Carnivorous plant packs big wonders into tiny genome

Feb 25, 2015

Credit: Enrique Ibarra-Laclette, Claudia Anahí Pérez-Torresand Paulina Lozano-Sotomayor

By Phys.org

Great, wonderful, wacky things can come in small genomic packages.

That’s one lesson to be learned from the carnivorous bladderwort, a plant whose tiny genome turns out to be a jewel box full of evolutionary treasures.

Called Utricularia gibba by scientists, the bladderwort is a marvel of nature. It lives in an aquatic environment. It has no recognizable roots. It boasts floating, thread-like branches, along with miniature traps that use vacuum pressure to capture prey.

A new study in the scientific journal Molecular Biology and Evolution breaks down the plant’s genetic makeup, and finds a fascinating story.

According to the research, the bladderwort houses more than several well-known plant species, such as grape, coffee or papaya—despite having a much smaller genome.


Read the full article by clicking the name of the source located below.

5 comments on “Carnivorous plant packs big wonders into tiny genome

  • What does # of genes and genome size correlate to? I read somewhere rice is huge. Humans are relatively small.

    What are the mechanisms or selection pressures to grow or shrink it?



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  • @OP link – In the realm of DNA gain, the study found that U. gibba has undergone three duplication events in which its entire genome was replicated, giving it redundant copies of every gene.

    What this is saying is that its genome was duplicated giving it a spare copy of genes as a polyploid. –
    http://www.polyploidy.org/index.php/Information:What_is_polyploidy
    Polyploidy is the process of genome doubling that gives rise to organisms with multiple sets of chromosomes. The term ploidy (see glossary for this and other related terms) refers to the number of complete genomes contained in a single cell. In general, polyploid organisms contain a multiple or combination of the chromosome sets found in the same or a closely related diploid species. Polyploidy can arise from spontaneous somatic chromosome duplication, or as a result of non-disjunction of the homologous chromosomes during meiosis resulting in diploid gametes

    Mutations of these genes were actively selected, while unneeded spare and unused copies, were also being deleted.



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  • I read the article and I don’t think it’s about the polyploidy of this particular species: they quite clearly state that the size of the genome is very small compared to the number of genes -the gene density in the genome is unusually high, in other words.
    As for why or how it may be beneficial to this plant to have a high gene density, I don’t have a clue…



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  • Lorenzo Feb 26, 2015 at 1:08 pm

    I read the article and I don’t think it’s about the polyploidy of this particular species:

    The duplication of the genome is polyploidy.
    It is the deletions which then reduce the numbers.

    As for why or how it may be beneficial to this plant to have a high gene density, I don’t have a clue…

    Chromosome pairs and gene numbers are very variable – especially in plants. The number of genes on a chromosome is also variable.

    http://en.wikipedia.org/wiki/List_of_organisms_by_chromosome_count



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  • Chromosome pairs and gene numbers are very variable – especially in plants. The number of genes on a chromosome is also variable.

    Yes I know that. Also, variation in ploidy in plants are often far less “devastating” than in mammals.

    The duplication of the genome is polyploidy.

    Ploidy is strongly related to the number of copies of your set of chromosomes you hold. Mammals are diployd, plants often are multiployd.
    The duplication of the genome (or parts of it) doesn’t automatically mean messing with the ploidy of an organism.
    The information is in your original quote:
    Polyploidy is the process of genome doubling that gives rise to organisms with multiple sets of chromosomes.
    You can, theoretically, duplicate the whole genome of an organism by writing two copies of every gene in each single chromosome, but that doesn’t touch the ploidy. This kind of duplication, though, is often restricted to sections of the genome and not the whole of it.

    By reading the article, I found no explicit reference to the ploidy of the plant, but it seems to be about the large number of genes for the amount of bases. At least, if I understand correctly that “the size of the genome” refers to one only copy of it.
    If the plant is 2-, 3- or 163-ployd, I don’t know, but I don’t think it’s immediately relevant for the article’s focus.



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