RT Journal Article SR Electronic T1 Vertical transmission of tissue microbiota in Caenorhabditis elegans JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.12.06.471348 DO 10.1101/2021.12.06.471348 A1 Jun Zheng A1 Xin Meng A1 Jiahao Fan A1 Dong Yang YR 2021 UL http://biorxiv.org/content/early/2021/12/07/2021.12.06.471348.abstract AB The past forty-five years has witnessed Caenorhabditis elegans as the most significant model animal in life science since its discovery seventy years ago1,2, as it introduced principles of gene regulated organ development, and RNA interference into biology3-5. Meanwhile, it has become one of the lab animals in gut microbiota studies as these symbionts contribute significantly to many aspects in host biology6,7. Meanwhile, the origin of gut microbiota remains debatable in human8- 11, and has not been investigated in other model animals. Here we show that the symbiont bacteria in C. elegans not only vertically transmit from the parent generation to the next, but also distributes in the worm tissues parallel with its development. We found that bacteria can enter into the embryos of C. elegans, a step associated with vitellogenin, and passed to the next generation. These vertically transmitted bacteria share global similarity, and bacterial distribution in worm tissues changes as they grow at different life stages. Antibiotic treatment of worms increased their vulnerability against pathogenic bacteria, and replenishment of tissue microbiota restored their immunity. These results not only offered a molecular basis of vertical transmission of bacteria in C. elegans, but also signal a new era for the mixed tissue cell-bacteria multi-species organism study.Competing Interest StatementThe authors have declared no competing interest.