The family Chamaeleonidae comprises 228 species, boasting an extensive geographic spread and an array of evolutionary novelties and adaptations, but a paucity of genetic and molecular analyses. Veiled chameleon () has emerged as a tractable research organism for the study of squamate early development and evolution. Here we report a chromosomal-level assembly and annotation of the veiled chameleon genome.
View Article and Find Full Text PDFDietary specializations in animals lead to adaptations in morphology, anatomy and physiology. Neotropical bats, with their high taxonomic and trophic diversity, offer a unique perspective on diet-driven evolutionary adaptations. Here we assess the metabolic response to different dietary sugars among wild-caught bats.
View Article and Find Full Text PDFThere is currently little information about the evolution of gene clusters, genome architectures and karyotypes in early branching animals. Slowly evolving anthozoan cnidarians can be particularly informative about the evolution of these genome features. Here we report chromosome-level genome assemblies of two related anthozoans, the sea anemones Nematostella vectensis and Scolanthus callimorphus.
View Article and Find Full Text PDFProgrammed DNA loss is a gene silencing mechanism that is employed by several vertebrate and nonvertebrate lineages, including all living jawless vertebrates and songbirds. Reconstructing the evolution of somatically eliminated (germline-specific) sequences in these species has proven challenging due to a high content of repeats and gene duplications in eliminated sequences and a corresponding lack of highly accurate and contiguous assemblies for these regions. Here, we present an improved assembly of the sea lamprey (Petromyzon marinus) genome that was generated using recently standardized methods that increase the contiguity and accuracy of vertebrate genome assemblies.
View Article and Find Full Text PDFSimilar to managing software packages, managing the ontology life cycle involves multiple complex workflows such as preparing releases, continuous quality control checking and dependency management. To manage these processes, a diverse set of tools is required, from command-line utilities to powerful ontology-engineering environmentsr. Particularly in the biomedical domain, which has developed a set of highly diverse yet inter-dependent ontologies, standardizing release practices and metadata and establishing shared quality standards are crucial to enable interoperability.
View Article and Find Full Text PDFAs the planarian research community expands, the need for an interoperable data organization framework for tool building has become increasingly apparent. Such software would streamline data annotation and enhance cross-platform and cross-species searchability. We created the Planarian Anatomy Ontology (PLANA), an extendable relational framework of defined Schmidtea mediterranea (Smed) anatomical terms used in the field.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2020
Genomes of all characterized higher eukaryotes harbor examples of transposable element (TE) bursts-the rapid amplification of TE copies throughout a genome. Despite their prevalence, understanding how bursts diversify genomes requires the characterization of actively transposing TEs before insertion sites and structural rearrangements have been obscured by selection acting over evolutionary time. In this study, rice recombinant inbred lines (RILs), generated by crossing a bursting accession and the reference Nipponbare accession, were exploited to characterize the spread of the very active / family through a small population and the resulting impact on genome diversity.
View Article and Find Full Text PDFVertebrates vary in their ability to regenerate, and the genetic mechanisms underlying such disparity remain elusive. Comparative epigenomic profiling and single-cell sequencing of two related teleost fish uncovered species-specific and evolutionarily conserved genomic responses to regeneration. The conserved response revealed several regeneration-responsive enhancers (RREs), including an element upstream to (), a known effector of vertebrate regeneration.
View Article and Find Full Text PDFIn biology and biomedicine, relating phenotypic outcomes with genetic variation and environmental factors remains a challenge: patient phenotypes may not match known diseases, candidate variants may be in genes that haven't been characterized, research organisms may not recapitulate human or veterinary diseases, environmental factors affecting disease outcomes are unknown or undocumented, and many resources must be queried to find potentially significant phenotypic associations. The Monarch Initiative (https://monarchinitiative.org) integrates information on genes, variants, genotypes, phenotypes and diseases in a variety of species, and allows powerful ontology-based search.
View Article and Find Full Text PDFWhen published, this article did not initially appear open access. This error has been corrected, and the open access status of the paper is noted in all versions of the paper. Additionally, affiliation 16 denoting equal contribution was missing from author Robb Krumlauf in the PDF originally published.
View Article and Find Full Text PDFIn the version of this article initially published, the present addresses for authors Dorit Hockman and Chris Amemiya were switched. The error has been corrected in the HTML and PDF versions of the article.
View Article and Find Full Text PDFPhylogenomic approaches have the potential to improve confidence about the inter-relationships of species in the order Mucorales within the fungal tree of life. species are especially important as plant and animal pathogens and bioindustrial fermenters for food and metabolite production. A dataset of 192 orthologous genes was used to construct a phylogenetic tree of 21 strains, classified into four species isolated from habitats of industrial, medical and environmental importance.
View Article and Find Full Text PDFThe sea lamprey (Petromyzon marinus) serves as a comparative model for reconstructing vertebrate evolution. To enable more informed analyses, we developed a new assembly of the lamprey germline genome that integrates several complementary data sets. Analysis of this highly contiguous (chromosome-scale) assembly shows that both chromosomal and whole-genome duplications have played significant roles in the evolution of ancestral vertebrate and lamprey genomes, including chromosomes that carry the six lamprey HOX clusters.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2017
To understand the success strategies of transposable elements (TEs) that attain high copy numbers, we analyzed two pairs of rice () strains, EG4/HEG4 and A119/A123, undergoing decades of rapid amplification (bursts) of the class 2 autonomous element and the nonautonomous miniature inverted repeat transposable element (MITE) Comparative analyses of whole-genome sequences of the two strain pairs validated that each pair has been maintained for decades as inbreds since divergence from their respective last common ancestor. Strains EG4 and HEG4 differ by fewer than 160 SNPs and a total of 264 new insertions. Similarly, strains A119 and A123 exhibited about half as many SNPs (277) as new insertions (518).
View Article and Find Full Text PDFThe epidermis is essential for animal survival, providing both a protective barrier and cellular sensor to external environments. The generally conserved embryonic origin of the epidermis, but the broad morphological and functional diversity of this organ across animals is puzzling. We define the transcriptional regulators underlying epidermal lineage differentiation in the planarian Schmidtea mediterranea, an invertebrate organism that, unlike fruitflies and nematodes, continuously replaces its epidermal cells.
View Article and Find Full Text PDFPlanarian neoblasts are pluripotent, adult somatic stem cells and lineage-primed progenitors that are required for the production and maintenance of all differentiated cell types, including the germline. Neoblasts, originally defined as undifferentiated cells residing in the adult parenchyma, are frequently compared to embryonic stem cells yet their developmental origin remains obscure. We investigated the provenance of neoblasts during embryogenesis, and report that neoblasts arise from an anarchic, cycling population wholly responsible for production of all temporary and definitive organs during embryogenesis.
View Article and Find Full Text PDFPlanarians have emerged as excellent models for the study of key biological processes such as stem cell function and regulation, axial polarity specification, regeneration, and tissue homeostasis among others. The most widely used organism for these studies is the free-living flatworm Schmidtea mediterranea. In 2007, the Schmidtea mediterranea Genome Database (SmedGD) was first released to provide a much needed resource for the small, but growing planarian community.
View Article and Find Full Text PDFCurr Top Dev Biol
October 2014
The freshwater planarian Schmidtea mediterranea has emerged as a powerful model system for studying regeneration and adult stem cell (ASC) biology. This is largely due to the developmental plasticity of these organisms and the abundant distribution and experimental accessibility of their ASCs. Techniques such as whole mount in situ hybridization, dsRNA-mediated interference, halogenated thymidine analogs for defining cell lineages, and fluorescence-activated cell sorting among other methods, have allowed researchers to interrogate the biology and attendant pluripotent stem cells of these animals in great detail.
View Article and Find Full Text PDFTransposable elements (TEs) are dynamic components of genomes that often vary in copy number among members of the same species. With the advent of next-generation sequencing TE insertion-site polymorphism can be examined at an unprecedented level of detail when combined with easy-to-use bioinformatics software. Here we report a new tool, RelocaTE, that rapidly identifies specific TE insertions that are either polymorphic or shared between a reference and unassembled next-generation sequencing reads.
View Article and Find Full Text PDFWe have developed a portable and easily configurable genome annotation pipeline called MAKER. Its purpose is to allow investigators to independently annotate eukaryotic genomes and create genome databases. MAKER identifies repeats, aligns ESTs and proteins to a genome, produces ab initio gene predictions, and automatically synthesizes these data into gene annotations having evidence-based quality indices.
View Article and Find Full Text PDFThe planarian Schmidtea mediterranea is rapidly emerging as a model organism for the study of regeneration, tissue homeostasis and stem cell biology. The recent sequencing, assembly and annotation of its genome are expected to further buoy the biomedical importance of this organism. In order to make the extensive data associated with the genome sequence accessible to the biomedical and planarian communities, we have created the Schmidtea mediterranea Genome Database (SmedGD).
View Article and Find Full Text PDFPlatyhelminthes are excellent models for the study of stem cell biology, regeneration and the regulation of scale and proportion. In addition, parasitic forms infect millions of people worldwide. Therefore, it is puzzling that they remain relatively unexplored at the molecular level.
View Article and Find Full Text PDFIn recent years, interest in planarians as a model system for the study of metazoan regeneration, adult stem cell biology, and the evolution of metazoan body plans has been growing steadily. The availability of RNA interference (RNAi), BrdU-labeling of planarian stem cells, and thousands of planarian cDNA sequences soon to be released into public databases has opened planarians to molecular dissection. However, the successful application of large-scale RNAi-based screens, for example, will depend in part on the availability of markers to characterize the resulting phenotypes.
View Article and Find Full Text PDF