To identify viruses and compare their abundance levels in the venom glands of hymenopteran species, we conducted venom gland-specific transcriptome assemblies and analyses of 22 Aculeate bees and wasps and identified the RNA genomes of picornaviruses. Additionally, we investigated the expression patterns of viruses in the venom glands over time following capture. Honeybee-infecting viruses, including black queen cell virus (BQCV), deformed wing virus (DWV), and Israeli acute paralysis virus (IAPV), were highly expressed in the venom glands of Apis mellifera and social wasps. This finding suggests that the venoms of bees and wasps likely contain these viruses, which can be transmitted horizontally between species through their stinger usage. A. mellifera exhibited an increasing pattern of abundance levels for BQCV, DWV, IAPV, and Triatovirus, while the social wasp Vespa crabro showed increasing abundance levels of IAPV and Triatovirus over different capture periods. This suggests that the venom glands of honeybees and wasps may provide suitable conditions for active viral replication and may be an organ for virus accumulation and transmission. Some viral sequences clearly reflected the phylogeny of Aculeate species, implying host-specific virus evolution. On the other hand, other viruses exhibited unique evolutionary patterns of phylogeny, possibly caused by specific ecological interactions. Our study provides insights into the composition and evolutionary properties of viral genes in the venom glands of certain Aculeate bees and wasps, as well as the potential horizontal transmission of these viruses among bee and wasp species.
Preserving intact genetic material and delivering it to the next generation are the most significant tasks of living organisms. The integrity of DNA sequences is under constant threat from endogenous and exogenous factors. The accumulation of damaged or incompletely-repaired DNA can cause serious problems in cells, including cell death or cancer development. Various DNA damage detection systems and repair mechanisms have evolved at the cellular level. Although the mechanisms of these responses have been extensively studied, the global RNA expression profiles associated with genomic instability are not well-known. To detect global gene expression changes under different DNA damage and hypoxic conditions, we performed RNA-seq after treating human cervical cancer cells with ionizing radiation (IR), hydroxyurea, mitomycin C (MMC), or 1% O2 (hypoxia). Results showed that the expression of 184–1037 genes was altered by each stimulus. We found that the expression of 51 genes changed under IR, MMC, and hypoxia. These findings revealed damage-specific genes that varied differently according to each stimulus and common genes that are universally altered in genetic instability.
The pea aphid, Acyrthosiphon pisum, requires the nutritional endosymbiont, Buchnera, for the production of essential amino acids. However, it is unclear if host plant diet that varies in essential amino acids influences aphid regulation of its nutritional symbioses. We hypothesized that aphid genes respond to host plant diet when aphids feed on their specialized (alfalfa) compared to universal host plant diet (fava), which vary in essential amino acid concentrations. Using RNA-Seq and whole genome bisulfite sequencing, we compared the gene expression profiles and DNA methylation distributions of specialized aphid cells that harbor Buchnera (bacteriocytes) when aphids feed on their specialized compared to their universal host plant diets. Our results show that bacteriocyte transcription and methylation patterns differ between host plant diets. When aphids feed on their specialized host plant, they significantly up-regulate and/or hypo-methylate key aphid genes in bacteriocytes related to the amino acid metabolism, including glutamine synthetase (GS) and the glutamine transporter ApGLNT1. Moreover, regardless of which host plant aphids feed on, we observed significant up-regulation and differential methylation of the key genes in the amino acid metabolism and the glycine/serine metabolism in aphid bacteriocytes. We suggest that the regulatory response of key symbiosis genes in bacteriocytes allows aphids to feed on a specialized host plant diet with suboptimal nitrogen concentrations.
The tyrosinase (TYR) genes have been accepted as major genes involved in the plumage pigmentation of chickens. Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Especially, most examples of color patterns in chicken have been due to differential in the tyrosinase gene. This study was conducted to the association of feather color and sequence polymorphism in the Tyrosinase(TYR) gene was investigated using Korean native chickens(red plumage, red-line plumage, Ogol = KNC) and white leghorn(WL). From WL and KNC breed analyses, 232 differential SNPs were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 50 SNPs were compared between KCR, KCRD and KCO represented homozygous SNP types in all the analyzed SNP positions while KNC displayed various SNP types. In this study, we conclude that the variation of a wild type sequence in intron 4 of the tyrosinase gene is pigmentation of the original native chickens in korean. This work was supported by a grant from the “Livestock Preservation of Genetic Resources", Rural Development Administration, Republic of Korea.
In our previous study, COPA (coatomer subunit alpha) gene from the two-spotted spider mite, Tetranychus urticae, exhibited RNA interference (RNAi)-based lethality when its double-stranded RNA (dsRNA) was systemically delivered via multi-unit chambers or its hairpin RNA was in planta-expressed by agroinfiltration. The cumulative mortality of T. urtcae was 55.0 ±14.2% in soybean plants agroinfiltrated with COPA gene. To investigate the temporal expression profiles of hairpin RNA following agroinfiltration, the amount of hairpin RNA expressed in plants was quantified over time by quantitative real-time PCR. Relative transient expression levels of T. urticae COPA hairpin RNA was highest at 46 h post-agroinfiltration and the extent of COPA gene knockdown was lowest at 12 h post-infestation on soybean plants. To investigate small interference RNA (siRNA) profiling, northern blot assay is currently under progress.
Differential gene regulation is crucial for development. Indianmeal moth is a global pest of stored and processed food products. Here, we determined the whole developmental expression patterns of 13 genes (shsp, hsp70, grp78, and hsp90), ecdysone receptor (EcR), ultraspiracle (USP), hemolin, β-1,3-glucan recognition protein (βgrp), prophenoloxidase (ProPO), superoxide dismutase (SOD) and thioredoxin peroxidase (Tpx), and two hexamerin storage protein genes (SP1 and SP2) related to growth, stress, metabolism, and host defense. We also studies effects of Bracon hebetor envenomation on these gene expressions to explore their role in host regulation. We found unexpected transcriptional peaks especially hsps which were high in egg and adult stages. This study provides comprehensive understanding about development and parasitoid regulation at molecular level.
To determine differential gene expression profiles in the salivary gland of a water stick-insect, Ranatra chinensis Mayrt, a subtractive cDNA library was constructed by suppression subtractive hybridization. The salivary gland was determined among three salivary gland-like tissues by investigating transcription levels of five trypsin genes isolated from R. chinensis. The major transcripts encoding trypsins (64.4% of the total ESTs) were eliminated from the library and then remaining salivary gland-specific genes were searched. A total of 643 expressed sequence tags (ESTs) were clustered and assembled into 148 contigs (49 multiple sequences and 99 singletons), among which 35 contigs had matched BLASTx hits (E ≤ 1.00E-4). Salivary apyrase occupied 5.6% (36 ESTs) of the library. Apyrase is known to be released by female mosquitoes or blood-sucking assassin bugs to prevent blood clots during blood sucking. Therefore, apyrase in the salivary of R. chinensis might allow R. chinensis to facilitate feeding. Several contigs encoding acid phosphatase, hyaluronidase, prophenoloxidase, and dipeptidylpeptidase IV, commonly found in venoms of Hymenoptera, were also identified from the salivary gland-specific library. Discovery of salivary glandspecific genes should promote further studies on biologically active components in the saliva of R. chinensis.
To determine differential gene expression profiles in the salivary gland of a predatory flower bug species, Orius laevigatus Fieber, a subtractive cDNA library was constructed by suppression subtractive hybridization. The major transcripts encoding trypsins (28.6% of the total ESTs) were eliminated from the library and then remaining salivary gland-specific genes were searched. A total of 513 expressed sequence tags (ESTs) were clustered and assembled into 129 contigs (64 multiple sequences and 65 singletons). About 58% were matched with insect genes. In total, 38 genes (179 ESTs) were found from the library by BLASTx search. A hemolysin-like protein occupied ca. 8% (41 ESTs) of the library. Hemolysin is known to destruct cells including blood cells by forming pores on the cell membrane. A hemolysin-like salivary protein of O. laevigatus might be hemolytic against the prey cells, thereby allowing O. laevigatus to facilitate feeding. Several contigs encoding lipase was also identified from the salivary gland-specific library. Discovery of salivary gland-specific genes should promote further studies on biologically active components in the saliva of O. laevigatus.
To determine differential gene expression profiles in the venom gland and sac (gland/sac) of a solitary hunting wasp species, Eumenes pomiformis Fabricius (1781), a subtractive cDNA library was constructed by suppression subtractive hybridization. A total of 541 expressed sequence tags (EST) were clustered and assembled into 102 contigs. In total, 37 genes were found from the library by BLASTx search and manual analysis. A eumenitin-like venom peptide, EpVP1, occupied ca. 26% of the library. A novel venom peptide, EpDTX, shared sequence similarity with trypsin inhibitors and dendrotoxin-like venom peptides known as K+ channel blockers, implying it could be responsible for the paralysis of prey. As well as phospholipase A2 and hyaluronidase known to be main components of wasp venoms, several contigs encoding enzymes, including metalloendopeptidases and a decarboxylase likely involved in the processing and activation of venomous proteins, peptides, and neurotransmitters, were also isolated from the library. The presence of a gene encoding insulin-like growth factor binding protein suggests that solitary hunting wasps might control the prey to stay in larval stage by their venom. The abundance of these venom components in the venom gland/sac and alimentary canal was confirmed by quantitative real-time PCR.
To determine differential gene expression profiles in a cypermethrin-resistant strain (CR) of diamondback moth, Plutella xylostella Linnaeus (1758), a subtractive cDNA library was constructed by suppression subtractive hybridization. A total of 1196 expressed sequence tags (EST) were clustered and assembled into 579 contigs (100 multiplets and 479 singletons). About 46% (267) of 579 contigs had the matched BLASTx hits (E ≤ 10-5). Among these, 143 contigs had similarity to proteins with assigned molecular function in the Functional Catalogue database, and most of them (86%) were homologous to the genes from insects, particularly to Lepidoptera (56%). The contigs encoding carboxylesterase and cytochrome P450 known to be involved in the insecticide resistance were found in the library. They were identified as pxest3, pxest4, and CYP9G2 gene by 5' and 3' RACE. Among these, pxest4 was determined to be 2-fold over-transcribed in the CR strain by qrtPCR. Several contigs encoding enzymes including cytochrome oxidase subunit I that are likely involved in the insecticide resistance were also identified from the library. Discovery of the genes specific to cypermethrin resistance should promote further studies on the molecular mechanisms of insecticide resistance in P. xylostella.