Is the Germline Immortal and Continuous? - Preprint

Kate MacCord and Duygu submitted a review discussing germline immortality and continuity in light of recent research on induced pluripotent stem cells and germline regeneration in several different research organisms.

We have posted a preprint of this manuscript on Zenodo, which you can download from here. If you have any feedback, we would love to hear from you! Post a comment here, or send us an email.

A)  Which component of the germline is immortal and continuous? Stars: points of change. Cells originating from germline (G) in blue, from soma (S) in yellow.  B)  Distribution of germline regeneration across animal phyla. Gray indicates the phylogenetic location of traditional model organisms which cannot regenerate the germline  in vivo  (indicated by "X"). Check marks indicate clades in which there is evidence for germline regeneration.

A) Which component of the germline is immortal and continuous? Stars: points of change. Cells originating from germline (G) in blue, from soma (S) in yellow. B) Distribution of germline regeneration across animal phyla. Gray indicates the phylogenetic location of traditional model organisms which cannot regenerate the germline in vivo (indicated by "X"). Check marks indicate clades in which there is evidence for germline regeneration.

Our work on Platynereis cell lineage is published in eLife

Access the article from here.

Cell lineage, cell cycle, and cell fate are tightly associated in developmental processes, but in vivo studies at single-cell resolution showing the intricacies of these associations are rare due to technical limitations. In this study on the marine annelid Platynereis dumerilii, we investigated the lineage of the 4d micromere, using high-resolution long-term live imaging complemented with a live-cell cycle reporter. 4d is the origin of mesodermal lineages and the germline in many spiralians. We traced lineages at single-cell resolution within 4d and demonstrate that embryonic segmental mesoderm forms via teloblastic divisions, as in clitellate annelids. We also identified the precise cellular origins of the larval mesodermal posterior growth zone. We found that differentially-fated progeny of 4d (germline, segmental mesoderm, growth zone) display significantly different cell cycling. This work has evolutionary implications, sets up the foundation for functional studies in annelid stem cells, and presents newly established techniques for live imaging marine embryos.

ML lineage tree indicating known and novel sub-lineages in  P. dumerilii , and comparison of  P. dumerilii  with the leech.

ML lineage tree indicating known and novel sub-lineages in P. dumerilii, and comparison of P. dumerilii with the leech.