Multiple Related Species Research Articles

Multispecies comparisons support a startle response origin for a novel vibrational signal in the cricket tribe Lebinthini.

Many animals communicate using call and response signals, but the evolutionary origins of this type of communication are largely unknown. In most cricket species, males sing and females walk or fly to calling males. In the tribe Lebinthini, however, males produce calls that trigger a vibrational reply from females, and males use the substrate vibrations to find the responding female. Here we assess two hypotheses regarding the behavioral origin of this multimodal duet in the Lebinthini. We conducted playback experiments and measured behavioral and neuronal responses in multiple related cricket species to assess whether the precursor to the lebinthine duet was 1) a startle response to high-frequency sound, or 2) elaboration of a preexisting courtship behavior. We found behavioral similarities between the vibrational response of Lebinthini females and the acoustic startle behavior in other gryllid crickets. Specifically, the amplitude of the vibrational reply increases with male song amplitude in Lebinthini, and the magnitude of vibrations produced by two gryllid species when startled with ultrasound also correlates with the stimulus amplitude. Like in-flight startle behavior, the startle vibrations produced by perched crickets are suppressed when low-frequency sound is played simultaneously. We also observed courtship behavior in four gryllid species and found few instances of female vibration. Vibrational signals observed in Gryllus pennsylvanicus females were not correlated with male calls and occurred more frequently in pairs that did not mate after courtship. Combined, accumulating evidence supports the hypothesis that the lebinthine duet more likely evolved from a startle precursor than courtship behavior.

Evolution of secondary metabolites, morphological structures and associated gene expression patterns in galls induced by four closely related aphid species on a host plant species.

Gall-forming insects induce various types of galls on their host plants by altering gene expression in host plant organs, and recent studies have been conducted for gene expression in galls. However, the evolutionary trajectories of gene expression patterns and the resulting phenotypes have not yet been studied using multiple related species. We investigated the speciation and the diversification process of galls induced by four closely related aphid species (Hormaphidini) on a host plant species (Hamamelis japonica) by examining the phylogenetic congruence between the geographical divergences of aphids and the host plant, and by comparing their gene expression patterns and resulting phenotypes. Phylogenetic analysis of aphids and the host plant showed that geographical isolation among host plant populations has interrupted gene flow in aphids and accelerated the speciation process. The concentration of phenolics and the complexity of the internal structure of galls were correlated with the expression levels of genes for the biosynthesis of phenolics and morphogenesis respectively. These results suggest that the expression levels of genes for the biosynthesis of phenolics and morphogenesis have evolutionarily increased in galls accelerated by the speciation process of aphids due to the distribution change of the host plant, leading to the related phenotypic evolution. Our study showed the evolutionary process of phenotypic traits in galls in the wild from both gene expression and actual phenotype levels.

Coordination compensated metal-organic framework fluorescent sensor for highly selective and sensitive dual-detection of phosphate and hydrogen sulfide

With the rapid development of aquaculture industry, it is of great significance to monitor the level of multiple related species in water for the sustainable development of the aquaculture industry and the protection of the surrounding ecological environment. In this paper, a novel fluorescent MOF sensor UiO-66-NH2@NDBPA has been developed conveniently based on coordination compensated strategy and applied for simultaneous dual-detection of both phosphate and hydrogen sulfide with non-interference to each other, which are two very important relative species in aquaculture water. The detection limits of phosphate and hydrogen sulfide were as low as 45 nM and 120 nM, respectively. Additionally, the practicability for the simultaneous dual-detection based on this sensor was further proved by the detection of phosphate and hydrogen sulfide in actual water samples and the recovery rate ranged from 98.8% to 103.2%.

Characteristics and potential functional effects of long insertions in Asian butternuts

BackgroundStructural variants (SVs) play important roles in adaptation evolution and species diversification. Especially, in plants, many phenotypes of response to the environment were found to be associated with SVs. Despite the prevalence and significance of SVs, long insertions remain poorly detected and studied in all but model species.ResultsWe used whole-genome resequencing of paired reads from 80 Asian butternuts to detect long insertions and further analyse their characteristics and potential functional effects. By combining of mapping-based and de novo assembly-based methods, we obtained a multiple related species pangenome representing higher taxonomic groups. We obtained 89,312 distinct contigs totaling 147,773,999 base pair (bp) of new sequences, of which 347 were putative long insertions placed in the reference genome. Most of the putative long insertions appeared in multiple species; in contrast, only 62 putative long insertions appeared in one species, which may be involved in the response to the environment. 65 putative long insertions fell into 61 distinct protein-coding genes involved in plant development, and 105 putative long insertions fell into upstream of 106 distinct protein-coding genes involved in cellular respiration. 3,367 genes were annotated in 2,606 contigs. We propose PLAINS (https://github.com/CMB-BNU/PLAINS.git), a streamlined, comprehensive pipeline for the prediction and analysis of long insertions using whole-genome resequencing.ConclusionsOur study lays down an important foundation for further whole-genome long insertion studies, allowing the investigation of their effects by experiments.

Landscape Connectivity and Genetic Structure in a Mainstem and a Tributary Stonefly (Plecoptera) Species Using a Novel Reference Genome.

Understanding how environmental variation influences population genetic structure can help predict how environmental change influences population connectivity, genetic diversity, and evolutionary potential. We used riverscape genomics modeling to investigate how climatic and habitat variables relate to patterns of genetic variation in 2 stonefly species, one from mainstem river habitats (Sweltsa coloradensis) and one from tributaries (Sweltsa fidelis) in 40 sites in northwest Montana, USA. We produced a draft genome assembly for S. coloradensis (N50 = 0.251 Mbp, BUSCO > 95% using "insecta_ob9" reference genes). We genotyped 1930 SNPs in 372 individuals for S. coloradensis and 520 SNPs in 153 individuals for S. fidelis. We found higher genetic diversity for S. coloradensis compared to S. fidelis, but nearly identical genetic differentiation among sites within each species (both had global loci median FST = 0.000), despite differences in stream network location. For landscape genomics and testing for selection, we produced a less stringently filtered data set (3454 and 1070 SNPs for S. coloradensis and S. fidelis, respectively). Environmental variables (mean summer precipitation, slope, aspect, mean June stream temperature, land cover type) were correlated with 19 putative adaptive loci for S. coloradensis, but there was only one putative adaptive locus for S. fidelis (correlated with aspect). Interestingly, we also detected potential hybridization between multiple Sweltsa species which has never been previously detected. Studies like ours, that test for adaptive variation in multiple related species are needed to help assess landscape connectivity and the vulnerability of populations and communities to environmental change.

Concurrent habitat fluctuations of two economically important marine species in the Southeast Pacific Ocean off Chile in relation to ENSO perturbations

AbstractENSO‐driven concurrent habitat fluctuations of two economically important marine species jumbo squid Dosidicus gigas and jack mackerel Trachurus murphyi in the Southeast Pacific Ocean off Chile during 1950–2017 were examined using a habitat suitability index (HSI) modeling approach. The optimal HSI models sourced from 10 weighing‐based scenarios were developed, selected and validated using the crucial factors water temperature at 400 m depth (Temp_400m), sea surface height anomaly (SSHA) and sea surface salinity (SSS) for D. gigas and sea surface temperature (SST), Temp_400m, and mixed layer depth (MLD) for T. murphyi. Results suggested that the optimal HSI model could accurately predict the habitat hotspots for D. gigas and T. murphyi. The ENSO event (indicated by Niño 3.4 index, NI) was significantly related to environmental conditions off Chile. Cross‐correlation revealed positive relationships between NI and SST, SSHA, SSS, and Temp_400m and negative correlation between NI and MLD. Synchronous opposite habitat fluctuations were shown between D. gigas and T. murphyi under different ENSO events. The NI was significantly negatively related to the HSI of D. gigas and positively correlated with the HSI of T. murphyi. Comparing with the El Niño years, suitable habitats of D. gigas and T. murphyi dramatically enlarged and contracted, respectively, during the La Niña years. Both suitable habitats moved southwestward under this climate conditions. Our finding suggested that ENSO‐driven environmental changes played important roles in the concurrent habitat fluctuations of D. gigas and T. murphyi. Such studies are conducive to the effective utilization and management of multiple related species.

Modern cryptic species and crocodylian diversity in the fossil record

AbstractAdvances in molecular biology and genetics are revealing that many recognized crocodylian species are complexes of two or more cryptic species. These discoveries will have a profound impact on interpretation of the crocodyliform fossil record. Our understanding of ranges of intraspecific variation in modern crocodylian morphology may be based on multiple species and thus express both intraspecific and interspecific variation. This raises questions about our ability to recognize modern species in the fossil record, and it also indicates that specimens from disparate localities or horizons may represent not single widespread species, but multiple related species. Ranges of variation in modern species require a thorough re-evaluation, and we may have to revisit previous perceptions of past crocodyliform diversity, rates of evolution or anagenetic lineages in stratigraphic succession. These challenges will not be unique to those studying crocodyliforms and will require sophisticated approaches to variation among modern and fossil specimens.

Diversification of floral orientation in Lonicera is associated with pollinator shift and flowering phenology

AbstractFloral orientation has been suggested to be a functional floral trait that can enhance reproductive fitness through adaptation to both biotic factors (e.g., pollination) and abiotic factors (e.g., temperature). However, whether those factors drive the diversification of floral orientation needs to be explored through multiple related species. Phylogenetic relationships in Lonicera were identified by incorporating the species’ floral orientation (upward vs. downward) and pollinator types. Furthermore, transitions in floral orientation were evaluated together with pollinator shift, and seven Lonicera species were used to detect the influence of floral orientation on pollination and reproductive success. The relationship between temperature and the angle of floral orientation was investigated. Floral orientation in Lonicera showed that most of the closely related species within the same node displayed a similar pattern of floral orientation, and pollinator shift can lead to transitions between upward and downward orientation. Additionally, the angle of floral orientation increased with flowering phenology from spring to summer, and changing floral orientation significantly decreased pollination and seed production. Moreover, the average daily temperature during flowering phenology was significantly correlated with the angle of floral orientation. Our results indicate that pollinator shift could be an important event, leading to the diversification of floral orientation. Results of field investigations inferred that floral orientation should be a functional floral trait adapted to flowering phenology. Downward‐facing flowers might help decrease heat loss to adapt to cold conditions. This study disentangled the influences of historical events and local adaptation on the evolution of floral orientation.

No place to run

Plants never had it easy. When their ancestors colonized the land about 460 M years ago during the Ordovician period, they were immediately followed by crustaceans—which eventually developed into insects—that found plants a ready source of food. Ever since plants have been at the bottom of the food chain for pathogens and predators from viruses to mammalian herbivores. Unlike animals, plants cannot run away, having given up motility to maximize their surface exposed to sunlight. In lieu, they became masters in chemical warfare and communication to recognize and fend off pathogens and herbivores. Their “claws and teeth” are a dazzling arsenal of chemicals, metabolic and regulatory pathways, producing sensing and communication molecules that attract increasing interest from chemists and biologists for their potential use in medicine and agriculture. > Humans have also learned to use toxic compounds such as digitalis, atropine, opium or nicotine for medicinal, cosmetic or recreational use. Among these molecules are many spices, including the pungent piperine and capsaicin from peppers, or the glucosinolates from mustard and horseradish, and the bitter polyphenols, flavonoids or terpenes from red grapes, coffee beans, tea or cabbage. Humans have long come to appreciate these tastes—that originally evolved as a warning signal to herbivores—for centuries, spices were the most valuable commodity in global trade. Humans have also learned to use toxic compounds such as digitalis, atropine, opium or nicotine for medicinal, cosmetic or recreational use. The alkaloid taxol from the bark of the Pacific yew is a potent chemotherapeutic drug for cancer treatment; artemisinin, isolated from the plant Artemisia annua, or sweet wormwood, has long been employed in Chinese herbal medicine and been refined into a treatment for malaria. The metabolic pathways of plant compounds with medicinal value are therefore an active field of research with the objective of engineering these into E. coli or …

Pheromone identification by proxy: identification of aggregation-sex pheromones of North American cerambycid beetles as a strategy to identify pheromones of invasive Asian congeners

Research over the past decade has shown that attractant pheromones used by cerambycid beetles are often highly conserved, with the same compound being used as a pheromone component by multiple related species, even among species on different continents which have been separated for millions of years. We describe how this conservation of structures can be exploited to identify possible pheromone components for Asian target species with a high risk of invading North America. Thus, collection and analysis of volatiles from five North American species, Semanotus amethystinus (LeConte), Semanotus ligneus (F.), Semanotus litigiosus (Casey), Callidium antennatum hesperum Casey, and Callidium pseudotsugae Fisher, showed that males of the two Callidium species sex-specifically produced 3-hydroxyhexan-2-one, a previously known cerambycid pheromone component, along with a novel natural product, 1-(1H-pyrrol-2-yl)-1,2-propanedione (henceforth pyrrole). In contrast, males of the three Semanotus species produced only the pyrrole. In field bioassays, both sexes of C. antennatum hesperum were significantly attracted to the blend of the two compounds, and S. amethystinus were equally attracted to the pyrrole alone, or the blend of the two compounds. Even before completing field bioassays with these species in California, field testing of the two compounds in Japan and China had revealed that several related target species, including the invasive Callidiellum rufipenne (Motschulsky), Callidiellum villosulum (Fairmaire), and Semanotus bifasciatus (Motschulsky), were attracted to one or both compounds (data reported elsewhere), providing proof of concept of the “pheromone identification by proxy” strategy.

Whole-genome sequences of Odocoileus hemionus deer adenovirus isolates from deer, moose and elk are highly conserved and support a new species in the genus Atadenovirus.

We present the first complete genome sequence of Odocoileus hemionus deer adenovirus 1 (OdAdV-1). This virus can cause sporadic haemorrhagic disease in cervids, although epizootics with high mortality have occurred in California. OdAdV-1 has been placed in the genus Atadenovirus, based on partial hexon, pVIII and fibre genes. Ten field isolates recovered from naturally infected mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginiana) and moose (Alces alces) from Wyoming, black-tailed deer (Odocoileus hemionus columbianus) from California, and Rocky Mountain elk (Cervus elaphus nelsoni) from Colorado and Washington state were sequenced. The genome lengths ranged from 30 620 to 30 699 bp, contained the predicted proteins and gene organization typical of members of genus Atadenovirus, and had a high percentage of A/T nucleotides (66.7 %). Phylogenic analysis found that the closest ancestry was with ruminant atadenoviruses, while a divergence of the hexon, polymerase and penton base proteins of more than 15 % supports classification as a new species. Genetic global comparison between the 10 isolates found an overall 99 % identity, but greater divergence was found between those recovered from moose and elk as compared to deer, and a single variable region contained most of these differences. Our findings demonstrate that OdAdV-1 is highly conserved between 10 isolates recovered from multiple related cervid species, but genotypic differences, largely localized to a variable region, define two strains. We propose that the virus type name be changed to cervid adenovirus 1, with the species name Cervid atadenovirus A. Sequence data were used to develop molecular assays for improved detection and genotyping.

Genetics and Genomics of Cotton Leaf Curl Disease, Its Viral Causal Agents and Whitefly Vector: A Way Forward to Sustain Cotton Fiber Security.

Cotton leaf curl disease (CLCuD) after its first epidemic in 1912 in Nigeria, has spread to different cotton growing countries including United States, Pakistan, India, and China. The disease is of viral origin—transmitted by the whitefly Bemisia tabaci, which is difficult to control because of the prevalence of multiple virulent viral strains or related species. The problem is further complicated as the CLCuD causing virus complex has a higher recombination rate. The availability of alternate host crops like tomato, okra, etc., and practicing mixed type farming system have further exaggerated the situation by adding synergy to the evolution of new viral strains and vectors. Efforts to control this disease using host plant resistance remained successful using two gene based-resistance that was broken by the evolution of new resistance breaking strain called Burewala virus. Development of transgenic cotton using both pathogen and non-pathogenic derived approaches are in progress. In future, screening for new forms of host resistance, use of DNA markers for the rapid incorporation of resistance into adapted cultivars overlaid with transgenics and using genome editing by CRISPR/Cas system would be instrumental in adding multiple layers of defense to control the disease—thus cotton fiber production will be sustained.

OrthoFiller: utilising data from multiple species to improve the completeness of genome annotations

BackgroundComplete and accurate annotation of sequenced genomes is of paramount importance to their utility and analysis. Differences in gene prediction pipelines mean that genome annotations for a species can differ considerably in the quality and quantity of their predicted genes. Furthermore, genes that are present in genome sequences sometimes fail to be detected by computational gene prediction methods. Erroneously unannotated genes can lead to oversights and inaccurate assertions in biological investigations, especially for smaller-scale genome projects, which rely heavily on computational prediction.ResultsHere we present OrthoFiller, a tool designed to address the problem of finding and adding such missing genes to genome annotations. OrthoFiller leverages information from multiple related species to identify those genes whose existence can be verified through comparison with known gene families, but which have not been predicted. By simulating missing gene annotations in real sequence datasets from both plants and fungi we demonstrate the accuracy and utility of OrthoFiller for finding missing genes and improving genome annotations. Furthermore, we show that applying OrthoFiller to existing “complete” genome annotations can identify and correct substantial numbers of erroneously missing genes in these two sets of species.ConclusionsWe show that significant improvements in the completeness of genome annotations can be made by leveraging information from multiple species.

Summertime tropospheric ozone enhancement associated with a cold front passage due to stratosphere‐to‐troposphere transport and biomass burning: Simultaneous ground‐based lidar and airborne measurements

AbstractStratosphere‐to‐troposphere transport (STT) and biomass burning (BB) are two important natural sources for tropospheric ozone that can result in elevated ozone and air‐quality episode events. High‐resolution observations of multiple related species are critical for complex ozone source attribution. In this article, we present an analysis of coinciding ground‐based and airborne observations, including ozone lidar, ozonesonde, high spectral resolution lidar (HSRL), and multiple airborne in situ measurements, made on 28 and 29 June 2013 during the Southeast Nexus field campaign. The ozone lidar and HSRL reveal detailed ozone and aerosol structures as well as the temporal evolution associated with a cold front passage. The observations also captured two enhanced (+30 ppbv) ozone layers in the free troposphere (FT), which were determined from this study to be caused by a mixture of BB and stratospheric sources. The mechanism for this STT is tropopause folding associated with a cutoff upper level low‐pressure system according to the analysis of its potential vorticity structure. The depth of the tropopause fold appears to be shallow for this case compared to events observed in other seasons; however, the impact on lower tropospheric ozone was clearly observed. This event suggests that strong STT may occur in the southeast United States during the summer and can potentially impact lower troposphere during these times. Statistical analysis of the airborne observations of trace gases suggests a coincident influence of BB transport in the FT impacting the vertical structure of ozone during this case study.

SigTree: A Microbial Community Analysis Tool to Identify and Visualize Significantly Responsive Branches in a Phylogenetic Tree

Microbial community analysis experiments to assess the effect of a treatment intervention (or environmental change) on the relative abundance levels of multiple related microbial species (or operational taxonomic units) simultaneously using high throughput genomics are becoming increasingly common. Within the framework of the evolutionary phylogeny of all species considered in the experiment, this translates to a statistical need to identify the phylogenetic branches that exhibit a significant consensus response (in terms of operational taxonomic unit abundance) to the intervention. We present the R software package SigTree, a collection of flexible tools that make use of meta-analysis methods and regular expressions to identify and visualize significantly responsive branches in a phylogenetic tree, while appropriately adjusting for multiple comparisons.

WHEN SHOULD WE NOT TRANSFER FUNCTIONAL ANNOTATION BETWEEN SEQUENCE PARALOGS?

Current automated computational methods to assign functional labels to unstudied genes often involve transferring annotation from orthologous or paralogous genes, however such genes can evolve divergent functions, making such transfer inappropriate. We consider the problem of determining when it is correct to make such an assignment between paralogs. We construct a benchmark dataset of two types of similar paralogous pairs of genes in the well-studied model organism S. cerevisiae: one set of pairs where single deletion mutants have very similar phenotypes (implying similar functions), and another set of pairs where single deletion mutants have very divergent phenotypes (implying different functions). State of the art methods for this problem will determine the evolutionary history of the paralogs with references to multiple related species. Here, we ask a first and simpler question: we explore to what extent any computational method with access only to data from a single species can solve this problem.We consider divergence data (at both the amino acid and nucleotide levels), and network data (based on the yeast protein-protein interaction network, as captured in BioGRID), and ask if we can extract features from these data that can distinguish between these sets of paralogous gene pairs. We find that the best features come from measures of sequence divergence, however, simple network measures based on degree or centrality or shortest path or diffusion state distance (DSD), or shared neighborhood in the yeast protein-protein interaction (PPI) network also contain some signal. One should, in general, not transfer function if sequence divergence is too high. Further improvements in classification will need to come from more computationally expensive but much more powerful evolutionary methods that incorporate ancestral states and measure evolutionary divergence over multiple species based on evolutionary trees.

Multi-species Identification of Polymorphic Peptide Variants via Propagation in Spectral Networks

Peptide and protein identification remains challenging in organisms with poorly annotated or rapidly evolving genomes, as are commonly encountered in environmental or biofuels research. Such limitations render tandem mass spectrometry (MS/MS) database search algorithms ineffective as they lack corresponding sequences required for peptide-spectrum matching. We address this challenge with the spectral networks approach to (1) match spectra of orthologous peptides across multiple related species and then (2) propagate peptide annotations from identified to unidentified spectra. We here present algorithms to assess the statistical significance of spectral alignments (Align-GF), reduce the impurity in spectral networks, and accurately estimate the error rate in propagated identifications. Analyzing three related Cyanothece species, a model organism for biohydrogen production, spectral networks identified peptides from highly divergent sequences from networks with dozens of variant peptides, including thousands of peptides in species lacking a sequenced genome. Our analysis further detected the presence of many novel putative peptides even in genomically characterized species, thus suggesting the possibility of gaps in our understanding of their proteomic and genomic expression. A web-based pipeline for spectral networks analysis is available at http://proteomics.ucsd.edu/software.

Cross-Study Comparison Reveals Common Genomic, Network, and Functional Signatures of Desiccation Resistance in Drosophila melanogaster.

Repeated attempts to map the genomic basis of complex traits often yield different outcomes because of the influence of genetic background, gene-by-environment interactions, and/or statistical limitations. However, where repeatability is low at the level of individual genes, overlap often occurs in gene ontology categories, genetic pathways, and interaction networks. Here we report on the genomic overlap for natural desiccation resistance from a Pool-genome-wide association study experiment and a selection experiment in flies collected from the same region in southeastern Australia in different years. We identified over 600 single nucleotide polymorphisms associated with desiccation resistance in flies derived from almost 1,000 wild-caught genotypes, a similar number of loci to that observed in our previous genomic study of selected lines, demonstrating the genetic complexity of this ecologically important trait. By harnessing the power of cross-study comparison, we narrowed the candidates from almost 400 genes in each study to a core set of 45 genes, enriched for stimulus, stress, and defense responses. In addition to gene-level overlap, there was higher order congruence at the network and functional levels, suggesting genetic redundancy in key stress sensing, stress response, immunity, signaling, and gene expression pathways. We also identified variants linked to different molecular aspects of desiccation physiology previously verified from functional experiments. Our approach provides insight into the genomic basis of a complex and ecologically important trait and predicts candidate genetic pathways to explore in multiple genetic backgrounds and related species within a functional framework.

BLSSpeller: exhaustive comparative discovery of conserved cis-regulatory elements.

Motivation: The accurate discovery and annotation of regulatory elements remains a challenging problem. The growing number of sequenced genomes creates new opportunities for comparative approaches to motif discovery. Putative binding sites are then considered to be functional if they are conserved in orthologous promoter sequences of multiple related species. Existing methods for comparative motif discovery usually rely on pregenerated multiple sequence alignments, which are difficult to obtain for more diverged species such as plants. As a consequence, misaligned regulatory elements often remain undetected.Results: We present a novel algorithm that supports both alignment-free and alignment-based motif discovery in the promoter sequences of related species. Putative motifs are exhaustively enumerated as words over the IUPAC alphabet and screened for conservation using the branch length score. Additionally, a confidence score is established in a genome-wide fashion. In order to take advantage of a cloud computing infrastructure, the MapReduce programming model is adopted. The method is applied to four monocotyledon plant species and it is shown that high-scoring motifs are significantly enriched for open chromatin regions in Oryza sativa and for transcription factor binding sites inferred through protein-binding microarrays in O.sativa and Zea mays. Furthermore, the method is shown to recover experimentally profiled ga2ox1-like KN1 binding sites in Z.mays.Availability and implementation: BLSSpeller was written in Java. Source code and manual are available at http://bioinformatics.intec.ugent.be/blsspellerContact: Klaas.Vandepoele@psb.vib-ugent.be or jan.fostier@intec.ugent.beSupplementary information: Supplementary data are available at Bioinformatics online.

Genome Evolution: Where Do New Introns Come From?

A new study reports creation of spliceosomal introns in multiple related fungal species by proliferation of cryptic elements. Resonances to a case in unrelated algae suggest such elements hold general answers to long-standing mysteries of intron evolution.