Impact of exposure to urban air pollution on grey squirrel (Sciurus carolinensis) lung health.

The increased rate of global urbanisation has recently exacerbated the significant public health problem of traffic related air pollution. Despite the known significant impact on human health, little is known about the effects of air pollution on wildlife health. The lung is the primary target organ for the effects of exposure to air pollution, leading to lung inflammation, altering the lung epigenome, culminating in respiratory disease. In this study, we aimed to assess lung health and DNA methylation profiles in Eastern grey squirrel (Sciurus carolinensis) populations living across an urban-rural air pollution gradient. Squirrel lung health was assessed in four populations situated across the most polluted inner-city boroughs to the less polluted edges of Greater London. We also assessed lung DNA methylation across three London sites and a further two rural sites in Sussex and North Wales. Lung and tracheal diseases were present in 28% and 13% of the squirrels respectively. Specifically, focal inflammation (13%), focal macrophages with vacuolated cytoplasm (3%) and endogenous lipid pneumonia (3%). There was no significant difference in prevalence of lung, tracheal diseases, anthracosis (carbon presence) or lung DNA methylation levels between urban sites and urban and rural sites respectively or NO2 levels. BALT (Bronchus-Associated Lymphoid Tissue) was significantly smaller in the site with highest NO2 and contained the highest carbon loading compared to sites with lower NO2, however differences in carbon loading in between sites were not significant. High pollution site individuals also had significantly higher numbers of alveolar macrophages which suggests that grey squirrels are exposed to and respond to traffic-related air pollution and further research is needed to understand the impact of traffic-related air pollutants on wildlife health.

Parentally deprived juvenile Owl monkeys suffer from long-term high infection rates but not from altered hair cortisol concentrations nor from stereotypic behaviours.

BACKGROUND: In captive colonies, owl monkeys' mothers sometimes reject their newborns. To prevent, mortality infants are manually raised by veterinarians. Both parental separation and rejection are stressful experiences, associated with elevated stress, physical, and behavioural disorders. The effect of parental deprivation in IVITA's owl monkeys stress profiles and health is unknown. METHODS: We compared stress biomarkers such as hair cortisol (using cortisol ELISA), stereotypic behaviours (with infrared cameras), and infection histories in juveniles separated from parents soon after birth (n = 14, ~17 months) and controls (n = 11, ~17 months). RESULTS: Parentally deprived owl monkeys show higher infection rates than controls (p = .001). However, they display no higher incidence of biomarkers of stress: Neither stereotypic behaviour nor cortisol in hair was different between cohorts. Irrespective of deprivation status, rates of infection, and concentration of cortisol in hair were positively associated (R2 = .29, p = .005). CONCLUSION: Early parental deprivation and natural high levels of cortisol secretion are associated with elevated infection levels in the IVITA owl monkey juveniles detectable up to 17 months post separation.

Regenerating hair cells in vestibular sensory epithelia from humans.

Human vestibular sensory epithelia in explant culture were incubated in gentamicin to ablate hair cells. Subsequent transduction of supporting cells with ATOH1 using an Ad-2 viral vector resulted in generation of highly significant numbers of cells expressing the hair cell marker protein myosin VIIa. Cells expressing myosin VIIa were also generated after blocking the Notch signalling pathway with TAPI-1 but less efficiently. Transcriptomic analysis following ATOH1 transduction confirmed up-regulation of 335 putative hair cell marker genes, including several downstream targets of ATOH1. Morphological analysis revealed numerous cells bearing dense clusters of microvilli at the apical surfaces which showed some hair cell-like characteristics confirming a degree of conversion of supporting cells. However, no cells bore organised hair bundles and several expected hair cell markers genes were not expressed suggesting incomplete differentiation. Nevertheless, the results show a potential to induce conversion of supporting cells in the vestibular sensory tissues of humans.

Low Incubation Temperature Induces DNA Hypomethylation in Lizard Brains.

Developmental stress can have organizational effects on suites of physiological, morphological, and behavioral characteristics. In lizards, incubation temperature is perhaps the most significant environmental variable affecting embryonic development. Wall lizards (Podarcis muralis) recently introduced by humans from Italy to England experience stressfully cool incubation conditions, which we here show reduce growth and increase the incidence of scale malformations. Using a methylation-sensitive AFLP protocol optimized for vertebrates, we demonstrate that this low incubation temperature also causes hypomethylation of DNA in brain tissue. A consistent pattern across methylation-susceptible AFLP loci suggests that hypomethylation is a general response and not limited to certain CpG sites. The functional consequences of hypomethylation are unknown, but it could contribute to genome stability and regulation of gene expression. Further studies of the effects of incubation temperature on DNA methylation in ectotherm vertebrates may reveal mechanisms that explain why the embryonic thermal environment often has physiological and behavioral consequences for offspring.

Investigation of the ZNF804A gene polymorphism with genetic risk for bipolar disorder in attention deficit hyperactivity disorder.

BACKGROUND: Genome-wide association studies (GWAS) have been conducted on many psychiatric disorders. Evidence from large GWAS indicates that the single nucleotide polymorphism (SNP) rs1344706 in the zinc-finger protein 804A gene (ZNF804A) is associated with psychotic disorders including bipolar disorder and schizophrenia. One study also found significant association between rs1344706 and the executive control network of attention. In this study we examine the role of the rs1344706 polymorphism that previously showed association with BD and is known to alter expression of the gene in two clinical family-based ADHD samples from the UK and Taiwan. FINDINGS: To investigate the association between rs1344706 and ADHD, two family samples of ADHD probands from the United Kingdom (n = 180) and Taiwan (n = 212) were genotyped using TaqMan SNP genotyping assays and analysed using within-family transmission disequilibrium test. No significant associations were found between rs1344706 polymorphism and ADHD in either of the samples from Taiwan (P = 0.91) and UK (P = 0.41). Even combining the two datasets together the A allele of rs1344706 SNP was still not significantly over-transmitted to affected probands (P = 0.50). Furthermore, there was no evidence of association with the specific symptoms subgroups of inattention or hyperactivity-impulsivity. CONCLUSIONS: In this study we used family-based ADHD data in the UK and Taiwanese population to test for an association between rs1344706 SNP in the ZNF804A gene and ADHD. Results showed no significant association of rs1344706 with ADHD in UK and Taiwanese samples.

Intronic tandem repeat in the serotonin transporter gene in Old World monkeys: a new transcriptional regulator?

The serotonin transporter gene (SLC6A4) is heavily involved in the regulation of social behaviour of primates. Old World monkeys (e.g. macaques, baboons) have been used to study interactions between variation in the SLC6A4 gene and behaviour. Correlations of variation at one polymorphism located in the promoter region (known as 5HTTLPR) and variation at SLC6A4 expression levels, serotonin turnover and behaviour has been widely studied. In Old World monkeys, the third intron of the SLC6A4 gene also presents a tandem repeat, which sequence varies across species by a few point substitutions. We predict that in these species, this repeated region also acts as transcriptional regulatory domain and that sequence variation at this polymorphic locus might result in differential levels of expression in gene-environment interactions. For testing these hypotheses, the tandem repeat of Mandrillus sphinx and Cercopithecus aethiops from the third intron were cloned into a reporter gene vector and delivered to either primary cultures of rat neonate frontal cortex or the human cell line (JAr) to analyse their transcriptional activities. These repeated sequences supported significantly different levels of gene expression only when delivered into frontal cortex cultures. Furthermore, we tested in silico if such substitutions could have an effect on their binding profile to RNA- and DNA-binding proteins and on splicing. Taken together our results suggest that the tandem repeat in the third intron of the SLC6A4 gene of Old World monkeys could constitute a second transcriptional regulator as suggested for the 5HTTLPR and therefore contribute to diversification of serotonin-related behaviour in these primates.

An evolutionary conserved region (ECR) in the human dopamine receptor D4 gene supports reporter gene expression in primary cultures derived from the rat cortex.

BACKGROUND: Detecting functional variants contributing to diversity of behaviour is crucial for dissecting genetics of complex behaviours. At a molecular level, characterisation of variation in exons has been studied as they are easily identified in the current genome annotation although the functional consequences are less well understood; however, it has been difficult to prioritise regions of non-coding DNA in which genetic variation could also have significant functional consequences. Comparison of multiple vertebrate genomes has allowed the identification of non-coding evolutionary conserved regions (ECRs), in which the degree of conservation can be comparable with exonic regions suggesting functional significance. RESULTS: We identified ECRs at the dopamine receptor D4 gene locus, an important gene for human behaviours. The most conserved non-coding ECR (D4ECR1) supported high reporter gene expression in primary cultures derived from neonate rat frontal cortex. Computer aided analysis of the sequence of the D4ECR1 indicated the potential transcription factors that could modulate its function. D4ECR1 contained multiple consensus sequences for binding the transcription factor Sp1, a factor previously implicated in DRD4 expression. Co-transfection experiments demonstrated that overexpression of Sp1 significantly decreased the activity of the D4ECR1 in vitro. CONCLUSION: Bioinformatic analysis complemented by functional analysis of the DRD4 gene locus has identified a) a strong enhancer that functions in neurons and b) a transcription factor that may modulate the function of that enhancer.

Genome-wide association study of major recurrent depression in the U.K. population.

OBJECTIVE: Studies of major depression in twins and families have shown moderate to high heritability, but extensive molecular studies have failed to identify susceptibility genes convincingly. To detect genetic variants contributing to major depression, the authors performed a genome-wide association study using 1,636 cases of depression ascertained in the U.K. and 1,594 comparison subjects screened negative for psychiatric disorders. METHOD: Cases were collected from 1) a case-control study of recurrent depression (the Depression Case Control [DeCC] study; N=1346), 2) an affected sibling pair linkage study of recurrent depression (probands from the Depression Network [DeNT] study; N=332), and 3) a pharmacogenetic study (the Genome-Based Therapeutic Drugs for Depression [GENDEP] study; N=88). Depression cases and comparison subjects were genotyped at Centre National de Génotypage on the Illumina Human610-Quad BeadChip. After applying stringent quality control criteria for missing genotypes, departure from Hardy-Weinberg equilibrium, and low minor allele frequency, the authors tested for association to depression using logistic regression, correcting for population ancestry. RESULTS: Single nucleotide polymorphisms (SNPs) in BICC1 achieved suggestive evidence for association, which strengthened after imputation of ungenotyped markers, and in analysis of female depression cases. A meta-analysis of U.K. data with previously published results from studies in Munich and Lausanne showed some evidence for association near neuroligin 1 (NLGN1) on chromosome 3, but did not support findings at BICC1. CONCLUSIONS: This study identifies several signals for association worthy of further investigation but, as in previous genome-wide studies, suggests that individual gene contributions to depression are likely to have only minor effects, and very large pooled analyses will be required to identify them.

Combinatorial interaction between two human serotonin transporter gene variable number tandem repeats and their regulation by CTCF.

Two distinct variable number tandem repeats (VNTRs) within the human serotonin transporter gene (SLC6A4) have been implicated as predisposing factors for CNS disorders. The linked polymorphic region in the 5'-promoter exists as short (s) and long (l) alleles of a 22 or 23 bp elements. The second within intron 2 (Stin2) exists as three variants containing 9, 10 or 12 copies of a 16 or 17 bp element. These VNTRs, individually or in combination, supported differential reporter gene expression in rat neonate prefrontal cortical cultures. The level of reporter gene activity from the dual VNTR constructs indicated combinatorial action between the two domains. Chromatin immunoprecipitation demonstrated that both these VNTR domains can bind the CCCTC-binding factor and this correlated with the ability of exogenously supplied CCCTC-binding factor to modulate the expression supported by these reporter gene constructs. We suggest that the potential for interaction between multiple polymorphic domains should be incorporated into genetic association studies.