Let-7 it grow
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| Researcher: |
| Dr Bernard Degnan (School of Life Sciences) |
| Funding: |
| 2000-2001 ARC ($293,000) |
| Email/Web link: |
| bdegnan@zoology.uq.edu.au |
| Faculty of Biological & Chemical Sciences |
The small gene, called let-7, is only 21-nucleotides (genetic units) long but is essential to development in the early stages of life.
Dr Bernard Degnan of the University's School of Life Sciences joined with scientists from around the world to search for the occurrence of let-7 across a wide range of species.
"The broad occurrence across animal life indicates that let-7 is important in animal development and evolution," Dr Degnan said.
The importance of this finding is not limited to understanding evolution and development but also has more practical applications.
"Due to the wide-ranging occurrence of let-7, we can also find out a lot more about how genes can be switched on and off. With this knowledge, we shall be able to understand the causes of normal and abnormal human development such as in genetic disorders and cancer," Dr Degnan said.
The large biodiversity of the Great Barrier Reef has played a key role in this search, with Dr Degnan using the UQ Heron Island Research Station as a base for investigating sponges, coral, ascidians and abalone.
The let-7 gene appears in exactly the same form in many animals including roundworms, fruit flies and also appears in three different human chromosomes. Near matches, with 20 out of 21 matching units, also appear in two other human chromosomes.
Although a gene may always be present in the DNA of a certain animal, it only has an effect on the animal once it becomes active.
Discovering when certain genes are expressed (become active) is crucial to understanding the developmental processes of life.
"A significant stage in the research occurred when members of the team observed the let-7 gene become active in roundworms passing from larval stage to adult form. Strikingly, this gene appears to be expressed in a similar developmental pattern in many animals including fruit flies, zebrafish and molluscs," Dr Degnan said.
"By comparing the genetic processes controlling development in animals with dramatically different body shapes and functions, we can move closer to an understanding of the origin and evolution of animal biodiversity."
The international team included researchers from the Australian National University, Harvard Medical School, University of California-Berkeley, California Institute of Technology, Yale University and the University of Basel, Switzerland.
Dr Degnan was recently awarded an Australian Research Council (ARC) Large Grant of more than $117,000 to continue his work in investigating how genes control development in animals.
