Title
Variation of mutational burden in healthy human tissues suggests non-random strand segregation and allows measuring somatic mutation rates.
Abstract
The immortal strand hypothesis poses that stem cells could produce differentiated progeny while conserving the original template strand, thus avoiding accumulating somatic mutations. However, quantitating the extent of non-random DNA strand segregation in human stem cells remains difficult in vivo. Here we show that the change of the mean and variance of the mutational burden with age in healthy human tissues allows estimating strand segregation probabilities and somatic mutation rates. We analysed deep sequencing data from healthy human colon, small intestine, liver, skin and brain. We found highly effective non-random DNA strand segregation in all adult tissues (mean strand segregation probability: 0.98, standard error bounds (0.97,0.99)). In contrast, non-random strand segregation efficiency is reduced to 0.87 (0.78,0.88) in neural tissue during early development, suggesting stem cell pool expansions due to symmetric self-renewal. Healthy somatic mutation rates differed across tissue types, ranging from 3.5 x 10(-9) /bp/division in small intestine to 1.6 x 10(-7)/bp/division in skin.
Year
DOI
Venue
2018
10.1371/journal.pcbi.1006233
PLOS COMPUTATIONAL BIOLOGY
Field
DocType
Volume
Stem cell,Biology,Coding strand,Mutation rate,Immortal DNA strand hypothesis,Somatic cell,Cellular differentiation,Genetics,Germline mutation,Mutation
Journal
14
Issue
Citations 
PageRank 
6
0
0.34
References 
Authors
2
2
Name
Order
Citations
PageRank
B. Werner150.75
Andrea Sottoriva271.87