Both host and diet shape bacterial communities of predatory mites

Microbial communities,derived from food,ambient,and inner,can affect host ecological adaption and evolution.Comparing with most phytophagous arthropods,predators may have more opportunities to develop specific microbiota depending on the level of prey specialization.To explore how diet sources affect host microbial communities and vary across predator species,we considered 3 types of predators from Phytoseiidae(Acari:Mesostigmata):polyphagous(Amblyseius orientalis Ehara,Neoseiulus barkeri Hughes,and Amblyseius swirski Athias-Henrio),oligophagous(Neoseiulus californicus McGregor),and monophagous(Phytoseiulus persimilis Athias-Henriot)predatory mites.The polyphagous species were fed on 2 types of diets,natural prey and alternative prey.By using 16S rRNA sequencing,we found that diet was the main source of microbiota in predatory mites,while there was no clear pattern affected by prey specialization.Among 3 polyphagous predators,host species had a larger impact than prey on microbial composition.Unlike A.orientalis or N.barkeri which showed consistency in their microbiota,prey switching significantly affectedβ-diversity of bacterial composition in A.swirskii,with 56%of the microbial alteration.In short,our results confirmed the substantial influence of diet on host microbial construction in predatory species,and highlighted species differences in shaping the microbiota which are not necessarily related to prey specialization.

Mutations of voltage-gated sodium channel contribute to pyrethroid resistance in Panonychus citri

Insecticide resistance in Panonychus citri is a major obstacle to mite control in citrus orchards.Pyrethroid insecticides are continually used to control mites in China,although resistance to pyrethroids has evolved in some populations.Here,the resistance to the pyrethroid fenpropathrin was investigated and 7 out of 8 field-collected populations of P citri exhibited a high level of resistance,ranging from 171-fold to 15391-fold higher than the susceptible(SS)comparison strain.Three voltage-gated sodium channel(VGSC)mutations were identified in the tested populations:L1031V,F1747L,and F17511.Amplicon sequencing was used to evaluate the frequency of these mutations in the 19 field populations.L1031V and F1751I were present in all populations at frequencies of 11.6%-82.1%and 0.5%-31.8%,respectively,whereas the F1747L mutation was only present in 12 populations from Chongqing,Sichuan,Guangxi,and Yunnan provinces.Introduction of these mutations singly or in combination into transgenic flies significantly increased their resistance to fenpropathrin and these flies also exhibited reduced mortality after exposure to the pyrethroids permethrin andβ-cypermethrin.Panonychus citri VGSC homology modeling and ligand docking indicate that F1747 and F1751 form direct binding contacts with pyrethroids,which are lost with mutation,whereas L1031 mutation may diminish pyrethroid effects through an allosteric mechanism.Overall,the results provide molecular markers for monitoring pest resistance to pyrethroids and offer new insights into the basis of pyrethroid actions on sodium channels.

BmCaspase-8-like regulates autophagy by suppressing BmDREDD-mediated cleavage of BmATG6

Autophagy plays an important role in tissue remodeling during insect development.The interplay between autophagy-related(ATG)proteins and caspases regulates the autophagic activity of ATGs,thereby modulating the process of autophagy.Our previous study characterized BmCaspase-8-like(BmCasp8L)as a caspase suppressor that inhibits apoptosis and immune signaling by suppressing the activation of death-related ced-3/Nedd2-like caspase(DREDD),a caspase-8 homolog in silkworm.In this study,we explored the regulatory role of BmCasp8L in autophagy.We found that the expression of Bmcasp8l increased from the late spinning stage to the pupa stage in the posterior silk gland(PSG),correlating with the expression patterns of Bmatg8 and Bmatg6.RNA interference-mediated downregulation of BmCasp8L expression significantly decreased starvation-induced autophagic influx as determined by the levels of BmATG8–phosphatidylethanolamine and the percentage of cells displaying punctate enhanced green fluorescent protein-BmATG8.Conversely,the overexpression of BmCasp8L significantly increased autophagic influx.We also found that BmCasp8L underwent autophagic degradation induced by starvation and that it was colocalized with BmATG8.Lastly,we demonstrated that BmDREDD attenuated autophagy and BmCasp8L suppressed BmDREDD-mediated cleavage of BmATG6.Taken together,our results demonstrated that BmCasp8L is a novel proautophagic molecule which suppresses BmDREDD-mediated cleavage of BmATG6 and is a target for autophagy.

Insulin peptides and their receptors regulate ovarian development and oviposition behavior in Diaphorina citri

Diaphorina citri is an important vector of Citrus Huanglongbing(HLB)disease.After feeding on young host plant shoots,the population of D.citri can increase significantly.Females also only lay eggs on young shoots.However,there are few studies on the mechanism of this phenomenon.Exogenous nutrient signals can affect the insulin signaling system of D.citri after feeding on young shoots.In this study,the expression of upstreamfactors DclLPl,DclLP2,and DclR in the insulin signaling system of D.citri was upregulated after feeding on young shoots.After being silenced by RNA interference technology,the results showed that the number of oviposited eggs of D.citri was significantly decreased and the ovarian development was inhibited with severe vacuolation.In addition,detection using quantitative reverse transcription-polymerase chain reaction showed that the upstream regulatory gene DcRheb of the target of rapamycin(TOR)pathway and the downstream reproduction-related DcVg gene were also significantly downregulated.These results suggest that feeding upon young shoots may upregulate the expression levels of upstream factors DclLPl,DclLP2,and DclR in the insulin signaling system.The signal will be through upregulating the expression of DcRheb,an upstream gene of the TOR signaling pathway.This in turn influences yolk metabolism,which eventually causes the ovaries of female D.citri to mature and therefore initiate oviposition behavior.

miRNAs targeting CYP6ER1 and CarE1 are involved in nitenpyram resistance in Nilaparvata lugens

The evolution of nitenpyram resistance has been confirmed to be related to overexpression of two key metabolic enzyme genes, CYP6ER1 and CarE1, in Nilaparvata lugens, a highly destructive rice pest that causes substantial economic losses and has developed insecticide resistance. As microRNAs (miRNAs) are important post-transcriptional regulators of gene expression, whether they are involved in nitenpyram resistance is poorly understood in N. lugens. In this study, knockdown of key genes in the miRNA biogenesis pathway (Dicer1, Drosha, and Argonaute1) changed CYP6ER1 and CarE1 abundance, which confirmed the importance of miRNAs in nitenpyram resistance. Furthermore, global screening of miRNAs associated with nitenpyram resistance in N. lugens was performed, and a total of 42 known and 178 novel miRNAs were identified;of these, 57 were differentially expressed between the susceptible and resistant strains, and two (novel_85 and novel_191) were predicted to target CYP6ER1 and CarE1, respectively. Luciferase reporter assays demonstrated that novel_85 and novel_191 bind to the CYP6ER1 and CarE1 coding regions, respectively, and downregulate their expression. Moreover, modulating novel_85 and novel_191 expression by injection of miRNA inhibitors and mimics significantly altered N. lugens nitenpyram susceptibility. This is the first study to systematically screen and identify miRNAs associated with N. lugens nitenpyram resistance, and provides important information that can be used to develop new miRNA-based targets in insecticide resistance management.

Methionine as a methyl donor regulates caste differentiation in the European honey bee(Apis mellifera)

Nutrition contributes to honey bee caste differentiation,but the role of individual nutrients is still unclear.Most essential amino acid contents,except that of methionine(Met),are greater in royal jelly than worker jelly.After〜3.5 i the Met content in the latter was slightly greater than in the former.Met is the major raw material used in the synthesis of S-adenosyl-L-methionine,an active methyl donor for DNA methylation,which is an epigenetic driver of caste differentiation.Here,we tested whether Met regulates caste differentiation in honey bees by determining its effects on the caste development of bees receiving four diets:the basic,basic+0.2%Met,basic+0.2%Met+20 mg/kg 5-azacytidine,and basic+20 mg/kg 5-azacytidine.The presence of Met decreased the adult bee body length and the numbers of ovarioles,indicating that Met may direct the development of female larvae toward worker bees.The upregulated expression of SAMS,Dnmtl,and Dnmt3 caused by Met exposure in 4-d-old larvae indicated that the worker-inductive effects of Met may occur through the promotion of DNA methylation.We investigated the co-effects of Met and glucose on bee development,and found that the effects of an increased glucose level on the number of ovarioles and body length did not strengthen the worker-inductive effects caused by Met.Our results contribute to caste development theory and suggest that Met-as a methyl donor一plays a regulatory,but not decisive,role in caste differentiation.

The piRNA response to BmNPV infection in the silkworm fat body and midgut

Bombyx mori nucleopolyhedrovirus(BmNPV)is a DNA virus that causes huge losses to the silkworm industry but the piRNA responses during BmNPV infection in the silkworm remain uninvestigated.Here,silkworm piRNA profiles of uninfected and BmNPV-infected fat body and midgut were determined by high-through sequencing in the early stages of BmNPV infection.A total of 2675 and 3396 genome-derived piRNAs were identified from fat body and midgut,respectively.These genome-derived piRNAs mainly originated from unannotated instead of transposon regions in the silkworm genome.In total,572 piRNAs were associated with 280 putative target genes in fat body and 805 piRNAs with 380 target genes in midgut.Compared to uninfected tissues,322 and 129 piRNAs were significantly upregulated in BmNPV-infected fat body and midgut,respectively.In addition,276 and 117 piRNAs were significantly downregulated.Moreover,differentially expressed(DE)piRNAs during BmNPV infection differed significantly between fat body and midgut.Putative DE piRNA-targeted genes were associated with“response to stimulus”and“environmental information processing”in fat body after infection with BmNPV,which may indicate an active piRNA response to BmNPV infection in fat body.This study may lay the foundation for future research of the potential roles of the piRNA pathway and specific piRNAs in BmNPV pathogenesis.

A dsRNA-degrading nuclease(dsRNase2)limits RNAi efficiency in the Asian corn borer(Ostrinia furnacalis)

The efficiency of RNA interference(RNAi)varies substantially among different insect species.Rapid degradation of double-stranded RNA(dsRNA)by dsRNA-degrading nucleases(dsRNases)has been implicated to cause low RNAi efficiency in several insect species.In this study,we identified four dsRNase genes(OfdsRNaseL Ofd-sRNase2,OfdsRNase3 and OfdsRNase4)from the Asian corn borer(Ostrinia furnacalis)transcriptome database.Bioinformatic analyses showed that each deduced protein sequence contained endonuclease NS domains and signal peptides.Gene expression analysis revealed that OfdsRNase2 was exclusively expressed in the midgut of larvae.RNAi efficiency was investigated in 2-d-old fifth-instar larvae(high expression of dsRNase2)and 2-d-old pupae(low expression of dsRNase2)by feeding or injecting dsRNA targeting a marker gene that encodes the lethal giant larvae protein(OfLgl).Our results showed that OfLgl only partially silenced the expression of OfLgl in pupae,but not in larvae,suggesting that OfdsRNase2 could contribute to lower RNAi efficiency in larval stages.This hypothesis was supported by our RNAi-of-RNAi experiment using a tissue culture technique where the silencing efficiency against the reporter gene,OfHexl,was significantly improved after knockdown of OfdsRNase2.When double luciferase assays were performed to evaluate the role of the four dsRNases in vitro,only OfdsRNase2 expressed in S2 cells significantly affected RNAi efficiency by degrading dsRNA.Taken together,our results suggested that the degradation of dsRNA by OfdsRNase2 in the midgut contributed to low RNAi efficiency in O.furnacalis larvae.

Northwestward range expansion of the bumblebee Bombus haematurus into Central Europe is associated with warmer winters and niche conservatism

Species range expansions are crucial for understanding niche formation and the interaction with the environment.Here,we studied the bumblebee Bombus haematurus Kriechbaumer,1870,a species historically distributed from northern Serbia through northern Iran which has very recently started expanding northwestward into Central Europe without human-mediated dispersal(i.e.,it is a natural spread).After updating the global distribution of this species,we investigated if niche shifts took place during this range expansion between newly colonized and historical areas.In addition,we have explored which climatic factors may have favored the natural range expansion of the species.Our results indicated that Bombus haematurus has colonized large territories in 7 European countries outside the historical area in the period from the 1980s to 2018,a natural expansion over an area that equals 20%of the historical distribution.In addition,this bumblebee performs generalism in flower visitation and it occurs in different habitats,although a preference for forested areas clearly emerges.The land-use associated with the species in the colonized areas is similar to the historical distribution,indicating that no major niche shifts occurred during the spread.Furthermore,in recently colonized localities,the range expansion was associated with warming temperatures during the winter and also during both queen overwintering and emergence phases.These findings document a case of natural range expansion due to environmental change rather than due to niche shifts,and specifically they suggest that warmer winters could be linked to the process of natural colonization of new areas.

Day length constrains the time budget of aphid predators

Phenology shifts and range expansions cause organisms to experience novel day length-temperature correlations.Depending on the temporal niche,organisms may benefit or suffer from changes in day length,thus potentially affecting phenological adaptation. We assessed the impact of day length changes on larvae of Chrysoperla carnea (Stephens) and Episyrphus balteatus (De Geer),both of which prey on aphids.Larvae ofE.balteatus are night-active,whereas those of C.carnea appear to be crepuscular.We subjected both species in climate chambers to day lengths of 16 :8 L :D and,to circumvent diapause responses,20 :4 L :D.We recorded development times and predation rates of both species. E.balteatus grew 13%faster in the 16 :8 L :D treatment and preyed on significantly more aphids.In contrast,C.carnea grew 13% faster in the 20 :4 L :D treatment and higher predation rates in 20 :4 L :D were marginally significant.Our results show that day length affects development and predation,but that the direction depends on species. Such differences in the use of day length may alter the efficiency ofbiocontrol agents in a changing climate.

Differences in egg hatching time between cyclical and obligate parthenogenetic lineages of aphids

Many aphid species exhibit a variation in reproductive mode which is influenced by winter climate regimes,with cyclical parthenogenetic (CP)lines dominating in cold winter areas (because they produce cold-resistant eggs)and obligate parthenogenetic (OP) ones in mild winter regions (because of their parthenogenetic overwintering).Genetic studies on several aphid species have shown that the OP trait can be transmitted during sexual events involving the 2 types of lines.This genetic system could be considered as a local safeguarding mechanism for OP alleles in case severe frost would have killed all parthenogenetically overwintering individuals.However,this strategy would only be efficient in restoring local polymorphism in breeding systems if the newly hatched OP recombinants remain competitive over their CP counterparts.In this study we compared egg hatching sequences of CP and OP F1 clones from several crosses obtained for 2 cereal aphid species,Sitobion avenae (constant 5℃,8 h of light)and Rhopalosiphum padi (winter outdoor conditions).For S.avenae,we obtained F1 offspring from 6 crosses, involving 4 clones while in R.padi F1 were obtained from 11 crosses involving 14 clones. We showed that in both species proportions of OP clones were higher in the first half of the progeny relative to the second half.In addition,F1 OP clones hatched in the mean about a week earlier than their CP sibs,which gives them a demographic advantage at the start of the growth season.We then discussed the consequences of this fitness advantage for the maintenance and spread of the OP trait in aphid populations.

Programmable activation of Bombyx gene expression using CRISPR/dCas9 fusion systems

The recently developed clustered regularly interspaced short palindromic repeats (CRISPR)-based techniques have made it possible to reprogram target gene expression without cloning complementary DNA or disturbing genomic sequence in mammalian cells and several multicellular organisms. We previously showed that CRISPR-associated protein 9 (Cas9) and CRISPR from Prevotella and Francisella 1 (Cpfl) could induce target mutations, deletions, inversions, and duplications both singly and multiplex in silkworm, Bombyx mori. However, it remains unknown whether the CRISPR activation (CRISPRa) system can be used in B. mori. In this study, we investigated the CRISPRa system, in which a nuclease dead Streptococcus pyogenes Cas9 (SpCas9) is fused to two transcription activation domains, including VP64 (a tetramer of the herpes simplex VP 16 transcriptional activator domain), and VPR (a tripartite activator, composed of VP64, p65, and Rta). The results showed that both dCas9-VP64 and dCas9-VPR systems could be used in B. mori cells, of which the latter showed significantly higher activity. The dCas9-VPR system showed considerable activity on all five tested target genes, and further analysis revealed that the up-regulation of genes was negatively correlated to their basal expression level. We also observed that this system could be used to upregulate a range of target genes. Taken together, our findings demonstrate that CRISPRa can be a powerful tool to study gene functions in B. mori and perhaps other non-drosophila insects.

New insight into foregut functions of xenobiotic detoxification in the cockroach Periplaneta americana

The physiological functions of insect foregut,especially in xenobiotic detox ification,are scarcely reported because of unimportance in appearance and insufficient molecular information.The cockroach Periplaneta americana,an entomological model organism,provides perfect material to study physiological functions of foregut tissue due to its architectuxal feature.Through Illumina sequencing of foregut tissue from P.amer icana individuals (control)or insects treated with cycloxaprid,as a novel neonicotinoid insecticide,54 193 166 clean reads were obtained and further assembled into 53 853 unigenes with an average length of 366 bp.Furthermore,the number of unigenes involved in xenobiofic detoxification was analyzed,mainly including 70 cytochrome P450s,12 glutathione S-transferases (GSTs),seven carboxylesterases (CarEs)and seven adenosine triphosphate-binding cassette (ABC)transporters.Compared to control,the expression of 22 xenobiotic detoxification unigenes was up-regulated after cycloxaprid application, mainly containing 18 P450s,one GST,two CarEs and one ABC adenosine triphosphate transporter,indicating that the oxidation-reduction was the major reactive process to cy cloxaprid application.Through quantitative real-time polymerase chitin reaction analysis, the expression of selected unigenes (six P450s,one GST and one CarE.)was up-regulated at least two-fold following cycloxaprid treatment,and was generally in agreement with transcriptome data.Compared to the previous midgut transcriptome of P.americana,it looks like the expressive abundance of the xenobiotic detoxification unigenes might be important factors to the detoxifying fimctional differences between foregut and midgut.In conclusion,insect foregut would also play important roles in the physiological processes related to xenobiotic detoxification.

Edible insects in China： Utilization and prospects

The use of edible insects has a long history in China, where they have been consumed for more than 2000 years. In general, the level of acceptance is high for the consumption of insects in China. Many studies on edible insects have been conducted in the last 20 years, and the scope of the research includes the culture ofentomophagy and the identification, nutritional value, farming and breeding of edible insects, in addition to food production and safety. Currently, 324 species of insects from 11 orders are documented that are either edible or associated with entomophagy in China, which include the common edible species, some less commonly consumed species and some medicinal insects. How- ever, only approximately 10 to 20 types of insects are regularly consumed. The nutritional values for 174 species are available in China, including edible, feed and medicinal species. Although the nutritional values vary among species, all the insects examined contain pro- tein, fat, vitamins and minerals at levels that meet human nutritional requirements. Edible insects were, and continue to be, consumed by different ethnic groups in many parts of China. People directly consume insects or food products made from insects. The processing of products from insect protein powder, oil and chitin, and the development of healthcare foods has been studied in China. People also consume insects indirectly by eating livestock that were fed insects, which may be a more acceptable pathway to use insects in human diets. Although limited, the data on the food safety of insects indicate that insects are safe for food or feed. Incidences of allergic reactions after consuming silkworm pupae, cicadas and crickets have been reported in China. Insect farming is a unique breeding industry in rural China and is a source of income for local people. Insects are reared and bred for human food, medicine and animal feed using two approaches in China： the insects are either fully domesticated and reared completely in captivity or are partially raised in cap- tivity, and the insect habitat is manipulated to increase production. Depending on the type of relationship the insect has with humans, plants and the environment, different farming strategies are used. The social and scientific communities must work together to promote the use of insects as food and feed.

Tyramides in male alates of black imported fire ants Solenopsis richteri

Two species of imported fire ants, the red imported fire ant, Solenopsis invieta Buren, and the black imported fire ant, Solenopsis richteri Forel, were introduced into the United States from South America at the port of Mobile, Alabama in 1918 and 1930s, respectively. Although S. richteri was introduced and established in the United States more than one decade earlier than S. invicta, the latter has gradually displaced S. riehteri throughout most of its distribution.

Characteristics of the draft genome of ＂Candidatus Arsenophonus nilaparvatae＂, a facultative endosymbiont of Nilaparvata lugens

There exists a kind of symbiotic bacterium named ＂Candidatus Arsenophonus nilaparvatae＂ in the brown planthopper （BPH）, Nilaparvata lugens. After being filtered and assembled from the BPH genome sequencing project, the genome sequence of this bacterial symbiont was obtained. After initial analysis based on the genome, we have found its potential role to synthesize B vitamins for the host. In order to better understand the lifestyle and the genomic changes of this symbiotic bacterium after the symbiotic relationship was established, we further report the characteristics of this draft genome. Compared with several other related bacteria, ＂Candidatus Arsenophonus nilaparvatae＂ has proven to be a facultative endosymbiont at the genomic level. Concurrently, the presence of fimbriae and flagella formation related genes indicates this maternally transmitted endosymbiont is most likely to retain the capacity to invade new hosts. Through further analysis of annotated gene sets, we also find evidence of genome reduction in its secretion system and metabolic pathways. These findings reflect its evolutionary trend to be an obligate one and enable a deeper study of microbe-insect interactions.

Gene expression analysis in the larval silk gland of the eri silkworm Samia ricini

Insects produce silk for a range of purposes. In the Lepidoptera, silk is utilized as a material for cocoon production and serves to protect larvae from adverse environmental conditions or predators. Species in the Saturniidae family produce an especially wide variety of cocoons, for example, large, golden colored cocoons and those with many small holes. Although gene expression in the silk gland of the domestic silkworm （Bombyx mori L.） has been extensively studied, considerably fewer investigations have focused on members of the saturniid family. Here, we established expression sequence tags from the silk gland of the eri silkworm （Samia ricini）, a saturniid species, and used these to analyze gene expression. Although we identified thefibroin heavy chain gene in the established library, genes for other major silk proteins, such asfibroin light chain andfibrohexamerin, were absent. This finding is consistent with previous reports that these latter proteins are lacking in saturniid silk. Recently, a series offibrohexamerin-like genes were identified in the Bombyx genome. We used this information to conduct a detailed analysis of the library established here. This analysis identified putative homologues of these genes. We also found several genes encoding small silk protein molecules that are also present in the silk of other Lepidoptera. Gene expression patterns were compared between eri and domestic silkworm, and both conserved and nonconserved expression patterns were identified for the tested genes. Such differential gene expression might be one of the major causes of the differences in silk properties between these species. We believe that our study can be of value as a basic catalogue for silk gland gene expression, which will yield to the further understanding of silk evolution.

Aggregation and mating success of Capnodis tenebrionis （Coleoptera： Buprestidae）

An understanding of the relative importance of extrinsic and intrinsic factors in determining the potential distribution and mating success of individuals is critical for the successful monitoring and management of pest species. Using a combination of field observations and a caged field experiment, we explored the roles of environmental and individual variation on the formation of mating aggregations and mating success in the buprestid beetle Capnodis tenebrionis （Linnaeus, 1767）, a pest species of stone fruit trees. Our field observations revealed that the formation of aggregations is influenced by a range of environmental factors including temperature, photoperiod, and population density. However, aggregations were not at random and were more likely to occur on the section of the plant with highest incidence of solar radiation and thus higher temperatures. Data from our experiment with caged beetles in the field further indicate that the reproductive behavior of this species varies with temperature. The probability of a successful mating occurring was also positively related to both male and female size. Females of C. tenebrionis mate several times over a 4-h period, but generally not with the same male. Information obtained from these studies is useful to define the most appropriate time for pest control, especially adopting strategies that interfere with reproduction.

Identification and characterization of a gene encoding a UBX domain-containing protein in the migratory locust, Locusta migratoria manilensis

Ubiquitin regulatory X （UBX） domain-containing proteins are believed to func- tion as cofactors for p97/CDC48, an adenosine triphosphatase shown to be involved in mul- tiple cellular processes. In the present study, a full-length complementary DNA （cDNA） of UBX domain-containing gene, termed LmUBX1, was cloned from Locusta migratoria manilensis and characterized, using random amplification of cDNA ends polymerase chain reaction （RACE PCR）, sequence analysis and quantitative real-time PCR. LmUBX1, 1 600 bp in length, is predicted to encode a 446-amino acid protein with a predicted molec- ular weight of 51.18 kDa that contains a central PUB domain and a carboxy-terminal UBX domain. Homology analysis revealed that LmUBX1 has higher similarity to the known UBX domain-containing proteins from insects than from other species. Moreover, based on sequence characteristics and phylogenetic relationships, it is suggested that LmUBX1 can be classified into the UBXD1 subfamily. Expression analysis founded that LmUBX1 exhibited significant expression variations at different developmental stages and in differ- ent tissues, suggesting that the expression of LmUBX1 was highly regulated. Interestingly, its messenger RNA transcript was more abundant in ovary and testis than in other tissues examined, suggesting that it may have more important roles in the reproductive system. In addition, LmUBX1 was differentially expressed in gregarious and solitary locusts and was significantly up-regulated in third and fifth instars of gregarious locusts, implying that LmUBX1 was also likely involved in the phase polyphenisms in L. migratoria manilen- sis. To our knowledge, this is the first report of cloning of a full-length cDNA of UBX domain-containing gene from L. migratoria manilensis.

The effect of bacterial challenge on ferritin regulation in the yellow fever mosquito, Aedes aegypti

Secreted ferritin is the major iron storage and transport protein in insects. Here, we characterize the message and protein expression profiles of yellow fever mosquito （Aedes aegypti） ferritin heavy chain homologue （HCH） and light chain homologue （LCH） subunits in response to iron and bacterial challenge. In vivo experiments demonstrated tissue-specific regulation of HCH and LCH expression over time post-blood meal （PBM）. Transcriptional regulation of HCH and LCH was treatment specific, with differences in regulation for na？ve versus mosquitoes challenged with heat-killed bacteria （HKB）. Translational regulation by iron regulatory protein （IRP） binding activity for the iron-responsive element （IRE） was tissue-specific and time-dependent PBM. However, mosquitoes challenged with HKB showed little change in IRP/IRE binding activity compared to na？ve animals. The changes in ferritin regulation and expression in vivo were confirmed with in vitro studies. We challenged mosquitoes with HKB followed by a blood meal to determine the effects on ferritin expression, and demonstrate a synergistic, time-dependent regulation of expression for HCH and LCH.