Seokjin Ham^1,2, Sieun S. Kim^1,2, Sangsoon Park¹, Eun Ji E. Kim¹, Sujeong Kwon^{1 5} , Hae-Eun H. Park¹, Yoonji Jung¹ and Seung-Jae V. Lee1, *

¹Department of Biological Sciences, Korea Advanced Institute of Science and 9 Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea, 34141
²These authors contributed equally to this work.
*Corresponding author; Seung-Jae V. Lee

Aging is associated with changes in a variety of biological processes at the transcriptomic level, including gene expression. Two types of aging occur during life time: chronological and physiological aging. However, dissecting the difference between chronological and physiological ages at the transcriptomic level has been a challenge because of its complexity. We analyzed the transcriptomic features associated with physiological and chronological aging using Caenorhabditis elegans as a model. Many structural and functional transcript elements, such as noncoding RNAs and intron-derived transcripts, were up-regulated with chronological aging. In contrast, mRNAs with many biological functions, including RNA processing, were down-regulated with physiological aging. We also identified an age-dependent increase in the usage of distal 3′ splice sites in mRNA transcripts as a biomarker of physiological aging. Our study provides crucial information for dissecting chronological and physiological aging at the transcriptomic level.