单 位：
临沂大学生命科学学院;四川农业大学动物科技学院
摘 要：
本试验旨在研究胚蛋注射甲氨蝶呤(MTX)和叶酸(FA)对鸡胚孵化率以及雏鸡屠宰性能、FA代谢相关血清指标和肝脏FA代谢相关基因表达的影响。选用300枚琅琊鸡商品代种蛋,随机分为4组,每组5个重复,每个重复15枚种蛋,孵化至7胚龄时分别注射0.1 mL 0.85%生理盐水(对照)、0.1 mL MTX(5μg)溶液、0.1 mL FA(90μg)+MTX(5μg)溶液、0.1 mL FA(90μg)溶液。出雏后统计总出雏数,计算孵化率;雏鸡出壳后禁食12 h,每个组随机选择雏鸡10只,测定血清生化指标、屠宰性能以及肝脏FA代谢相关基因的表达水平。结果表明:1)与对照组相比,胚蛋注射5μg MTX显著降低了鸡胚孵化率(P<0.05);注射MTX和FA均未对雏鸡屠宰性能和器官指数产生显著影响(P>0.05)。2)与对照组相比,胚蛋注射5μg MTX极显著降低了雏鸡血清中FA含量(P<0.01);注射90μg FA+5μg MTX或90μg FA极显著增加了雏鸡血清中FA含量(P<0.01);注射5μg MTX极显著升高了雏鸡血清中同型半胱氨酸(Hcy)含量(P<0.01),注射90μg FA极显著降低了雏鸡血清中Hcy含量(P<0.01);注射5μg MTX、90μg FA+5μg MTX或90μg FA极显著增加了雏鸡血清中二氢叶酸还原酶(DHFR)、亚甲基四氢叶酸还原酶(MTHFR)活性与胰岛素样生长因子2(IGF2)含量(P<0.01)。3)与对照组相比,胚蛋注射90μg FA极显著降低了MTHFR基因在肝脏中的表达量(P<0.01);注射5μg MTX极显著提高了还原型叶酸载体(RFC)在肝脏中的表达量(P<0.01);注射90μg FA+5μg MTX或90μg FA对肝脏中RFC、DHFR、IGF2、质子耦合叶酸转运体(PCFT)的表达量均无显著影响(P>0.05)。由此可见,MTX能干扰鸡胚FA代谢,导致孵化率下降;鸡胚孵化期注射MTX和FA对雏鸡血清FA代谢酶活性和Hcy含量有重要调控作用,并对肝脏中MTHFR和RFC的表达具有显著影响。
译 名：
Effects of in Ovo Injecting Methotrexate and Folic Acid on Slaughter Performance,Serum Biochemical Indexes and Expression of Liver Folic Acid Metabolism Related Genes in Chicks
作 者：
TANG Weiqi;ZHANG Yujie;YAN Chengguang;XING Jinyi;SHUAI Surong;College of Animal Sciences and Technology,Sichuan Agricultural University;College of Life Sciences,Linyi University;
关键词：
chick embryo;;folic acid;;hatchability;;slaughter performance;;gene expression
摘 要：
The purpose of this experiment was to investigate the effects of in ovo injecting methotrexate(MTX)and folic acid(FA)on hatchability of chick embryo,slaughter performance,serum biochemical indexes and expression of genes related to FA metabolism in liver of chicks. A total of 300 fertile eggs of Langya chickens were selected for hatching. They were randomly divided into 4 groups,and each group had 5 replicates with 15 eggs per replicate. The fertile eggs were injected on 7 embryonic day of incubation according to following solution:0. 1 mL 0. 85% of saline(control),0. 1 mL MTX(5μg)solution,0. 1 mL FA(90μg)+MTX(5μg)solution,and 0.1 mL FA(90μg)solution. The total number of chicks after hatching was counted to calculate the hatchability. After the newly hatched chicks fasted for 12 h,ten chicks were randomly selected in each group and were used to measure slaughter performance,serum biochemical indexes and expression levels of genes related to FA metabolism in liver. The results showed as follows:1)compared with the control group,in ovo injecting 5μg MTX significantly reduced the hatchability of chick embryo(P <0.05),and injecting MTX and FA did not have significant effects on the slaughter performance and organ indexes of chicks(P>0.05). 2)Compared with the control group,in ovo injecting 5μg MTX significantly reduced the content of FA in serum of chicks(P<0.01);injecting 90μg FA+5μg MTX or 90μg FA significantly increased the content of FA in serum of chicks(P<0.01);injecting 5μg MTX significantly increased the content of homocysteine(Hcy)in serum of chicks(P<0.01),but injecting 90μg FA significantly decreased the content of Hcy in serum of chicks(P<0.01);injecting 5μg MTX,90μg FA+5μg MTX or90μg FA all significantly increased the activities of dihydrofolate reductase(DHFR)and methylenetetrahydrofolate reductase(MTHFR)and the content of insulin-like growth factor 2(IGF2)in serum of chicks(P <0.01). 3)Compared with the control group,the expression level of MTHFR in liver was significantly decreased by in ovo injecting 90μg FA(P<0.01),conversely,the expression level of reduced folate carrier(RFC)in liver was significantly increased by injecting 5μg MTX(P<0.01);injecting 90μg FA+5μg MTX or 90μg FA did not significantly affect the expression levels of liver RFC,DHFR,IGF2 and proton-coupled folate transporter(PCFT)(P>0.05). Thus,MTX can interfere with the FA metabolism of chicken embryo,resulting in the decrease of hatchability;in ovo injecting MTX and FA can effectively regulate the FA metabolizing enzyme activities and Hcy content in serum of chicks,and has a significant effect on the expression of MTHFR and RFC in liver.[Chinese Journal of Animal Nutrition,2020,32(11):5221-5229]
