Two thymosin-repeated molecules with structural and functional diversity coexist in Chinese mitten crab Eriocheir sinensis

A TMT-based proteomic approach for investigating the effect of electron beam irradiation on the textural profiles of Litopenaeus vannamei during chilled storage

To elucidate the effect of electron beam irradiation (EBI) on the textural quality of Litopenaeus vannamei, the tandem-mass-tag labeled proteomic method was conducted to illustrate the protein changes in shrimp muscle. The results suggested that shrimp irradiated with 5 kGy exhibited optimum textural traits of hardness, springiness, and chewiness. In total, 486 proteins were identified as differentially abundance proteins (DAPs) in multiple comparison groups. Bioinformatics analysis revealed that most of DAPs participated in cellular process, binding, and catalytic. etc. Various signaling pathways, such as RNA transport and oxidative phosphorylation, were notably enriched by DAPs. The correlation analysis indicated that some DAPs such as Myosin-XVIIIa, projectin, and beta-thymosin 3 were remarkably correlated with the textural properties, which could be proposed as potential biomarkers to assess the irradiation-induced textural variation in shrimp. This study provided an insightful understanding at the protein level to improve the application of EBI to shrimp preservation.

Multiple functions of thymosin β4 in the pearl oyster Pinctada fucata suggest its multiple potential roles in artificial pearl culture

Thymosin β4 is a multifunctional protein in vertebrates that participates in physiological processes, such as wound healing, immune response, cell proliferation and migration. We assessed the multifarious roles of this small peptide in Pinctada fucata, an oyster commonly used in pearl culture in China. Our results showed that when P. fucata was challenged by bacterial pathogens or LPS, the relative expression level of Pfthymosin β4 mRNA was significantly up-regulated, suggesting its involvement in immune response of the animal. Recombinant Pfthymosin β4 (rPfthymosin β4) was produced and showed in vitro different antibacterial activities against different pathogenic bacteria; the inhibitory effect of rPfthymosin β4 on bacterial growth was relatively stronger in the broth culture than agar culture. The overexpression of Pfthymosin β4 in Escherichia coli BL21(DE3) cells could improve their resistance to Cu²⁺, Zn²⁺, Cd²⁺, and H₂O₂, suggesting that Pfthymosin β4 is likely involved with antioxidant. rPfthymosin β4 also significantly promoted the proliferation and migration of mouse aortic vascular smooth muscle cells as indicated by MTT assay and cell scratch assay, respectively. In addition, chemically synthesized or recombinant Pfthymosin β4 could transiently increase the circulating total hemocytes counts but down-regulated by RNAi in P. fucata. Taking together above results and previous studies suggested that Pfthymosin β4 is potentially able to promote wound healing through enhancing antibacterial activity and antioxidant capacity, promotion of cell proliferation and migration, and increase of circulating hemocytes in P. fucata due to nucleus implantation injury. Thus, the future of recombinant Pfthymosin β4 should be promising in the culture of pearls in P. fucata.

Cloning, Expression and Effects of P. americana Thymosin on Wound Healing

The American cockroach (Periplaneta americana) is a medicinal insect. Its extract is used clinically to promote wound healing and tissue regeneration, but the effective medicinal components and mechanisms are not yet clear. It has been reported that human thymosin beta 4 (Tβ4) may accelerate skin wound healing, however, the role of P. americana thymosin (Pa-THYs) is still poorly understood. In the present study, we identify and analyze the DNA sequences of Pa-THYs by bioinformatics analysis. Then we clone, express, and purify the Pa-THYs proteins and evaluate the activity of recombinant Pa-THYs proteins by cell migration and proliferation assays in NIH/3T3 cells. To elucidate the role of Pa-THYs in wound healing, a mouse model is established, and we evaluate wound contraction, histopathological parameters, and the expressions of several key growth factors after Pa-THYs treatment. Our results showed that three THY variants were formed by skipping splicing of exons. Pa-THYs could promote fibroblast migration, but have no effect on fibroblast proliferation. In wound repair, Pa-THYs proteins could effectively promote wound healing through stimulating dermal tissue regeneration, angiogenesis, and collagen deposition. On the molecular mechanism, Pa-THYs also stimulated the expression of several key growth factors to promote wound healing. The data suggest that Pa-THYs could be a potential drug for promoting wound repair.

Thymosin participates in antimicrobial immunity in zebrafish

Thymosin hormones, which were shown to be involved in immune system development and differentiation in previous studies, have antimicrobial functions in different animals. Zebrafish are a useful model for immunology research. Although thymosin has been reported to be involved in the embryonic development of zebrafish, it is necessary to uncover the antimicrobial function of thymosin in zebrafish. In this study, we expressed thymosin β (Tβ) in zebrafish in vitro and studied its antimicrobial function. The Tβ protein consists of 45 amino acids and is conserved among its family members, especially the actin-binding motif (LKKTET). Tβ was expressed in all tested tissues and was highly expressed in the brain, liver and hindgut. After Aeromonas hydrophila challenge, the Tβ transcript level increased in the skin, liver, kidney, spleen, thymus, foregut, gills and midgut. Purified recombinant thymosin β (rTβ) protein was used to study the antimicrobial mechanism. rTβ could inhibit the growth of Staphylococcus aureus, Aeromonas hydrophila, Vibrio anguillarum, Pseudomonas aeruginosa and Klebsiella pneumoniae. rTβ also binds to and agglutinates certain bacteria. Further study showed that rTβ could combine with the polysaccharides from gram-negative and gram-positive bacterial walls. All results suggested that the Tβ of zebrafish plays a significant role in innate antibacterial immune responses.

Transcriptome-wide identification of differentially expressed genes in Procambarus clarkii in response to chromium challenge

Because of the high protein content and rich meat quality of crayfish Procambarus clarkii, it has become widely popular in China in recent years and has a high economic value. When P. clarkii is stimulated by heavy metals, it reacts to oxidation. P. clarkii has evolved antioxidant defense systems, including antioxidant enzymes such as catalase (CAT). The hexavalent form of Cr (VI) is a pathogenic factor that is of particular concern in aqueous systems because of its great toxicity to living organisms. In this study, we characterized the transcriptome of P. clarkii using a RNA sequencing method and performed a comparison between K₂Cr₂O₇-treated samples and controls. In total, 34,237 unigenes were annotated. We identified 5098 significantly differentially expressed genes (DEGs), including 2536 and 2562 were significantly up-regulated and down-regulated, respectively. In addition, quantitative real time-PCR (qRT-PCR) confirmed the up-regulation of a random selection of DEGs. Our results contribute to a more comprehensive understanding of the antioxidant defense system used by P. clarkii in response to heavy metal stress.

Comparative study of β-thymosin in two scallop species Argopecten irradians and Chlamys farreri

The β-thymosin (Tβ) proteins participate in numerous biological processes, such as cell proliferation and differentiation, anti-inflammatory and antimicrobial mechanism. To date, Tβ proteins have been well studied in vertebrates, especially mammals. While limited Tβ or Tβ-like proteins have been reported in invertebrates. Moreover, rare information of Tβ or Tβ-like proteins is available in scallop species yet. In the present study, two Tβ homologues, AiTβ and CfTβ, were identified and characterized from two scallop species bay scallop Argopecten irradians and Zhikong scallop Chlamys farreri. They were both 41 amino acid peptide and contained one THY domain, a highly conserved actin-binding motif and two conserved helix forming regions. Tissue distribution and expression profiles of their mRNA transcripts were roughly similar yet different in detail, while their recombinant proteins exhibited different immunomodulation activity on the downstream immune parameters. These results collectively indicated that the function of Tβ family in scallop were functionally differentiated.

Anti-Inflammatory Activity of β-thymosin Peptide Derived from Pacific Oyster (Crassostrea gigas) on NO and PGE₂ Production by Down-Regulating NF-κB in LPS-Induced RAW264.7 Macrophage Cells

β-thymosin is known for having 43 amino acids, being water-soluble, having a light molecular weight and ubiquitous polypeptide. The biological activities of β-thymosin are diverse and include the promotion of wound healing, reduction of inflammation, differentiation of T cells and inhibition of apoptosis. Our previous studies showed that oyster β-thymosin originated from the mantle of the Pacific oyster, Crassostrea gigas and had antimicrobial activity. In this study, we investigated the anti-inflammatory effects of oyster β-thymosin in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells using human β-thymosin as a control. Oyster β-thymosin inhibited the nitric oxide (NO) production as much as human β-thymosin in LPS-induced RAW264.7 cells. It also showed that oyster β-thymosin suppressed the expression of prostaglandin E₂ (PGE₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, oyster β-thymosin reduced inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Oyster β-thymosin also suppressed the nuclear translocation of phosphorylated nuclear factor-κB (NF-κB) and degradation of inhibitory κB (IκB) in LPS-induced RAW264.7 cells. These results suggest that oyster β-thymosin, which is derived from the mantle of the Pacific oyster, has as much anti-inflammatory effects as human β-thymosin. Additionally, oyster β-thymosin suppressed NO production, PGE₂ production and inflammatory cytokines expression via NF-κB in LPS-induced RAW264.7 cells.

Thymosins participate in antibacterial immunity of kuruma shrimp, Marsupenaeus japonicus

Thymosins β are actin-binding proteins that play a variety of different functions in inflammatory responses, wound healing, cell migration, angiogenesis, and stem cell recruitment and differentiation. In crayfish, thymosins participate in antiviral immunology. However, the roles of thymosin during bacterial infection in shrimp remain unclear. In the present study, four thymosins were identified from kuruma shrimp, Marsupenaeus japonicus, and named as Mjthymosin2, Mjthymosin3, Mjthymosin4, and Mjthymosin5 according the number of their thymosin beta actin-binding motifs. Mjthymosin3 was selected for further study because its expression level was the highest in hemocytes. Expression analysis showed that Mjthymosin3 was upregulated in hemocytes after challenged by Vibrio anguillarum or Staphylococcus aureus. The recombinant Mjthymosin3 protein could inhibit the growth of certain bacteria in an in vitro antibacterial test. Mjthymosins could facilitate external bacterial clearance in shrimp, and were beneficial to shrimp survival post V. anguillarum or S. aureus infection. The results suggested that Mjthymosins played important roles in the antibacterial immune response of kuruma shrimp.

Transcriptomic analysis of immune-related genes in the lipopolysaccharide-stimulated hepatopancreas of the mudflat crab Helice tientsinensis

The mudflat crab Helice tientsinensis is one of the most economically important aquaculture species in China. Nevertheless, it is susceptible to various diseases caused by viruses, bacteria and rickettsia-like organisms. A better understanding of the immune system and genes related to the responses to bacterial and viral infection is required. Herein, the hepatopancreas transcriptome of H. tientsinensis was analyzed by comparing control and lipopolysaccharide (LPS)-stimulated RNA-Seq data, yielding 91,885,038 bp and 13.78 Gb of clean reads. Following assembly and annotation, 93,207 unigenes with an average length of 883 bp were identified, of which 31,674 and 13,700 were annotated in Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Following LPS, 4845 differentially expressed genes (DEGs) were identified, of which 2491 and 2354 were up- and down-regulated, respectively. To further investigate immune-related DEGs, KEGG enrichment analysis identified immune response pathways, most notably the peroxisome and Toll-like receptor signaling pathways. Quantitative real time-PCR (qRT-PCR) confirmed the up-regulation of a random selection of DEGs. This systematic transcriptomic analysis of the innate immune pathway in H. tientsinensis expands our understanding of the immune system in crabs.

A thymosin repeated protein1 reduces white spot syndrome virus replication in red claw crayfish Cherax quadricarinatus

The β-thymosins are a group of structurally related, highly conserved intracellular small peptides in vertebrates with various biological functions, including cytoskeletal remodeling, neuronal development, cell migration, cell survival, tissue repair and inhibition of inflammation. In contrast to vertebrates, the function of β-thymosin is not fully understood in crustaceans. Previously, we found that a thymosin-repeated protein1 (CqTRP1) gene was up-regulated after white spot syndrome virus (WSSV) challenge in hematopoietic tissue (Hpt) cells from the red claw crayfish Cherax quadricarinatus. To further identify the effect of CqTRP1 on WSSV infection, a full length cDNA sequence of β-thymosin homologue was cloned and analyzed from red claw crayfish followed by functional study. The CqTRP1 cDNA contains an open reading frame of 387 nucleotides encoding a protein of 129 amino acids with a putative molecular mass of 14.3 kDa. The amino acid sequence showed high identity with other β-thymosins and contained three characteristic thymosin β actin-binding motifs, suggesting that CqTRP1 was a member of the β-thymosin family. Tissue distribution analysis revealed a ubiquitous presence of CqTRP1 in all the examined tissues with the highest expression in hemocytes, Hpt and gonad at the transcriptional level. Interestingly, the gene silencing of endogenous CqTRP1 by RNAi enhanced the WSSV replication in Hpt cells. Meanwhile, the WSSV replication was significantly reduced in the Hpt cell cultures if overloaded with a recombinant CqTRP1. Taken together, these data clearly indicated that CqTRP1 was likely to be associated with the anti-WSSV response in a crustacean C. quadricarinatus, which provides new strategy against white spot disease in crustacean aquaculture.

Thymosin β4 is involved in the antimicrobial immune response of Golden pompano, Trachinotus ovatus

Thymosin beta belongs to the thymosin family, which consists of a series of highly conserved peptides involved in various biological processes. In teleosts, understanding of the immunological functions of thymosin beta is limited, particularly in vivo, which is essentially unknown. In the current study, we cloned and identified thymosin beta 4 from the teleost fish Golden pompano (Trachinotus ovatus), which we have named TroTβ4. We investigated the expression patterns and functions of TroTβ4 in both in vivo and in vitro assays. TroTβ4 is composed of 44 amino acids and shares high sequence identities with known thymosin β4 species in other teleosts, which contains a highly conserved actin-binding motif (LKKTET). The expression of TroTβ4 was most abundant in immune organs, and was significantly up-regulated in response to infection bacterial with one of a number of bacteria (including Edwardsiella tarda, Vibrio harveyi, and Streptococcus agalactiae). Purified recombinant TroTβ4 (rTroTβ4) inhibited the growth of bacteria, as measured using an automatic growth curve analyzer, indicating that TroTβ4 has antimicrobial functions. When administered in vivo, overexpression of TroTβ4 in T. ovatus, bacterial colonization of tissues was significantly reduced. In contrast, when a DNA vector-based siRNA technology was used to knock down TroTβ4 expression, bacterial dissemination and colonization of tissues increased significantly. Taken together, these results provide the first in vivo evidence to indicate that teleost thymosin beta 4 plays a significant role in innate antibacterial immune responses in addition to in vitro bacteriostatic activity. This provides valuable information regarding the biological functions of teleost thymosin beta.

A thymosin beta-4 is involved in production of hemocytes and immune defense of Hong Kong oyster, Crassostrea hongkongensis

Thymosin beta-4 (Tβ4) is a ubiquitous protein with multiple and diverse intracellular and extracellular functions in vertebrates. In this study, the full-length cDNA of Tβ4 was cloned and identified in Crassostrea hongkongensis, designated as ChTβ4. The full-length cDNA of ChTβ4 consists of 530 bp with an open reading frame of 126 bp encoding a 41 amino acid polypeptide. SMART analysis indicated that there is one thymosin domain and a highly conserved actin-binding motif (18LKKTET23) in ChTβ4. In vivo injection of recombinant ChTβ4 protein could significantly increase total hemocytes count in oysters, and knockdown of the expression of ChTβ4 resulted in a significant decrease in the circulating hemocytes. Tissue distribution analysis revealed a ubiquitous presence of ChTβ4, with the highest expression in hemocytes. The upregulated transcripts of ChTβ4 in response to bacterial challenge and tissue injury suggest that ChTβ4 is involved in both innate immunity against pathogen infection and wound healing. Moreover, bacteria-clearance experiment showed ChTβ4 could facilitate the clearance of injected bacteria in oysters. In vivo injection with ChTβ4 resulted in reduction of the intracellular ROS in hemocytes, which was associated with increased expression of antioxidant enzymes Cu/Zn superoxide dismutase (SOD), Catalase, and Glutathione Peroxidase (GPX) by pre-treatment with ChTβ4. These results suggest that ChTβ4 is a thymosin beta-4 homolog and plays a vital role in the immune defense of C. hongkongensis.

Molecular and Physiological Characterization of Two Novel Multirepeat β-Thymosins from Silkworm, Bombyx mori

β-thymosin plays important roles in the development of the lymphatic system and the central nervous system in vertebrates. However, its role and function in invertebrates remain much less explored. Here, we firstly isolated a gene encoding β-thymosin in silkworm (Bombyx mori L.). Interestingly, this gene encodes two polypeptides, named as BmTHY1 and BmTHY2, via two different modes of RNA splicing. The recombinant proteins fused with an N-term GST tag were over-expressed in Escherichia coli (E. coli) and further purified to near homogenity to prepare mouse antibodies. The Western blot analysis showed that these proteins were expressed in various tissues and organs, as well as in different developmental stages. Amazingly, the expression of BmTHY2 was hugely increased during the pupae stage, indicating a specialized role in this period. The expression of these proteins was gradually decreased in BmN cells infected by BmNPV, suggesting they may play different roles in the virus infection. In addition, both BmTHY1 and BmTHY2 can interact with 14-3-3 of silkworm and Ubiquitin of BmNPV as shown by GST pull down and Co-IP assays, consistent with their roles in the regulation of the development of nervous system.

β-Thymosins participate in antiviral immunity of red swamp crayfish (Procambarus clarkii)

β-Thymosins participate in numerous biological activities, including cell proliferation and differentiation, wound healing, and anti-inflammatory and antimicrobial activities. Many studies have investigated vertebrate β-thymosins, whereas few reports have focused on invertebrate β-thymosins. In this study, nine isoforms of β-thymosins (PcThy-1 to PcThy-8) were identified from the red swamp crayfish Procambarus clarkii. The isoforms contained different numbers of the thymosin β actin-binding motif. PcThy-1 contained one thymosin β actin-binding motif, whereas PcThy-8 contained eight motifs. Western blot analysis with anti-PcThy-4 antibody showed that three to six isoforms were present in one tissue, and PcThy-4, PcThy-5, PcThy-6, and PcThy-7 were the main isoforms in several tissues. Time course expression analysis of PcThys at the protein level showed that PcThy-4 was upregulated in hemocytes and gills after white spot syndrome virus (WSSV) challenge. PcThy-4, which contained four thymosin β actin-binding motifs, was selected for further research. Tissue distribution analysis by quantitative real-time PCR showed that PcThy-4 was present in tissues of the hemocytes, heart, hepatopancreas, gills, stomach, and intestine at the transcriptional level. Transcriptional expression profiles showed that PcThy-4 was upregulated after WSSV challenge. In vivo RNAi and protein injection assay results showed that PcThy-4 inhibited the replication of WSSV in crayfish and enhanced the survival rate after WSSV infection. Furthermore, PcThy-4 promoted hemocyte phagocytosis of WSSV. Overall, results suggested that PcThys protected crayfish from WSSV infection and played an important role in antiviral immune response.

Characterization of two thymosins as immune-related genes in common carp (Cyprinus carpio L.)

Prothymosin alpha (ProTα) and thymosin beta (Tβ) belong to thymosin family, which consists of a series of highly conserved peptides involved in stimulating immune responses. ProTα b and Tβ are still poorly studied in teleost. Here, the full-length cDNAs of ProTα b and Tβ-like (Tβ-l) were cloned and identified in common carp (Cyprinus carpio L.). The expressions of carp ProTα b and Tβ-l exhibited rise-fall pattern and then trended to be stable during early development. After spring viraemia of carp virus (SVCV) infection, the carp ProTα b and Tβ-l transcripts were significantly up-regulated in some immune-related organs. When transiently over-expressed carp ProTα b and Tβ-l in zebrafish, these two proteins up-regulated the expressions of T lymphocytes-related genes (Rag 1, TCR-γ, CD4 and CD8α). These results suggest that carp ProTα b and Tβ may ultimately enhance the immune response during viral infection and modulate the development of T lymphocytes in teleost.

The involvement of PDGF/VEGF related factor in regulation of immune and neuroendocrine in Chinese mitten crab Eriocheir sinensis

Members of the platelet-derived growth factor/vascular endothelial growth factor (PDGF/VEGF) family have been implicated in cell proliferation, cell differentiation, and cell migration, vascular development, angiogenesis and neural development. In the present study, a novel PDGF/VEGF related factor gene was cloned and identified in Chinese mitten crab Eriocheir sinensis (designated as EsPVF1). The full-length cDNA of EsPVF1 was of 1173 bp, consisting a 5' untranslated region (UTR) of 54 bp, a 3' UTR of 1131 bp with a poly (A) tail, and an open reading frame (ORF) of 588 bp encoding 196 amino acid residues. A signal peptide of 20 amino acid residues, a PDGF/VEGF homology growth factor domain of 81 amino acids, and a typical cysteine knot motif (CXCXC) were identified in the deduced amino acid sequence of EsPVF1. By fluorescent quantitative real-time PCR, the EsPVF1 mRNA was detected ubiquitously in the select tissues of hemocytes, gonad, heart, muscle, hepatopancreas and gill, with the high abundance in hemocytes and gonad. The mRNA expression level of EsPVF1 was up-regulated and reached the highest at 24 h after Vibrio anguillarum challenge, while it was induced at 3 h, 6 h, 12 h, 24 h and 48 h compared with the untreated group after Pichia pastoris GS115 challenge. Tissue injury also induced the mRNA expression of EsPVF1 in hemocytes of crabs, and the expression level increased obviously at 8 h. The cDNA fragment encoding mature peptide of EsPVF1 was recombined and expressed in Escherichia coli BL21 (DE3) pLysS. Biogenic amine in hemolymph pre-incubated with recombinant protein of EsPVF1 (rEsPVF1) was detected by fluorimetric method. Norepinephrine and dopamine in hemolymph incubated with rEsPVF1 were higher than that in the blank group. Therefore, EsPVF1 could significantly provoke the release of norepinephrine and dopamine. The results collectively indicated that EsPVF1 was involved in regulation of the immune response and neuroendocrine system in crabs.

Gene expression of tissue-specific molecules in ex vivo Dermacentor variabilis (Acari: Ixodidae) during rickettsial exposure

Ticks serve as both vectors and the reservoir hosts capable of transmitting spotted fever group Rickettsia by horizontal and vertical transmission. Persistent maintenance of Rickettsia species in tick populations is dependent on the specificity of the tick and Rickettsia relationship that limits vertical transmission of particular Rickettsia species, suggesting host-derived mechanisms of control. Tick-derived molecules are differentially expressed in a tissue-specific manner in response to rickettsial infection; however, little is known about tick response to specific rickettsial species. To test the hypothesis that tissue-specific tick-derived molecules are uniquely responsive to rickettsial infection, a bioassay to characterize the tick tissue-specific response to different rickettsial species was used. Whole organs of Dermacentor variabilis (Say) were exposed to either Rickettsia montanensis or Rickettsia amblyommii, two Rickettsia species common, or absent, in field-collected D. variabilis, respectively, for 1 and 12 h and harvested for quantitative real time-polymerase chain reaction assays of putative immune-like tick-derived factors. The results indicated that tick genes are differently expressed in a temporal and tissue-specific manner. Genes encoding glutathione S-transferase 1 (dvgst1) and Kunitz protease inhibitor (dvkpi) were highly expressed in midgut, and rickettsial exposure downregulated the expression of both genes. Two other genes encoding glutathione S-transferase 2 (dvgst2) and beta-thymosin (dvpbeta-thy) were highly expressed in ovary, with dvbeta-thy expression significantly downregulated in ovaries exposed to R. montanensis, but not R. amblyommii, at 12-h postexposure, suggesting a selective response. Deciphering the tissue-specific molecular interactions between tick and Rickettsia will enhance our understanding of the key mechanisms that mediate rickettsial infection in ticks.

β-Thymosin is upregulated by the steroid hormone 20-hydroxyecdysone and microorganisms

Thymosins have diverse biological activities including actin-sequestering and tissue repair in vertebrates, however, there is little information about the function of thymosins in invertebrates. We isolated a β-thymosin gene in Helicoverpa armigera. It has two transcript variants, HaTHY1 and HaTHY2, encoding 19.0 kDa and 14.5 kDa peptides, respectively. HaTHY1 was mainly transcribed in the integument and midgut, while HaTHY2 was principally presented in the fat body and haemocytes. The transcript levels of HaTHY2 showed some fluctuation; there was an obvious increase at the metamorphic stage in the integument or fat body. HaTHY was able to be upregulated by 20-hydroxyecdysone or by bacterial and viral challenge. These data suggest that HaTHY is upregulated by the steroid hormone and by responses to microorganism infection.