孕期应激对绵羊子代表型编程效应研究进展

家畜孕期应激对子代行为、生理和神经方面有着复杂的影响,这种影响可以持续到子代成年甚至跨代遗传。家畜孕期管理不当会对母体产生应激,使母体及其子代的生长、健康和福利受损,从而影响家畜的经济价值。本文以绵羊孕期应激模型和人工合成糖皮质激素模拟应激模型的试验结果为切入点,系统总结了绵羊孕期应激对子代表型的影响,并讨论了研究结果异同的可能原因。研究发现,绵羊孕期应激可以影响子代出生体重、调节子代下丘脑—垂体—肾上腺轴发育、影响子代行为模式和认知能力、改变子代基因表达和大脑形态,并且母体糖皮质激素水平是决定子代表型变化的主要因素。未来研究方向应该侧重于绵羊孕期应激对子代基因表达、免疫功能、生产性能和母性行为的影响,以及不同妊娠时期母体应激的比较研究、对子代影响的连续研究和探讨孕期应激不良编程的应对策略研究。

Research progress on the programming effects of prenatal stress in sheep on its offspring's phenotype

Prenatal stress results in complex behavioral,physiological and neurological consequences for the developing of offspring,which can last into adulthood or even propagate to subsequent generations.Inadequate management practices of the farm animals during pregnancy may be potential stressors for the mother,with detrimental effects on the growth,health and welfare of the dam and its offspring,and thus can affect the economic consequences of the farm animals.The outcomes from different experimental models using either maternal stress paradigms or artificially increased maternal glucocorticoid are presented,the effects of prenatal stress on the phenotype of the offspring are systematically summarized,and possible reasons for consistent or divergent results are discussed.It is revealed that the prenatal stress can impair birth weights,regulate the development of hypothalamic-pituitary-adrenal axis,modify behaviour pattern and cognitive ability,and alter gene expression and brain morphology of the offspring.There is evidence that the maternal glucocorticoid regulation is a major determinant of the alterations in offspring.Further research should focus on the gene expression,immune function and production performance in offspring and maternal behavior in female offspring used as breeding animals,as well as the comparative study of prenatal stress during different gestational period,the continuous study of the effects of prenatal stress on the offspring and the treatment strategies that effectively reverse the detrimental programming effects of prenatal stress.