Metamorphosis-associated immune system maturation in Senegalese sole

Area of Science:

• Developmental biology
• Immunology
• Endocrinology
• Aquatic biology

Background:

• Thyroid hormones (THs) are crucial for vertebrate development, particularly metamorphosis.
• The role of THs in immune system maturation in developing fish is not fully understood.
• Teleost fish, like the Senegalese sole, undergo significant TH-driven metamorphic changes.

Purpose of the Study:

• To investigate the role of thyroid hormones in immune system development during teleost metamorphosis.
• To identify immune-related genes regulated by thyroid hormones in Senegalese sole.
• To analyze the binding sites of thyroid hormone receptors on candidate immune genes.

Main Methods:

• Differential gene expression analysis across six developmental stages of Senegalese sole.
• Clustering analysis to correlate immune gene expression with hypothalamus-pituitary-thyroid (HPT) axis genes.
• Promoter region analysis of candidate immune genes to identify thyroid hormone receptor binding sites (TREs).

Main Results:

• Metamorphosis involved the differential expression of 8145 genes.
• 133 candidate immune genes were identified as potentially TH-regulated.
• 84 candidate genes possessed putative TREs, with two consensus sequences identified: one TRα-exclusive and one common to TRα and TRβ.

Conclusions:

• Thyroid hormones play a significant role in regulating immune gene expression during teleost metamorphosis.
• Specific thyroid hormone receptor binding sites (TREs) were identified in the promoter regions of TH-regulated immune genes.
• The findings provide insights into the molecular mechanisms linking thyroid hormone signaling and immune system development in fish.