Objective The purpose of the study is to breed homozygous interferon-γ knockout(IFN-γ-/-)mice and optimize the breeding strategies to achieve continuous and stable reproduction of IFN-γ-/-mice,which could be used as an ideal animal model for fundamental research.Methods Initially,heterozygous IFN-γ knockout(IFN-γ+/-)C57BL/6J mice were used as the parental generation for breeding.Subsequently,3 breeding strategies were employed using the offspring:(1)female heterozygotes mated with male heterozygotes;(2)male homozygotes mated with female heterozygotes;(3)female homozygotes mated with male homozygotes.The number and survival rate of IFN-γ-/-mice were compared across the three breeding strategies to determine the optimal breeding strategy.Under the optimal strategy,the effects of female mating age and diet type on the reproductive performance of IFN-γ-/-mice were further evaluated.Data from the first three litters of 60 IFN-γ-/-female mice,including litter size,number of weaning survivors,and weaning survival rate,were recorded and analyzed.In addition,the effects of dietary supplementation of pregnant mice and environmental optimization measures,such as the provision of shelters,were evaluated.Results Under conditions where the nutritional needs of pregnant mice were adequately met by supplementation with egg yolk and sunflower seeds,mating of female and male IFN-γ-/-mice result ed in a litter size of five to eight IFN-γ-/-mice,demonstrating higher efficiency compared to other breeding strategies.In addition,diet type and mating age significantly influenced female reproductive performance.When 7～9 weeks old female IFN-γ-/-mice were mated to male IFN-γ-/-mice and fed a high-protein breeding diet,litter size(6.9±1.7),weaning survival number(6.5％±2.0％)and weaning survival rate(93.2％±17.8％)were higher than those under other conditions.In addition,providing shelters to prevent fighting between breeding pairs further improved reproductive outcomes.Conclusions By adopting an optimized breeding strategy,combined with a high-protein diet,nutritional supplementation,and standardized mating age management,the breeding efficiency and stability of IFN-γ-/-mice can be significantly improved.This provides a reliable animal model for related research.

Objective The purpose of the study is to breed homozygous interferon-γ knockout(IFN-γ-/-)mice and optimize the breeding strategies to achieve continuous and stable reproduction of IFN-γ-/-mice,which could be used as an ideal animal model for fundamental research.Methods Initially,heterozygous IFN-γ knockout(IFN-γ+/-)C57BL/6J mice were used as the parental generation for breeding.Subsequently,3 breeding strategies were employed using the offspring:(1)female heterozygotes mated with male heterozygotes;(2)male homozygotes mated with female heterozygotes;(3)female homozygotes mated with male homozygotes.The number and survival rate of IFN-γ-/-mice were compared across the three breeding strategies to determine the optimal breeding strategy.Under the optimal strategy,the effects of female mating age and diet type on the reproductive performance of IFN-γ-/-mice were further evaluated.Data from the first three litters of 60 IFN-γ-/-female mice,including litter size,number of weaning survivors,and weaning survival rate,were recorded and analyzed.In addition,the effects of dietary supplementation of pregnant mice and environmental optimization measures,such as the provision of shelters,were evaluated.Results Under conditions where the nutritional needs of pregnant mice were adequately met by supplementation with egg yolk and sunflower seeds,mating of female and male IFN-γ-/-mice result ed in a litter size of five to eight IFN-γ-/-mice,demonstrating higher efficiency compared to other breeding strategies.In addition,diet type and mating age significantly influenced female reproductive performance.When 7～9 weeks old female IFN-γ-/-mice were mated to male IFN-γ-/-mice and fed a high-protein breeding diet,litter size(6.9±1.7),weaning survival number(6.5％±2.0％)and weaning survival rate(93.2％±17.8％)were higher than those under other conditions.In addition,providing shelters to prevent fighting between breeding pairs further improved reproductive outcomes.Conclusions By adopting an optimized breeding strategy,combined with a high-protein diet,nutritional supplementation,and standardized mating age management,the breeding efficiency and stability of IFN-γ-/-mice can be significantly improved.This provides a reliable animal model for related research.

[Abstract] Objective: To investigate the molecular mechanism of miR-143-3p regulating the proliferation, migration and invasion of colon cancer RKO cells via targeting enhancer of zeste homolog 2 (EZH2). Methods: A total of 40 pairs of colon cancer tissues and corresponding para-cancerous tissues resected in the First Affiliated Hospital of Kunming Medical University from March 2015 to July 2017 were collected for this study. In addition, colon cancer cell lines (COLO320, RKO and CL-11) and normal intestinal mucosa NCM460 cells were also collected. qPCR was applied to detect the expression level of miR-143-3p in colon cancer tissues and cell lines. miR-143-3p mimics, miR-143-3p inhibitor, EZH2 siRNA and negative control plasmids were transfected into RKO cells, respectively. The effect of miR-143-3p/EZH2 axis on the proliferation, migration and invasion of RKO cells were detected by CCK-8 and Transwell assay, respectively. Western blotting was used to detect the expression level of EZH2 protein in RKO cells. The targeting relationship between miR-143-3p and EZH2 was verified by Dual luciferase reporter gene assay. Results: The expression level of miR-143-3p was downregulated in colon cancer tissues and cell lines (all P<0.01). Overexpression of miR-143-3p significantly inhibited the proliferation, migration and invasion of RKO cells (all P<0.01). Dual luciferase reporter gene assay confirmed that EZH2 was a target gene of miR-143-3p. Simultaneous knockdown of miR-143-3p and EZH2 attenuated the inhibition of EZH2 knockdown on the proliferation, migration and invasion of RKO cells. Conclusion: miR-143-3p suppresses the proliferation, migration and invasion of colon cancer cells via targetedly down-regulating EZH2.