Short Generation Time Research Articles

The relationship between chrysophyte cyst assemblages and meteorological conditions: Evidence from a sediment-trap study in northeast Poland

Climate change causes alterations in lake systems, thus influencing lake biota. Studies of phytoplankton with short generation times and seasonal replacement provide an opportunity for assessing how aquatic organisms respond to changes in environmental conditions. This study explores the potential of chrysophyte cysts as indicators of seasonal and interannual changes in meteorological conditions in Lakes Łazduny and Rzęśniki, located in northern Poland. Monthly chrysophyte cyst data from sediment traps, biweekly limnological and hydrochemical data, and daily meteorological data were used to find and explain the relationships between chrysophyte cysts and changes in meteorological conditions. We showed that cyst seasonality indirectly corresponds to meteorological conditions acting through changes in the mixing regimes, which in turn influences nutrient and light availability. Statistical analyses revealed that the taxonomic structure and interannual variability of chrysophyte cysts are dependent on multiple variables. Nevertheless, air temperature was the most important meteorological variable influencing cyst assemblages. Cysts were indicative of different periods of lake physical structure, suggesting the potential of chrysophyte cysts in paleoclimatic studies.

Microalgae as a Source of Mycosporine-like Amino Acids (MAAs); Advances and Future Prospects.

Mycosporine-like amino acids (MAAs), are secondary metabolites, first reported in 1960 and found to be associated with the light-stimulated sporulation in terrestrial fungi. MAAs are nitrogenous, low molecular weight, water soluble compounds, which are highly stable with cyclohexenone or cycloheximine rings to store the free radicals. Microalgae are considered as a good source of different kinds of MAAs, which in turn, has its own applications in various industries due to its UV absorbing, anti-oxidant and therapeutic properties. Microalgae can be easily cultivated and requires a very short generation time, which makes them environment friendly source of biomolecules such as mycosporine-like amino acids. Modifying the cultural conditions along withmanipulation of genes associated with mycosporine-like amino acids biosynthesis can help to enhance MAAs synthesis and, in turn, can make microalgae suitable bio-refinery for large scale MAAs production. This review focuses on properties and therapeutic applications of mycosporine like amino acids derived from microalgae. Further attention is drawn on various culture and genetic engineering approaches to enhance the MAAs production in microalgae.

Microbial Fibrinolytic Enzymes as Anti-Thrombotics: Production, Characterisation and Prodigious Biopharmaceutical Applications.

Cardiac disorders such as acute myocardial infarction, embolism and stroke are primarily attributed to excessive fibrin accumulation in the blood vessels, usually consequential in thrombosis. Numerous methodologies including the use of anti-coagulants, anti-platelet drugs, surgical operations and fibrinolytic enzymes are employed for the dissolution of fibrin clots and hence ameliorate thrombosis. Microbial fibrinolytic enzymes have attracted much more attention in the management of cardiovascular disorders than typical anti-thrombotic strategies because of the undesirable after-effects and high expense of the latter. Fibrinolytic enzymes such as plasminogen activators and plasmin-like proteins hydrolyse thrombi with high efficacy with no significant after-effects and can be cost effectively produced on a large scale with a short generation time. However, the hunt for novel fibrinolytic enzymes necessitates complex purification stages, physiochemical and structural-functional attributes, which provide an insight into their mechanism of action. Besides, strain improvement and molecular technologies such as cloning, overexpression and the construction of genetically modified strains for the enhanced production of fibrinolytic enzymes significantly improve their thrombolytic potential. In addition, the unconventional applicability of some fibrinolytic enzymes paves their way for protein hydrolysis in addition to fibrin/thrombi, blood pressure regulation, anti-microbials, detergent additives for blood stain removal, preventing dental caries, anti-inflammatory and mucolytic expectorant agents. Therefore, this review article encompasses the production, biochemical/structure-function properties, thrombolytic potential and other surplus applications of microbial fibrinolytic enzymes.

Different extinction debts among plants and arthropods after loss of grassland amount and connectivity

A decrease in habitat amount and connectivity causes immediate or delayed species extinctions in transformed landscapes due to reduced functional connections among populations and altered environmental conditions. We assessed the effects of present and historical grassland amount and connectivity as well as local habitat factors typical of the present landscape on the current species richness of grassland specialist and generalist plants and arthropods in grassland fragments. We surveyed herbaceous plants, ants, orthopterans, true bugs and rove beetles in 60 dry grassland fragments in Hungary. We recorded the area of the focal grassland, the slope and the cover of woody vegetation. By using habitat maps of the present and historical landscape, we calculated grassland amount and connectivity for four time periods covering 158 years (1858–2016). We found evidence for an unpaid extinction debt in specialist plants, suggesting that they have not come to equilibrium with the grassland amount and connectivity of the present landscape yet. This localised and typically long-lived group responded slowly to the landscape changes. Specialist arthropod taxa with short generation times responded much faster to habitat loss than plants and did not show an extinction debt. Generalist plants and animals adapted to a wide range of habitats were affected by the landscape-scale decline of grassland habitats. Despite decreased habitat connectivity, grassland fragments with dry environmental conditions and high environmental heterogeneity can sustain specialist plants in transformed landscapes. Unpaid extinction debt should be considered an early warning signal: Restoration of grassland connectivity is necessary to halt ongoing extinction processes.

Identification and structural studies of natural inhibitors against SARS-CoV-2 viral RNA methyltransferase (NSP16)

Pathogenic RNA viruses are emerging as one of the major threats and posing challenges to human community. RNA viruses have an exceptionally shorter generation time and easy to adapt in host cells. The recent emergence of SARS-CoV-2, a long RNA virus, has shown us how difficult it is to overcome this kind of pandemic without understanding the viral infection and replication mechanisms. It is essential to comprehend replications of the viral genome, including RNA polymerization and the final capping process. The mRNAs of SARS-CoV-2 coronaviruses are protected at their 5′-ends by cap structure. The cap-like system plays a significant role in viral translational process, viral RNA stability, and scatting in detecting innate immune recognition in host cells. Two coronavirus enzymes, Nsp14 and Nsp16, critically help in the formation of capping and are considered as potential drug targets for antiviral therapy. Natural and herbal medicines have a past record of treating various acute respiratory diseases. In this work, we have exploited 56000 natural compounds to screen potential inhibitors against NSP16. In silico virtual screening, docking and Molecular Dynamics (MD) simulation studies were performed to understand how these potential inhibitors are bound to NSP16. We observed that the most highly screened compound binds to protein molecules with a high dock score, primarily through hydrophobic interactions and hydrogen bonding, as previously reported for NSP16. Compound-13 (2-hydroxy-N-({1-[2-hydroxy-1-(hydroxymethyl)ethyl]piperidin-3-yl}methyl)-5-methylbenzamide) and compound-51 (N-(2-isobutoxybenzyl)-N,2-dimethyl-2,8-diazaspiro[4.5]decane-3-carboxamide) occupied in active site along with good pharmokinetices properties. In conclusion, the selected compounds could be used as a novel therapeutic against SARS-CoV-2. Communicated by Ramaswamy H. Sarma

Bifidobacteria exhibited stronger ability to utilize fructooligosaccharides, compared with other bacteria in the mouse intestine.

Fructooligosaccharides (FOS) have been identified as important prebiotics. Previous studies have found that they can significantly promote the proliferation of Bifidobacterium pseudolongum in the mouse intestine. However, it is still unclear which other bacteria in the mouse intestine can utilize FOS, and the differences in the ability to utilize FOS. In this study, the bacteria capable of utilizing FOS were isolated from mice feces and their ability to utilize FOS was compared. Draft genome sequencing was also applied to explain the differences in FOS utilization at the gene levels. A total of 15 species were isolated from mouse feces and 13 species were able to utilize fructofuranosylnystose (GF2). Eleven species could utilize nistose (GF3), but not Enterococcus hirae and Lactobacillus reuteri. In contrast, 1-kestose (GF4) was hardly utilized. The enzyme activity determination and draft genome sequencing-based analyses revealed that all isolated species used the phosphotransferase system or permease system to transport FOS into the cells before hydrolysis by β-fructofuranosidase. Although β-fructofuranosidase exists in all strains, there are big differences in the corresponding coding genes between bifidobacteria and non-bifidobacteria. Compared with the other isolates, Bifidobacterium species exhibited higher enzyme activity and shorter generation time, leading to a stronger ability to utilize FOS. © 2021 Society of Chemical Industry.

Inheritance of Acquired Traits in Insects and Other Animals and the Epigenetic Mechanisms That Break the Weismann Barrier.

The credibility of the Weismann barrier has come into question. Several studies in various animal systems, from mice to worms, have shown that novel environmental stimuli can generate an altered developmental or behavioral trait that can be transmitted to offspring of the following generation. Recently, insects have become ideal models to study the inheritance of acquired traits. This is because insects can be reared in high numbers at low cost, they have short generation times and produce abundant offspring. Numerous studies have shown that an insect can modify its phenotype in response to a novel stimulus to aid its survival, and also that this modified phenotypic trait can be inherited by its offspring. Epigenetic mechanisms are likely at play but, most studies do not address the mechanisms that underlie the inheritance of acquired traits in insects. Here we first review general epigenetic mechanisms such as DNA methylation, histone acetylation and small noncoding RNAs that have been implicated in the transmission of acquired traits in animals, then we focus on the few insect studies in which these mechanisms have been investigated.

Inference of local invasion pathways in two invasive crayfish species displaying contrasting genetic patterns

Abstract The efficient management of invasive alien species (IAS) requires the identification of their introduction pathways. Genetic assessments have proven useful to inform invasion pathways at large (national to worldwide) scales, but studies at local scales are still rare, despite their importance for guiding management. In this study, genetic analyses were used to identify local invasion pathways of two invasive crayfish species (the spiny‐cheek crayfish Faxonius limosus and the red swamp crayfish Procambarus clarkii) in a dense network of artificial lakes. We first characterized the spatial patterns of genetic variability, effective population sizes (Ne) and among‐lakes recent migration events for each species using neutral microsatellite markers. We then identified the environmental factors affecting genetic variability and inferred the potential local invasion pathways. Results revealed different patterns of genetic variability between the two species: F. limosus displayed very low levels of genetic diversity, Ne and spatial structuring compared to P. clarkii, which displayed high genetic diversity, Ne and spatial genetic structuring. We also demonstrated context‐dependent effects of different environmental factors (fishery management, spatial distribution and lake size) on genetic variability indices. We did not identify local invasion pathways for F. limosus due to limited genetic variability, likely caused by a strong founder effect and potential parthenogenetic reproduction. Contrastingly, multiple invasion pathways (release, contaminant, unaided/corridor spread and stowaway) were identified for P. clarkii. Synthesis and applications. Although limited in some particular cases (e.g. for species having experienced strong shaping events and/or displaying asexual reproductive modes), neutral genetic variation assessments can provide important insights for inferring local invasion pathways in complex landscapes for invasive alien species displaying short generation times and complex invasion histories.

Polychaetes as bioindicators of environmental pollution: Impact of bisphenol A on the reproduction rate of Ophryotrocha diadema (Åkesson, 1976) (Eunicida: Dorvilleidae)

Bisphenol A (BPA) is one of the most used additives in the production of many plastic products and may be released into the environment by commonly used products, such as food containers and polycarbonate bottles. BPA is recognized as an endocrine disruptor able to produce adverse effects on the reproduction system of benthonic and pelagic species. Polychaetes of the genus Ophryotrocha are small worms living amongst the interstitial fauna in nutrient-rich and polluted habitats. Owing to easy rearing in the laboratory and short generation times, this species is a useful model organism for studying different biological aspects. This study describes the effects of different BPA concentrations on egg production in Ophryotrocha diadema. We tested six different concentrations of BPA in a 5-week experiment. Strong negative correlation between BPA concentrations and the number of eggs produced was found. The t-test revealed a significant reduction in egg production after exposure to BPA concentrations over 1461.1 μg/L. The latter concentration value is higher than that observed in the marine environment, although for many species of crustaceans, echinoderms and isopods, the impairment of reproductive function was observed even at much lower BPA concentrations.

How will mosquitoes adapt to climate warming?

The potential for adaptive evolution to enable species persistence under a changing climate is one of the most important questions for understanding impacts of future climate change. Climate adaptation may be particularly likely for short-lived ectotherms, including many pest, pathogen, and vector species. For these taxa, estimating climate adaptive potential is critical for accurate predictive modeling and public health preparedness. Here, we demonstrate how a simple theoretical framework used in conservation biology—evolutionary rescue models—can be used to investigate the potential for climate adaptation in these taxa, using mosquito thermal adaptation as a focal case. Synthesizing current evidence, we find that short mosquito generation times, high population growth rates, and strong temperature-imposed selection favor thermal adaptation. However, knowledge gaps about the extent of phenotypic and genotypic variation in thermal tolerance within mosquito populations, the environmental sensitivity of selection, and the role of phenotypic plasticity constrain our ability to make more precise estimates. We describe how common garden and selection experiments can be used to fill these data gaps. Lastly, we investigate the consequences of mosquito climate adaptation on disease transmission using Aedes aegypti-transmitted dengue virus in Northern Brazil as a case study. The approach outlined here can be applied to any disease vector or pest species and type of environmental change.

Applicability of Enchytraeus bulbosus as a model species in ecotoxicology and risk assessment

Enchytraeus bulbosus is listed in the ISO and OECD standard guidelines as a possible test species of enchytraeid. However, in contrast to other listed species, its applicability in ecotoxicological studies as well as its sensitivity is widely unknown. Therefore, copper, pentachlorophenol(PCP), carbendazim, and chloroacetamide have been investigated by performing two-generation studies with multiple endpoints. Comparable toxicity trends to the existing studies were shown for copper and PCP in the two-generation studies of E. bulbosus. Dose-related abnormal swelling of clitella were found for the first time with PCP and chloroacetamide treatments. Sensitivity comparisons of E. bulbosus to other terrestrial test species were also conducted. E. bulbosus showed high sensitivity, it has comparable sensitivity as other sensitive species of genus Enchytraeus ( E. albidus or E. luxuriosus)to different chemicals, and was more sensitive than E. crypticus and earthworm species ( Eisenia fetida or Eisenia andrei). Combined with the phylogenetic and biological characterization, the results lead to the conclusion that E.bulbosus is a suitable model species in ecotoxicology and the chemical risk assessment (especially in multi-generation) because it has a short generation time, comparatively moderate fecundity, ideal and reasonable sensitivity.

Growth of Lactobacillus casei FNCC0900 in Media Based Umbi Porang Plant (Amorphophallus muelleri BI.)

Porang tuber (Amorphophallus muellerii BI.) Is a type of tuber that has a high enough glucomannan content of 67%. Glucomannan is very difficult to digest by humans directly so it takes the role of probiotics. L. casei bacteria FNCC0900 as a probiotic agent capable of utilizing glucomannan as a carbon source for growth. The purpose of this study was to determine the growth pattern and changes in environmental factors, namely the pH value of the probiotic bacteria L. casei FNCC0900 growth medium. The parameters in this study consisted of the highest cell density, generation time and pH value changes in Glucose Yeast Peptone Liquid Media, Porang Boiled Water Media and Porang Flour Liquid Media using the drop plate method which had 4 repeated calculations. Porang Boiled Water Liquid Media has a faster log phase period with a higher cell density than Porang Flour Liquid Media, but the shortest generation time is found in Porang Flour Liquid Media with the highest number of generations. L. casei FNCC0900 bacteria are more able to reduce the pH of Glucose Yeast Peptone Liquid Media compared to porang tuber-based media, so in this case L. casei FNCC0900 can be stated to be able to grow on porang tuber-based media with growth patterns, generation time, cell density and pH value. which varies.

Efficient RNA Virus Targeting via CRISPR/CasRx in Fish.

The emergence of the CRISPR/Cas system as a technology has transformed our ability to modify nucleic acids, and the CRISPR/Cas13 system has been used to target RNA. CasRx is a small type VI-D effector (Cas13d) with RNA knockdown efficiency that may have an interference effect on RNA viruses. However, the RNA virus-targeting activity of CasRx still needs to be verified in vivo in vertebrates. In this study, we successfully engineered a highly effective CasRx system for fish virus interference. We designed synthetic mRNA coding for CasRx and used CRISPR RNAs to guide it to target the red-spotted grouper nervous necrosis virus (RGNNV). This technique resulted in significant interference with virus infections both in vitro and in vivo. These results indicate that CRISPR/CasRx can be used to engineer interference against RNA viruses in fish, which provides a potential novel mechanism for RNA-guided immunity against other RNA viruses in vertebrates. IMPORTANCE RNA viruses are important viral pathogens infecting vertebrates and mammals. RNA virus populations are highly dynamic due to short generation times, large population sizes, and high mutation frequencies. Therefore, it is difficult to find widely effective ways to inhibit RNA viruses, and we urgently need to develop effective antiviral methods. CasRx is a small type VI-D effector (Cas13d) with RNA knockdown efficiency that can have an interference effect on RNA viruses. Nervous necrosis virus (NNV), a nonenveloped positive-strand RNA virus, is one of the most serious viral pathogens, infecting more than 40 cultured fish species and resulting in huge economic losses worldwide. Here, we establish a novel effective CasRx system for RNA virus interference using NNV and grouper (Epinephelus coioides) as a model. Our data showed that CasRx was most robust for RNA virus interference applications in fish, and we demonstrate its suitability for studying key questions related to virus biology.

Year-round high abundances of the world\u2019s smallest marine vertebrate (Schindleria) in the Red Sea and worldwide associations with lunar phases

Very little is known about the ecology and biology of the smallest marine vertebrates, fishes in the genus Schindleria. Even though over half of named Schindleria species have been identified in the Red Sea, the collection of only very few specimens has been documented. Here, we assessed abundance patterns of nearly two thousand Red Sea long dorsal fin (LDF) adults and found evidence for putative seasonal and spatial differences, likely related to differing habitat and environmental conditions. The highest abundances were outside local seasonal temperature extremes and decoupled from peaks of coral reef fish recruitment. We also found evidence for global trends in abundances related to lunar cycles using our Red Sea data and that from a recently published large collection of specimens from the DANA Expedition (1928–1930). The abundance of adult LDF Schindleria in relation to lunar phases differed significantly, with most Schindleria caught outside the full moon, and mostly during the new moon in the Red Sea and the 3rd quarter moon in the DANA collection. We further suggest that the abundances of Schindleria at coral reefs may be related to reproductive cycles and that these cycles may be timed with the moon as back-calculations of hatch dates from otoliths from the Red Sea significantly resulted after the new moon, making Schindleria the fastest-lived coral reef fish with the shortest generation times. Schindleria could be the most numerous coral reef fish in the world, for which we encourage increased research.

Replication Dynamics for Six Gram-Negative Bacterial Species during Bloodstream Infection.

ABSTRACTBloodstream infections (BSI) are a major public health burden due to high mortality rates and the cost of treatment. The impact of BSI is further compounded by a rise in antibiotic resistance among Gram-negative species associated with these infections. Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Enterobacter hormaechei, Citrobacter freundii, and Acinetobacter baumannii are all common causes of BSI, which can be recapitulated in a murine model. The objective of this study was to characterize infection kinetics and bacterial replication rates during bacteremia for these six pathogens to gain a better understanding of bacterial physiology during infection. Temporal observations of bacterial burdens of the tested species demonstrated varied abilities to establish colonization in the spleen, liver, or kidney. K. pneumoniae and S. marcescens expanded rapidly in the liver and kidney, respectively. Other organisms, such as C. freundii and E. hormaechei, were steadily cleared from all three target organs throughout the infection. In situ replication rates measured by whole-genome sequencing of bacterial DNA recovered from murine spleens demonstrated that each species was capable of sustained replication at 24 h postinfection, and several species demonstrated <60-min generation times. The relatively short generation times observed in the spleen were in contrast to an overall decrease in bacterial burden for some species, suggesting that the rate of immune-mediated clearance exceeded replication. Furthermore, bacterial generation times measured in the murine spleen approximated those measured during growth in human serum cultures. Together, these findings provide insight into the infection kinetics of six medically important species during bacteremia.

An efficient papaya leaf distortion mosaic potyvirus vector for virus-induced gene silencing in papaya

Papaya (Carica papaya L.) is regarded as an excellent model for genomic studies of tropical trees because of its short generation time and its small genome that has been sequenced. However, functional genomic studies in papaya depend on laborious genetic transformations because no rapid tools exist for this species. Here, we developed a highly efficient virus-induced gene silencing (VIGS) vector for use in papaya by modifying an artificially attenuated infectious clone of papaya leaf distortion mosaic virus (PLDMV; genus: Potyvirus), PLDMV-E, into a stable Nimble Cloning (NC)-based PLDMV vector, pPLDMV-NC, in Escherichia coli. The target fragments for gene silencing can easily be cloned into pPLDMV-NC without multiple digestion and ligation steps. Using this PLDMV VIGS system, we silenced and characterized five endogenous genes in papaya, including two common VIGS marker genes, namely, phytoene desaturase, Mg-chelatase H subunit, putative GIBBERELLIN (GA)-INSENSITIVE DWARF1A and 1B encoding GA receptors; and the cytochrome P450 gene CYP83B1, which encodes a key enzyme involved in benzylglucosinolate biosynthesis. The results demonstrate that our newly developed PLDMV VIGS vector is a rapid and convenient tool for functional genomic studies in papaya.

First circumpolar assessment of Arctic freshwater phytoplankton and zooplankton diversity: Spatial patterns and environmental factors

Abstract Arctic freshwaters are facing multiple environmental pressures, including rapid climate change and increasing land___use activities. Freshwater plankton assemblages are expected to reflect the effects of these stressors through shifts in species distributions and changes to biodiversity. These changes may occur rapidly due to the short generation times and high dispersal capabilities of both phyto___ and zooplankton. Spatial patterns and contemporary trends in plankton diversity throughout the circumpolar region were assessed using data from more than 300 lakes in the U.S.A. (Alaska), Canada, Greenland, Iceland, the Faroe Islands, Norway, Sweden, Finland, and Russia. The main objectives of this study were: (1) to assess spatial patterns of plankton diversity focusing on pelagic communities; (2) to assess dominant component of __ diversity (turnover or nestedness); (3) to identify which environmental factors best explain diversity; and (4) to provide recommendations for future monitoring and assessment of freshwater plankton communities across the Arctic region. Phytoplankton and crustacean zooplankton diversity varied substantially across the Arctic and was positively related to summer air temperature. However, for zooplankton, the positive correlation between summer temperature and species numbers decreased with increasing latitude. Taxonomic richness was lower in the high Arctic compared to the sub___ and low Arctic for zooplankton but this pattern was less clear for phytoplankton. Fennoscandia and inland regions of Russia represented hotspots for, respectively, phytoplankton and zooplankton diversity, whereas isolated regions had lower taxonomic richness. Ecoregions with high __ diversity generally also had high __ diversity, and turnover was the most important component of __ diversity in all ecoregions. For both phytoplankton and zooplankton, climatic variables were the most important environmental factors influencing diversity patterns, consistent with previous studies that examined shorter temperature gradients. However, barriers to dispersal may have also played a role in limiting diversity on islands. A better understanding of how diversity patterns are determined by colonisation history, environmental variables, and biotic interactions requires more monitoring data with locations dispersed evenly across the circumpolar Arctic. Furthermore, the importance of turnover in regional diversity patterns indicates that more extensive sampling is required to fully characterise the species pool of Arctic lakes.

Light competition and phenological adaptation of annual plants to a changing climate

Shifting flowering seasons is a global effect of climate change that can have important long-term evolutionary and demographic effects on plant communities. Life history optimization theory can be a valuable tool to assert the adaptive value and fitness effects of observed phenological shifts, but takes plant-plant competition rarely into account. Here we combine energy allocation models with evolutionary game theory to assess how size-asymmetric competition for light can influence phenological adaptations and fitness responses to a changing climate – here represented as changes of the start, end and intensity of the growing season. We focus on annual plants which, due to their short generation times, are particularly likely to exhibit rapid demographic and evolutionary responses to environmental change. We find that while light competition favors late flowering times, it does not affect the direction of selection in the climate changes scenarios considered here. We predict, however, that plants adapted to light competition face more detrimental fitness consequences if the growing season advances, becomes shorter or less intense. We also show that adaptation to changing growing seasons under light competition can favor increased investment in vegetative growth with the counterintuitive side effect that seed production is reduced at the same time. In sum, our study highlights several effects of light competition that may help to interpret phenological trends and idiosyncratic fitness effects of climate change in wild plant communities.

Long-distance dispersal events rather than growth habit and life-history traits affect diversification rate in tribe Apieae (Apiaceae)

AbstractFactors influencing diversification rates may be of intrinsic (e.g. morphological novelties) or extrinsic (e.g. long-distance dispersal, availability of ecological niches) nature. Growth habit may influence diversification rates because herbaceous plants often have shorter generation times and a more pronounced r reproductive strategy than their woody relatives. We examined life history and habit evolution, wood anatomy and biogeographical history of Apiaceae tribe Apieae in conjunction with diversification rate analysis to explore which factors may have affected clade species richness and to elucidate the constraints on the evolution of secondary woodiness in this group. We demonstrate that diversification rates are similar in morphologically homogeneous and diverse clades and in herbaceous and woody lineages. The only clade with a significantly elevated diversification rate is Southern Hemisphere Apium, in which diversity probably resulted from several long-distance dispersal events. We also show that wood anatomy in herbaceous and woody species does not differ considerably regardless of their continental or insular origin, but it is affected by stem architecture and plant reproductive strategy. As the taxonomy of Apieae suffers from inflation with numerous monotypic genera, we propose to include Canaria in Rutheopsis, and Foeniculum, Schoenoselinum, Ridolfia and Pseudoridolfia in Anethum.

The Genome Assembly and Annotation of the Apollo Butterfly Parnassius apollo, a Flagship Species for Conservation Biology.

Conservation genomics has made dramatic improvements over the past decade, leveraging the power of genomes to infer diverse parameters central to conservation management questions. However, much of this effort has focused upon vertebrate species, despite insects providing similar flagship status with the added benefit of smaller genomes, shorter generation times and extensive historical collections in museums. Here we present the genome of the Apollo butterfly (Parnassius apollo, Papilionidae), an iconic endangered butterfly, which like many species in this genus, needs conservation genomic attention yet lacks a genome. Using 68.7 Gb of long-read data (N50 = 15.2 kb) we assembled a 1.4 Gb genome for the Apollo butterfly, making this the largest sequenced Lepidopteran genome to date. The assembly was highly contiguous (N50 = 7.1 Mb) and complete (97% of Lepidopteran BUSCOs were single-copy and complete) and consisted of 1,707 contigs. Using RNAseq data and Arthropoda proteins, we annotated 28.3K genes. Alignment with the closest-related chromosome-level assembly, Papilio bianor, reveals a highly conserved chromosomal organization, albeit genome size is highly expanded in the Apollo butterfly, due primarily to a dramatic increase in repetitive element content. Using this alignment for superscaffolding places the P. apollo genome in to 31 chromosomal scaffolds, and together with our functional annotation, provides an essential resource for advancing conservation genomics in a flagship species for insect conservation.