The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite...The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.展开更多
采用聚丙烯酰胺凝胶垂直板电泳(PAGE)技术,对11株Ei meria maxima和1株E.tenella的孢子化卵囊,进行了乳酸脱氢酶(LDH)、葡萄糖磷酸异构酶(GPI)、葡萄糖-6-磷酸脱氢酶(G6PD)、葡萄糖磷酸变位酶(PGM)和苹果酸脱氢酶(MDH)的同工酶分析。试...采用聚丙烯酰胺凝胶垂直板电泳(PAGE)技术,对11株Ei meria maxima和1株E.tenella的孢子化卵囊,进行了乳酸脱氢酶(LDH)、葡萄糖磷酸异构酶(GPI)、葡萄糖-6-磷酸脱氢酶(G6PD)、葡萄糖磷酸变位酶(PGM)和苹果酸脱氢酶(MDH)的同工酶分析。试验结果显示,E.maxima和E.tenella在LDH、GPI、G6PD、PGM和MDH的酶谱上有明显差异,而在11株E.maxima之间无差异,表明E.maxima的酶变异相当保守。展开更多
For prediction of the extreme significant wave height in the ocean areas where long term wave data are not available, the empirical method of extrapolating short term data (1 similar to3 years) is used in design pract...For prediction of the extreme significant wave height in the ocean areas where long term wave data are not available, the empirical method of extrapolating short term data (1 similar to3 years) is used in design practice. In this paper two methods are proposed to predict extreme significant wave height based on short-term daily maxima. According to the daa recorded by the Oceanographic Station of Liaodong Bay at the Bohai Sea, it is supposed that daily maximum wave heights are statistically independent. The data show that daily maximum wave heights obey log-normal distribution, and that the numbers of daily maxima vary from year to year, obeying binomial distribution. Based on these statistical characteristics, the binomial-log-normal compound extremum distribution is derived for prediction of extreme significant wave heights (50 similar to 100 years). For examination of its accuracy and validity, the prediction of extreme wave heights is based on 12 years' data at this station, and based on each 3 years' data respectively. The results show that with consideration of confidence intervals, the predicted wave heights based on 3 years' data are very close to those based on 12 years' data. The observed data in some ocean areas in the Atlantic Ocean and the North Sea show it is not correct to assume that daily maximum wave heights are statistically independent; they are subject to Markov chain condition, obeying log-normal distribution. In this paper an analytical method is derived to predict extreme wave heights in these cases. A comparison of the computations shows that the difference between the extreme wave heights based on the assumption that daily maxima are statistically independent and that they are subject to Markov Chain condition is smaller than 10%.展开更多
Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color we...Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color were used in the study,the orange’312-1’and white’98-2’.Changes in seven carotenoid contents and compositions in the flesh of fruit produced by inbred lines’312-1’and’98-2’were analyzed during fruit development.The expression of eight key carotenoid biosynthesis genes in the fruit flesh were investigated during five fruit development stage in two inbred lines.As the flesh color intensified,the orange flesh color of’312-1’was determined mainly by the increased contents of lutein,β-carotene and zeaxanthin and the lack of carotenoid accumulation led to the formation of white flesh in’98-2’fruit.The expression of the LCY-e and CHYb genes was significantly stronger in’312-1’than in’98-2’,and their expression was strongly correlated with lutein andβ-carotene contents during fruit development.This study provides a deep understanding of the molecular mechanism of carotenoid biosynthesis in fruit flesh and provides a basis for additional studies on the highly refined improvement of squash quality.展开更多
The genes coding for the α-and β-subunit of allophycocyanin (apcA and apcB) fromthe cyanophyte Spirulina maxima were cloned and sequenced. The results revealed 44.4% of nucleotidesequence similarity and 30.4% of sim...The genes coding for the α-and β-subunit of allophycocyanin (apcA and apcB) fromthe cyanophyte Spirulina maxima were cloned and sequenced. The results revealed 44.4% of nucleotidesequence similarity and 30.4% of similarity of deduced amino acid sequence between them. The aminoacid sequence identities between S. maxima and S. platensis are 99 .4% for α subunit and 100% for βsubunit.展开更多
To cope with the problems that edge detection operators are liable to make the detected edges too blurry for synthetic aperture radar(SAR)images,an edge detection method for detecting river in SAR images is proposed b...To cope with the problems that edge detection operators are liable to make the detected edges too blurry for synthetic aperture radar(SAR)images,an edge detection method for detecting river in SAR images is proposed based on contourlet modulus maxima and improved mathematical morphology.The SAR image is firstly transformed to a contourlet domain.According to the directional information and gradient information of directional subband of contourlet transform,the modulus maximum and the improved mathematical morphology are used to detect high frequency and low frequency sub-image edges,respectively.Subsequently,the edges of river in SAR image are obtained after fusing the high frequency sub-image and the low frequency sub-image.Experimental results demonstrate that the proposed edge detection method can obtain more accurate edge location and reduce false edges,compared with the Canny method,the method based on wavelet and Canny,the method based on contourlet modulus maxima,and the method based on improved(ROEWA).The obtained river edges are complete and clear.展开更多
基金supported by the Hainan Province Science and Technology Talent Innovation Project(KJRC2023A02)Project of Sanya Yazhouwan Science and Technology City Management Foundation(SKJC-KJ-2019KY01)Sanya Science and Technology Special Fund(2022KJCX91)。
文摘The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.
文摘采用聚丙烯酰胺凝胶垂直板电泳(PAGE)技术,对11株Ei meria maxima和1株E.tenella的孢子化卵囊,进行了乳酸脱氢酶(LDH)、葡萄糖磷酸异构酶(GPI)、葡萄糖-6-磷酸脱氢酶(G6PD)、葡萄糖磷酸变位酶(PGM)和苹果酸脱氢酶(MDH)的同工酶分析。试验结果显示,E.maxima和E.tenella在LDH、GPI、G6PD、PGM和MDH的酶谱上有明显差异,而在11株E.maxima之间无差异,表明E.maxima的酶变异相当保守。
基金This project was supported by the 9-th National Five-Year Key Program of China 96-922-03-03
文摘For prediction of the extreme significant wave height in the ocean areas where long term wave data are not available, the empirical method of extrapolating short term data (1 similar to3 years) is used in design practice. In this paper two methods are proposed to predict extreme significant wave height based on short-term daily maxima. According to the daa recorded by the Oceanographic Station of Liaodong Bay at the Bohai Sea, it is supposed that daily maximum wave heights are statistically independent. The data show that daily maximum wave heights obey log-normal distribution, and that the numbers of daily maxima vary from year to year, obeying binomial distribution. Based on these statistical characteristics, the binomial-log-normal compound extremum distribution is derived for prediction of extreme significant wave heights (50 similar to 100 years). For examination of its accuracy and validity, the prediction of extreme wave heights is based on 12 years' data at this station, and based on each 3 years' data respectively. The results show that with consideration of confidence intervals, the predicted wave heights based on 3 years' data are very close to those based on 12 years' data. The observed data in some ocean areas in the Atlantic Ocean and the North Sea show it is not correct to assume that daily maximum wave heights are statistically independent; they are subject to Markov chain condition, obeying log-normal distribution. In this paper an analytical method is derived to predict extreme wave heights in these cases. A comparison of the computations shows that the difference between the extreme wave heights based on the assumption that daily maxima are statistically independent and that they are subject to Markov Chain condition is smaller than 10%.
基金the National Key Research and Development Program of China(Grant No.2018YFD0100706)。
文摘Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color were used in the study,the orange’312-1’and white’98-2’.Changes in seven carotenoid contents and compositions in the flesh of fruit produced by inbred lines’312-1’and’98-2’were analyzed during fruit development.The expression of eight key carotenoid biosynthesis genes in the fruit flesh were investigated during five fruit development stage in two inbred lines.As the flesh color intensified,the orange flesh color of’312-1’was determined mainly by the increased contents of lutein,β-carotene and zeaxanthin and the lack of carotenoid accumulation led to the formation of white flesh in’98-2’fruit.The expression of the LCY-e and CHYb genes was significantly stronger in’312-1’than in’98-2’,and their expression was strongly correlated with lutein andβ-carotene contents during fruit development.This study provides a deep understanding of the molecular mechanism of carotenoid biosynthesis in fruit flesh and provides a basis for additional studies on the highly refined improvement of squash quality.
文摘The genes coding for the α-and β-subunit of allophycocyanin (apcA and apcB) fromthe cyanophyte Spirulina maxima were cloned and sequenced. The results revealed 44.4% of nucleotidesequence similarity and 30.4% of similarity of deduced amino acid sequence between them. The aminoacid sequence identities between S. maxima and S. platensis are 99 .4% for α subunit and 100% for βsubunit.
基金Supported by the CRSRI Open Research Program(CKWV2013225/KY)the Open Project Foundation of Key Laboratory of the Yellow River Sediment of Ministry of Water Resource(2014006)+2 种基金the Open Project Foundation of Key Lab of Port,Waterway and Sedimentation Engineering of the Ministry of Transportthe State Key Lab of Urban Water Resource and Environment(HIT)(ES201409)the Priority Academic Program Development of Jiangsu Higher Education Institution
文摘To cope with the problems that edge detection operators are liable to make the detected edges too blurry for synthetic aperture radar(SAR)images,an edge detection method for detecting river in SAR images is proposed based on contourlet modulus maxima and improved mathematical morphology.The SAR image is firstly transformed to a contourlet domain.According to the directional information and gradient information of directional subband of contourlet transform,the modulus maximum and the improved mathematical morphology are used to detect high frequency and low frequency sub-image edges,respectively.Subsequently,the edges of river in SAR image are obtained after fusing the high frequency sub-image and the low frequency sub-image.Experimental results demonstrate that the proposed edge detection method can obtain more accurate edge location and reduce false edges,compared with the Canny method,the method based on wavelet and Canny,the method based on contourlet modulus maxima,and the method based on improved(ROEWA).The obtained river edges are complete and clear.
