Search Results

Showing 1-6 of 6 Resources
  • Gene Switch

    Gene Switch


    (1 min 15 sec) Regulatory "switches" are found upstream from a gene. Regulatory molecules bind to the switches and recruit RNA polymerase to bind to the gene's promoter region, increasing the transcription of the gene into messenger RNA.

  • Paintbrush Gene

    Paintbrush Gene


    (49 sec) In two related Drosophila species, a so-called paintbrush gene is activated to "paint" the pigment on the body. In one species, an extra switch activates the gene, resulting in spotted wings.

  • Pitx1 Expression

    Pitx1 Expression


    (55 sec) In the stickleback fish, pelvic-fin reduction resulted from changes in the regulatory switch elements of the Pitx1 gene. In the marine ancestor, the Pitx1 gene is activated in the pelvic-fin region during development to generate the fin. In the pelvic-reduced stickleback, the regulatory switch that normally turns on the Pitx1 gene is either missing or non-functional.

  • Wing Morph

    Wing Morph


    (29 sec) This "morph" animation demonstrates how the expression of a particular toolkit gene in a butterfly larva corresponds to the location of the wing eyespots in an adult butterfly.

  • The Y Chromosome

    The Y Chromosome


    (2 min 46 sec) The Y chromosome has been likened to a hall of mirrors because its sequence contains many sections that appear to be palindromes. These palindromes provide a clue to some interesting events that may have occurred during the course of the chromosome's evolution.

  • Evolution of the Y Chromosome

    Evolution of the Y Chromosome


    (5 min 39 sec) How did the human Y chromosome become so small relative to its X counterpart? This animation depicts the 300-million-year odyssey of the sex chromosomes that began when the proto X and Y were an identical pair.