transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbi...transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbitae(Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized. Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae. Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny. The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable. The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae. Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control.展开更多
The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of...The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of tra-2 in the Chinese mitten crab Eriocheir sinensis were characterized.Four tra-2 isoforms,designated as Estra-2a,Estra-2b,Estra-2c,and Estra-2d,were isolated.They all contained an RNA-recognition motif(RRM) and a linker region,which shared high similarity with other reported tra-2s.Sequence analysis revealed that Estra-2a,Estra-2b and Estra-2c are encoded by the same genomic locus and are generated by alternative splicing of the pre-mRNA.Compared with the other three isoforms,Estra-2d lacks the RS2 domain.Quantitative real-time PCR showed that all four isoforms were highly expressed in the fertilized egg,and in the 2-4 cell and blastula stages compared with larval stages(P<0.01),suggesting their maternal origin in early embryonic developmental stages.Notably,Estra-2a was highly expressed in male somatic tissues,while Estra-2c was significantly highly expressed in the ovary.These results suggest that Estra-2c is involved in sexual differentiation of the Chinese mitten crab.Our findings provide basic information for further functional studies of the tra-2 gene/protein in this species.展开更多
高频直流变压器(high-frequency DC transformer,HDCT)是直流电网的关键设备。为了满足中高压直流电网母线互联、电压变换、功率双向传输和电气隔离的需求,两端皆为模块化多电平变换器(modularmultilevel converter,MMC)结构的模块化多...高频直流变压器(high-frequency DC transformer,HDCT)是直流电网的关键设备。为了满足中高压直流电网母线互联、电压变换、功率双向传输和电气隔离的需求,两端皆为模块化多电平变换器(modularmultilevel converter,MMC)结构的模块化多电平高频直流变压器(modular multilevel DC transformer,M2DCT)尤受关注。目前,移相控制是提高M2DCT性能的有效方法之一,而现有的移相控制方法主要优化M2DCT的单一特性。因此,为了同时降低电流应力,最小化功率损耗,改善软开关特性,实现M2DCT性能的多目标综合优化,提出了一种基于多目标性能优化的双相移(dual-phase-shift,DPS)控制策略。建立M2DCT电流应力,功率损耗和软开关特性的数学模型,提出多目标性能优化DPS的控制策略。通过M2DCT样机实验结果,验证了所提策略的有效性和优越性。展开更多
基金supported by the Hainan Provincial Natural Science Foundation of China(321CXTD435)the National Natural Science Foundation of China(31860523,31660339,31702059,and 32260665)the National Key R&D Program of China(2022YFC2601400)。
文摘transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbitae(Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized. Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae. Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny. The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable. The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae. Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A409)the Scientific and Technological Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘The transformer-2(tra-2) gene plays a key role in the regulatory hierarchy of sexual differentiation in somatic tissues and in the germline of Drosophila melanogaster.In this study,sequences and expression profiles of tra-2 in the Chinese mitten crab Eriocheir sinensis were characterized.Four tra-2 isoforms,designated as Estra-2a,Estra-2b,Estra-2c,and Estra-2d,were isolated.They all contained an RNA-recognition motif(RRM) and a linker region,which shared high similarity with other reported tra-2s.Sequence analysis revealed that Estra-2a,Estra-2b and Estra-2c are encoded by the same genomic locus and are generated by alternative splicing of the pre-mRNA.Compared with the other three isoforms,Estra-2d lacks the RS2 domain.Quantitative real-time PCR showed that all four isoforms were highly expressed in the fertilized egg,and in the 2-4 cell and blastula stages compared with larval stages(P<0.01),suggesting their maternal origin in early embryonic developmental stages.Notably,Estra-2a was highly expressed in male somatic tissues,while Estra-2c was significantly highly expressed in the ovary.These results suggest that Estra-2c is involved in sexual differentiation of the Chinese mitten crab.Our findings provide basic information for further functional studies of the tra-2 gene/protein in this species.
文摘高频直流变压器(high-frequency DC transformer,HDCT)是直流电网的关键设备。为了满足中高压直流电网母线互联、电压变换、功率双向传输和电气隔离的需求,两端皆为模块化多电平变换器(modularmultilevel converter,MMC)结构的模块化多电平高频直流变压器(modular multilevel DC transformer,M2DCT)尤受关注。目前,移相控制是提高M2DCT性能的有效方法之一,而现有的移相控制方法主要优化M2DCT的单一特性。因此,为了同时降低电流应力,最小化功率损耗,改善软开关特性,实现M2DCT性能的多目标综合优化,提出了一种基于多目标性能优化的双相移(dual-phase-shift,DPS)控制策略。建立M2DCT电流应力,功率损耗和软开关特性的数学模型,提出多目标性能优化DPS的控制策略。通过M2DCT样机实验结果,验证了所提策略的有效性和优越性。
