Changes in pituitary gene expression may underlie multiple domesticated traits in chickens

Area of Science:

• Genetics and Evolutionary Biology
• Comparative Genomics
• Animal Physiology

Background:

• Domesticated animals exhibit a shared 'domesticated phenotype' with similar traits across species.
• Previous research on domestication mechanisms primarily focused on the brain, neglecting other endocrine systems.
• The pituitary gland's role in regulating key domesticated traits remains understudied.

Purpose of the Study:

• To investigate the role of the pituitary gland in the domestication of chickens.
• To identify specific genes within the pituitary gland that are differentially expressed between domesticated chickens and their wild ancestors.

Main Methods:

• Comparative gene expression analysis of the pituitary gland between White Leghorn chickens and Red Junglefowl.
• Identification of differentially expressed genes by overlapping with a list of functionally important pituitary genes.
• Focus on genes related to pigmentation, metabolism, reproduction, and stress response.

Main Results:

• 34 candidate genes were identified with altered expression in the domesticated chicken pituitary.
• Higher expression of pigmentation inhibitors (ASIP), metabolism/reproduction stimulators (TSHB, DIO2), and broodiness inhibitors (PRLR) in domesticated chickens.
• Upregulated expression of stress response inhibitors (NR3C1, CRHR2) in the domesticated breed.

Conclusions:

• Pituitary gene expression changes contribute to the domesticated phenotype in chickens, affecting stress response, pigmentation, development, and reproduction.
• The pituitary gland is a significant target for domestication.
• Similar pituitary transcriptome alterations may underlie domestication across diverse animal species.