Background:Sperm abnormalities are one of the primary factors leading to male sterility,but their pathogenesis is still unclear.Although miRNAs are suggested to exert important roles in the regulation of spermatogenes...Background:Sperm abnormalities are one of the primary factors leading to male sterility,but their pathogenesis is still unclear.Although miRNAs are suggested to exert important roles in the regulation of spermatogenesis at both transcriptional and posttranscriptional levels,little is currently known regarding the regulation of sperm flagella assembly by microRNAs(miRNAs).The role of miRNAs in the development of sperm abnormalities in sterile triploid fish has not been studied.Results:In this study,we found that miR-199-5p was widely expressed in all detected tissues of different-ploidy crucian carp.As one of the testis-specific candidate markers,Tekt1 was predominantly expressed in the testis.Quantitative real-time PCR(qRT-PCR)analyses showed that the expression trend of miR-199-5p was exactly opposite to that of Tekt1.Through bioinformatics analysis,we identified a putative miR-199-5p binding site in the Tekt1 mRNA.We further identified Tekt1 as a target of miR-199-5p using luciferase reporter assay.Finally,we confirmed that miR-199-5p was necessary for sperm flagellar assembly and spermatogenesis in vivo via intraperitoneal injection of miR-199-5p antagomir or agomir in diploid red crucian carp.Moreover,miR-199-5p gainof-function could lead to spermatids apoptosis and abnormal spermatozoa structure,which is similar to that of allotriploid crucian carp.Conclusions:Our studies suggested that abnormally elevated miR-199-5p inhibited the sperm flagella formation in spermiogenesis by negatively regulating the expression of Tekt1,thereby causing sperm abnormalities of male allotriploid crucian carp.展开更多
In this study,we take a machine learning-based approach to measure institutional investor attention to corporate social responsibility(CSR)issues when communicating with firms during site visits.We find that institut...In this study,we take a machine learning-based approach to measure institutional investor attention to corporate social responsibility(CSR)issues when communicating with firms during site visits.We find that institutional investors can effectively enhance CSR performance through CSR-related communication.This effect remains robust to various checks and is more pronounced for non-state-owned enterprises and firms with lower levels of institutional ownership and in periods following the issuance of Green Investment Guidelines.We also identify information asymmetry and financing constraints as the two mechanisms underlying this effect.Overall,our findings highlight the importance of private interactions between management and institutional investors in promoting CSR.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31872551)Laboratory of Lingnan Modern Agriculture Project(Grant No.NT2021008)+4 种基金the Natural Science Foundation of Hunan Province for Distinguished Young Scholars(Grant No.2020JJ2022)Hunan Provincial Innovation Foundation for Postgraduate(Grant No.CX20200480)the earmarked fund for China Agriculture Research System(Grant No.CARS-45)the Key Research and Development Program of Hunan Province(Grant No.2020NK2016)111 Project(D20007).
文摘Background:Sperm abnormalities are one of the primary factors leading to male sterility,but their pathogenesis is still unclear.Although miRNAs are suggested to exert important roles in the regulation of spermatogenesis at both transcriptional and posttranscriptional levels,little is currently known regarding the regulation of sperm flagella assembly by microRNAs(miRNAs).The role of miRNAs in the development of sperm abnormalities in sterile triploid fish has not been studied.Results:In this study,we found that miR-199-5p was widely expressed in all detected tissues of different-ploidy crucian carp.As one of the testis-specific candidate markers,Tekt1 was predominantly expressed in the testis.Quantitative real-time PCR(qRT-PCR)analyses showed that the expression trend of miR-199-5p was exactly opposite to that of Tekt1.Through bioinformatics analysis,we identified a putative miR-199-5p binding site in the Tekt1 mRNA.We further identified Tekt1 as a target of miR-199-5p using luciferase reporter assay.Finally,we confirmed that miR-199-5p was necessary for sperm flagellar assembly and spermatogenesis in vivo via intraperitoneal injection of miR-199-5p antagomir or agomir in diploid red crucian carp.Moreover,miR-199-5p gainof-function could lead to spermatids apoptosis and abnormal spermatozoa structure,which is similar to that of allotriploid crucian carp.Conclusions:Our studies suggested that abnormally elevated miR-199-5p inhibited the sperm flagella formation in spermiogenesis by negatively regulating the expression of Tekt1,thereby causing sperm abnormalities of male allotriploid crucian carp.
基金supported by the Major Program of National Fund of Philosophy and Social Science of China(No.19ZDA105).
文摘In this study,we take a machine learning-based approach to measure institutional investor attention to corporate social responsibility(CSR)issues when communicating with firms during site visits.We find that institutional investors can effectively enhance CSR performance through CSR-related communication.This effect remains robust to various checks and is more pronounced for non-state-owned enterprises and firms with lower levels of institutional ownership and in periods following the issuance of Green Investment Guidelines.We also identify information asymmetry and financing constraints as the two mechanisms underlying this effect.Overall,our findings highlight the importance of private interactions between management and institutional investors in promoting CSR.
