Grafting as it pretains to coral propagation

[MrAnderson]

the selective breeding process stops but i thought F1 individuals (for such selectively-bred plants) can sometimes become able to sexually reproduce.

 

not saying they all reproduce sexually but i thought sometimes the breeding process produces organisms that can. whereas mr.a says they all can't. i'm not sure and just wanted a confirmation if possible.

 

We're talking about animals though. Plant capacity for viable polyploids is much greater than animals like corals. Plants can speciate through hybridization and the offspring are usually sterile, or else lose distinguishing characteristics, i.e. keep changing. You can't keep adding and losing whole sets of chromosomes without a phenotypic change.

 

As it would apply to corals (animals), hybrid speciation in animals is a really really really rare occurance and has been observed in fruitflies and polychaete worms. But even when the offspring are viable, they become sterile after a few generations.

 

Is it possible to happen in corals, whose genetics are poorly understood? Sure. But it's really unlikely to happen by human design, and more likely in nature by the "numbers game" of population genetics over time.

 

The poppies in our front yard are (supposedly) F1 hybrids. They come up every year, though, and since they're annuals, I can only conclude that they are reproducing sexually.

 

Bulb division is vegetative reproduction. The offspring are clones.

[jeremai]

Bulb division is vegetative reproduction. The offspring are clones.

 

Poppies are annuals in Las Vegas, we get an average of three hard frosts a year. But even in California, they're not bulbs

[tinyreef]

ok, good info. thanks!

[MrAnderson]

Poppies are annuals in Las Vegas, we get an average of three hard frosts a year. But even in California, they're not bulbs

 

oops, wrong poppy plant!

[scarf_ace1981]

i got this favia coral and was told by someone on this site that it looks grafted. do you guys agree? i just thought the different color variations grew until they met.

[Six]

no, there are faviids that naurally grow close to eachother competing for space. you dont see them often in the hobby, but that's one of them.

[supernip]

this thread moves way too fast... i cant keep up. =(

 

edit: and half of it is way over my head =/

[Caesar777]

That's natural. It happens often with those particular strains of Faviid (don't ask me to ID by species/subspecies! )

[jeremai]

I think, for the sake of argument on this thread, anyway, that a graft would be the combination of two individual polyps into a single polyp, instead of the fusion of two seperate colonies. Am I right? Please?

[MrAnderson]

I think, for the sake of argument on this thread, anyway, that a graft would be the combination of two individual polyps into a single polyp, instead of the fusion of two seperate colonies. Am I right? Please?

 

I agree!

 

That's why I thought that the original reefkeeping article describing "grafts" seemed to be no different than a zoo mat with different color polyps, rather than a true "graft".

 

I thought your analogy using fruit trees and roses demonstrated that difference, whereas the author misapplied the same analogy to his little project, which in my mind isn't analogous at all.

[Caesar777]

Yeh....In which case you can't just graft two animals together on the macro level! Again, it's the ear-rat. It may have a human ear on its back, but it's still a rat.

[Biotoper]

Although Mr. Anderson's been providing a lot of good clarification on the science, I thought I'd throw in some clarification. Hybridization is very common in plants, thru two main modes: 1) normal sexual reproduction as most think of it between two supposed discrete species - this can produce fertile offspring if the parents are from closely related species (usually described as Genus speciesA x speciesB), sometimes they are fertile, often by selfing (sexual reproduction between pollen and egg from the same parent), but if sterile, the hybrid can persist thru vegetative reproduction. 2) thru polyploidy, which is normally where the pollen and egg gametes do not halve their chromosomse as normal but have the same # of chromosomes as the parents - if these join, the resulting zygote has a chromosome # of speciesA + speciesB and can be fertile, as each species' DNA can sort of do their thing separately during meiosis (the sorting of DNA in a cell into 4 gametes, each with one copy of each chromosome). Polyploidy appears to be a common if not dominant source of speciation in many plant families such as grasses, whereas normal hybridization also appears to be a dominant source of speciation in certain groups such as orchids. Everyone still with me? Hybridization is rarer in animals, polyploidy more so, but on the other hand there are plenty of obscure animal families that have very funky genetics, and people are learning new stuff everyday. It seems if you can think of some way for DNA to get shuffled around, it's occurred in something! And with any animal group that can reproduce asexually, like coral, I would bet that there are probably plenty of hybrid populations out there in the wild, the result of a very rare successful establishment of a hybrid zygote proceeding to reproduce asexually and persist.

 

That said, this genetics lesson is pretty irrelevant to grafting. Grafting in plant and animals is simply the joining of tissue from two individuals together, often resulting in some physiological changes between the tissue as opposed to in an ungrafted individual. However, the gamete-forming tissue is from just one individual, so frex the plant's flowers do not share DNA with the grafted roots. In coral, as people said, true grafting of a single "organism" would require for example cutting two LPS polyps in half and joining the halves so you have a single polyp or frex cutting an anemone head onto another anemone's foot - this could result in significant changes in the tissue physiology due to the grafting - but I expect most of us would be disgusted by such frankenstein techniques. However, in the case of multi-polyp grafting as this article is mainly looking at (I'll refer to them as interspecific polyp colonies), I think there is still much potential for interesting interactions. I am not familar with how colonial polyps interact, such as passing nutrients and biochemical compounds between each other, but clearly there is a more or less interaction depending on the species, and this would be influenced in interspecific colonies.

 

Lastly, in relation to reintroducing grafted coral to the wild, given our poor understanding of the coral species identification, let alone intraspecific genetic variation, I would dissuade anyone from introducing aquarium organisms into the wild, grafted or otherwise, except from official propogation programs developed for reintroduction of threatened organisms into specific localities.

 

Ryan

[jeremai]

It may have a human ear on its back, but it's still a rat.

Darwin applauds.

 

Now, I haven't read the article in a few days, but the author was basically trying to make what scarf_ace1981 bought, right? Except he stuck the two colonies right next to eachother right off the bat. :::knocks on head...think, think:::

 

Wouldn't it make more sense to place the colonies apart from each other and let them grow into one another naturally? I imagine that would give them time to 'get used' to the idea of sharing the same rock. And, like it was so eloquently put a few pages back, that came fresh from my ass.

[Caesar777]

It's rarely a reasonable idea to release animals back into the wild, especially genetically-altered ones! Why?!

[jeremai]

Lastly, in relation to reintroducing grafted coral to the wild, given our poor understanding of the coral species identification, let alone intraspecific genetic variation, I would dissuade anyone from introducing aquarium organisms into the wild, grafted or otherwise, except from official propogation programs developed for reintroduction of threatened organisms into specific localities.

Right. I mentioned this as an option waaaaaaay back on the first page. It was an example of something that, perhaps, we would consider doing far in the future, when we have all our stuff figured out and know what we're doing. I don't in any way condone doing it right now - I don't even pee in the ocean, much less want to release any organism kept in a captive system.

[tinyreef]

It's rarely a reasonable idea to release animals back into the wild, especially genetically-altered ones! Why?!

actually, that's done quite a bit (not genetically-altered ones though) to rebuild reefs or biotopes damaged by man. backed by oil-money to allow off-shore drills imo.

 

i just read an article on dendronephthyas being researched on such by Benayahu. he's conducted a lot (most of what i've read so far) of such re-reefing studies, specifically with artificial structures.

[Caesar777]

That's why I said rarely. But corals? Really?

[tinyreef]

I don't even pee in the ocean, much less want to release any organism kept in a captive system.

all drains lead to the ocean, nemo.

[MrAnderson]

Biotoper made a good point: this hybrid speciation topic really doesn't have much to do with the topic of grafting.

 

Thanks for typing that all out, I'm way to lazy to articulate and infer all the "exceptions to the rule" regarding hybrid speciation and polyploidy. Rather I figured I would concentrate on the "rules".

 

What is relevant though is the topic of histocompatibility, and once again I'm not going to try and simplify another complicated topic, because frankly it's ... well, complicated.

 

The distinction of this guy's experiment from just putting two frags on a rock is that the coenenchyme of the polyps actually fuse. As he points out, this is distinct from the common occurrence of some coral species being able to tolerate growing right up against another, touching but not fusing.

 

From what I understand, and which makes sense immunologically, is that there are some established rules for coral histocompatibility. Autografts work. Allografts don't. Xenografts don't. Of course there are probably exceptions to these "rules", just like almost all biological "rules", but that seems to be in step with histocompatibility with most other animal families.

 

So what exactly is this guy doing? Are his corals properly IDed? Could his "grafting" of same-species morphs actually be just reattachment of the alternately adapted offspring of a previously asexually reproduced parent? These are my main questions, but since this is a hobby article rather than a scientific one, it'll go unanswered and in my opinion just represents phenomenology.

[tinyreef]

That's why I said rarely. But corals? Really?

well, we're talking corals. i'm not saying they do that for lobsters, fish, etc. they might but i don't know.

 

so far, most of the studies i've seen seem to be "recovery" projects due to man-made problems. loya and benayahu do other stuff but so far they seem to have a niche in re-reefing from what i've seen (pers pref? benayahu did study under loya as a grad so maybe).

[MrAnderson]

Lastly, in relation to reintroducing grafted coral to the wild, given our poor understanding of the coral species identification, let alone intraspecific genetic variation, I would dissuade anyone from introducing aquarium organisms into the wild, grafted or otherwise, except from official propogation programs developed for reintroduction of threatened organisms into specific localities.

 

Yeah I don't think any non-biologists should take it upon themselves to repopulate the reefs, but I still don't see what problem there is with using captive-bred organisms to repopulate lost ecosystems. That's the basis of many conseration efforts, why should corals be any different? Using grafted corals is an unlikely and undesirable scenario though, and that specific proposition is what led to suggesting hybrid speciation as the only risk that I thought others were suggesting...

[jeremai]

all drains lead to the ocean, nemo.

 

Not when you live off the grid in the middle of the desert.

 

But anyway, I was talking from a hobbyist standpoint, not a scientific research one. Most aquariums, public and private, were established based on conservation efforts, or include them (Sea World, Birch-Scripps, Monterrey Bay, Mystic, etc.), and almost all have re-released some form of life back into the ocean.

 

But some random dork cutting and slicing his way through RC.com shouldn't be dropping his rejects into the East River.

 

I'm just saying

[Caesar777]

Sea World?! Yick. They lose more dolphins every day than...pff. Anyway.... My main beef is this guy posing as some scientifically-minded person when it's just about $$, clearly. That, and he could at least use science in addition to his greed!

[jeremai]

I whole-heartedly agree with the second part. But Sea World... are you kidding me? Oh, wait - you're thinking of the muddy puddle in Florida, must not be talking about the sparkling tower of achievement that is Sea World San Diego...

[MrAnderson]

On the side though, marine biologists really need to learn how to spell D-N-A.

 

IMO coral scientists need to take experiments to the next level in terms of molecular biology; whenever I read a paper I feel like I'm back in my 40-year-old high school bio lab with jars of specimens and analog balances with only methylene blue at my disposal...