Differences in translational dynamics between lactation and nonlactation period in dairy goat mammary glands

Dairy goat milk possesses substantial nutritional value, and comprehending the regulatory mechanisms of lactation is crucial for enhancing the milk production performance of dairy goats. During lactation, the mammary gland of dairy goats exhibits marked alterations in the expression of numerous genes. While extensive research has clarified the mechanisms governing mammary gene expression at the transcriptional level, the regulation of these genes at the translational level remains largely unexplored. In this study, ribosome-sequencing and RNA-sequencing analyses were conducted on the mammary glands of dairy goats during both the nonlactation and lactation periods. The findings revealed that the lactation process significantly influences both the translation and transcription of genes, with a notably higher overall translation efficiency (TE) observed during lactation compared with the nonlactation period. Transcription and translation collaboratively regulate gene expression in mammary tissues, thereby constructing a complex regulatory network. We systematically identified small open reading frames (sORF) in mammary glands, demonstrating that upstream open reading frames suppress the translation of main open reading frames. The RNA-binding proteins (RBP) were found to significantly influence the gene TE. Notably, the sORF3917 located in the 5' untranslated region of the FASN gene was shown to regulate fatty acid synthesis-related gene expression, highlighting the role of sORF in lactation. This study presents novel insights into the regulatory mechanisms of lactation in dairy goats and provides valuable genetic resources for gene editing and breeding strategies aimed at enhancing dairy goat production.