Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.

As an important and fundamental resource of scientific research,laboratory animals have become essential tools for the continuous advancements in life sciences,medical research,drug development,and other fields.With the development of related laws and regulations,the welfare of laboratory animals is increasingly valued by the general public and international research communities alike.To ensure the welfare of laboratory animals,the ethical review and conduct of laboratory animal practitioners should be standardized,incorporating and adapting advanced international practices with those in China.This article primarily outlines the process for reviewing and approving animal use protocols,along with the standards for evaluation,with the aim of providing a reference for researchers writing animal use protocols and for International Animal Care and Use Committee members conducting ethical reviews of laboratory animal welfare.

Objective To establish a rapid and accurate droplet digital PCR(ddPCR)detection method for detecting Staphylococcus aureus(SA)in laboratory animals and the environment.Methods Using the heat-stable nuclease gene(nuc)of SA as the target gene,a pair of specific primers and probes are designed within its conserved region.Optimize the reaction conditions,test the dynamic range,and evaluate the specificity and stability of the method.Using the same template,test reactions were performed with both ddPCR and real-time quantitative PCR(qPCR)method to assess the interchangeability between the two approaches.Finally,the method is applied to the detection of various clinical samples.Results The kinetic range of the established SA ddPCR method is 100～15 000 copies/μL,with a detection limit of 2.5 copies and a quantification limit of 10 copies;The specificity of this method was tested,and only SA showed positive droplets,while no positive droplets were found for other pathogens;After measuring three parallel samples,the standard deviation and relative standard deviation were calculated.It was found that within the dynamic detection interval of ddPCR,as the target copy number gradually decreased,the relative standard deviation showed an upward trend,but remained below 25％.This result indicates that the detection method has good stability.Conclusions The established ddPCR method for detecting SA has the advantages of high sensitivity,strong specificity,good stability,and good reproducibility.This method can be applied for the detection of SA in laboratory animals.

Objective To establish a rapid and accurate droplet digital PCR(ddPCR)detection method for detecting Staphylococcus aureus(SA)in laboratory animals and the environment.Methods Using the heat-stable nuclease gene(nuc)of SA as the target gene,a pair of specific primers and probes are designed within its conserved region.Optimize the reaction conditions,test the dynamic range,and evaluate the specificity and stability of the method.Using the same template,test reactions were performed with both ddPCR and real-time quantitative PCR(qPCR)method to assess the interchangeability between the two approaches.Finally,the method is applied to the detection of various clinical samples.Results The kinetic range of the established SA ddPCR method is 100～15 000 copies/μL,with a detection limit of 2.5 copies and a quantification limit of 10 copies;The specificity of this method was tested,and only SA showed positive droplets,while no positive droplets were found for other pathogens;After measuring three parallel samples,the standard deviation and relative standard deviation were calculated.It was found that within the dynamic detection interval of ddPCR,as the target copy number gradually decreased,the relative standard deviation showed an upward trend,but remained below 25％.This result indicates that the detection method has good stability.Conclusions The established ddPCR method for detecting SA has the advantages of high sensitivity,strong specificity,good stability,and good reproducibility.This method can be applied for the detection of SA in laboratory animals.

Objective We aimed to investigate the effects of different non-surgical embryo transfer devices,number of transferred embryos,embryo stage,and embryos obtained from different mouse strains on the efficiency of non-surgical embryo transfer in mice,and to compare the efficiencies of surgical and non-surgical embryo transfer,in order to establish a stable non-surgical embryo transfer technology system.Methods Mouse embryo transfer was carried out using non-surgical method.Results The pregnancy rates using two different non-surgical transfer devices were(75.00±0.00)％and(66.67±14.43)％,and the birth rates were(46.11±6.31)％and(18.89±0.96)％,respectively.Transfer of 10,15,and 20 embryos resulted in pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,and(66.67±23.09)％,and birth rates of(29.33±4.16)％,(38.67±4.81)％,and(17.00±3.46)％,respectively.When blastocysts and morulae were transferred non-surgically,the resulting pregnancy rates were(80.00±0.00)％and(46.67±11.55)％and the birth rates were(38.67±4.81)％and(10.22±2.77)％,respectively.Four strains(C57BL/6J,ICR,genetically modified mice A,genetically modified mice B)were used as donors for non-surgical embryo transfer,with resulting pregnancy rates of(66.67±11.55)％,(80.00±0.00)％,(73.33±11.55)％,and(80.00±0.00)％,and birthrates of(26.67±2.67)％,(38.67±4.81)％,(32.00±3.53)％,and(29.34±2.31)％,respectively.Fifteen pseudo-pregnant mice were transplanted surgically and 15 were transplanted non-surgically,with pregnancy rates of(80.00±0.00)％and(86.67±11.55)％,and birth rates of(38.67±4.81)％and(36.00±5.82)％,respectively.Conclusions Transfer device A resulted in a higher birth rate in this study.The embryo transfer efficiency was higher when 15 embryos were transferred into unilateral uterine horns of pseudo-pregnant 2.5-day recipients.Blastocyst-stage embryo transfer was more efficient than morula-stage transfer.There was no significant difference in efficiency between surgical and non-surgical embryo transfer procedures.

As an important and fundamental resource of scientific research,laboratory animals have become essential tools for the continuous advancements in life sciences,medical research,drug development,and other fields.With the development of related laws and regulations,the welfare of laboratory animals is increasingly valued by the general public and international research communities alike.To ensure the welfare of laboratory animals,the ethical review and conduct of laboratory animal practitioners should be standardized,incorporating and adapting advanced international practices with those in China.This article primarily outlines the process for reviewing and approving animal use protocols,along with the standards for evaluation,with the aim of providing a reference for researchers writing animal use protocols and for International Animal Care and Use Committee members conducting ethical reviews of laboratory animal welfare.

Improving the reproducibility of biomedical research results is a major challenge.Transparent and accurate reporting of the research process enables readers to evaluate the reliability of the research results and further explore the experiment by repeating it or building upon its findings. The ARRIVE 2.0 guidelines, released in 2019 by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), provide a checklist applicable to any in vivo animal research report. These guidelines aim to improve the standardization of experimental design, implementation, and reporting, as well as the reliability, repeatability, and clinical translatability of animal experimental results. The use of ARRIVE 2.0 guidelines not only enriches the details of animal experimental research reports, ensuring that information on animal experimental results is fully evaluated and utilized, but also enables readers to understand the content expressed by the author accurately and clearly, promoting the transparency and integrity of the fundamental research review process. At present, the ARRIVE 2.0 guidelines have been widely adopted by international biomedical journals. This article is a Chinese translation based on the best practices of international journals following the ARRIVE 2.0 guidelines in international journals, specifically for the complete interpretation of the ARRIVE 2.0 guidelines published in the PLoS Biology journal in 2020 (original text can be found at https://arriveguidelines.org). The fourth part of the article includes the items 1-5 of ARRIVE 2.0 Recommended 11 section, which covers "Abstract" "Background" "Objectives" "Ethical statement" and "Housing and husbandry". Its aim is to promote the full understanding and use of the ARRIVE 2.0 guidelines by domestic researchers, enhance the standardization of experimental animal research and reporting, and promote the high-quality development of experimental animal technology and comparative medicine research in China.

Many people affected by fragile X syndrome (FXS) and autism spectrum disorders have sensory processing deficits, such as hypersensitivity to auditory, tactile, and visual stimuli. Like FXS in humans, loss of Fmr1 in rodents also cause sensory, behavioral, and cognitive deficits. However, the neural mechanisms underlying sensory impairment, especially vision impairment, remain unclear. It remains elusive whether the visual processing deficits originate from corrupted inputs, impaired perception in the primary sensory cortex, or altered integration in the higher cortex, and there is no effective treatment. In this study, we used a genetic knockout mouse model (Fmr1^KO), in vivo imaging, and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex (V1). Specifically, Fmr1^KO mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli. This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons. These effects were ameliorated by the acute application of GABA_A receptor activators, which enhanced the activity of inhibitory neurons, or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice. Overall, V1 plays an important role in the visual abnormalities of Fmr1^KO mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.
Animals ; Disease Models, Animal ; Fragile X Mental Retardation Protein/metabolism* ; Fragile X Syndrome/metabolism* ; Humans ; Mice ; Mice, Knockout ; Neurons/metabolism*