Barley Anther and Meiocyte Transcriptome Dynamics in Meiotic Prophase I

Area of Science:

• Plant reproductive biology
• Molecular genetics
• Transcriptomics

Background:

• Meiosis is crucial for sexual reproduction in flowering plants.
• Transcriptional regulation governs germ cell development and meiotic recombination.
• Environmental and genetic factors influence these processes.

Purpose of the Study:

• To investigate the temporal dynamics of gene expression during barley meiosis.
• To identify key transcriptional changes and regulatory elements involved in early meiotic stages.
• To understand the role of long non-coding RNAs in meiotic progression.

Main Methods:

• Short- and long-read RNA sequencing (RNA-seq) of immuno-cytologically staged barley anthers and meiocytes.
• Analysis of temporal transcript abundance dynamics from pre-meiosis through prophase I.
• Bioinformatic analysis to identify differentially expressed genes and long non-coding RNAs.

Main Results:

• Significant transcriptional reprogramming occurs at the transition from pre-meiosis to leptotene-zygotene.
• Pre-meiotic anthers show enrichment in long non-coding RNAs (lncRNAs), which are downregulated upon entry to meiosis.
• Transcript abundance remains relatively stable in meiocytes from prophase I to metaphase I-tetrad.
• A subset of meiotic gene orthologs (24%) exhibited differential expression.
• Specific proteins like Argonautes, E3 ubiquitin ligases, and de-ubiquitinating enzymes are enriched in prophase I meiocytes.

Conclusions:

• Meiosis entry in barley involves substantial transcriptomic reprogramming, particularly the downregulation of lncRNAs.
• Meiocyte transcriptomes are remarkably stable throughout prophase I after initial reprogramming.
• Complex regulatory networks involving specific protein families orchestrate early meiotic processes.