Maternal effects affect offspring phenotype and fitness. However, the roles of offspring sex-specific sensitivity to maternal glucocorticoids and sex-biased maternal investment remain unclear. It is also uncertain whether telomere length (a marker associated with lifespan) depends on early growth in a sex-specific manner. We assessed whether maternal traits including corticosterone (CORT; the main avian glucocorticoid) and in ovo growth rate are sex-specifically related to offspring CORT exposure, relative telomere length (RTL) and body condition in eiders (Somateria mollissima). We measured feather CORT (fCORT), RTL and body condition of newly hatched ducklings, and growth rate in ovo was expressed as tarsus length at hatching per incubation duration. Maternal traits included baseline plasma CORT, RTL, body condition and breeding experience. We found that fCORT was negatively associated with growth rate in daughters, while it showed a positive association in sons. Lower offspring fCORT was associated with higher maternal baseline plasma CORT, and fCORT was higher in larger clutches and in those hatching later. The RTL of daughters was negatively associated with maternal RTL, whereas that of males was nearly independent of maternal RTL. Higher fCORT in ovo was associated with longer RTL at hatching in both sexes. Duckling body condition was mainly explained by egg weight, and sons had a slightly lower body condition. Our correlational results suggest that maternal effects may have heterogeneous and even diametrically opposed effects between the sexes during early development. Our findings also challenge the view that prenatal CORT exposure is invariably associated with shorter telomeres.

中文翻译：

---

卵内环境对绒毛动物早期表型的性别特异性影响。

产妇影响后代的表型和适应性。然而，后代性别特异性对母体糖皮质激素的敏感性和性别偏向的母体投资的作用仍不清楚。还不确定端粒长度（与寿命相关的标志）是否取决于性别特异性的早期生长。我们评估了包括皮质类固醇（CORT；主要禽类糖皮质激素）和卵内生长速率在内的母体特征是否与后代CORT暴露，相对端粒长度（RTL）和绒毛的身体状况（Somateria mollissima）性别相关。我们测量了羽毛CORT（fCORT），RTL和新孵出的雏鸭的身体状况，卵内生长速率表示为每个孵化期间孵化时的架长度。产妇特征包括基线血浆CORT，RTL，身体状况和繁殖经验。我们发现，fCORT与女儿的生长速度呈负相关，而与儿子的生长呈正相关。较低的后代fCORT与较高的母体基线血浆CORT相关，在较大的离合和后期孵化中，fCORT较高。女儿的RTL与母亲的RTL负相关，而男性的RTL几乎与母亲的RTL独立。卵内较高的fCORT与更长的性别孵化率相关。小鸭的身体状况主要由卵重来解释，儿子的身体状况略低。我们的相关结果表明，在早期发育过程中，母体效应可能在性别之间产生异质性甚至截然相反的效应。