Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.

Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago.

M5 receptor activation produces opposing physiological outcomes in dopamine neurons depending on the receptor's location.

Of the five muscarinic receptor subtypes, the M5 receptor is the only one detectable in midbrain dopaminergic neurons, making it an attractive potential therapeutic target for treating disorders in which dopaminergic signaling is disrupted. However, developing an understanding of the role of M5 in regulating midbrain dopamine neuron function has been hampered by a lack of subtype-selective compounds. Here, we extensively characterize the novel compound VU0238429 and demonstrate that it acts as a positive allosteric modulator with unprecedented selectivity for the M5 receptor. We then used VU0238429, along with M5 knock-out mice, to elucidate the role of this receptor in regulating substantia nigra pars compacta (SNc) neuron physiology in both mice and rats. In sagittal brain slices that isolate the SNc soma from their striatal terminals, activation of muscarinic receptors induced Ca2+ mobilization and inward currents in SNc dopamine neurons, both of which were potentiated by VU0238429 and absent in M5 knock-out mice. Activation of M5 also increased the spontaneous firing rate of SNc neurons, suggesting that activation of somatodendritic M5 increases the intrinsic excitability of SNc neurons. However, in coronal slices of the striatum, potentiation of M5 with VU0238429 resulted in an inhibition in dopamine release as monitored with fast scan cyclic voltammetry. Accordingly, activation of M5 can lead to opposing physiological outcomes depending on the location of the receptor. Although activation of somatodendritic M5 receptors on SNc neurons leads to increased neuronal firing, activation of M5 receptors in the striatum induces an inhibition in dopamine release.

Glycine transporter-1 inhibition promotes striatal axon sprouting via NMDA receptors in dopamine neurons.

NMDA receptor activity is involved in shaping synaptic connections throughout development and adulthood. We recently reported that brief activation of NMDA receptors on cultured ventral midbrain dopamine neurons enhanced their axon growth rate and induced axonal branching. To test whether this mechanism was relevant to axon regrowth in adult animals, we examined the reinnervation of dorsal striatum following nigral dopamine neuron loss induced by unilateral intrastriatal injections of the toxin 6-hydroxydopamine. We used a pharmacological approach to enhance NMDA receptor-dependent signaling by treatment with an inhibitor of glycine transporter-1 that elevates levels of extracellular glycine, a coagonist required for NMDA receptor activation. All mice displayed sprouting of dopaminergic axons from spared fibers in the ventral striatum to the denervated dorsal striatum at 7 weeks post-lesion, but the reinnervation in mice treated for 4 weeks with glycine uptake inhibitor was approximately twice as dense as in untreated mice. The treated mice also displayed higher levels of striatal dopamine and a complete recovery from lateralization in a test of sensorimotor behavior. We confirmed that the actions of glycine uptake inhibition on reinnervation and behavioral recovery required NMDA receptors in dopamine neurons using targeted deletion of the NR1 NMDA receptor subunit in dopamine neurons. Glycine transport inhibitors promote functionally relevant sprouting of surviving dopamine axons and could provide clinical treatment for disorders such as Parkinson's disease.

AGAP1/AP-3-dependent endocytic recycling of M5 muscarinic receptors promotes dopamine release.

Of the five mammalian muscarinic acetylcholine (ACh) receptors, M(5) is the only subtype expressed in midbrain dopaminergic neurons, where it functions to potentiate dopamine release. We have identified a direct physical interaction between M(5) and the AP-3 adaptor complex regulator AGAP1. This interaction was specific with regard to muscarinic receptor (MR) and AGAP subtypes, and mediated the binding of AP-3 to M(5). Interaction with AGAP1 and activity of AP-3 were required for the endocytic recycling of M(5) in neurons, the lack of which resulted in the downregulation of cell surface receptor density after sustained receptor stimulation. The elimination of AP-3 or abrogation of AGAP1-M(5) interaction in vivo decreased the magnitude of presynaptic M(5)-mediated dopamine release potentiation in the striatum. Our study argues for the presence of a previously unknown receptor-recycling pathway that may underlie mechanisms of G-protein-coupled receptor (GPCR) homeostasis. These results also suggest a novel therapeutic target for the treatment of dopaminergic dysfunction.

Dual control of dopamine synthesis and release by presynaptic and postsynaptic dopamine D2 receptors.

Dysfunctions of dopaminergic homeostasis leading to either low or high dopamine (DA) levels are causally linked to Parkinson's disease, schizophrenia, and addiction. Major sites of DA synthesis are the mesencephalic neurons originating in the substantia nigra and ventral tegmental area; these structures send major projections to the dorsal striatum (DSt) and nucleus accumbens (NAcc), respectively. DA finely tunes its own synthesis and release by activating DA D2 receptors (D2R). To date, this critical D2R-dependent function was thought to be solely due to activation of D2Rs on dopaminergic neurons (D2 autoreceptors); instead, using site-specific D2R knock-out mice, we uncover that D2 heteroreceptors located on non-DAergic medium spiny neurons participate in the control of DA levels. This D2 heteroreceptor-mediated mechanism is more efficient in the DSt than in NAcc, indicating that D2R signaling differentially regulates mesolimbic- versus nigrostriatal-mediated functions. This study reveals previously unappreciated control of DA signaling, shedding new light on region-specific regulation of DA-mediated effects.

Lipid biomarkers and metal pollution in the Holocene record of Cartagena Bay (SE Spain): Coupled natural and human induced environmental history in Punic and Roman times.

We reconstructed the palaeoenvironmental conditions of Cartagena Bay during the Holocene after a multidisciplinary study to identify natural variations and the anthropic processes of this coastal area. A total of 119 samples were recovered for amino acid racemization dating, 3 for radiocarbon dating (14C), and four sets of 80 samples for sedimentological and palaeontological determination, mineralogical content, biomarker and trace elements quantification. Two natural scenarios were identified from the variations of n-alkane indices and palaeobiological content. The first period (6650-5750 yr cal BP) was marked by the development of euhaline marine conditions with strong inputs from aquatic macrophytes and high biodiversity. After a hiatus, the area underwent a profound change, becoming a paucispecific brackish marsh environment with increasing inputs from land plants, with possible episodes of emersion with a greater presence from terrestrial gastropods (3600-300 cal yr BP). By combining trace element abundance and stanol distributions, our study also provides a novel approach to identify the predominant influence of anthropogenic factors in the last three millennia in the coastal record of Cartagena Bay. Findings confirmed that Pb mining and metallurgy began during the Bronze Age, with considerable inputs of this heavy metal into the atmosphere during Phoenician, Punic and particularly Roman times compared to the Middle Ages. Pollution by Cu and Zn was also observed during Punic and Roman times, and was first documented in the Middle Ages. In addition, faecal stanols, such as coprostanol, derived mainly from humans, and 24-ethylcoprostanol from herbivores were present, thereby indicating for the first time a continuous presence of human populations and significant pollution input since 3600 yr cal BP, this being greater in the late Bronze Age and Phoenician, Punic and Roman times than during Late Antiquity and the Middle Ages, when the city was in decline.

Keys to discern the Phoenician, Punic and Roman mining in a typical coastal environment through the multivariate study of trace element distribution.

Trace element concentrations in the Cartagena Bay coastal record reveal a contribution of natural processes. However, the influence of anthropogenic factors predominates in the last three millennia, particularly aerosol deposition linked to mining and industrial activities in the area. The coastal record of Cartagena can be considered a preserved environment, suitable to search for regional human activity fingerprinting, specifically that related to the deposition of heavy metals such as Pb and Cu. A multivariate statistical analysis was carried out to clarify the geochemical behaviour of trace and major elements. Our study design represents a novel approach to assign natural contributions, such as eolian and riverine input, to coastal deposits, and organic matter preservation under anoxic environments. Therefore, synergies obtained by the simultaneous study of multivariate statistics and enrichment factors allow robust conclusions about palaeoenvironmental evolution and human activities. Anthropogenic influence suggested that Pb mining and metallurgy began during the Chalcolithic period, with considerable inputs of Pb and Cu to atmospheric pollution during Phoenician, Punic and Roman times.

Solution-phase racemization in the presence of an enantiopure solid phase.

Solution-phase racemization drives the evolution of single chirality in the solid phase by the "chiral amnesia" process first described by Viedma. The current investigations lay the basis for a better understanding of the mechanism of the solid-phase deracemization by uncoupling the chemical rate processes associated with the interconversion of enantiomers in the solution phase from the physical processes associated with solution-solid phase transfer via dissolution and reaccretion of molecules onto crystals. In addition, the enantiomer concentration profiles presented in this work, together with an analytical treatment of the racemization process in the presence of excess enantiopure solid, unequivocally reconfirm the validity of the Meyerhoffer double solubility rule for systems under solution racemization conditions.

Pasteur made simple - mechanochemical transformation of racemic amino acid crystals into racemic conglomerate crystals.

Conglomerate crystallization is required for many deracemization or enantioenrichment protocols. Here, we report the metal-mediated mechanochemical transformation of racemic compounds of some proteinogenic amino acids - valine, leucine and isoleucine - into their corresponding conglomerates. Specifically, ZnO has the ability to promote and stabilize the conglomerate phase of these amino acids to an extent where the racemic compound is not observed.

Arylsulfatase A pseudodeficiency in Mexico: Enzymatic activity and haplotype analysis.

BACKGROUND: Metachromatic Leukodystrophy (MLD, OMIM 250100) is a neurodegenerative disease caused by mutations in the ARSA gene (OMIM 607574) that lead to deficiency in Arylsulfatase A (ASA). ASA pseudodeficiency (PD-ASA) is a biochemical condition that substantially diminishes ASA activity but is not associated with clinical manifestations. PD-ASA is associated with the c.1055A>G (p.Asn352Ser) (rs2071421) and c.*96A>G (rs6151429) variants, which have an estimated frequency of 2% in the population. OBJECTIVE: To determine the activity of Arylsulfatase A and to identify variants and haplotypes in the ARSA gene in Mexican individuals with pseudodeficiency. METHODS: Two-hundred apparently healthy individuals were included to determine the enzymatic activity of ASA in leukocytes by spectrophotometric analysis, and identification of the PD-ASA alleles was performed by PCR-RFLP assays. Genotypes were confirmed by semi-automated Sanger sequencing. Haplotypes were constructed using Arlequin v.10.04, and linkage disequilibrium analysis was performed with Cube X. RESULTS: The enzymatic activity of ASA was determined to be 1.74-2.09 nmol/mg protein/min and later correlated with genotypes and haplotypes. For the (p.Asn352Ser) variant, we found 126 (0.63) individuals with the AA genotype, 62 with AG (0.31) and 12 with GG (0.06); the frequency of the polymorphic allele was 0.215 (86 alleles, 21.5%), and the variant was in HWE (p = .2484). The variant c.*96A>G was also in HWE (p = .2105): 185 individuals (0.925) with the AA genotype, 14 (0.07) with AG, and 1 (0.005) with (GG), with a frequency of 0.04 (4%) for the polymorphic allele. The inference of haplotypes resulted in 312 (0.78) AA, 72 (0.18) GA, and 16 (0.04) GG haplotypes. The AG haplotype was not found. The variants were found to be in linkage disequilibrium (D' = 1). Of the nine possible diplotypes, AA/AG, AA/GG, and AG/GG were not found, in concordance with the hypothesis that the G allele of c.*96A>G does not occur in the absence of the G allele of c.1055A>G. We found a slight correlation between ASA biochemical activity and variants, mainly due to the G allele of c.*96A>G in either genotypes or haplotypes. CONCLUSIONS: In Northwestern Mexico, the presence of PD-ASA alleles was biochemically and molecularly determined, and the frequencies were found to be in HWE. The frequency of PD-ASA for the North Western Mexican mestizo is 8%.

A multivariate examination of the timing and accumulation of potentially toxic elements at Las Conchas bog (NW Spain).

The inorganic content of the well-preserved 3.2-m record of Las Conchas bog (NW Spain), covering 8000 cal yr BP., was analysed. To study natural vs. human contributions, we applied an innovative approach, namely the sequential study of multivariate statistics (factor analysis followed by clustering of the factor score matrix) and enrichment factors (EFs). The increasing weight of potentially toxic elements (PTEs) such as the geochemical association of Zn, Pb and Cd (EFs higher than 10, 20 and 40 in the last two centuries) was revealed, and corroborated by the contrast between the contents of anthropogenic Pb and total Rare Earth Elements (a suitable proxy for natural geogenic supplies). Furthermore, elements such as Hg, Tl and As also showed enrichment in the most recent samples of the study core. Some of them are commonly associated with global atmospheric transport; however, in this case, their increasing contents could also be explained by nearby industrial and mining activities. In summary, severe pollution was observed in the uppermost part of the record, thereby pointing to an important environmental concern. Given that local and regional sources of PTEs, such as mining and heavy industry, especially Zn smelting, were probably the main historical causes of this contamination and that some of these industries are still active, we consider that our findings deserve further attention.

Amphetamine enantiomers inhibit homomeric α7 nicotinic receptor through a competitive mechanism and within the intoxication levels in humans.

Amphetamine-type stimulants (ATS) are the second most consumed illicit drug worldwide and lack good treatments for associated substance use disorders, lagging behind other addictive drugs. For this reason, a deeper understanding of the pharmacodynamics of ATS is required. The present study seeks to determine amphetamine (AMPH) enantiomers' effects on the homomeric α7 nicotinic acetylcholine receptor (α7 nAChR). Here we have shown that AMPH enantiomers bind to the α7 nAChR and competitively inhibit acetylcholine responses. Our in silico docking analysis suggests that AMPH binds close to the ß7 strand of the B-loop of a chimera comprising of the human α7 nAChR and the acetylcholine binding protein from Lymnaea stagnalis. This may inhibit the required movement of the C-loop for channel opening, due to steric hindrance, providing a structural mechanism for its antagonist effect. Finally, we have shown that, in α7 nAChR full knockout mice, the behavioral response to D-AMPH is attenuated, providing direct evidence for the role of α7 nAChRs on the physiological response to D-AMPH. Importantly, D-AMPH exerts these effects at concentrations predicted to be pharmacologically relevant for chronic methamphetamine users and during binges. In conclusion, our data present new findings that implicate the α7 nAChR on the pharmacodynamics of ATS, which may be important for behavioral responses to these drugs, indicating a potential role for α7 nAChRs in ATS substance-use disorders.

Evolution of solid phase homochirality for a proteinogenic amino acid.

The inexorable evolution of solid-phase single chirality is demonstrated for the first time for a proteinogenic amino acid. Enantioenrichment is observed both under attrition-enhanced conditions and without the aid of particle grinding. Differences in the form of the conversion profiles for the process under the two sets of conditions provide suggestions concerning the mechanism of the transformation.

Uncommon runs of homozygosity disclose homozygous missense mutations in two ciliopathy-related genes (SPAG17 and WDR35) in a patient with multiple brain and skeletal anomalies.

We describe a patient severely affected with multiple congenital anomalies, including brain malformations and skeletal dysplasia suggestive of cranioectodermal dysplasia (CED) ciliopathy, who unusually carries several homozygosity tracts involving homozygous missense mutations in SPAG17 (exon 8; c.1069G > C; p.Asp357His) and WDR35 (exon 13; c.1415G > A; p.Arg472Gln) as revealed by homozygosity mapping and next generation sequencing. SPAG17 is essential for the function and structure of motile cilia, while WDR35 belongs to the same intraflagellar transport (IFT) gene family whose protein products are part of functional IFT A and B complexes. Formerly, SPAG17 was related - through polymorphic variants - to an influence on individuals' height; more recently, Spag17-/- mice models were reported to present skeletal and bone defects, reduced mucociliary clearance, respiratory distress, and cerebral ventricular enlargement. Homozygous or compound heterozygous mutations in WDR35 have mainly been related to CED2 or short-rib thoracic dysplasia 7, with only three cases showing some brain anomalies. Given that our patient presents these clinical features and the close functional relationship between SPAG17 and WDR35, it is feasible that the combined effects from both mutations contribute to his phenotype. To our knowledge, this patient is the first to harbor a likely pathogenic homozygous mutation in both genes at the same time. Thus, the resulting complex phenotype of this patient illustrates the heterogeneity associated with ciliopathies and further expands the clinical and mutational spectrum of these diseases. Finally, we highlight the combined use of high-throughput tools to diagnose and support the proper handling of this and other patients.

Alopecia Areata. Current situation and perspectives. / Alopecia areata. Actualidad y perspectivas.

Alopecia areata (AA) is a dermatological disease characterized by non-scarring hair loss of the scalp and/or body, with an unpredictable and variable evolution in the patients in which, despite multidisciplinary efforts, its etiology is not entirely known, although some evidence suggests that environmental, immunological and genetic factors could be generating the disease. The aim of this review is to provide an updated panorama of the clinical characteristics, diagnosis and treatment of AA, to analyze the mechanisms that could participate in its etiology, as well as to review some of the most important genetic variants that could confer susceptibility to the development of this disease.

La alopecia areata es un padecimiento dermatológico caracterizado por la pérdida de pelo no cicatricial del cuero cabelludo y/o del cuerpo, con una evolución impredecible y variable en los pacientes. A pesar de esfuerzos multidisciplinarios, su etiología sigue sin conocerse con exactitud, aunque algunas evidencias sugieren que factores ambientales, inmunológicos y genéticos podrían estar originando la enfermedad. El objetivo de esta revisión consiste en dar un panorama actual de las características clínicas, diagnóstico y tratamiento de la alopecia areata, analizar los mecanismos que podrían participar en su etiología, así como revisar algunas de las variantes génicas más importantes, que podrían conferir susceptibilidad al desarrollo de la enfermedad.

SMCHD1 mutations associated with a rare muscular dystrophy can also cause isolated arhinia and Bosma arhinia microphthalmia syndrome.

Arhinia, or absence of the nose, is a rare malformation of unknown etiology that is often accompanied by ocular and reproductive defects. Sequencing of 40 people with arhinia revealed that 84% of probands harbor a missense mutation localized to a constrained region of SMCHD1 encompassing the ATPase domain. SMCHD1 mutations cause facioscapulohumeral muscular dystrophy type 2 (FSHD2) via a trans-acting loss-of-function epigenetic mechanism. We discovered shared mutations and comparable DNA hypomethylation patterning between these distinct disorders. CRISPR/Cas9-mediated alteration of smchd1 in zebrafish yielded arhinia-relevant phenotypes. Transcriptome and protein analyses in arhinia probands and controls showed no differences in SMCHD1 mRNA or protein abundance but revealed regulatory changes in genes and pathways associated with craniofacial patterning. Mutations in SMCHD1 thus contribute to distinct phenotypic spectra, from craniofacial malformation and reproductive disorders to muscular dystrophy, which we speculate to be consistent with oligogenic mechanisms resulting in pleiotropic outcomes.

[Anterior cervical hypertrichosis: case report]. / Hipertricosis cervical anterior: caso dínico.

The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

La hipertricosis cervical anterior no sindrómica (OMIM N° 600457) es un desorden genético caracterizado por un parche de pelo a nivel de la prominencia laríngea. Se presenta a un niño de 12 años de edad con hipertricosis cervical anterior e hipertricosis generalizada leve, sin alteraciones neurológicas, oftalmológicas ni esqueléticas, en seguimiento clínico por un lapso de 10 años.

Bosma arrhinia microphthalmia syndrome in a Mexican patient with a molecular analysis of PAX6.

The association of anophthalmia, arrhinia, and hypogonadism constitutes the major clinical features for Bosma arrhinia microphthalmia syndrome. However, there is variability in the presentation of this disease; arrhinia is the most constant clinical feature, which is then combined with a spectrum of anophthalmia/microphthalmia and/or hypogonadism. This rare entity is not associated with any specific genes, but the genes that are related to arrhinia and anophthalmia have been studied in an attempt to explain this phenomenon. We analyzed the PAX6 gene in a Bosma arrhinia microphthalmia syndrome patient but found no variation or mutation that could constitute or establish a causal association in our patient.

Parkinsonism Driven by Antipsychotics Originates from Dopaminergic Control of Striatal Cholinergic Interneurons.

Typical antipsychotics can cause disabling side effects. Specifically, antagonism of D2R signaling by the typical antipsychotic haloperidol induces parkinsonism in humans and catalepsy in rodents. Striatal dopamine D2 receptors (D2R) are major regulators of motor activity through their signaling on striatal projection neurons and interneurons. We show that D2R signaling on cholinergic interneurons contributes to an in vitro pause in firing of these otherwise tonically active neurons and to the striatal dopamine/acetylcholine balance. The selective ablation of D2R from cholinergic neurons allows discrimination between the motor-reducing and cataleptic effects of antipsychotics. The cataleptic effect of antipsychotics is triggered by blockade of D2R on cholinergic interneurons and the consequent increase of acetylcholine signaling on striatal projection neurons. These studies illuminate the critical role of D2R-mediated signaling in regulating the activity of striatal cholinergic interneurons and the mechanisms of typical antipsychotic side effects.

Two girls with a de novo Xq rearrangement of paternal origin: t(X;9)(q24;q12) or rea(X)dup q.

OBJECTIVE: We report on two rare Xq rearrangements, namely a t(X;9)(q24;q12) found in a mildly-affected girl (Patient 1) and a rea(X)dup q concomitant with a rob(14;21)mat in a Down syndrome girl (Patient 2). CASE REPORT: Both rearrangements were characterized by banding techniques [Giemsa (G), constitutive heterochromatin (C), and bromodeoxyuridine (BrdU) pulse], fluorescence in situ hybridization (FISH) assays, human androgen receptor (HUMAR) assays, and microarray analyses. Patient 1 had a t(X;9)(q24;q12)dn. Patient 2 had a de novo rea(X)(qter→q23 or q24::p11.2→qter) concomitant with an unbalanced rob(14;21)mat. X-Inactivation studies in metaphases and DNA revealed a fully skewed inactivation: the normal homolog was silenced in Patient 1 and the rea(X) in Patient 2. Both rearranged X chromosomes were of paternal descent. Microarray analyses revealed no imbalances in Patient 1 whereas loss of Xp (∼52 Mb) and duplication of Xq (∼44 Mb) and 21q were confirmed in Patient 2. CONCLUSION: Our observations further document the cytogenetic heterogeneity and predominant paternal origin of certain de novo X-chromosome rearrangements.