Institute of Medical Sciences, University of Toronto, Mississauga, Ontario.
Genes Brain Behav. 2011 Apr;10(3):325-33. doi: 10.1111/j.1601-183X.2010.00671.x. Epub 2011 Jan 13.
Maternal behavior in the new mother is a multidimensional set of responses to infant cues that are influenced by the mother's early life experiences. In this study, we wanted to test if mothers' early life experiences and mothers' genotype have interactive effects on maternal behaviors and attitudes, something which has not been previously explored. In a sample of 204 mothers, we assessed maternal genotype at the serotonin transporter-linked polymorphic region (5-HTTLPR) and an adjacent upstream polymorphism (rs25531), together giving rise to three alleles: short (S), L(G) and L(A). Controlling for maternal age and parity, we showed that this genotype can predict differences in maternal sensitivity at 6 months postpartum: mothers with an S (or the functionally similar L(G)) allele were more sensitive than mothers who lacked the allele during a 30-min recorded mother-infant interaction (F (4,140) = 3.43; P = 0.01). Furthermore, we found highly significant gene-environment interactions in association with maternal behavior, such that mothers with no S or L(G) alleles oriented away more frequently from their babies if they also reported more negative early care quality (F (5,138) = 3.28; P = 0.008). Finally, we found significant gene-environment associations with maternal attitudes; mothers with the S allele and with greater early care quality scored higher on ratings of their perceived attachment to their baby (F (5,125) = 3.27; P = 0.008). The regression results show significant interactions between the reported quality of care mothers received from their own parents and genotype on both their frequency of orienting away from the infant during the interaction (F(5, 138) = 3.28; P = 0.008, Fig. 1a) and their perceived attachment feelings to the infant (F(5, 125) = 3.27; P = 0.008, Fig. 1b); however the direction of the effects for these two outcome measures were different from one another. With increasing care quality, mothers with the L(A)L(A) genotype (no S or L(G) allele) oriented away less frequently, while S or L(G) allele carriers showed no significant change. In contrast, with increasing early care quality. L(A)L(A) (no S or L(G) allele) mothers scored lower on perceived attachment to their infants, whereas S or L(G) allele carrying mothers scored higher. [corrected].
新妈妈的母性行为是对婴儿线索的多维反应，受母亲早期生活经历的影响。在这项研究中，我们想测试母亲的早期生活经历和母亲的基因型是否对母性行为和态度有交互作用，这一点以前没有被探索过。在 204 名母亲的样本中，我们评估了母亲在 5-羟色胺转运体连接多态性区域（5-HTTLPR）和相邻上游多态性（rs25531）的基因型，这两种多态性共同产生了三种等位基因：短（S）、L(G)和 L(A)。在控制了母亲的年龄和产次后，我们发现这种基因型可以预测产后 6 个月母亲敏感性的差异：携带 S（或功能相似的 L(G)）等位基因的母亲比缺乏该等位基因的母亲在 30 分钟的记录母婴互动中更敏感（F (4,140) = 3.43；P = 0.01）。此外，我们发现与母婴行为高度相关的基因-环境相互作用，例如，如果母亲没有 S 或 L(G)等位基因，并且报告的早期护理质量更差，她们更频繁地从婴儿身边转开（F (5,138) = 3.28；P = 0.008）。最后，我们发现母婴态度也存在显著的基因-环境关联；携带 S 等位基因和早期护理质量较高的母亲，在对自己婴儿的依恋程度的评分上得分更高（F (5,125) = 3.27；P = 0.008）。回归结果显示，母亲从自己父母那里得到的护理质量报告和基因型与母婴互动中母亲从婴儿身边转开的频率（F(5, 138) = 3.28；P = 0.008，图 1a）以及对婴儿的依恋感（F(5, 125) = 3.27；P = 0.008，图 1b）之间存在显著的相互作用；然而，这两个结果测量的效应方向彼此不同。随着护理质量的提高，携带 L(A)L(A)基因型（没有 S 或 L(G)等位基因）的母亲转身离开的频率降低，而 S 或 L(G)等位基因携带者则没有明显变化。相比之下，随着早期护理质量的提高，L(A)L(A)（无 S 或 L(G)等位基因）的母亲对婴儿的依恋程度评分较低，而携带 S 或 L(G)等位基因的母亲评分较高。
