Organisms that have more than two parents

  1. Do you mean genetically or in terms of the number of individuals rearing and taking care of a given offspring?

    Edit: Challenge accepted, I’ll try to answer both with one species.

    Marmosets sometimes live in polyandrous groups where more than one male participates in rearing the offspring of a given female. Furthermore, multiple males may copulate with said female. Now, here’s where the genetic bit may come in. Tetragametic chimerism is a form of genetic mosaicism acquired in utero. Two eggs are released, two separate sperm fertilize each, and then the eggs fuse. If the two sperm originate from two different fathers, technically there are three parents. “This is particularly true for the marmoset. Recent research shows most marmosets are chimeras, sharing DNA with their fraternal twins. 95% of Marmoset fraternal twins trade blood through chorionic fusions, making them hematopoietic chimeras.”

    Edit: formatting, plus I misspelled a word and it made me grumpy

  2. Just off the top of my head I know there are prokaryotes that can absorb and express genetic material from another cell. Although this isn’t exactly like ‘having another parent’, one organism could feasibly have it’s own genetics from a variety of sources. This process is known as Transformation. I learned it from this experiment in Biology many years ago.

  3. One way a seedless watermelon is produce is exposing a regular watermelon to a mutagen derived from the sap of the crocus flower. this results in plants with 4 sets of chromosomes vs the normal 2 sets. the tetraploids are then crossed with normal 2 set plants witch results in plants with 3 sets of chromosomes or tripoloid. the resulting Watermelon plants develop seedless fruit. Similarly seedless banana are also Triploid. commercial stew berries on the other hand have been mutated and crossed so many times that some plants have 10 pair of chromosomes

  4. There was an article in science a few months ago about a new procedure called mitochondrial DNA replacement therapy. It involves taking a females egg, and replacing the mitochondrial DNA with some from a donor. The resulting offspring have DNA from the mother, the father, and the donor. It can be used to fight genetic diseases in the mitochondrial DNA, and can help to treat infertility. It is currently being tested in monkeys.

    Sorry for those of you without subscriptions who can’t see the article.

  5. Getting the proper number of chromosomes is a major barrier to having more than two genetic contributors.

    There are polyploid animals (meaning they have more than two copies of each chromosome), but stable polyploidy is rare because it interferes with sexual reproduction. Monoploids are also often sterile (edit: I don’t know much about bees). Essentially, as a higher-order animal, if you don’t have the right number of chromosomes it is difficult to breed. The usual exceptions apply to some flatworms, etc.

    In addition, for any animal with an egg-cell the egg depolarizes as soon as it detects fertilization by sperm, thereby preventing any other competing sperm from entering. This is an important feature, as multiple sperm would mean multiple male chromosomes and instable polyploidy, leading to death or sterility. Not a good outcome.

    As for plants, they can get all kinds of crazy with their number of chromosomes. Theoretically this would mean that they could freely reproduce with multiple gametes… little sex-cell orgies, if you will. Plants are not my speciality, but as I recall from my botany class about eight years ago they do have other barriers to fertilization.

    So, in answer to your question, and based on numbers of chromosomes only, animal gametes cannot be stably fertilized by more than one sperm, while plants could theoretically be gamete swingers.

    *edit:clarified a bit

  6. Though this may foot the bill it is quite arcane.

    What it describes is an organism, S.pandora, that reproduces both sexually and asexually. In sexual reproduction the male attaches to a feeding stage and impregnates a budding female. The female then separates from the feeding stage and attaches herself to another host, where the larva in her develops.

  7. Well, clones can have multiple parents at multiple levels. There’s the DNA doner, who has two parents, so that could count as one to three biological parents. Then you have the egg donor; she donates mitochondrial DNA. Then there’s the surrogate, and after the offspring is born, he or she could have one, two, or more adoptive parents.

  8. Generally no. Although having one parent is not particularly rare (parthenogenesis in animals, self-fertilization in plants). In humans it is possible for an egg to be fertilized by multiple sperm (polyspermy), however this almost always leads to a non-viable fetus.

    source
    also, MA and PhD in biology.

  9. A little late to the party but I just read an article for a biology class on zygotes having 3 sets of parental DNA due to a mitochondrial disease in the biological mother.

    Since you can only obtain mitochondrial DNA (which is separate from the rest of your DNA) from the maternal side, if there’s a family history of mitochondrial illness then the mother has little chance of having a child with functional mitochondria.

    Enter a donor with healthy mitochondria: their mitochondrial DNA is transplanted to the egg cell either before or following fertilization and viola! you technically have 3 parents.

  10. Well, there are many animals that use “communal mating” where many males fertilize a females eggs (ex: salmon) but I do believe that in the majority of animals it would be impossible as it would cause issues in the number of chromosomes supplied. So even if multiple males fertilize, there is only one true father.

  11. Yes, the Tralfamadorians have done much research into this.

    In all seriousness there are many species in which multiple gametes unit in order to form a zygote. Also many organisms which go through alternations of generations could be said to have multiple parents. DIatoms and Apicomplexa are just a few who have such odd reproductive cycles.

    http://moodleshare.org/mod/book/view.php?id=2124&chapterid=275
    http://en.wikipedia.org/wiki/Apicomplexa