81 research outputs found
Brown marmorated stink bug, Halyomorpha halys (Stål), genome: putative underpinnings of polyphagy, insecticide resistance potential and biology of a top worldwide pest
Background
Halyomorpha halys (Stål), the brown marmorated stink bug, is a highly invasive insect species due in part to its exceptionally high levels of polyphagy. This species is also a nuisance due to overwintering in human-made structures. It has caused significant agricultural losses in recent years along the Atlantic seaboard of North America and in continental Europe. Genomic resources will assist with determining the molecular basis for this species’ feeding and habitat traits, defining potential targets for pest management strategies.
Results
Analysis of the 1.15-Gb draft genome assembly has identified a wide variety of genetic elements underpinning the biological characteristics of this formidable pest species, encompassing the roles of sensory functions, digestion, immunity, detoxification and development, all of which likely support H. halys’ capacity for invasiveness. Many of the genes identified herein have potential for biomolecular pesticide applications.
Conclusions
Availability of the H. halys genome sequence will be useful for the development of environmentally friendly biomolecular pesticides to be applied in concert with more traditional, synthetic chemical-based controls
The Genome of Rhyzopertha dominica (Fab.) (Coleoptera: Bostrichidae): Adaptation for Success
The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), is a major global pest of cereal grains. Infestations are difficult to control as larvae feed inside grain kernels, and many populations are resistant to both contact insecticides and fumigants. We sequenced the genome of R. dominica to identify genes responsible for important biological functions and develop more targeted and efficacious management strategies. The genome was assembled from long read sequencing and long-range scaffolding technologies. The genome assembly is 479.1 Mb, close to the predicted genome size of 480.4 Mb by flow cytometry. This assembly is among the most contiguous beetle assemblies published to date, with 139 scaffolds, an N50 of 53.6 Mb, and L50 of 4, indicating chromosome-scale scaffolds. Predicted genes from biologically relevant groups were manually annotated using transcriptome data from adults and different larval tissues to guide annotation. The expansion of carbohydrase and serine peptidase genes suggest that they combine to enable efficient digestion of cereal proteins. A reduction in the copy number of several detoxification gene families relative to other coleopterans may reflect the low selective pressure on these genes in an insect that spends most of its life feeding internally. Chemoreceptor genes contain elevated numbers of pseudogenes for odorant receptors that also may be related to the recent ontogenetic shift of R. dominica to a diet consisting primarily of stored grains. Analysis of repetitive sequences will further define the evolution of bostrichid beetles compared to other species. The data overall contribute significantly to coleopteran genetic research
The genome of the water strider Gerris buenoi reveals expansions of gene repertoires associated with adaptations to life on the water.
BACKGROUND: Having conquered water surfaces worldwide, the semi-aquatic bugs occupy ponds, streams, lakes, mangroves, and even open oceans. The diversity of this group has inspired a range of scientific studies from ecology and evolution to developmental genetics and hydrodynamics of fluid locomotion. However, the lack of a representative water strider genome hinders our ability to more thoroughly investigate the molecular mechanisms underlying the processes of adaptation and diversification within this group. RESULTS: Here we report the sequencing and manual annotation of the Gerris buenoi (G. buenoi) genome; the first water strider genome to be sequenced thus far. The size of the G. buenoi genome is approximately 1,000 Mb, and this sequencing effort has recovered 20,949 predicted protein-coding genes. Manual annotation uncovered a number of local (tandem and proximal) gene duplications and expansions of gene families known for their importance in a variety of processes associated with morphological and physiological adaptations to a water surface lifestyle. These expansions may affect key processes associated with growth, vision, desiccation resistance, detoxification, olfaction and epigenetic regulation. Strikingly, the G. buenoi genome contains three insulin receptors, suggesting key changes in the rewiring and function of the insulin pathway. Other genomic changes affecting with opsin genes may be associated with wavelength sensitivity shifts in opsins, which is likely to be key in facilitating specific adaptations in vision for diverse water habitats. CONCLUSIONS: Our findings suggest that local gene duplications might have played an important role during the evolution of water striders. Along with these findings, the sequencing of the G. buenoi genome now provides us the opportunity to pursue exciting research opportunities to further understand the genomic underpinnings of traits associated with the extreme body plan and life history of water striders
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The genome of the water strider Gerris buenoi reveals expansions of gene repertoires associated with adaptations to life on the water
Background: Having conquered water surfaces worldwide, the semi-aquatic bugs occupy ponds, streams, lakes, mangroves, and even open oceans. The diversity of this group has inspired a range of scientific studies from ecology and evolution to developmental genetics and hydrodynamics of fluid locomotion. However, the lack of a representative water strider genome hinders our ability to more thoroughly investigate the molecular mechanisms underlying the processes of adaptation and diversification within this group.
Results: Here we report the sequencing and manual annotation of the Gerris buenoi (G. buenoi) genome; the first water strider genome to be sequenced thus far. The size of the G. buenoi genome is approximately 1,000Mb, and this sequencing effort has recovered 20,949 predicted protein-coding genes. Manual annotation uncovered a number of local (tandem and proximal) gene duplications and expansions of gene families known for their importance in a variety of processes associated with morphological and physiological adaptations to a water surface lifestyle. These expansions may affect key processes associated with growth, vision, desiccation resistance, detoxification, olfaction and epigenetic regulation. Strikingly, the G. buenoi genome contains three insulin receptors, suggesting key changes in the rewiring and function of the insulin pathway. Other genomic changes affecting with opsin genes may be associated with wavelength sensitivity shifts in opsins, which is likely to be key in facilitating specific adaptations in vision for diverse water habitats.
Conclusions: Our findings suggest that local gene duplications might have played an important role during the evolution of water striders. Along with these findings, the sequencing of the G. buenoi genome now provides us the opportunity to pursue exciting research opportunities to further understand the genomic underpinnings of traits associated with the extreme body plan and life history of water striders
Expression patterns of cysteine peptidase genes across the Tribolium castaneum life cycle provide clues to biological function
The red flour beetle, Tribolium castaneum, is a major agricultural pest responsible for considerable loss of stored grain and cereal products worldwide. T. castaneum larvae have a highly compartmentalized gut, with cysteine peptidases mostly in the acidic anterior part of the midgut that are critical to the early stages of food digestion. In previous studies, we described 26 putative cysteine peptidase genes in T. castaneum (types B, L, O, F, and K) located mostly on chromosomes 3, 7, 8, and 10. In the present study, we hypothesized that specific cysteine peptidase genes could be associated with digestive functions for food processing based on comparison of gene expression profiles in different developmental stages, feeding and non-feeding. RNA-Seq was used to determine the relative expression of cysteine peptidase genes among four major developmental stages (egg, larvae, pupae, and adult) of T. castaneum. We also compared cysteine peptidase genes in T. castaneum to those in other model insects and coleopteran pests. By combining transcriptome expression, phylogenetic comparisons, response to dietary inhibitors, and other existing data, we identified key cysteine peptidases that T. castaneum larvae and adults use for food digestion, and thus new potential targets for biologically-based control products
Proline-Specific Fungal Peptidases: Genomic Analysis and Identification of Secreted DPP4 in Alkaliphilic and Alkalitolerant Fungi
Proline-specific peptidases (PSP) play a crucial role in the processing of fungal toxins, pheromones, and intracellular signaling. They are of particular interest to biotechnology, as they are able to hydrolyze proline-rich oligopeptides that give a bitter taste to food and can also cause an autoimmune celiac disease. We performed in silico analysis of PSP homologs in the genomes of 42 species of higher fungi which showed the presence of PSP homologs characteristic of various kingdoms of living organisms and belonging to different families of peptidases, including homologs of dipeptidyl peptidase 4 (DPP4) and prolyl aminopeptidase 1 found in almost all the studied fungal species. Homologs of proliniminopeptidases from the S33 family absent in humans were also found. Several studied homologs are characteristic of certain taxonomic groups of fungi. Phylogenetic analysis suggests a duplication of ancestral DPP4 into transmembrane and secreted versions, which predate the split of ascomycete and basidiomycete lineages. Comparative biochemical analysis of DPP4 in alkaliphilic and alkali-tolerant strains of fungi showed that, notwithstanding some individual features of these enzymes, in both cases, the studied DPP4 are active and stable under alkaline conditions and at high salt concentrations, which makes them viable candidates for biotechnology and bioengineering
Original Russian Text Originally published in Biochemistry (Moscow) On Line Papers in Press, as Manuscript BM04 310
Trypsin like proteinases play an important role in digestion in most insects studied [1 4]. They are also involved in processing of insecticide toxins of Bacillus thuringiensis, and this underlines protease dependent resistance of these species to the toxins In this paper, we describe a relatively simple method for purification of the main trypsin like enzyme of the posterior part of the midgut of yellow mealworm (Tenebrio molitor) larvae (TmT1) and characterize the proteinase of this stored product pest. MATERIALS AND METHODS Yellow mealworm (Tenebrio molitor) larvae were reared on a mixture of wheat flour, bran, and brewer's yeast and transferred to milled oat flakes (Raisio, Finland) 1 1.5 weeks prior to dissection. Proteinase purification. Isolated larvae midguts were separated into anterior and posterior parts. The collected posterior parts were homogenized in 0.14 M NaCl and centrifuged at 15,000g for 10 min. The supernatant dia lyzed against 20 mM K,Na phosphate buffer, pH 6.9, containing 0.02% NaN 3 , was centrifuged again and sub jected to batch chromatography on DEAE Sephadex A 50 using the same buffer. The filtrate containing the Vol. 70, No. 3, 2005, pp. 300 305. Translated from Biokhimiya, Vol. 70, No. 3, 2005, pp. 370 377. Original Russian Text Copyright © 2005 by Tsybina, Dunaevsky, Belozersky, Zhuzhikov, Oppert, Elpidina. Originally published in Biochemistry (Moscow) On Line Papers in Press, as Manuscript BM04 310, February 20, 2005 ACCELERATED PUBLICATION 0006 2979/05/7003 0300 ©2005 Pleiades Publishing, Inc. Abbreviations: Bz) benzoyl; FPLC) fast performance liquid chromatography; For) formyl; PMSF) phenylmethylsulfonyl fluoride; pNA) p nitroanilide; TLCK) N α p tosyl L lysine chloromethyl ketone; TmT1) trypsin like proteinase from T. molitor larvae; E 64) L trans epoxysuccinyl L leucine amido(4 guanidine)butane; Z) N benzoyloxycarbonyl. * To whom correspondence should be addressed. Abstract-A new trypsin like proteinase was purified to homogeneity from the posterior midgut of Tenebrio molitor larvae by ion exchange chromatography on DEAE Sephadex A 50 and gel filtration on Superdex 75. The isolated enzyme had molec ular mass of 25.5 kD and pI 7.4. The enzyme was also characterized by temperature optimum at 55°C, pH optimum at 8.5, and K m value of 0.04 mM (for hydrolysis of Bz Arg pNA). According to inhibitor analysis the enzyme is a trypsin like serine proteinase stable within the pH range of 5.0 9.5. The enzyme hydrolyzes peptide bonds formed by Arg or Lys residues in the P1 position with a preference for relatively long peptide substrates. The N terminal amino acid sequence, IVGGSSI SISSVPXQIXLQY, shares 50 72% identity with other insect trypsin like proteinases, and 44 50% identity to mammalian trypsins. The isolated enzyme is sensitive to inhibition by plant proteinase inhibitors and it can serve as a suitable target for control of digestion in this stored product pest. Digestive Proteinases of Yellow Mealworm (Tenebrio molitor
Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants
Effective Degradation of Gluten and Its Fragments by Gluten-Specific Peptidases: A Review on Application for the Treatment of Patients with Gluten Sensitivity
To date, there is no effective treatment for celiac disease (CD, gluten enteropathy), an autoimmune disease caused by gluten-containing food. Celiac patients are supported by a strict gluten-free diet (GFD). However, in some cases GFD does not negate gluten-induced symptoms. Many patients with CD, despite following such a diet, retain symptoms of active disease due to high sensitivity even to traces of gluten. In addition, strict adherence to GFD reduces the quality of life of patients, as often it is difficult to maintain in a professional or social environment. Various pharmacological treatments are being developed to complement GFD. One promising treatment is enzyme therapy, involving the intake of peptidases with food to digest immunogenic gluten peptides that are resistant to hydrolysis due to a high prevalence of proline and glutamine amino acids. This narrative review considers the features of the main proline/glutamine-rich proteins of cereals and the conditions that cause the symptoms of CD. In addition, we evaluate information about peptidases from various sources that can effectively break down these proteins and their immunogenic peptides, and analyze data on their activity and preliminary clinical trials. Thus far, the data suggest that enzyme therapy alone is not sufficient for the treatment of CD but can be used as a pharmacological supplement to GFD
Complex of Proline-Specific Peptidases in the Genome and Gut Transcriptomes of Tenebrionidae Insects and Their Role in Gliadin Hydrolysis
A detailed analysis of the complexes of proline-specific peptidases (PSPs) in the midgut transcriptomes of the larvae of agricultural pests Tenebrio molitor and Tribolium castaneum and in the genome of T. castaneum is presented. Analysis of the T. castaneum genome revealed 13 PSP sequences from the clans of serine and metal-dependent peptidases, of which 11 sequences were also found in the gut transcriptomes of both tenebrionid species’ larvae. Studies of the localization of PSPs, evaluation of the expression level of their genes in gut transcriptomes, and prediction of the presence of signal peptides determining secretory pathways made it possible to propose a set of peptidases that can directly participate in the hydrolysis of food proteins in the larvae guts. The discovered digestive PSPs of tenebrionids in combination with the post-glutamine cleaving cysteine cathepsins of these insects effectively hydrolyzed gliadins, which are the natural food substrates of the studied pests. Based on the data obtained, a hypothetical scheme for the complete hydrolysis of immunogenic gliadin peptides by T. molitor and T. castaneum digestive peptidases was proposed. These results show promise regarding the development of a drug based on tenebrionid digestive enzymes for the enzymatic therapy of celiac disease and gluten intolerance
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