Ecdysteroids play an important role in regulating diverse physiological processes in arthropods,such as molting,metamorphosis,reproduction and diapause.Ecdysteroids mediate the response by binding to a heterodimeric c...Ecdysteroids play an important role in regulating diverse physiological processes in arthropods,such as molting,metamorphosis,reproduction and diapause.Ecdysteroids mediate the response by binding to a heterodimeric complex of two nuclear receptors:the ecdysone receptor and the ultraspiracle(USP).To investigate the role of USP in development of the Asian gypsy moth(Lymantria dispar),a USP cDNA was obtained from the transcriptome of L.dispar and verified by PCR.In-depth profiling of transcript levels of L.dispar USP-1(LdUSP-1)at different developmental stages and over time in thirdinstar larvae and different tissues isolated during the thirdinstar stage of L.dispar was then carried out.Transcript levels of LdUSP-1 were relatively high before 72 h in the third-instar larvae after ecdysis and in the adult male.The function of LdUSP-1 in molting was analyzed by knockdown of LdUSP-1 in third instar larvae using RNA interference.Silencing of LdUSP-1 significantly downregulated the transcript level of E75,an ecdysone-inducible gene,and of Sad,a Halloween gene.In addition,the duration of the third-instar stage was slightly shortened and larval mortality increased after the LdUSP-1 knockdown.展开更多
Lycosidae females demonstrate meticulous maternal care of offspring by carrying egg sacs and juvenile spiderlings during the reproductive stage. Nuclear receptors(NRs), especially the ecdysone receptor(EcR) and ultras...Lycosidae females demonstrate meticulous maternal care of offspring by carrying egg sacs and juvenile spiderlings during the reproductive stage. Nuclear receptors(NRs), especially the ecdysone receptor(EcR) and ultraspiracle(USP), have attracted considerable attention in the regulation of arthropod development and reproduction due to their pivotal roles in ecdysteroid signaling cascades. In the present study, 23 NRs, including one EcR and two USPs, were identified in the genome of the predatory wolf spider Pardosa pseudoannulata. RNA interference(RNAi) targeting EcR and USP-1inhibited spiderling development and resulted in nonviable eggs in the egg sacs. EcR and USP-1responded to changes in ecdysteroid levels, and interference in ecdysteroid biosynthesis led to similar phenotypes as ds EcR and ds USP-1 treatments.These findings suggest that EcR/USP-1-mediated ecdysteroid signaling regulates P. pseudoannulata development and reproduction. The P.pseudoannulata females with suppressed ecdysteroid signaling proactively consumed their non-viable egg sacs, resulting in a 7.19 d shorter first reproductive cycle than the controls. Termination of the failed reproductive cycle enabled the spiders to produce a new egg sac more rapidly. This reproductive strategy may partially rescue the reduction in population growth due to non-viable eggs and compensate for the physiological expenditure of wasted maternal care, which would be beneficial for the conservation of P.pseudoannulata populations and their natural control of insect pests.展开更多
Ecdysone receptor （EcR） and ultraspiracle （USP） form heterodimers to mediate ecdysteroid signaling during molting and metamorphosis. Various EcR/USP heterodimers have been reported. However, it is unclear what kin...Ecdysone receptor （EcR） and ultraspiracle （USP） form heterodimers to mediate ecdysteroid signaling during molting and metamorphosis. Various EcR/USP heterodimers have been reported. However, it is unclear what kind of EcR/USP combination is adopted by lepidopteran insects during the larval-pupal metamorphosis and whether the EcR/USP heterodimer varies among different tissues. To address these questions, two isoforms of each EcR and USP were cloned from the common cutworm, their messenger RNA expression patterns were examined by real-time quantitative polymerase chain reaction in different tissues during the larval-pupal metamorphosis and in the midgut in response to hormonal induction. Furthermore, their subcellular localization and protein-protein interaction were explored by transient expression and far-western blotting, respectively. All the four genes were significantly up-regulated in prepuae and/or pupae. The expression profiles of EcRB1 and USP1 were nearly identical to each other in the epidermis, fat body and midgut, and a similar situation also applied to EcRA and USP2. The three genes responded to 20-hydroxyecdysone （20E） induction except for USP2, and USP1 could be up-regulated by both 20E and juvenile hormone. The four proteins mainly localized in the nucleus and the nuclear localization was promoted by 20E. The protein-protein interaction between each EcR and USP was found in vitro. These results suggest that two types of EcR/USP heterodimer （EeRA/USP2 and EcRB 1/USP1） may exist simultaneously in the common cutworm, and the latter should play more important roles during the larval-pupal metamorphosis. In addition, the types of EcR/USP heterodimer do not vary in the tissues which undergo histolysis and regeneration during metamorphosis.展开更多
基金This research was supported by Grants from the Natural Science Foundation of China(31770688)the Fundamental Research Funds for the Central Universities(2572017AA17)+1 种基金the Ph.D.Programs Foundation of HeZe University(XY18BS06)the Ph.D.Programs Foundation of HeZe University(XY18BS05).
文摘Ecdysteroids play an important role in regulating diverse physiological processes in arthropods,such as molting,metamorphosis,reproduction and diapause.Ecdysteroids mediate the response by binding to a heterodimeric complex of two nuclear receptors:the ecdysone receptor and the ultraspiracle(USP).To investigate the role of USP in development of the Asian gypsy moth(Lymantria dispar),a USP cDNA was obtained from the transcriptome of L.dispar and verified by PCR.In-depth profiling of transcript levels of L.dispar USP-1(LdUSP-1)at different developmental stages and over time in thirdinstar larvae and different tissues isolated during the thirdinstar stage of L.dispar was then carried out.Transcript levels of LdUSP-1 were relatively high before 72 h in the third-instar larvae after ecdysis and in the adult male.The function of LdUSP-1 in molting was analyzed by knockdown of LdUSP-1 in third instar larvae using RNA interference.Silencing of LdUSP-1 significantly downregulated the transcript level of E75,an ecdysone-inducible gene,and of Sad,a Halloween gene.In addition,the duration of the third-instar stage was slightly shortened and larval mortality increased after the LdUSP-1 knockdown.
基金supported by the National Natural Science Foundation of China(31972296,32172482)。
文摘Lycosidae females demonstrate meticulous maternal care of offspring by carrying egg sacs and juvenile spiderlings during the reproductive stage. Nuclear receptors(NRs), especially the ecdysone receptor(EcR) and ultraspiracle(USP), have attracted considerable attention in the regulation of arthropod development and reproduction due to their pivotal roles in ecdysteroid signaling cascades. In the present study, 23 NRs, including one EcR and two USPs, were identified in the genome of the predatory wolf spider Pardosa pseudoannulata. RNA interference(RNAi) targeting EcR and USP-1inhibited spiderling development and resulted in nonviable eggs in the egg sacs. EcR and USP-1responded to changes in ecdysteroid levels, and interference in ecdysteroid biosynthesis led to similar phenotypes as ds EcR and ds USP-1 treatments.These findings suggest that EcR/USP-1-mediated ecdysteroid signaling regulates P. pseudoannulata development and reproduction. The P.pseudoannulata females with suppressed ecdysteroid signaling proactively consumed their non-viable egg sacs, resulting in a 7.19 d shorter first reproductive cycle than the controls. Termination of the failed reproductive cycle enabled the spiders to produce a new egg sac more rapidly. This reproductive strategy may partially rescue the reduction in population growth due to non-viable eggs and compensate for the physiological expenditure of wasted maternal care, which would be beneficial for the conservation of P.pseudoannulata populations and their natural control of insect pests.
基金Acknowledgments The research was supported by the grants from National Natural Science Foundation of China （Grant No. 31172154） and the National Basic Research Program of China （973 Program, No. 2012CB114101）.
文摘Ecdysone receptor （EcR） and ultraspiracle （USP） form heterodimers to mediate ecdysteroid signaling during molting and metamorphosis. Various EcR/USP heterodimers have been reported. However, it is unclear what kind of EcR/USP combination is adopted by lepidopteran insects during the larval-pupal metamorphosis and whether the EcR/USP heterodimer varies among different tissues. To address these questions, two isoforms of each EcR and USP were cloned from the common cutworm, their messenger RNA expression patterns were examined by real-time quantitative polymerase chain reaction in different tissues during the larval-pupal metamorphosis and in the midgut in response to hormonal induction. Furthermore, their subcellular localization and protein-protein interaction were explored by transient expression and far-western blotting, respectively. All the four genes were significantly up-regulated in prepuae and/or pupae. The expression profiles of EcRB1 and USP1 were nearly identical to each other in the epidermis, fat body and midgut, and a similar situation also applied to EcRA and USP2. The three genes responded to 20-hydroxyecdysone （20E） induction except for USP2, and USP1 could be up-regulated by both 20E and juvenile hormone. The four proteins mainly localized in the nucleus and the nuclear localization was promoted by 20E. The protein-protein interaction between each EcR and USP was found in vitro. These results suggest that two types of EcR/USP heterodimer （EeRA/USP2 and EcRB 1/USP1） may exist simultaneously in the common cutworm, and the latter should play more important roles during the larval-pupal metamorphosis. In addition, the types of EcR/USP heterodimer do not vary in the tissues which undergo histolysis and regeneration during metamorphosis.
