODS: The analysis is based on medical records of the Homburg State Hospital's (HSH) clinic for nervous diseases from 1929 to 1945 (n =7,816) found in the Saarland University Medical Centre. RESULTS: 1,452 patients were sterilised by force between 1935 and 1939 in the HSH. The most frequent diagnoses were congenital debility, schizophrenia, and epilepsy. Some of the 441 Homburg patients who were transferred to other mental hospitals from 1939 to 1940 were killed in the context of "Aktion T4" and presumably in a nonsystematic manner. CONCLUSIONS: NS health care policies were implemented immediately after incorporation of the Saar territory in 1935. Physicians of the HSH were involved directly in compulsory sterilisation of neuropsychiatric patients. An initial intention to kill by the time of patient transfers from Homburg cannot be proven. Further research concerning the killing centres is necessary.
Subject(s)
Delivery of Health Care/history , Euthanasia/history , National Socialism/history , Nervous System Diseases/history , Neurology/history , Sterilization, Involuntary/history , Eugenics/history , Euthanasia/statistics & numerical data , Germany/epidemiology , Health Policy , History, 20th Century , Humans , Nervous System Diseases/epidemiology , Sterilization, Involuntary/statistics & numerical dataABSTRACT
BACKGROUND AND PURPOSE: Cingulotomy is a well-accepted stereotactic procedure in the treatment of debilitating pain syndromes. At our institution, we used a 980-nm diode laser to perform MR imaging-guided laser-assisted cingulotomy. We report the early MR imaging changes associated with this technique. MATERIALS AND METHODS: In this retrospective analysis, MR imaging-guided laser-assisted cingulotomy was performed in 4 patients with intractable pain secondary to metastatic disease. Patients were imaged at various time points postprocedure, with visual analysis of MR imaging changes in the cingulate gyri during that timeframe. RESULTS: Twenty-four hours postablation, 4 distinct zones of concentric rings reminiscent of an "owl eye" shape were noted in the cingulate gyri. Extrapolating from the imaging characteristics of the rings, we defined each zone as follows: The central zone (zone 1) represents a laser probe void with fluid, zones 2 and 3 have signal characteristics that represent hemorrhage and leaked protein, and zone 4 has a peripheral ring of acute infarction, enhancement, and surrounding edema. One patient with 1-year follow-up showed persistent concentric rings with resolution of enhancement and edema. CONCLUSIONS: Post-MR imaging-guided laser-assisted cingulotomy rings appear to represent a continuum of injury created by the laser probe and thermal injury. The imaging changes are similar to those described for laser ablation of tumor-infiltrated brain with a 1064-nm laser. This is the first study to characterize early MR imaging changes after MR imaging-guided laser-assisted cingulotomy by using a 980-nm laser. It is important for neuroradiologists and neurosurgeons to understand expected imaging findings as laser ablation cingulotomy re-emerges to treat intractable pain.
Subject(s)
Gyrus Cinguli/pathology , Gyrus Cinguli/surgery , Laser Therapy/methods , Pain Management/methods , Pain, Intractable/surgery , Adult , Brain Neoplasms/secondary , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Retrospective StudiesABSTRACT
The presence of congenital appendages (wattles) on the throat of goats is supposed to be under genetic control with a dominant mode of inheritance. Wattles contain a cartilaginous core covered with normal skin resembling early stages of extremities. To map the dominant caprine wattles (W) locus, we collected samples of 174 goats with wattles and 167 goats without wattles from nine different Swiss goat breeds. The samples were genotyped with the 53k goat SNP chip for a subsequent genome-wide association study. We obtained a single strong association signal on chromosome 10 in a region containing functional candidate genes for limb development and outgrowth. We sequenced the whole genomes of an informative family trio containing an offspring without wattles and its heterozygous parents with wattles. In the associated goat chromosome 10 region, a total of 1055 SNPs and short indels perfectly co-segregate with the W allele. None of the variants were perfectly associated with the phenotype after analyzing the genome sequences of eight additional goats. We speculate that the causative mutation is located in one of the numerous gaps in the current version of the goat reference sequence and/or represents a larger structural variant which influences the expression of the FMN1 and/or GREM1 genes. Also, we cannot rule out possible genetic or allelic heterogeneity. Our genetic findings support earlier assumptions that wattles are rudimentary developed extremities.
Subject(s)
Fetal Proteins/genetics , Goats/anatomy & histology , Goats/genetics , Intercellular Signaling Peptides and Proteins/genetics , Microfilament Proteins/genetics , Nuclear Proteins/genetics , Pharynx/anatomy & histology , Alleles , Animals , Formins , Genetic Association Studies , Polymorphism, Single NucleotideABSTRACT
The recent development of a goat SNP genotyping microarray enables genome-wide association studies in this important livestock species. We investigated the genetic basis of the black and brown coat colour in Valais Blacknecked and Coppernecked goats. A genome-wide association analysis using goat SNP50 BeadChip genotypes of 22 cases and 23 controls allowed us to map the locus for the brown coat colour to goat chromosome 8. The TYRP1 gene is located within the associated chromosomal region, and TYRP1 variants cause similar coat colour phenotypes in different species. We thus considered TYRP1 as a strong positional and functional candidate. We resequenced the caprine TYRP1 gene by Sanger and Illumina sequencing and identified two non-synonymous variants, p.Ile478Thr and p.Gly496Asp, that might have a functional impact on the TYRP1 protein. However, based on the obtained pedigree and genotype data, the brown coat colour in these goats is not due to a single recessive loss-of-function allele. Surprisingly, the genotype distribution and the pedigree data suggest that the (496) Asp allele might possibly act in a dominant manner. The (496) Asp allele was present in 77 of 81 investigated Coppernecked goats and did not occur in black goats. This strongly suggests heterogeneity underlying the brown coat colour in Coppernecked goats. Functional experiments or targeted matings will be required to verify the unexpected preliminary findings.
Subject(s)
Goats/genetics , Hair Color/genetics , Membrane Glycoproteins/genetics , Oxidoreductases/genetics , Animals , Chromosome Mapping/veterinary , Genetic Association Studies , Genetic Loci , Genotype , Hair , Sequence Analysis, DNAABSTRACT
INTRODUCTION: Capecitabine, a 5-fluorouracil (5FU) pro-drug, is increasingly used in breast and gastrointestinal cancers due to its more convenient oral route of administration when compared to 5FU. Despite its widespread use, there are only a few reports on capecitabine CNS toxicity, while the pathogenic basis of such toxicity remains unclear. CASE: A 69-year-old male presented with recurrent generalized seizures 2.5 months after preoperative chemoradiotherapy with capecitabine in locally advanced rectal cancer. Brain MRI revealed a diffuse, subcortical white matter alteration suggestive of vasogenic edema. The diagnosis of toxic encephalopathy was supported after elimination of alternative causes of the neurological dysfunction and complete resolution of clinical and imaging findings after 3 months of no further chemotherapy. CONCLUSIONS: Given the expanding use of capecitabine, physicians should be aware of this potential complication when a neurological worsening occurs during or after treatment with this chemotherapeutic agent. In our case, as in previously described cases encephalopathy was characterized by a favorable course after cessation of the drug. Vasogenic edema rather than cytotoxic edema may play a pivotal pathogenetic role in this form of encephalopathy.
Subject(s)
Brain Edema/pathology , Deoxycytidine/analogs & derivatives , Fluorouracil/analogs & derivatives , Neurotoxicity Syndromes/pathology , Aged , Brain Edema/chemically induced , Brain Edema/complications , Capecitabine , Deoxycytidine/adverse effects , Fluorouracil/adverse effects , Humans , Magnetic Resonance Imaging , Male , Neuroimaging , Neurotoxicity Syndromes/complications , Prodrugs/adverse effects , White Matter/drug effects , White Matter/pathologyABSTRACT
Altitudinal gradients offer valuable study systems to investigate how adaptive genetic diversity is distributed within and between natural populations and which factors promote or prevent adaptive differentiation. The environmental clines along altitudinal gradients tend to be steep relative to the dispersal distance of many organisms, providing an opportunity to study the joint effects of divergent natural selection and gene flow. Temperature is one variable showing consistent altitudinal changes, and altitudinal gradients can therefore provide spatial surrogates for some of the changes anticipated under climate change. Here, we investigate the extent and patterns of adaptive divergence in animal populations along altitudinal gradients by surveying the literature for (i) studies on phenotypic variation assessed under common garden or reciprocal transplant designs and (ii) studies looking for signatures of divergent selection at the molecular level. Phenotypic data show that significant between-population differences are common and taxonomically widespread, involving traits such as mass, wing size, tolerance to thermal extremes and melanization. Several lines of evidence suggest that some of the observed differences are adaptively relevant, but rigorous tests of local adaptation or the link between specific phenotypes and fitness are sorely lacking. Evidence for a role of altitudinal adaptation also exists for a number of candidate genes, most prominently haemoglobin, and for anonymous molecular markers. Novel genomic approaches may provide valuable tools for studying adaptive diversity, also in species that are not amenable to experimentation.
Subject(s)
Altitude , Genetic Variation , Phenotype , AnimalsABSTRACT
Adaptive radiations are an important source of biodiversity and are often characterized by many speciation events in very short succession. It has been proposed that the high speciation rates in these radiations may be fuelled by novel genetic combinations produced in episodes of hybridization among the young species. The role of such hybridization events in the evolutionary history of a group can be investigated by comparing the genealogical relationships inferred from different subsets of loci, but such studies have thus far often been hampered by shallow genetic divergences, especially in young adaptive radiations, and the lack of genome-scale molecular data. Here, we use a genome-wide sampling of SNPs identified within restriction site-associated DNA (RAD) tags to investigate the genomic consistency of patterns of shared ancestry and adaptive divergence among five sympatric cichlid species of two genera, Pundamilia and Mbipia, which form part of the massive adaptive radiation of cichlids in the East African Lake Victoria. Species pairs differ along several axes: male nuptial colouration, feeding ecology, depth distribution, as well as the morphological traits that distinguish the two genera and more subtle morphological differences. Using outlier scan approaches, we identify signals of divergent selection between all species pairs with a number of loci showing parallel patterns in replicated contrasts either between genera or between male colour types. We then create SNP subsets that we expect to be characterized to different extents by selection history and neutral processes and describe phylogenetic and population genetic patterns across these subsets. These analyses reveal very different evolutionary histories for different regions of the genome. To explain these results, we propose at least two intergeneric hybridization events (between Mbipia spp. and Pundamilia spp.) in the evolutionary history of these five species that would have lead to the evolution of novel trait combinations and new species.
Subject(s)
Adaptation, Physiological/genetics , Cichlids/classification , Cichlids/genetics , Metagenomics , Animals , Biodiversity , Biological Evolution , Chimera , Gene Flow , Genetic Speciation , Lakes , Phylogeny , Polymorphism, Single Nucleotide , TanzaniaABSTRACT
Many neglect patients show deficits in the mental representation of their contralesional body side or body parts, termed personal neglect. These deficits include impairments in identifying body parts on schematic drawings of human bodies. Limb activation and alertness cues have been shown to modulate neglect transiently, and are effective treatments for several symptoms of the neglect syndrome. Here, we tested on eight patients with right-hemispheric stroke and left-sided spatial neglect whether these two techniques modulate deficits in the mental representation of hands, assessed with a hand-test in which the subjects had to decide whether a depicted schematic hand belongs to the left or right side of the human body. The results showed that neglect patients made marginally significant (p = 0.065) more errors in left-hand-decisions than right-hand-decisions, indicating a neglect-specific disorder. Moreover, we found that left-sided limb activation but not non-lateralized alertness cueing (a loud noise immediately before patients made their perceptual decision) significantly reduced misidentifications for depicted left hands as compared to baseline. No effect of any intervention was observed on error rates for depicted right hands. We conclude that the amelioration of the performance in the hand task is modulated by the activation of the body schema or other body representations through left-sided limb activation.
ABSTRACT
Long-distance migrants are, by definition, highly mobile but it is poorly understood if this leads to high rates of gene flow and an essentially panmictic global population structure. Genetic divergence in migratory species could be promoted, for example, by fidelity to distinct migratory pathways. In this study, we investigate the population genetic structure of tufted duck (Aythya fuligula), a long-distance migrant with a largely continuous breeding distribution across Eurasia. Distinct, longitudinally oriented flyways have been postulated based on geographically disjunct wintering areas and are supported by evidence from ringing data. We generated sequences of the mitochondrial control region and multi-locus microsatellite genotypes for several hundreds of samples from the European and Asian breeding and wintering grounds including some individuals infected with highly pathogenic avian influenza virus H5N1. Significant differentiation between breeding sites was observed for both marker types, but F(ST) values were approximately 10 times higher for maternally inherited mitochondrial DNA than for biparentally transmitted nuclear markers. The genetic differentiation between the postulated European and Asian flyways was similar to that observed within continents and, in general, genetic divergence was not associated with geographic distance. Neither marker type showed evidence of genetic substructure among aggregations on the European wintering grounds. Our results suggest some breeding site fidelity, especially in females, but extensive population admixture on the wintering grounds. Several scenarios may explain the observed lack of genetic divergence between Europe and Asia including non-equilibrium conditions following a recent range expansion or contemporary gene flow across the postulated migratory divides.
Subject(s)
Animal Migration , Breeding , Ducks/genetics , Animals , Anseriformes/genetics , DNA, Mitochondrial/genetics , Ducks/classification , Ducks/physiology , Female , Gene Flow , Genetic Variation , Male , Microsatellite Repeats , Phylogeny , Phylogeography , SeasonsABSTRACT
Optokinetic stimulation (OKS) modulates many facets of the neglect syndrome. This sensory stimulation technique is known to activate multiple brain regions (temporo-parietal cortex, basal ganglia, brain stem, cerebellum) some of which are involved in auditory and visual space coding. Here, we evaluated whether OKS modulates auditory neglect transiently and induces a sustained effect (Study 1), and whether repetitive OKS permanently recovers auditory neglect (Study 2). In Study 1, 20 patients with visuospatial neglect and auditory neglect in an auditory midline task following rightsided stroke were randomly allocated to an experimental and a control group matched for neglect severity and socio-demographic factors. Both groups showed a stable, pathological shift of their auditory subjective median plane (ASMP) in front space to the right side. During leftward OKS the experimental group showed a complete normalization of the shift of the ASMP, which endured until 30 min poststimulation, and returned almost to baseline values 24h after OKS. In contrast, the control group who viewed the identical but static dot pattern, showed neither change in their ASMP during this condition, nor any significant change at 30 min or 24h poststimulation. In Study 2, we show in two samples of neglect patients (N = 3 each) that repetitive leftward OKS with smooth pursuit eye movements as a therapy induces lasting improvements in auditory (the ASMP) and visual neglect while visual scanning therapy yielded no measurable effects on auditory and significantly smaller effects on visual neglect. In conclusion, the experiments show that a single session of OKS induces rapid though transient recovery from auditory neglect including a sustained effect after termination of stimulation, while repetitive OKS therapy yields enduring and multimodal recovery from auditory and visual neglect. OKS therapy with pursuit eye movements therefore represents a multimodally effective and easily applicable technique for the treatment of auditory and visual neglect.
Subject(s)
Auditory Perception/physiology , Functional Laterality , Nystagmus, Optokinetic/physiology , Perceptual Disorders/rehabilitation , Recovery of Function/physiology , Visual Perception/physiology , Acoustic Stimulation/methods , Adult , Aged , Attention , Brain/pathology , Brain/physiopathology , Female , Follow-Up Studies , Hearing Tests , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Photic Stimulation/methods , Psychomotor Performance/physiology , Reading , Statistics as Topic , Statistics, NonparametricABSTRACT
Ecological speciation is defined as the emergence of reproductive isolation as a direct or indirect consequence of divergent ecological adaptation. Several empirical examples of ecological speciation have been reported in the literature which very often involve adaptation to biotic resources. In this review, we investigate whether adaptation to different thermal habitats could also promote speciation and try to assess the importance of such processes in nature. Our survey of the literature identified 16 animal and plant systems where divergent thermal adaptation may underlie (partial) reproductive isolation between populations or may allow the stable coexistence of sibling taxa. In many of the systems, the differentially adapted populations have a parapatric distribution along an environmental gradient. Isolation often involves extrinsic selection against locally maladapted parental or hybrid genotypes, and additional pre- or postzygotic barriers may be important. Together, the identified examples strongly suggest that divergent selection between thermal environments is often strong enough to maintain a bimodal genotype distribution upon secondary contact. What is less clear from the available data is whether it can also be strong enough to allow ecological speciation in the face of gene flow through reinforcement-like processes. It is possible that intrinsic features of thermal gradients or the genetic basis of thermal adaptation make such reinforcement-like processes unlikely but it is equally possible that pertinent systems are understudied. Overall, our literature survey highlights (once again) the dearth of studies that investigate similar incipient species along the continuum from initial divergence to full reproductive isolation and studies that investigate all possible reproductive barriers in a given system.
Subject(s)
Acclimatization/genetics , Ecosystem , Genetic Speciation , Reproductive Isolation , Temperature , Animals , Genotype , Plants/geneticsABSTRACT
Recent evidence suggests that patients with left-sided visuospatial neglect often show deviations in their visual and haptic perception of verticality in the frontal and sagittal plane. However, little is known about the multimodality of these impairments and the relationship between deviations in the frontal and the sagittal plane. Moreover, no previous study has combined investigations of verticality judgments in both modalities and both spatial planes within the same sample of subjects using the same apparatus. Thus, the aim of the present study was to investigate both subjective visual vertical (SVV) and subjective haptic vertical (SHV) judgments in the frontal and the sagittal plane in right-brain-damaged patients with visuospatial neglect (n=16), right-brain-damaged patients without neglect (n=18) and age-matched healthy individuals (n=16) using the same testing device for all tasks. This allowed for direct comparisons of visual vs. haptic and frontal vs. sagittal verticality judgments. Neglect patients showed significant counterclockwise tilts in their SVV and SHV judgments in the frontal plane as well as marked backward (upper end of the rod towards the observer) tilts in the sagittal plane. In contrast, right-brain-damaged patients without neglect and healthy individuals showed no marked deviations in the frontal plane, but small forward (upper end of the rod away from the observer) tilts in the sagittal plane. Moreover, neglect patients showed significantly higher unsigned errors in all tasks. These results demonstrate multimodal and multispatial deficits in the judgment of verticality in patients with visuospatial neglect which are most likely due to an altered representation of verticality caused by lesions of brain areas related to multisensory integration and space representation in the right temporo-parietal cortex.
Subject(s)
Brain Injuries/physiopathology , Perceptual Disorders/physiopathology , Space Perception/physiology , Visual Perception/physiology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
In diverse animal species, from insects to mammals, females display a more efficient immune defence than males. Bateman's principle posits that males maximize their fitness by increasing mating frequency whereas females gain fitness benefits by maximizing their lifespan. As a longer lifespan requires a more efficient immune system, these implications of Bateman's principle may explain widespread immune dimorphism among animals. Because in most extant animals, the provisioning of eggs and a higher parental investment are attributes of the female sex, sex-role reversed species provide a unique opportunity to assess whether or not immune dimorphism depends on life history and not on sex per se. In the broad-nosed pipefish Syngnathus typhle, males brood and nourish the eggs in a ventral pouch and thus invest more into reproduction than females. We found males to have a more active immune response both in field data from four populations and also in an experiment under controlled laboratory conditions. This applied to different measures of immunocompetence using innate as well as adaptive immune system traits. We further determined the specificity of immune response initiation after a fully factorial primary and secondary exposure to a common marine pathogen Vibrio spp. Males not only had a more active but also a more specific immune defence than females. Our results thus indeed suggest that the sex that invests more into the offspring has the stronger immune defence.
Subject(s)
Behavior, Animal/physiology , Sex Characteristics , Smegmamorpha/immunology , Animals , Demography , Female , Fish Diseases/immunology , Fish Diseases/microbiology , Host-Parasite Interactions , Lymphocyte Count , Lymphocytes/physiology , Male , Monocytes/physiology , Reproduction , Respiratory Burst , Smegmamorpha/physiology , Vibrio/immunology , Vibrio Infections/immunology , Vibrio Infections/veterinaryABSTRACT
Many parasites infect multiple host species. In coevolving host-parasite interactions, theory predicts that parasites should be adapted to locally common hosts, which could lead to regional shifts in host preferences. We studied the interaction between freshwater Gammarus (Crustacea, Amphipoda) and their acanthocephalan parasites using a large-scale field survey and experiments, combined with molecular identification of cryptic host and parasite species. Gammarus pulex is a common host for multiple species of Acanthocephala in Europe but, in Switzerland, is less common than two cryptic members of the Gammarus fossarum species complex (type A and type B). We found that natural populations of these cryptic species were frequently infected by Pomphorhynchus tereticollis and Polymorphus minutus. Four additional parasite species occurred only locally. Parasites were more common in G. fossarum type B than in type A. Infection experiments using several host and parasite sources confirmed consistently lower infection rates in G. pulex than in G. fossarum type A, suggesting a general difference in susceptibility between the two species. In conclusion, we could show that cryptic host species differ in their interactions with parasites, but that these differences were much less dramatic than differences between G. fossarum (type A) and G. pulex. Our data suggest that the acanthocephalans in Switzerland have adapted to the two most common Gammarus species in this region where host species frequencies differ from near-by regions in Europe.