对非亲缘母亲产出的体外受精(IVF)儿童的分析让科学家可以区分基因和产前环境对胎儿产生的影响。科学家长久以来知道子宫环境是胎儿发育的一个关键,而且在子宫内的经历——诸如产前暴露在母亲吸烟的环境下——可能对胎儿产生永久性的影响。
英国研究人员Frances Rice及其同事分析了779名通过IVF出生的儿童,以确定产前暴露在吸烟环境下的影响。低出生体重和反社会行为已经与孕妇吸烟联系在了一起,但是这组科学家证明了反社会行为只与有亲缘关系的母亲产出的婴儿有联系。体外受精应用的不断增加带来了一个研究非亲缘关系母亲产出的婴儿的结果的机会。这组科学家说,这些发现有可能让科学家区分基因和环境对各种其他疾病的影响。(生物谷Bioon.com)
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PNAS Published online before print February 2, 2009, doi: 10.1073/pnas.0808798106
Disentangling prenatal and inherited influences in humans with an experimental design
Frances Ricea,1,2, Gordon T. Haroldb,3, Jacky Boivinb, Dale F. Hayb, Marianne van den Breea and Anita Thapara,1
aDepartment of Psychological Medicine, School of Medicine and
bSchool of Psychology, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
Abstract
Exposure to adversity in utero at a sensitive period of development can bring about physiological, structural, and metabolic changes in the fetus that affect later development and behavior. However, the link between prenatal environment and offspring outcomes could also arise and confound because of the relation between maternal and offspring genomes. As human studies cannot randomly assign offspring to prenatal conditions, it is difficult to test whether in utero events have true causal effects on offspring outcomes. We used an unusual approach to overcome this difficulty whereby pregnant mothers are either biologically unrelated or related to their child as a result of in vitro fertilization (IVF). In this sample, prenatal smoking reduces offspring birth weight in both unrelated and related offspring, consistent with effects arising through prenatal mechanisms independent of the relation between the maternal and offspring genomes. In contrast, the association between prenatal smoking and offspring antisocial behavior depended on inherited factors because association was only present in related mothers and offspring. The results demonstrate that this unusual prenatal cross-fostering design is feasible and informative for disentangling inherited and prenatal effects on human health and behavior. Disentangling these different effects is invaluable for pinpointing markers of prenatal adversity that have a causal effect on offspring outcomes. The origins of behavior and many common complex disorders may begin in early life, therefore this experimental design could pave the way for identifying prenatal factors that affect behavior in future generations.