Cameron Nicole M
Center for Development and Behavioral Neuroscience, Psychology and Biology Departments, Binghamton University - State University of New York Binghamton, NY, USA.
Front Evol Neurosci. 2011 Dec 22;3:10. doi: 10.3389/fnevo.2011.00010. eCollection 2011.
Parental investment can be used as a forecast for the environmental conditions in which offspring will develop to adulthood. In the rat, maternal behavior is transmitted to the next generation through epigenetic modifications such as methylation and histone acetylation, resulting in variations in estrogen receptor alpha expression. Natural variations in maternal care also influence the sexual strategy adult females will adopt later in life. Lower levels of maternal care are associated with early onset of puberty as well as increased motivation to mate and greater receptivity toward males during mating. Lower levels of maternal care are also correlated with greater activity of the hypothalamus-pituitary-gonadal axis, responsible for the expression of these behaviors. Contrary to the transition of maternal care, sexual behavior cannot simply be explained by maternal attention, since adoption studies changed the sexual phenotypes of offspring born to low caring mothers but not those from high caring dams. Indeed, mothers showing higher levels of licking/grooming have embryos that are exposed to high testosterone levels during development, and adoption studies suggest that this androgen exposure may protect their offspring from lower levels of maternal care. We propose that in the rat, maternal care and the in utero environment interact to influence the reproductive strategy female offspring display in adulthood and that this favors the species by allowing it to thrive under different environmental conditions.
亲代投资可被用作预测后代发育至成年期时的环境条件。在大鼠中，母性行为通过甲基化和组蛋白乙酰化等表观遗传修饰传递给下一代，导致雌激素受体α表达发生变化。母性关怀的自然差异也会影响成年雌性个体日后所采用的性策略。较低水平的母性关怀与青春期提前开始、交配动机增加以及交配期间对雄性的接受度提高有关。较低水平的母性关怀还与下丘脑-垂体-性腺轴的活性增强相关，该轴负责这些行为的表达。与母性关怀的传递情况相反，性行为不能简单地用母性关注来解释，因为收养研究改变了低关怀母亲所生后代的性表型，但未改变高关怀母鼠所生后代的性表型。事实上，表现出较高舔舐/梳理水平的母亲所生的胚胎在发育过程中会接触到高水平的睾酮，收养研究表明，这种雄激素暴露可能会保护其后代免受较低水平母性关怀的影响。我们提出，在大鼠中，母性关怀和子宫内环境相互作用，影响雌性后代成年后所表现出的生殖策略，并且这有利于该物种在不同环境条件下茁壮成长。
