Russell SL, Chappell L, Sullivan W (2019) A symbiont’s guide to the germline. In: Current Topics in Developmental Biology. Elsevier, pp 315–351
Russell SL, Chappell L, Sullivan W (2019) A symbiont’s guide to the germline. In: Current Topics in Developmental Biology. Elsevier, pp 315–351
Russell SL, Chappell L, Sullivan W (2019) A symbiont’s guide to the germline. In: Current Topics in Developmental Biology. Elsevier, pp 315–351
Russell SL, Chappell L, Sullivan W (2019) A symbiont’s guide to the germline. In: Current Topics in Developmental Biology. Elsevier, pp 315–351
Abstract
Microbial symbioses exhibit astounding adaptations, yet all symbionts face the problem of how to reliably associate with host offspring every generation. A common strategy is vertical transmission, in which symbionts are directly transmitted from the female to her offspring. The diversity of symbionts and vertical transmission mechanisms is as expansive as the diversity of eukaryotic host taxa that house them. However, there are several common themes among these mechanisms based on the degree to which symbionts associate with the host germline during transmission. In this review, we detail three distinct vertical transmission strategies, starting with associations that are transmitted from host somatic cells to offspring somatic cells, either due to lacking a germline or avoiding it. A second strategy involves somatically-localized symbionts that migrate into the germline during host development. The third strategy we discuss is one in which the symbiont maintains continuous association with the germline throughout development. Unexpectedly, the vast majority of documented vertically inherited symbionts rely on the second strategy: soma-to-germline migration. Given that not all eukaryotes contain a sequestered germline and instead produce offspring from somatic stem cell lineages, this soma-to-germline migration is discussed in the context of multicellular evolution. Lastly, as recent genomics data have revealed an abundance of horizontal gene transfer events from symbiotic and non-symbiotic bacteria to host genomes, we discuss their impact on eukaryotic host evolution.
Keywords
endosymbiosis, germline, vertical transmission, cell-to-cell transfer
Subject
Biology and Life Sciences, Cell and Developmental Biology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.