Koi Fish Information Centre

See my replies below your questions:
> > In your very first post, you released “data” or at least some anecdotal information on the colors of the offspring.
I did not provide numbers or any “data” other than the general nature of what we are seeing from our initial crosses.
> > Based on that and common knowledge that offspring resemble their parents to > some degree, I don’t think it was a stretch for me to say that as these > “pink”, “bluish” and “gold” mutated offspring cross breed, the eventual > color will end up a grayish-brown.
The Transgene is a dominant gene, according to the literature at this point. And, if it holds true that the trait is dominant-lethal, then any fish that gets 2 copies of the genes do not develop at all. If the danio appears normal (no color), then the gene isn’t present at all, and the fish is “wild type” normal in all respects, and the gene will not show up in subsequent generations.
This would not be the case if the gene was recessive, but it is a dominant trait. The colors don’t really “mix” as the trait isn’t co- dominant–at least from what has been reported to date…I can say that it is behaving like a dominant trait, which is what they would want in developing such an organism.
> recessive glofish gene which may appear in subsequent generations? I know > generation skipping genes and recessive genes becoming dominant in future > generations happens with us humans.
A recessive gene can’t become dominant in subsequent generations…recessive is always recessive, and the only way it shows up later is when an individual receives two recessive genes, which is what happens in many human diseases.
I’m still not opposed to them, per se, but your original post was > about distributing experimental offspring and acquiring other fish for > experimental purposes, including some hybrid cross breeds (bloody parrot) > that many in the hobby frown upon.
We are only crossing the danios to examine inheritance of the color in the Glos and to document what happens when different GMO glos are crossed with one another.
While I’m not a geneticist, I do have a > little biology background and know that in future years someone could think > they are breeding pure zebra danios, only to have a percentage of the > offspring come out with the glofish gene in them once the gene gets into the > mainstream.
Because the trait is dominant, this cannot happen. Even the 1/4 of normal-looking danios from glowing parents are 100% normal danios, with no GMO gene.
Over time, the pure bred zebra danio could be lost forever > according to some of the published scientific articles opposing GMO > (genetically mutated organisms).
GMO = Genetically modified, not genetically mutated. A mutation is a naturally occuring phenomenon, and 99.9999% of the time, results in death of the individual. Mutations have been important in the development of strains, but, usually we see that a human has somewhat protected the “new” one from predation, etc. Think of how a fancy- tail guppy could compete in the wild as compared to the “feeders” which are wild type.
> We already have enough “mutt” fish in the industry, including the “fancy” > fish from many species that are usually cross bred and inbred to develop the > “fancy” status… without telling people that this cross breeding and > inbreeding, while mutating the external appearance of the fish, also mutates > the internal organs of the fish, resulting in fish that are much more prone > to health problems, swim bladder issues, etc.
Cross-breeding usually produces an organism with increased fitness (called heterosis), and this is why many cultured species are a cross between two breeds/strains/lines. Cross-breeding maximizes the amount of heterozygosity of the animal, resulting in a superior performer. Crossbreeding different species is of even greater benefit in maximizing heterosis. Keep in mind that “species” are determined by man, and may not represent the actual genetic lineage of the organism. Many species are now being reclassified based on new DNA evidence.
It’s not until unsuspecting > buyers (namely moi) purchase these “fancy” fish, that they find out all of > the health issues they have to deal with and the shortened lifespans of > these fish.
This is not always the case. I’m sure that problems can arise, but line-breeding and cross-breeding and inbreeding do not cause problems unless you are increasing the number of recessive, deleterious alleles.
Inbreeding is breeding genetically related individuals, and this can result in the opposite effect of cross breeding. Not always, but it can result in “inbreeding depression”
I simply do not want you distributing the offspring to the general > population. Further, based on your zeal to trade the fish for other > species, I’m presuming you would not have thought twice about trading the offspring from any experiments done with those fish.
The “experiments” at hand would be to examine specific things for each species…the glofish is an odd one because it is easy to breed & track the genetics of the color. > > At least one of the fish mentioned in your wish list is already a frowned > upon crossbred hybrid… the blood parrot.
The blood parrot would be evaluated to examine the reported sterility and fertility of the fish. I feel that this is an important biological question, esp when more and more reports are suggesting these fish are fertile. So, does it differ between individuals? We don’t know, and this would be very interesting to find out.
Some hate the parrot, some love it, but it has proven to be a very hardy and welcome addition to many tanks…and has remained a part of the hobby for those reasons. (supports the notion of heterosis in crossbred animals)
Fishes such as the galaxy rasbora, etc, would only be bred in their pure form without any plans to be a Dr. Frankenstein. I FIRMLY believe that captive propagation will save the habitat. Same thing was reported for the “new” cardinal fish (marine fish) added to the hobby years ago. Captive propagation of this fish has made it more widely available, cheaper, healthier, and with less impact on the wild stocks.
> If you were attempting to acquire these endangered fish for the purposes of > pure breeding them to maintain their pure status and get the fish out of the > endangered list, that was not stated in your original post which was all > about cross breeding since that seemed to peak the interest of your > students.
If the galaxy or others are listed as endangered, two schools of thought 1. breed them if you have such ability 2. hope we can stop importation, which isn’t likely
Cross-breeding of the colors of one species of Danio is the only cross-breeding experiment I mentioned.
Cross-breeding isn’t the only thing to spark someone’s interest, but it sure beats counting a million fruit flies.
Adding a variety of species that we can captively propagate will show the students the wonder of the aquatic world, both GMO, cross-bred, and natural…
We have specific reasons for wanting to evaluate these species, and my Dr. Frankenstein nature only applies to the already GMO danio, and with that fish alone.

Category: Philippines Internet Koi Society