Deciphering teleost testis development throughout the annual cycle: Insights from transcriptomic features and thyroid...

Area of Science:

• Reproductive Biology
• Endocrinology
• Aquaculture Science

Background:

• Teleost testis development and spermatogenesis are seasonally regulated, involving complex cellular and molecular changes.
• The precise molecular mechanisms governing these annual reproductive cycles remain incompletely understood.

Purpose of the Study:

• To construct an integrated histological and molecular landscape of S. schlegelii testis development across its annual reproductive cycle.
• To elucidate the molecular pathways and key regulators involved in critical developmental transitions.

Main Methods:

• Histological analysis of testis development stages.
• Transcriptomic and proteomic profiling.
• In vivo experiments to assess the effects of thyroid hormone T3.
• Protein-protein interaction assays.

Main Results:

• The transition from the Rg to the E_Dif stage is a critical period, involving cell cycle, microtubule dynamics, and thyroid hormone signaling.
• Thyroid hormone T3 accelerates germ cell meiosis and cell cycle progression, enhancing testis development.
• The thyroid hormone receptor thrb regulates cell cycle and meiotic gene expression and interacts with RXRBA and RXRBB transcription factors.

Conclusions:

• This study provides a comprehensive molecular understanding of the annual cycle of teleost testis development.
• Thyroid hormone signaling plays a crucial role in regulating spermatogenesis and testis maturation in teleosts.
• Findings may inform strategies for optimizing testicular development and spermatogenesis in aquaculture.