As one of the 100 most-threatening invasive alien species, the giant African snail (
) has successfully invaded and established itself in most areas of southern China. Protection against recurrent ...pathogen infections is vital to biological invasion. Enhanced immune protection has been previously found in other invertebrates, but not in the unique immune system of the giant African snail. In the present study, the survival rate of the giant African snail was recorded following a second infection with lethal doses of
after a previous first injection using lipopolysaccharide (LPS), and the mechanism of immune enhancement was investigated by examining the cellular and transcriptomic response of the giant African snail after two successive stimuli using LPS. Snails injected first with LPS, sterilized physiologic (0.9%) saline (SPS), phosphate-buffered saline (PBS) or untreated (Blank) were rechallenged at 7d with
(Ec), and were named as LPS + Ec, SPS + Ec, PBS + Ec, Ec, and Blank. The log-rank test shows the survival rate of the LPS + Ec group as significantly higher than that of other control groups after the second injection (
< 0.05). By performing cell counting and BrdU labeling on newly generated circulating hemocytes, we found that the total hemocyte count (THC) and the ratio of BrdU-positive cells to total cells increased significantly after primary stimulation with LPS and that they further increased after the second challenge. Then, caspase-3 of apoptosis protease and two antioxidant enzyme activities (CAT and SOD) increased significantly after infection, and were significantly higher in the second response than they had been in the first round. Moreover, transcriptome analysis results showed that 84 differentially expressed genes (DEGs) were expressed at higher levels in both the resting and activating states after the second immune response compared to the levels observed after the first challenge. Among them, some DEGs, including Toll-like receptor 4 (TLR4) and its downstream signaling molecules, were verified using qRT-PCR and were consistent with the transcriptome assay results. Based on gene expression levels, we proposed that these genes related to the TLR signaling cascade participate in enhanced immune protection. All results provide evidence that enhanced immune protection exists in the giant African snail.
A. Gray, an ornamental submerged plant indigenous to tropical America, has been introduced to numerous countries in Europe, Asia, and Oceania, impacting native aquatic ecosystems. Given this species ...is a popular aquarium plant and widely traded, there is a high risk of introduction and invasion into other environments. In the current study the potential global geographic distribution of
was predicted under the effects of climate change and human influence in an optimised MaxEnt model. The model used rigorously screened occurrence records of
from hydro informatic datasets and 20 associated influencing factors. The findings indicate that temperature and human-mediated activities significantly influenced the distribution of
. At present,
covers an area of approximately 1531×10
km
of appropriate habitat, especially in the south-eastern parts of South, central and North America, Southeast Asia, eastern Australia, and most of Europe. The suitable regions are anticipated to expand under future climate scenarios; however, the dynamics of the changes vary between different extents of climate change. For example,
is expected to expand to higher latitudes, following global temperature increases under SSP1-2.6 and SSP2-4.5 scenarios, however, intolerance to temperature extremes may mediate invasion at higher latitudes under future extreme climate scenarios, e.g., SSP5-8.5. Owing to the severe impacts its invasion causes, early warning and stringent border quarantine processes are required to guard against the introduction of
especially in the invasion hotspots such as, Peru, Italy, and South Korea.
Thermal adaptation plays a fundamental role in the expansion and distribution of insects, and heat shock proteins (Hsps) play important roles in the temperature adaptation of various organisms. To ...determine the roles of Hsp genes (
,
, and
) on the high temperature tolerance of
, we obtained complete cDNA (complementary DNA) sequences for
,
, and
by rapid amplification of cDNA ends (RACE), analyzed their expression profiles under different high temperature treatments by quantitative reverse transcription polymerase chain reaction (RT-qPCR), and performed functional verification by RNA interference (RNAi). The open reading frames of
,
, and
were 1940, 543, and 567 bp, encoding 650, 180, and 188 amino acids, respectively. Their molecular weights (MWs) were 71.757, 20.879, and 21.510 kDa, and the isoelectric points were 5.63, 6.45, and 6.24, respectively. Phylogenetic tree analysis showed that the
,
, and
genes of
were relatively conserved in evolution. The
and
genes in
were homologous to those in
(87 and 79% similarity, respectively), and the
gene in
was homologous to that in
(74% similarity). The amino acid polypeptide chain had highly conserved sequences of DLGGGTFD, VLVGGSTR, and GPTIEEVD. The sequence of EEVD was the characteristic motif of cytoplasmic
, and the highly conserved sequences of MALFR and MSLLP were characteristic sequences of
and
, respectively. Relative quantitative real time PCR showed that the three
could be induced by 4-h treatment at high temperatures. Significant upregulation of these
was observed when the temperature was further increased. The RNAi results showed that the injection of the three
' dsRNA could suppress the expression at the gene level significantly. Compared with the control group, high temperature heat shock reduced the fecundity of
significantly, and the fecundity decreased with the increase in temperature. Our results suggest that
,
, and
might play key roles in high temperature adaptation of
and help improve our understanding of their mechanism of thermotolerance.
Serine protease inhibitors (serpins) appear to be ubiquitous in almost all living organisms, with a conserved structure and varying functions. Serpins can modulate immune responses by negatively ...regulating serine protease activities strictly and precisely. The codling moth, Cydia pomonella (L.), a major invasive pest in China, can cause serious economic losses. However, knowledge of serpin genes in this insect remain largely unknown. In this study, we performed a systematic analysis of the serpin genes in C. pomonella, obtaining 26 serpins from the C. pomonella genome. Subsequently, their sequence features, evolutionary relationship, and expression pattern were characterized. Comparative analysis revealed the evolution of a number of serpin genes in Lepidoptera. Importantly, the evolutionary relationship and putative roles of serpin genes in C. pomonella were revealed. Additionally, selective pressure analysis found amino acid sites with strong evidence of positive selection. Interestingly, the serpin1 gene possessed at least six splicing isoforms with distinct reactive-center loops, and these isoforms were experimentally validated. Furthermore, we observed a subclade expansion of serpins, and these genes showed high expression in multiple tissues, suggesting their important roles in C. pomonella. Overall, this study will enrich our knowledge of the immunity of C. pomonella and help to elucidate the role of serpins in the immune response.
The issue of biological invasions in aquatic ecosystems is becoming increasingly severe in the contemporary world. Due to the lack of monitoring and management systems for aquatic invasive species, ...the difficulty in identifying aquatic invasive species, and the limited effectiveness of conventional control methods in aquatic environments, biological control in water bodies is comparatively more challenging than other types of interventions. In recent years, environmental DNA (eDNA) survey methods have rapidly developed in various fields, such as biological monitoring, community ecology, paleoenvironmental research, conservation biology, and invasion ecology, due to their unique advantages of being rapid, sensitive, efficient, and non-invasive. Because of these characteristics, this innovative molecular approach has gained wider acceptance and is being increasingly utilized for the detection of biological diversity in aquatic environments. Furthermore, it has emerged as a novel technology to address the pressing and significant issue of aquatic invasive species in the vast freshwater and marine resources of the East Asian region. This paper summarizes a variety of literature sources to summarize the major aquatic invasive species in East Asian countries and the current application status of eDNA technology in their survey processes. Using China as a case study, it expounds on the prospective incorporation of the 4E strategy with eDNA technology for the surveillance of biological invasions. Furthermore, it explores the potential prospects of eDNA technology in species diversity management and policy formulation, offering theoretical guidance for establishing aquatic invasive species monitoring systems. From a technological standpoint, the integration of eDNA technology with the 4E strategy holds significant potential for application, thereby offering a promising reference for the formulation of policies related to the management of aquatic biological invasions and biodiversity.
Western flower thrips (WFT),
Frankliniella occidentalis
, has become an important pest of vegetables worldwide, due to its economic damage to crop production. In order to control WFT, chemical ...insecticides are widely used. However, WFT has developed a high resistance against many kinds of insecticides. Na
+
, K
+
-ATPase, playing an important role in the ionic transmission across the membrane, is commonly considered to be the target of several xenobiotic compounds. However, whether the Na
+
, K
+
-ATPase can be used as one of the target sites for controlling WFT is still unknown. In this study, resistance levels of WFT to four insecticides (chlorpyrifos, beta cypermethrin, abamectin, and thiamethoxam) were measured. It was found that all four insecticides exhibited significant inhibitory effects on WFT, especially on nymphs. The activity of Na
+
, K
+
-ATPase was estimated after the treatment of four insecticides. Additionally, mRNA expression levels of three Na
+
, K
+
-ATPase α-subunit isoforms (X1, X2 and X3) were detected using RT-qPCR. The transcription profile of three Na
+
, K
+
-ATPase α-subunit isoforms were diverse after treatment by these four insecticides, which indicated that these isoforms might play different roles in the tolerance to insecticides. The results suggested that Na
+
, K
+
-ATPase can obviously be inhibited by these four classes of insecticide, and may serve as the new target for controlling WFT.
Antennal olfaction plays a key role in insect survival, which mediates important behaviors like host search, mate choice, and oviposition site selection. As an oligophagous insect, olfaction is ...extremely important for Ophraella communa to locate host plants. However, information on the olfactory genes has been lacking in O. communa. Using next generation sequencing, we assembled the antennal transcriptome of O. communa and first reported the major chemosensory genes necessary for olfaction in this species. In this study, a total 105 candidate chemosensory genes were identified in O. communa antennae, including 25 odorant-binding proteins (OBPs), 11 chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs), 30 odorant receptors (ORs), 18 ionotropic receptors (IRs), and 17 gustatory receptors (GRs). We also identified full-length sequences of the highly conserved ORco and IR8a/25a family in O. communa. In addition, the expression profile of 15 ORs and four OBPs were validated by quantitative real-time polymerase chain reaction (qPCR). We found that OcomOR2/4/19 and OcomOBP19/20 had a biased expression in male antennae, and OcomOR8 had a biased expression in the female antennae. This large number of chemosensory genes handled by homology analysis and qPCR results will provide the first insights into molecular basis for the olfactory systems of O. communa as well as advance our understanding of olfactory mechanisms in Coleoptera.
Mile-a-minute weed (
Kunth) is considered as one of top 100 most dangerous invasive species in the world. A fast and accurate detection technology will be needed to identify
. It will help to ...mitigate the extensive ecologic and economic damage on our ecosystems caused by this alien plant. Hyperspectral technology fulfills the above requirement. However, when working with hyperspectral images, preprocessing, dimension reduction, and classifier are fundamental to achieving reliable recognition accuracy and efficiency. The spectral data of
were collected using hyperspectral imaging in the spectral range of 450-998 nm. A different combination of preprocessing methods, principal component analysis (for dimension reduction), and three classifiers were used to analyze the collected hyperspectral images. The results showed that a combination of Savitzky-Golay (SG) smoothing, principal component analysis (PCA), and random forest (RF) achieved an accuracy (A) of 88.71%, an average accuracy (AA) of 88.68%, and a Kappa of 0.7740 with an execution time of 9.647 ms. In contrast, the combination of SG, PCA and a support vector machine (SVM) resulted in a weaker performance in terms of A (84.68%), AA(84.66%), and Kappa (0.6934), but with less execution time (1.318 ms). According to the requirements for specific identification accuracy and time cost, SG-PCA-RF and SG-PCA-SVM might represent two promising methods for recognizing
in the wild.
The spotted-wing Drosophila (Drosophila suzukii Matsumura) is native to eastern Asia, but has become a global threat to fruit production. In recent years, CRISPR/Cas9 targeting was established in ...this species allowing for functional genomic and genetic control studies. Here, we report the generation and characterization of Cas9-expressing strains of D. suzukii. Five independent transgenic lines were generated using a piggyBac construct containing the EGFP fluorescent marker gene and the Cas9 gene under the control of the D. melanogaster heat shock protein 70 promoter and 3’UTR. Heat-shock (HS) treated embryos were analyzed by reverse transcriptase PCR, revealing strong heat inducibility of the transgenic Cas9 expression. By injecting gRNA targeting EGFP into one selected line, 50.0% of G0 flies showed mosaic loss-of-fluorescence phenotype, and 45.5% of G0 flies produced G1 mutants without HS. Such somatic and germline mutagenesis rates were increased to 95.4% and 85.7%, respectively, by applying a HS. Parental flies receiving HS resulted in high inheritance of the mutation (92%) in their progeny. Additionally, targeting the endogenous gene yellow led to the lack of pigmentation and male lethality. We discuss the potential use of these efficient and temperature-dependent Cas9-expressing strains for the genetic studies in D. suzukii.
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