How do estrogen pathways interact with androgens in pad development

Estrogen pathways act in direct opposition to androgen pathways, effectively preventing nuptial pad development in female frogs and regulating the process in males.

The key interactions are:

1. Antagonistic Action: Estrogens (like estradiol) and androgens are antagonistic. High levels of circulating estrogens in females ensure that any low-level androgenic signals are overridden, and the skin cells on their thumbs remain undifferentiated.
2. Enzymatic Regulation via Aromatase: An enzyme called aromatase plays a crucial role by converting androgens directly into estrogens. High levels of aromatase activity in certain tissues can effectively neutralize the masculinizing effects of testosterone. This is a key mechanism in female sexual differentiation.
3. Inhibition of Androgen Production: The endocrine feedback loops in females that maintain high estrogen levels also suppress the pituitary signals (like LH) that would otherwise stimulate high levels of androgen production from the gonads.

Essentially, the presence of a strong estrogen pathway creates a hormonal environment where the development of male characteristics like nuptial pads is actively blocked.