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1.
Mayo Clin Proc ; 99(7): 1178-1186, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38960499

ABSTRACT

This article is the third of 3 articles in a series about managing the care of physicians as patients. In part 1, the authors reviewed unique characteristics of physicians as patients with some general guidance for how to approach their care. Part 2 highlighted role clarity for the treating physician with discussion of the physical and cognitive issues that commonly arise when treating physician-patients along with licensure issues and reporting requirements. This final installment will focus on physician mental health and work-related stress.


Subject(s)
Mental Health , Physicians , Humans , Physicians/psychology , Physician-Patient Relations , Occupational Stress , Stress, Psychological
2.
Mayo Clin Proc ; 99(6): 997-1005, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38839190

ABSTRACT

This second installment in a 3-part series about physicians as patients explores challenges in communication and role definition while managing their care and safe return to work. In the first article of the series, authors reviewed unique characteristics that make physicians different as patients, with some general guidance about how to approach their care. Although most treating physicians receive little occupational training, health issues commonly have an impact on work with imperative to address work issues promptly for best outcome. This paper demystifies the challenge of managing work status and discusses navigating common physical and cognitive issues while maintaining role clarity. The treating clinician reading this paper will learn to avoid common pitfalls and be better equipped to provide initial assessments and interventions to keep physicians working safely, keeping in mind licensure issues and reporting requirements. Part Three of the series will focus on the most common mental health issues seen in physicians.


Subject(s)
Return to Work , Humans , Physician-Patient Relations , Physician's Role , Physicians/psychology
3.
Mayo Clin Proc ; 99(5): 836-843, 2024 May.
Article in English | MEDLINE | ID: mdl-38702130

ABSTRACT

This is the first article of a 3-part series about physician health. In this installment, we outline the unique characteristics of physicians as patients, challenges and opportunities presented by physician-patients, and recommendations for treating physicians. Future articles will delve into role clarity, occupational considerations, mental health, and interactions with third parties such as the physician's employer or licensing board. Ultimately, this series will help treating clinicians provide the best care to their physician-patients and successfully navigate the unique challenges that may arise, especially when the diagnosis may have an impact on their ability to practice medicine.


Subject(s)
Physician-Patient Relations , Physicians , Humans , Physicians/psychology , Physician's Role , Mental Health
4.
Insects ; 13(3)2022 Mar 07.
Article in English | MEDLINE | ID: mdl-35323562

ABSTRACT

The light brown apple moth, Epiphyas postvittana is an invasive, polyphagous pest of horticultural systems around the world. With origins in Australia, the pest has subsequently spread to New Zealand, Hawaii, California and Europe, where it has been found on over 500 plants, including many horticultural crops. We have produced a genomic resource, to understand the biological basis of the polyphagous and invasive nature of this and other lepidopteran pests. The assembled genome sequence encompassed 598 Mb and has an N50 of 301.17 kb, with a BUSCO completion rate of 97.9%. Epiphyas postvittana has 34% of its assembled genome represented as repetitive sequences, with the majority of the known elements made up of longer DNA transposable elements (14.07 Mb) and retrotransposons (LINE 17.83 Mb). Of the 31,389 predicted genes, 28,714 (91.5%) were assigned to 11,438 orthogroups across the Lepidoptera, of which 945 were specific to E. postvittana. Twenty gene families showed significant expansions in E. postvittana, including some likely to have a role in its pest status, such as cytochrome p450s, glutathione-S-transferases and UDP-glucuronosyltransferases. Finally, using a RAD-tag approach, we investigated the population genomics of this pest, looking at its likely patterns of invasion.

5.
Insect Biochem Mol Biol ; 141: 103708, 2022 02.
Article in English | MEDLINE | ID: mdl-34973420

ABSTRACT

Sex pheromones facilitate species-specific sex communication within the Lepidoptera. They are detected by specialised pheromone receptors (PRs), most of which to date fall into a single monophyletic receptor lineage (frequently referred to as "the PR clade") within the odorant receptor (OR) family. Here we investigated PRs of the invasive horticultural pest, Epiphyas postvittana, commonly known as the light brown apple moth. Ten candidate PRs were selected, based on their male-biased expression in antennae or their relationship to the PR clade, for functional assessment in both HEK293 cells and Xenopus oocytes. Of these, six ORs responded to compounds that include components of the E. postvittana ('Epos') sex pheromone blend or compounds that antagonise sex pheromone attraction. In phylogenies, four of the characterised receptors (EposOR1, 6, 7 and 45) fall within the PR clade and two other male-biased receptors (EposOR30 and 34) group together well outside the PR clade. This new clade of pheromone receptors includes the receptor for (E)-11-tetradecenyl acetate (EposOR30), which is the main component of the sex pheromone blend for this species. Interestingly, receptors of the two clades do not segregate by preference for compounds associated with behavioural response (agonist or antagonist), isomer type (E or Z) or functional group (alcohol or acetate), with examples of each scattered across both clades. Phylogenetic comparison with PRs from other species supports the existence of a second major clade of lepidopteran ORs including, EposOR30 and 34, that has been co-opted into sex pheromone detection in the Lepidoptera. This second clade of sex pheromone receptors has an origin that likely predates the split between the major lepidopteran families.


Subject(s)
Moths/genetics , Receptors, Pheromone/genetics , Sex Attractants/genetics , Animals , Female , HEK293 Cells , Humans , Male , Phylogeny , Receptors, Pheromone/classification
6.
Genome Biol Evol ; 13(5)2021 05 07.
Article in English | MEDLINE | ID: mdl-33885769

ABSTRACT

Some animal groups, such as stick insects (Phasmatodea), have repeatedly evolved alternative reproductive strategies, including parthenogenesis. Genomic studies have found modification of the genes underlying meiosis exists in some of these animals. Here we examine the evolution of copy number, evolutionary rate, and gene expression in candidate meiotic genes of the New Zealand geographic parthenogenetic stick insect Clitarchus hookeri. We characterized 101 genes from a de novo transcriptome assembly from female and male gonads that have homology with meiotic genes from other arthropods. For each gene we determined copy number, the pattern of gene duplication relative to other arthropod orthologs, and the potential for meiosis-specific expression. There are five genes duplicated in C. hookeri, including one also duplicated in the stick insect Timema cristinae, that are not or are uncommonly duplicated in other arthropods. These included two sister chromatid cohesion associated genes (SA2 and SCC2), a recombination gene (HOP1), an RNA-silencing gene (AGO2) and a cell-cycle regulation gene (WEE1). Interestingly, WEE1 and SA2 are also duplicated in the cyclical parthenogenetic aphid Acyrthosiphon pisum and Daphnia duplex, respectively, indicating possible roles in the evolution of reproductive mode. Three of these genes (SA2, SCC2, and WEE1) have one copy displaying gonad-specific expression. All genes, with the exception of WEE1, have significantly different nonsynonymous/synonymous ratios between the gene duplicates, indicative of a shift in evolutionary constraints following duplication. These results suggest that stick insects may have evolved genes with novel functions in gamete production by gene duplication.


Subject(s)
Gene Duplication , Insecta/genetics , Animals , Female , Gene Expression Profiling , Insecta/classification , Insecta/cytology , Insecta/metabolism , Male , Meiosis , Phylogeny , Transcriptome
7.
Mol Ecol Resour ; 21(5): 1416-1421, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33629477

ABSTRACT

With the ever-increasing number of publicly available eukaryotic genome assemblies and user-friendly bioinformatics tools, there are increasing opportunities for researchers to use genomic resources in their research. While there are multiple dimensions to genome quality, it is often reduced to a single score that may not be correlated with other metrics, or appropriate for all applications of an assembly. To assess whether the commonly reported N50 value could reliably predict a separate dimension of genome quality, gene space completeness, we performed a meta-analysis of 611 published articles on eukaryotic genomes that used BUSCO scores, in addition to the typical N50 score. We found that although assemblies with relatively high contig and scaffold N50 values consistently had high BUSCO scores, a high BUSCO score could also be obtained from assemblies with a low N50. This reinforces that despite its ubiquity, N50 is not a perfect proxy for all measures of genome accuracy. Our data also suggests that variations in BUSCO scores among assemblies with poor N50 scores may be related to the number of introns in conserved eukaryotic genes. We stress the importance of screening and evaluating assembly quality based on the appropriate tools and urge increased reporting of additional genome assessment metrics in addition to N50. We also discuss the potential limitations of BUSCO and suggest improvements for assessing gene space within genome assemblies.


Subject(s)
Computational Biology , Genome , Genomics , Genomics/methods
8.
Nature ; 584(7821): 403-409, 2020 08.
Article in English | MEDLINE | ID: mdl-32760000

ABSTRACT

The tuatara (Sphenodon punctatus)-the only living member of the reptilian order Rhynchocephalia (Sphenodontia), once widespread across Gondwana1,2-is an iconic species that is endemic to New Zealand2,3. A key link to the now-extinct stem reptiles (from which dinosaurs, modern reptiles, birds and mammals evolved), the tuatara provides key insights into the ancestral amniotes2,4. Here we analyse the genome of the tuatara, which-at approximately 5 Gb-is among the largest of the vertebrate genomes yet assembled. Our analyses of this genome, along with comparisons with other vertebrate genomes, reinforce the uniqueness of the tuatara. Phylogenetic analyses indicate that the tuatara lineage diverged from that of snakes and lizards around 250 million years ago. This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features. The sequencing of the tuatara genome provides a valuable resource for deep comparative analyses of tetrapods, as well as for tuatara biology and conservation. Our study also provides important insights into both the technical challenges and the cultural obligations that are associated with genome sequencing.


Subject(s)
Evolution, Molecular , Genome/genetics , Phylogeny , Reptiles/genetics , Animals , Conservation of Natural Resources/trends , Female , Genetics, Population , Lizards/genetics , Male , Molecular Sequence Annotation , New Zealand , Sex Characteristics , Snakes/genetics , Synteny
10.
J Biol Chem ; 295(13): 4181-4193, 2020 03 27.
Article in English | MEDLINE | ID: mdl-32071083

ABSTRACT

Strigolactones (SLs) are terpenoid-derived plant hormones that regulate various developmental processes, particularly shoot branching, root development, and leaf senescence. The SL receptor has an unusual mode of action. Upon binding SL, it hydrolyzes the hormone, and then covalently binds one of the hydrolytic products. These initial events enable the SL receptor DAD2 (in petunia) to interact with the F-box protein PhMAX2A of the Skp-Cullin-F-box (SCF) complex and/or a repressor of SL signaling, PhD53A. However, it remains unclear how binding and hydrolysis structurally alters the SL receptor to enable its engagement with signaling partners. Here, we used mutagenesis to alter DAD2 and affect SL hydrolysis or DAD2's ability to interact with its signaling partners. We identified three DAD2 variants whose hydrolytic activity had been separated from the receptor's interactions with PhMAX2A or PhD53A. Two variants, DAD2N242I and DAD2F135A, having substitutions in the core α/ß hydrolase-fold domain and the hairpin, exhibited hormone-independent interactions with PhMAX2A and PhD53A, respectively. Conversely, the DAD2D166A variant could not interact with PhMAX2A in the presence of SL, but its interaction with PhD53A remained unaffected. Structural analyses of DAD2N242I and DAD2D166A revealed only small differences compared with the structure of the WT receptor. Results of molecular dynamics simulations of the DAD2N242I structure suggested that increased flexibility is a likely cause for its SL-independent interaction with PhMAX2A. Our results suggest that PhMAX2A and PhD53A have distinct binding sites on the SL receptor and that its flexibility is a major determinant of its interactions with these two downstream regulators.


Subject(s)
Heterocyclic Compounds, 3-Ring/chemistry , Lactones/chemistry , Petunia/chemistry , Plant Growth Regulators/genetics , Plant Proteins/chemistry , F-Box Proteins/chemistry , F-Box Proteins/genetics , Gene Expression Regulation, Plant/genetics , Hydrolases/chemistry , Hydrolases/genetics , Petunia/genetics , Plant Growth Regulators/chemistry , Plant Proteins/genetics , Protein Binding/genetics , SKP Cullin F-Box Protein Ligases/chemistry , SKP Cullin F-Box Protein Ligases/genetics , Signal Transduction/genetics
11.
Clin Infect Dis ; 71(2): 284-290, 2020 07 11.
Article in English | MEDLINE | ID: mdl-31552416

ABSTRACT

BACKGROUND: US public health strategy for eliminating tuberculosis (TB) prioritizes treatment of latent TB infection (LTBI). Healthcare personnel (HCP) are less willing to accept treatment than other populations. Little is known about factors associated with HCP LTBI therapy acceptance and completion. METHODS: We conducted a retrospective chart review to identify all employees with LTBI at time of hire at a large academic medical center during a 10-year period. Personal demographics, occupational factors, and clinic visit variables were correlated with LTBI treatment acceptance and completion rates using multivariate logistic regression. RESULTS: Of 470 HCP with LTBI for whom treatment was recommended, 193 (41.1%) accepted treatment, while 137 (29.1%) completed treatment. Treatment adherence was better with 4 months of rifampin than 9 months of isoniazid (95% vs 68%, P < .005). Increased age of the healthcare worker was independently associated with lower rates of treatment acceptance (odds ratio [95% confidence interval]: 0.97 [0.94-0.99] per year), as was having an occupation of clinician (0.47 [0.26-0.85]) or researcher (0.34 [0.19-0.64]). Male gender was associated with higher treatment acceptance (1.90 [1.21-2.99]). Treatment completion was associated with being from a low- (9.49 [2.06-43.73]) or medium- (8.51 [3.93-18.44]) TB-burden country. CONCLUSIONS: Geographic and occupational factors affect acceptance and completion of LTBI therapy. Short-course regimens may improve adherence. Physicians, researchers, and HCP from high-TB-burden countries have lower treatment rates than other HCP. Improving LTBI treatment in HCP will require attending to cultural and occupational differences.


Subject(s)
Latent Tuberculosis , Antitubercular Agents/therapeutic use , Delivery of Health Care , Health Personnel , Humans , Isoniazid , Latent Tuberculosis/drug therapy , Latent Tuberculosis/epidemiology , Male , Retrospective Studies
12.
Genome Biol Evol ; 11(4): 1293-1306, 2019 04 01.
Article in English | MEDLINE | ID: mdl-30957857

ABSTRACT

Exposure to low temperatures requires an organism to overcome physiological challenges. New Zealand weta belonging to the genera Hemideina and Deinacrida are found across a wide range of thermal environments and therefore subject to varying selective pressures. Here we assess the selection pressures across the weta phylogeny, with a particular emphasis on identifying genes under positive or diversifying selection. We used RNA-seq to generate transcriptomes for all 18 Deinacrida and Hemideina species. A total of 755 orthologous genes were identified using a bidirectional best-hit approach, with the resulting gene set encompassing a diverse range of functional classes. Analysis of ortholog ratios of synonymous to nonsynonymous amino acid changes found 83 genes that are under positive selection for at least one codon. A wide variety of Gene Ontology terms, enzymes, and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways are represented among these genes. In particular, enzymes involved in oxidative phosphorylation, melanin synthesis, and free-radical scavenging are represented, consistent with physiological and metabolic changes that are associated with adaptation to alpine environments. Structural alignment of the transcripts with the most codons under positive selection revealed that the majority of sites are surface residues, and therefore have the potential to influence the thermostability of the enzyme, with the exception of prophenoloxidase where two residues near the active site are under selection. These proteins provide interesting candidates for further analysis of protein evolution.


Subject(s)
Evolution, Molecular , Orthoptera/metabolism , Selection, Genetic , Transcriptome , Animals , Female , Male , Phylogeny
13.
Ecol Appl ; 29(4): e01877, 2019 06.
Article in English | MEDLINE | ID: mdl-30811075

ABSTRACT

Invertebrates are a major component of terrestrial ecosystems, however, estimating their biodiversity is challenging. We compiled an inventory of invertebrate biodiversity along an elevation gradient on the temperate forested island of Hauturu, New Zealand, by DNA barcoding of specimens obtained from leaf litter samples and pitfall traps. We compared the barcodes and biodiversity estimates from this data set with those from a parallel DNA metabarcoding analysis of soil from the same locations, and with pre-existing sequences in reference databases, before exploring the use of combined data sets as a basis for estimating total invertebrate biodiversity. We obtained 1,282 28S and 1,610 COI barcodes from a total of 1,947 invertebrate specimens, which were clustered into 247 (28S) and 366 (COI) OTUs, of which ≤ 10% were represented in GenBank. Coleoptera were most abundant (730 sequenced specimens), followed by Hymenoptera, Diptera, Lepidoptera, and Amphipoda. The most abundant OTU from both the 28S (153 sequences) and COI (140 sequences) data sets was an undescribed beetle from the family Salpingidae. Based on the occurrences of COI OTUs along the elevation gradient, we estimated there are ~1,000 arthropod species (excluding mites) on Hauturu, including 770 insects, of which 344 are beetles. A DNA metabarcoding analysis of soil DNA from the same sites resulted in the identification of similar numbers of OTUs in most invertebrate groups compared with the DNA barcoding, but less than 10% of the DNA barcoding COI OTUs were also detected by the metabarcoding analysis of soil DNA. A mark-recapture analysis based on the overlap between these data sets estimated the presence of approximately 6,800 arthropod species (excluding mites) on the island, including ~3,900 insects. Estimates of New Zealand-wide biodiversity for selected arthropod groups based on matching of the COI DNA barcodes with pre-existing reference sequences suggested over 13,200 insect species are present, including 4,000 Coleoptera, 2,200 Diptera, and 2,700 Hymenoptera species, and 1,000 arachnid species (excluding mites). These results confirm that metabarcoding analyses of soil DNA tends to recover different components of terrestrial invertebrate biodiversity compared to traditional invertebrate sampling, but the combined methods provide a novel basis for estimating invertebrate biodiversity.


Subject(s)
DNA Barcoding, Taxonomic , Ecosystem , Animals , Biodiversity , DNA , Invertebrates , Islands , New Zealand
14.
J Occup Environ Med ; 61(2): 120-125, 2019 02.
Article in English | MEDLINE | ID: mdl-30475315

ABSTRACT

OBJECTIVE: To assess current medical surveillance monitoring practices for health care workers who prepare, handle, or administer hazardous medications. METHODS: A cross-sectional survey was distributed to members of the American College of Occupational and Environmental Medicine and the National Comprehensive Cancer Network. RESULTS: Forty-six of the 91 survey respondents indicated that their institution had a hazardous medication surveillance program. We identified the most frequent laboratory (complete blood count) and physical (skin) examination components. A health history was frequently used. Statistical analysis did not suggest an association between institutions with greater resources and presence of a surveillance program. CONCLUSIONS: A consensus standard for medical monitoring was not reported by the respondents. We recommend using a standardized surveillance questionnaire and applying uniform laboratory testing across institutions, in addition to establishing a national repository for surveillance data.


Subject(s)
Drug-Related Side Effects and Adverse Reactions/prevention & control , Health Facilities/statistics & numerical data , Occupational Exposure/prevention & control , Adult , Health Personnel/statistics & numerical data , Humans , Middle Aged , Occupational Exposure/statistics & numerical data , Population Surveillance
15.
BMC Genomics ; 19(1): 94, 2018 01 26.
Article in English | MEDLINE | ID: mdl-29373972

ABSTRACT

BACKGROUND: Sex pheromone communication in moths has attracted the attention of evolutionary biologists due to the vast array of pheromone compounds used, addressing questions of how this diversity arose and how male reception has evolved in step with the female signal. Here we examine the role of changing gene expression in the evolution of mate recognition systems in leafroller moths, particularly focusing on genes involved in the biosynthetic pathways of sex pheromones in female pheromone glands and the peripheral reception repertoire in the antennae of males. From tissue-specific transcriptomes we mined and compared a database of genes expressed in the pheromone glands and antennae of males and females of four closely related species of leafroller moths endemic to New Zealand, Ctenopseutis herana and C. obliquana, and Planotortrix excessana and P. octo. The peculiarity of this group, compared to other Lepidoptera, is the use of (Z)-5-tetradecenyl acetate, (Z)-7-tetradecenyl acetate, and (Z)-8-tetradecenyl acetate as sex pheromone components. RESULTS: We identify orthologues of candidate genes from the pheromone biosynthesis pathway, degradation and transport, as well as genes of the periphery olfactory repertoire, including large families of binding proteins, receptors and odorant degrading enzymes. The production of distinct pheromone blends in the sibling species is associated with the differential expression of two desaturase genes, deast5 and desat7, in the pheromone glands. In male antennae, three odorant receptors, OR74, OR76a and OR30 are over-expressed, but their expression could not be clearly associated with the detection of species-specific pheromones components. In addition these species contain duplications of all three pheromone binding proteins (PBPs) that are also differentially expressed among species. CONCLUSIONS: While in females differences in the expression of desaturases may be sufficient to explain pheromone blend differences among these New Zealand leafroller species, in males differential expression of several genes, including pheromone binding proteins, may underpin differences in the response by males to changing pheromone components among the species.


Subject(s)
Biological Evolution , Gene Expression Profiling/methods , Gene Expression Regulation , Moths/genetics , Sex Attractants/metabolism , Animals , Fatty Acid Desaturases/genetics , Fatty Acid Desaturases/metabolism , Female , Male , Moths/classification , New Zealand , Receptors, Odorant/genetics , Receptors, Odorant/metabolism , Species Specificity , Transcriptome
16.
J Occup Environ Med ; 60(1): 83-89, 2018 01.
Article in English | MEDLINE | ID: mdl-28961593

ABSTRACT

OBJECTIVE: The impact of "real world" collaborative care on depression and absenteeism for depressed employees seen in primary care practices using objective employer absence data. METHODS: A retrospective cohort study comparing depressed employees seen in primary care practices who enrolled for a "real world" collaborative care program to practice as usual (PAU) on objective absence days and depression response and remission at 6, and 12-month time periods. RESULTS: Absence days were more in the collaborative care group compared with the PAU group at 3 and 6 months but at 12 months the difference was no longer statistically significant. Collaborative care led to better response and remission depression scores compared with PAU at 12 months. CONCLUSIONS: Collaborative care led to faster improvement in depression symptoms but did not translate to less time away from work.


Subject(s)
Absenteeism , Depression/therapy , Patient Care Team , Primary Health Care , Adult , Female , Humans , Male , Middle Aged , Occupational Health , Psychiatric Status Rating Scales , Retrospective Studies , Symptom Assessment , Time Factors , Treatment Outcome
17.
J Occup Environ Med ; 60(6): 521-527, 2018 06.
Article in English | MEDLINE | ID: mdl-29200189

ABSTRACT

OBJECTIVE: The National Institute for Occupational Safety and Health recommends that institutions establish a medical surveillance program for workers who handle hazardous drugs. Our aim was to investigate current practices with occupational medicine practice (OMP) national leaders. METHODS: A series of qualitative telephone interviews were conducted with 11 OMP national leaders from medical centers in 10 states. Interviews were recorded, transcribed, and coded using a directed content analysis. Codes were organized into themes. RESULTS: All respondents were board-certified physicians in medical center OMP. Interviews up to 45 minutes found three themes: policy interpretation, benefits and barriers to surveillance, and potential respondent-generated solutions. Three of 10 medical centers provided medical surveillance. CONCLUSIONS: Medical surveillance for hazardous drugs is infrequent, and consensus is lacking regarding standard practices. Further work is needed to minimize risk to health care workers.


Subject(s)
Hazardous Substances , Occupational Exposure/analysis , Occupational Health/standards , Occupational Medicine/methods , Pharmaceutical Preparations , Population Surveillance/methods , Academic Medical Centers , Adult , Aged , Female , Guidelines as Topic , Humans , Interviews as Topic , Male , Middle Aged , Occupational Exposure/legislation & jurisprudence , Occupational Exposure/standards , Organizational Policy , Qualitative Research
18.
PLoS One ; 12(11): e0188147, 2017.
Article in English | MEDLINE | ID: mdl-29131842

ABSTRACT

Animal reproductive proteins, especially those in the seminal fluid, have been shown to have higher levels of divergence than non-reproductive proteins and are often evolving adaptively. Seminal fluid proteins have been implicated in the formation of reproductive barriers between diverging lineages, and hence represent interesting candidates underlying speciation. RNA-seq was used to generate the first male reproductive transcriptome for the New Zealand tree weta species Hemideina thoracica and H. crassidens. We identified 865 putative reproductive associated proteins across both species, encompassing a diverse range of functional classes. Candidate gene sequencing of nine genes across three Hemideina, and two Deinacrida species suggests that H. thoracica has the highest levels of intraspecific genetic diversity. Non-monophyly was observed in the majority of sequenced genes indicating that either gene flow may be occurring between the species, or that reciprocal monophyly at these loci has yet to be attained. Evidence for positive selection was found for one lectin-related reproductive protein, with an overall omega of 7.65 and one site in particular being under strong positive selection. This candidate gene represents the first step in the identification of proteins underlying the evolutionary basis of weta reproduction and speciation.


Subject(s)
Evolution, Molecular , Orthoptera/genetics , Selection, Genetic , Animals , Haplotypes , Likelihood Functions , New Zealand , Polymorphism, Genetic , Transcriptome
19.
Mol Biol Evol ; 34(11): 2733-2746, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29126322

ABSTRACT

Pheromone receptors (PRs) are essential in moths to detect sex pheromones for mate finding. However, it remains unknown from which ancestral proteins these specialized receptors arose. The oldest lineages of moths, so-called non-ditrysian moths, use short-chain pheromone components, secondary alcohols, or ketones, so called Type 0 pheromones that are similar to many common plant volatiles. It is, therefore, possible that receptors for these ancestral pheromones evolved from receptors detecting plant volatiles. Hence, we identified the odorant receptors (ORs) from a non-ditrysian moth, Eriocrania semipurpurella (Eriocraniidae, Lepidoptera), and performed functional characterization of ORs using HEK293 cells. We report the first receptors that respond to Type 0 pheromone compounds; EsemOR3 displayed highest sensitivity toward (2S, 6Z)-6-nonen-2-ol, whereas EsemOR5 was most sensitive to the behavioral antagonist (Z)-6-nonen-2-one. These receptors also respond to plant volatiles of similar chemical structures, but with lower sensitivity. Phylogenetically, EsemOR3 and EsemOR5 group with a plant volatile-responding receptor from the tortricid moth Epiphyas postvittana (EposOR3), which together reside outside the previously defined lepidopteran PR clade that contains the PRs from more derived lepidopteran families. In addition, one receptor (EsemOR1) that falls at the base of the lepidopteran PR clade, responded specifically to ß-caryophyllene and not to any other additional plant or pheromone compounds. Our results suggest that PRs for Type 0 pheromones have evolved from ORs that detect structurally-related plant volatiles. They are unrelated to PRs detecting pheromones in more derived Lepidoptera, which, in turn, also independently may have evolved a novel function from ORs detecting plant volatiles.


Subject(s)
Lepidoptera/genetics , Receptors, Pheromone/genetics , Sex Attractants/genetics , Animals , Carrier Proteins/metabolism , Evolution, Molecular , HEK293 Cells/metabolism , Humans , Ketones/metabolism , Moths/genetics , Pheromones/metabolism , Phylogeny , Polycyclic Sesquiterpenes , Receptors, Odorant/genetics , Receptors, Odorant/metabolism , Receptors, Pheromone/metabolism , Sesquiterpenes/metabolism , Sex Attractants/metabolism
20.
BMC Genomics ; 18(1): 884, 2017 Nov 16.
Article in English | MEDLINE | ID: mdl-29145825

ABSTRACT

BACKGROUND: Stick insects (Phasmatodea) have a high incidence of parthenogenesis and other alternative reproductive strategies, yet the genetic basis of reproduction is poorly understood. Phasmatodea includes nearly 3000 species, yet only the genome of Timema cristinae has been published to date. Clitarchus hookeri is a geographical parthenogenetic stick insect distributed across New Zealand. Sexual reproduction dominates in northern habitats but is replaced by parthenogenesis in the south. Here, we present a de novo genome assembly of a female C. hookeri and use it to detect candidate genes associated with gamete production and development in females and males. We also explore the factors underlying large genome size in stick insects. RESULTS: The C. hookeri genome assembly was 4.2 Gb, similar to the flow cytometry estimate, making it the second largest insect genome sequenced and assembled to date. Like the large genome of Locusta migratoria, the genome of C. hookeri is also highly repetitive and the predicted gene models are much longer than those from most other sequenced insect genomes, largely due to longer introns. Miniature inverted repeat transposable elements (MITEs), absent in the much smaller T. cristinae genome, is the most abundant repeat type in the C. hookeri genome assembly. Mapping RNA-Seq reads from female and male gonadal transcriptomes onto the genome assembly resulted in the identification of 39,940 gene loci, 15.8% and 37.6% of which showed female-biased and male-biased expression, respectively. The genes that were over-expressed in females were mostly associated with molecular transportation, developmental process, oocyte growth and reproductive process; whereas, the male-biased genes were enriched in rhythmic process, molecular transducer activity and synapse. Several genes involved in the juvenile hormone synthesis pathway were also identified. CONCLUSIONS: The evolution of large insect genomes such as L. migratoria and C. hookeri genomes is most likely due to the accumulation of repetitive regions and intron elongation. MITEs contributed significantly to the growth of C. hookeri genome size yet are surprisingly absent from the T. cristinae genome. Sex-biased genes identified from gonadal tissues, including genes involved in juvenile hormone synthesis, provide interesting candidates for the further study of flexible reproduction in stick insects.


Subject(s)
Genome Size , Genome, Insect , Neoptera/genetics , Animals , Female , Gene Expression Profiling , Gene Ontology , Gonads/metabolism , Insect Proteins/genetics , Male , Molecular Sequence Annotation , Repetitive Sequences, Nucleic Acid , Reproduction/genetics , Sex Characteristics
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