Genes Affecting Vocal and Facial Anatomy Went Through Extensive Regulatory Divergence in Modern Humans, bioRxiv, 2017-02-09
SummaryRegulatory changes are broadly accepted as key drivers of phenotypic divergence. However, identifying regulatory changes that underlie human-specific traits has proven very challenging. Here, we use 63 DNA methylation maps of ancient and present-day humans, as well as of six chimpanzees, to detect differentially methylated regions that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting the face and vocal tract went through particularly extensive methylation changes. Specifically, we identify widespread hypermethylation in a network of face- and voice-affecting genes (SOX9, ACAN, COL2A1, NFIX and XYLT1). We propose that these repression patterns appeared after the split from Neanderthals and Denisovans, and that they might have played a key role in shaping the modern human face and vocal tract.
biorxiv genomics 0-100-users 2017Salmonella entericagenomes recovered from victims of a major 16th century epidemic in Mexico, bioRxiv, 2017-02-09
AbstractIndigenous populations of the Americas experienced high mortality rates during the early contact period as a result of infectious diseases, many of which were introduced by Europeans. Most of the pathogenic agents that caused these outbreaks remain unknown. Using a metagenomic tool called MALT to search for traces of ancient pathogen DNA, we were able to identifySalmonella entericain individuals buried in an early contact era epidemic cemetery at Teposcolula-Yucundaa, Oaxaca in southern Mexico. This cemetery is linked to the 1545-1550 CE epidemic locally known as “cocoliztli”, the cause of which has been debated for over a century. Here we present two reconstructed ancient genomes forSalmonella entericasubsp.entericaserovar Paratyphi C, a bacterial cause of enteric fever. We propose thatS.Paratyphi C contributed to the population decline during the 1545cocoliztlioutbreak in Mexico.One Sentence SummaryGenomic evidence of enteric fever identified in an indigenous population from early contact period Mexico.
biorxiv genomics 0-100-users 2017High-throughput annotation of full-length long noncoding RNAs with Capture Long-Read Sequencing, bioRxiv, 2017-02-02
AbstractAccurate annotations of genes and their transcripts is a foundation of genomics, but no annotation technique presently combines throughput and accuracy. As a result, reference gene collections remain incomplete many gene models are fragmentary, while thousands more remain uncatalogued–particularly for long noncoding RNAs (lncRNAs). To accelerate lncRNA annotation, the GENCODE consortium has developed RNA Capture Long Seq (CLS), combining targeted RNA capture with third-generation long-read sequencing. We present an experimental re-annotation of the GENCODE intergenic lncRNA population in matched human and mouse tissues, resulting in novel transcript models for 3574 561 gene loci, respectively. CLS approximately doubles the annotated complexity of targeted loci, outperforming existing short-read techniques. Full-length transcript models produced by CLS enable us to definitively characterize the genomic features of lncRNAs, including promoter- and gene-structure, and protein-coding potential. Thus CLS removes a longstanding bottleneck of transcriptome annotation, generating manual-quality full-length transcript models at high-throughput scales.Abbreviations<jatsdef-list><jatsdef-item>bpbase pair<jatsdef-item><jatsdef-item>FLfull length<jatsdef-item><jatsdef-item>ntnucleotide<jatsdef-item><jatsdef-item>ROIread of insert, i.e. PacBio read<jatsdef-item><jatsdef-item>SJsplice junction<jatsdef-item><jatsdef-item>SMRTsingle-molecule real-time<jatsdef-item><jatsdef-item>TMtranscript model<jatsdef-item><jatsdef-list>
biorxiv genomics 0-100-users 2017SvABA Genome-wide detection of structural variants and indels by local assembly, bioRxiv, 2017-02-02
AbstractStructural variants (SVs), including small insertion and deletion variants (indels), are challenging to detect through standard alignment-based variant calling methods. Sequence assembly offers a powerful approach to identifying SVs, but is difficult to apply at-scale genome-wide for SV detection due to its computational complexity and the difficulty of extracting SVs from assembly contigs. We describe SvABA, an efficient and accurate method for detecting SVs from short-read sequencing data using genome-wide local assembly with low memory and computing requirements. We evaluated SvABA’s performance on the NA12878 human genome and in simulated and real cancer genomes. SvABA demonstrates superior sensitivity and specificity across a large spectrum of SVs, and substantially improved detection performance for variants in the 20-300 bp range, compared with existing methods. SvABA also identifies complex somatic rearrangements with chains of short (< 1,000 bp) templated-sequence insertions copied from distant genomic regions. We applied SvABA to 344 cancer genomes from 11 cancer types, and found that templated-sequence insertions occur in ~4% of all somatic rearrangements. Finally, we demonstrate that SvABA can identify sites of viral integration and cancer driver alterations containing medium-sized SVs.
biorxiv genomics 0-100-users 2017A computational toolbox and step-by-step tutorial for the analysis of neuronal population dynamics in calcium imaging data, bioRxiv, 2017-01-29
The development of new imaging and optogenetics techniques to study the dynamics of large neuronal circuits is generating datasets of unprecedented volume and complexity, demanding the development of appropriate analysis tools. We present a tutorial for the use of a comprehensive computational toolbox for the analysis of neuronal population activity imaging. It consists of tools for image pre-processing and segmentation, estimation of significant single-neuron single-trial signals, mapping event-related neuronal responses, detection of activity-correlated neuronal clusters, exploration of population dynamics, and analysis of clusters’ features against surrogate control datasets. They are integrated in a modular and versatile processing pipeline, adaptable to different needs. The clustering module is capable of detecting flexible, dynamically activated neuronal assemblies, consistent with the distributed population coding of the brain. We demonstrate the suitability of the toolbox for a variety of calcium imaging datasets, and provide a case study to explain its implementation.
biorxiv neuroscience 0-100-users 2017A randomized placebo-controlled trial on the antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression, bioRxiv, 2017-01-28
AbstractRecent open label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression. In order to further test the antidepressant effects of ayahuasca, we conducted a parallel-arm, double-blind randomized placebo-controlled trial in 29 patients with treatment-resistant depression. Patients received a single dose of either ayahuasca or placebo. Changes in depression severity were assessed with the Montgomery–Åsberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating scale (HAM-D). Assessments were made at baseline, and at one (D1), two (D2) and seven (D7) days after dosing. We observed significant antidepressant effects of ayahuasca when compared to placebo at all timepoints. MADRS scores were significantly lower in the ayahuasca group compared to placebo (at D1 and D2 p=0.04; and at D7 p<0.0001). Between-group effect sizes increased from D1 to D7 (D1 Cohen’ s d=0.84; D2 Cohen’ s d=0.84; D7 Cohen’ s d=1.49). Response rates were high for both groups at D1 and D2, and significantly higher in the ayahuasca group at D7 (64% vs. 27%; p=0.04), while remission rate was marginally significant at D7 (36% vs. 7%, p=0.054). To our knowledge, this is the first controlled trial to test a psychedelic substance in treatment-resistant depression. Overall, this study brings new evidence supporting the safety and therapeutic value of ayahuasca, dosed within an appropriate setting, to help treat depression.
biorxiv clinical-trials 0-100-users 2017