Characterizing age-related features for assessing biological age and characteristics in Xinjiang Brown cattle.

BACKGROUND

Productive lifespan is a critical economic trait for both dual-purpose and dairy cows, as it determines lifetime milk production. Xinjiang Brown cattle, a dual-purpose breed widely raised in China's Xinjiang region, have a population of nearly two million and play a vital role in the local economy. However, the molecular mechanisms influencing aging and productive lifespan in Xinjiang Brown cattle remain largely unknown. In this study, we collected white blood cell (leukocyte) transcriptome data from 66 Xinjiang Brown cattle, aged 31 to 160 months, to investigate the dynamic changes in their gene expression profiles across different ages and identify genes potentially influencing their aging process.

RESULTS

A total of 1140 genes were identified as exhibiting a linear change in expression with age, while 697 genes showed non-linear changes, mainly enriched in immune and disease-related pathways. Linear genes were selected using elastic network regression to construct a transcriptomic clock and estimate the biological age of each sample. Individuals with older biological ages trend to highly express aging-related genes such as S100A8, while individuals with younger biological ages will highly express anti-aging genes such as BLVRB. We identified PGA5, LOC789748, ENSBTAG00000048555, and ENSBTAG00000050566 as crucial targets for anti-aging interventions, which exhibit reduced expression in biologically younger individuals and increased expression in biologically older ones. Performing sliding window analysis on non-linear genes, we elucidated changes in the expression of candidate genes at the age of 67 months, which are predominantly associated with endocrine pathways, such as GnRH and insulin secretion.

CONCLUSIONS

This study characterized the age-related gene expression changes in Xinjiang Brown cattle and developed a transcriptomic clock specifically for calculating their biological age. It provides a valuable tool for assessing the aging status of Xinjiang Brown cattle and identifies key genes that may influence their aging process.