Embryo Transfer for the Study of Transgenerational Modifications in Morphine Sens

描述(由申请人提供)：许多研究表明，药物滥用的遗传性质是由遗传和环境因素造成的。调节基因和环境之间相互作用的一种机制是表观遗传修饰。在此背景下，术语表观遗传学是指调节基因表达的DNA和组蛋白修饰，这些修饰从母细胞传递到子细胞，或从亲代传递给后代，但不改变潜在的DNA序列。虽然很明显，表观遗传修饰可以从一代传到下一代，但这些效应的传递所涉及的机制还不完全清楚。最近的一些发现表明，母体环境，无论是出生前还是出生后，可能在表观遗传转移中发挥关键作用。到目前为止，表观遗传学在药物滥用家族模式中的作用还没有得到很好的研究。我们在雌性大鼠身上建立了青春期吗啡暴露的动物模型，以检验在这一独特的发育期使用鸦片类药物的长期后果。我们的发现表明，除了在青春期暴露于吗啡的成年雌性大鼠的基因表达发生显著变化外，暴露于青春期的雌性大鼠的后代对吗啡的反应增强。这一模型的一个重要方面是，接触吗啡的青春期女性在交配前几周内不使用药物，因此不存在直接的宫内接触。这项建议的目的是在青少年发育期间接触吗啡的女性中开发、改进和实施非手术胚胎移植。然后，这项技术将被用来描述由胚胎水平的修饰直接介导的后代效应。 由出生前和/或出生后环境的变化引起的。主要的焦点将放在吗啡敏感性(行为和生理)的跨代变化上，因为这些影响是有充分特征的。此外，了解药物诱导的吗啡敏感性变化如何代代相传，可能有助于确定药物使用家族模式背后的基本机制。

DESCRIPTION (provided by applicant): Many studies demonstrate that the hereditary nature of drug abuse is due to both genetic and environmental factors. One mechanism regulating interactions between genes and the environment are epigenetic modifications. In this context, the term epigenetics refers to DNA and histone protein modifications that regulate gene expression and which are transmitted from a mother cell to a daughter cell, or from a parent to its progeny, but which do not change the underlying DNA sequence. While it is clear that epigenetic modifications can be passed from one generation to the next, the mechanisms involved in the transmission of these effects are not fully understood. Several recent findings indicate that the maternal environment, both pre- and postnatal, may play a critical role in epigenetic transfer. To date, the role of epigenetics in familial patterns of drug abuse has not been well-studied. We have developed an animal model of adolescent morphine exposure in female rats to examine the long-term consequences of opiate use during this unique developmental period. Our findings demonstrate that, in addition to significant alterations in gene expression in adult female rats exposed to morphine during adolescence, the offspring of adolescent-exposed females demonstrate enhanced responsiveness to morphine. One important aspect of this model is that adolescent morphine- exposed females are drug-free for several weeks prior to mating, and thus there is no direct in utero exposure. The purpose of this proposal is to develop, refine, and implement non-surgical embryo transfer in females exposed to morphine during adolescent development. This technique will then be used to delineate offspring effects that are directly mediated by modifications at the level of the embryo from those induced by alterations in the pre- and/or postnatal environment. The primary focus will be on transgenerational alterations in morphine sensitivity (behavioral and physiological) as these effects are well-characterized. Moreover, understanding how drug-induced alterations in morphine sensitivity may be passed from one generation to the next may help identify basic mechanisms underlying familial patterns of substance use.