[Coral-List] [Cnidarian-dinoflagellate-symbiosis] genetic connectivity of Symbiodinium individuals within a single colony

[Daniel Merselis]

Hi everyone- Very interesting topic!!

It seems that possibility #1 "endogenous only" is a hypotheses which can
never be falsified, because doing so means destroying the entire colony.

Under an "endogenous only" model, how do we explain cryptic symbionts
spreading from the remote corner of a colony to eventually dominate it?
Presumably this would require distribution by means of the gastrovascular
space and independent phagocytosis events by gastrodermal cells elsewhere
in the colony. This gastrodermal space is also a route of entry for
seawater likely containing the occasional exogenous symbiont. How could the
host gastrodermal cell have a mechanism of specificity that will allow the
cryptic symbiont from some far corner of the host, but deny the exogenous
symbiont? -here I'm not talking about specificity or favor a host may have
for a particular species of symbiont, but how would the host know what's
endogenous and what's exogenous even if of the same species?

If not through independent phagocytosis, does the "endogenous only"
hypothesis require a mechanism for symbiont passing from one gastrodermal
cell to another without entering the gastrovascular cavity?

What have I gotten wrong?

Best,
Dan

Dan Merselis
PhD candidate
Rodriguez-Lanetty Lab

On Fri, Mar 22, 2019 at 10:59 AM John Ware via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Hello List, Misha, Andrew, et al (I always wonder: who is al?)
>
> Andrew states that "this same discussion has been playing out for at
> least 18 year...".
>
> Looking at papers related to this issue of trading symbionts that have
> come out over the past 10 yrs or so, I no longer see references to the
> Adaptive Bleaching Hypothesis published by Bob Buddemeier and Daphne
> Fautin in 1993 - so how about over 25 years!!
>
> John
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