Profiling Trait Anxiety: Transcriptome Analysis Reveals Cathepsin B (Ctsb) as a Novel Candidate Gene for Emotionality in Mice

Behavioral endophenotypes are determined by a multitude of counteracting but precisely balanced molecular and physiological mechanisms. In this study, we aim to identify potential novel molecular targets that contribute to the multigenic trait “anxiety”. We used microarrays to investigate the gene expression profiles of different brain regions within the limbic system of mice which were selectively bred for either high (HAB) or low (LAB) anxiety-related behavior, and also show signs of comorbid depression-like behavior

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome - State of the art: Report of the 2nd international meeting at the Charité fatigue center.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment. During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies. Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies

Lingual deficits in neurotrophin double knockout mice

Brain-derived neurotrophic factor (BDNF) and Neurotrophin 3 (NT-3) are members of the neurotrophin family and are expressed in the developing and adult tongue papillae. BDNF null-mutated mice exhibit specific impairments related to innervation and development of the gustatory system while NT-3 null mice have deficits in their lingual somatosensory innervation. To further evaluate the functional specificity of these neurotrophins in the peripheral gustatory system, we generated double BDNF/NT-3 knockout mice and compared the phenotype to BDNF −/− and wild-type mice. Taste papillae morphology was severely distorted in BDNF −/− x NT-3 −/− mice compared to single BDNF −/− and wild-type mice. The deficits were found throughout the tongue and all gustatory papillae. There was a significant loss of fungiform papillae and the papillae were smaller in size compared to BDNF −/− and wild-type mice. Circumvallate papillae in the double knockouts were smaller and did not contain any intraepithelial nerve fibers. BDNF −/− x NT-3 −/− mice exhibited additive losses in both somatosensory and gustatory innervation indicating that BDNF and NT-3 exert specific roles in the innervation of the tongue. However, the additional loss of fungiform papillae and taste buds in BDNF −/− x NT-3 −/− mice compared to single BDNF knockout mice indicate a synergistic functional role for both BDNF-dependent gustatory and NT-3-dependent somatosensory innervations in taste bud and taste papillae innervation and development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47465/1/11068_2005_Article_3330.pd

Data from: Stress hormone receptors change as range expansion progresses in house sparrows

As ranges expand, individuals encounter different environments at the periphery than at the centre of the range. Previously, we have shown that glucocorticoids (GCs) vary with range expansion: individuals at the range edge release more GCs in response to restraint. Here, we measured hippocampal mRNA expression of GC receptors (mineralocorticoid, MR and glucocorticoid, GR) in eight house sparrow (Passer domesticus) populations varying in age. We found that individuals closest to the range edge had the lowest expression of MR relative to GR; in all likelihood, this relationship was driven by a marginal reduction of MR mRNA at the range edge. Reduced MR (relative to GR) might allow enhanced GC binding to GR, the lower affinity receptor that would enhance a rapid physiological and behavioural response to stressors. The insights gained from this study are not only enlightening to introduced species, but may also predict how certain species will react as their ranges shift owing to anthropogenic changes

Gene expression Values

Raw values from qPCR output, standard curves from each plate; quantity of each gene for each individua

Dissection

Individual mass, tarsus, wing cord values as well as cDNA concentrations for each sample

Data from: Range expansion of house sparrows (Passer domesticus) in Kenya: evidence of genetic admixture and human-mediated dispersal

Introduced species offer an opportunity to study the ecological process of range expansions. Recently, 3 mechanisms have been identified that may resolve the genetic paradox (the seemingly unlikely success of introduced species given the expected reduction in genetic diversity through bottlenecks or founder effects): multiple introductions, high propagule pressure, and epigenetics. These mechanisms are probably also important in range expansions (either natural or anthropogenic), yet this possibility remains untested in vertebrates. We used microsatellite variation (7 loci) in house sparrows (Passer domesticus), an introduced species that has been spreading across Kenya for ~60 years, to determine if patterns of variation could explain how this human commensal overcame the genetic paradox and expresses such considerable phenotypic differentiation across this new range. We note that in some cases, polygenic traits and epistasis among genes, for example, may not have negative effects on populations. House sparrows arrived in Kenya by a single introduction event (to Mombasa, ~1950) and have lower genetic diversity than native European and introduced North American populations. We used Bayesian clustering of individuals (n = 233) to detect that at least 2 types of range expansion occurred in Kenya: one with genetic admixture and one with little to no admixture. We also found that genetic diversity increased toward a range edge, and the range expansion was consistent with long-distance dispersal. Based on these data, we expect that the Kenyan range expansion was anthropogenically influenced, as the expansions of other introduced human commensals may also be

Methylation patterns at fledging predict delayed dispersal in a cooperatively breeding bird.

Individuals may delay dispersing from their natal habitat, even after maturation to adulthood. Such delays can have broad consequences from determining population structure to allowing an individual to gain indirect fitness by helping parents rear future offspring. Dispersal in species that use delayed dispersal is largely thought to be opportunistic; however, how individuals, particularly inexperienced juveniles, assess their environments to determine the appropriate time to disperse is unknown. One relatively unexplored possibility is that dispersal decisions are the result of epigenetic mechanisms interacting between a genome and environment during development to generate variable dispersive phenotypes. Here, we tested this using epiRADseq to compare genome-wide levels of DNA methylation of blood in cooperatively breeding chestnut-crowned babblers (Pomatostomus ruficeps). We measured dispersive and philopatric individuals at hatching, before fledging, and at 1 year (following when first year dispersal decisions would be made). We found that individuals that dispersed in their first year had a reduced proportion of methylated loci than philopatric individuals before fledging, but not at hatching or as adults. Further, individuals that dispersed in the first year had a greater number of loci change methylation state (i.e. gain or lose) between hatching and fledging. The existence and timing of these changes indicate some influence of development on epigenetic changes that may influence dispersal behavior. However, further work needs to be done to address exactly how developmental environments may be associated with dispersal decisions and which loci in particular are manipulated to generate such changes

Invasion genetics : lessons from a ubiquitous bird, the house sparrow Passer domesticus

Following an introduction, non-native species are exposed to environments that differ from those found in their native range; further, as these non-native species expand beyond the site of introduction, they must constantly adapt to novel environments. Although introduced species are present across most ecosystems, few species have successfully established themselves on a truly global scale. One such species, the house sparrow Passer domesticus, is now one of the world’s most broadly distributed vertebrate species and has been introduced to a great part of its current range. To date, work on four continents suggests both genetic and phenotypic variation exists between native and introduced ranges. As such, house sparrows represent an excellent opportunity to study adaptations to novel environments and how these adaptations are derived. The global distribution of this species and the multiple independent introductions to geographically isolated sites allow researchers to ask questions regarding genetic variation and adaptation on a global scale. Here, we summarize the molecular studies of invasive house sparrows from the earliest work using allozymes through more recent work on epigenetics; using these studies, we discuss patterns of dispersal of this species. We then discuss future directions in techniques (e.g. next generation sequencing) and how they will provide new insight into questions that are fundamental to invasion biology. Finally, we discuss how continued research on the house sparrow in light of these genetic changes and adaptations will elucidate answers of adaptation, invasion biology, range expansion, and resilience in vertebrate systems generally.12 page(s