Unique Sertoli cell adaptations support enhanced spermatogenesis in chickens.

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genomics

Background:

• The cellular mechanisms behind chicken testicular development and high sperm density are not well understood.
• Understanding poultry testicular molecular characteristics is key to explaining their enhanced spermatogenesis.

Purpose of the Study:

• To profile the single-cell transcriptome of chicken testes from hatching to maturity.
• To identify molecular drivers of germ cell development, Sertoli cells, and Leydig cells.
• To compare chicken testicular adaptations with other species.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) of chicken testes.
• Bioinformatic analysis of transcriptional dynamics.
• Comparative genomics across species.

Main Results:

• Identified dynamic transcriptional changes in germ cell fate and somatic cell development.
• Discovered that Sertoli cells are the dominant somatic cell type and exhibit sustained proliferation post-maturity in chickens, unlike mammals.
• Revealed an enriched cell-cell interaction network in chicken testes, particularly involving Sertoli cells (e.g., TGF-β, BMP, EGF, activin).
• Found that cAMP responsive element binding protein 5 (CREB5) is crucial for Sertoli cell function and that circadian rhythms regulate Leydig cell development and testosterone secretion.

Conclusions:

• Chicken testicular adaptations include sustained Sertoli cell proliferation, a rich signaling network, and regulation by CREB5 and circadian rhythms.
• These unique features provide a framework for understanding enhanced spermatogenesis in poultry.
• The findings have significant implications for poultry reproductive biology and development.