Experimental evidence for genetic heritability of maternal hormone transfer to offspring
Monika Okuliarova1, Ton G G Groothuis, Peter Skrobánek
1Department of Animal Physiology and Ethology, Comenius University, Mlynská dolina, Bratislava, Slovak Republic. okuliarova@fns.uniba.sk
Abstract:
In many animal species, embryos are exposed to maternal hormones that affect their development. Maternal hormone transfer varies with environmental conditions of the mother and is often interpreted as being shaped by natural selection to adjust the offspring to prevailing environmental conditions. Such hormone transfer requires genetic variability, which has not yet been experimentally demonstrated. Our study reports direct evidence for additive genetic variance of maternal androgens through a bidirectional selection on yolk testosterone (T) levels in Japanese quail. Lines selected for high egg T (HET) and low egg T (LET) concentration differed in yolk levels of this androgen, resulting in high realized heritability (h² = 0.42)Correlated responses to selection on other gonadal hormones indicated that selection specifically targeted biologically active androgens. Eggs of HET quail contained higher androstenedione and lower estradiol concentrations than did those of LET quail, with no line differences in yolk progesterone concentration. Plasma T concentrations in adult females were not affected by selection, seriously challenging the hypothesis that transfer of maternal hormones to offspring is constrained by hormone levels in a mother's circulation. Our results suggest that transfer of maternal T represents an indirect genetic effect that has important consequences for the evolution of traits in offspring.
More Related Videos
Related Concept Videos
Heritability
Behavioral Genetics and Its Designs
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique...
Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Animal Mitochondrial Genetics
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Regression Toward the Mean


