Genome Studies of Slug Might be Applicable to Humans

Identifying the function of genes in a microscopic slug might help scientists piece together the human genetic puzzle.

Researchers at Baylor College of Medicine are collaborating with European scientists to decode the genome, or genetic blueprint, of a soil amoeba called Dictyostelium.

"This single-celled slug is only about a millimeter long, and its genome is about one percent of the size of the human genome," says Dr. Adam Kuspa, Baylor associate professor of biochemistry. "But its small size and fast development cycle are ideal for studying mutations that might provide clues to the functions of similar genes in humans."

Dictyostelium consists of only six chromosomes and approximately 8,000 genes. The DNA in those genes comprises 34 million pairs of chemicals called bases that contain instructions for the role each gene plays.

By "knocking out" or deleting a gene and observing the effect of the mutation on Dictyostelium's development, Dr. Kuspa can determine the gene's function. It takes only a month to generate a mutation in Dictyostelium, but in a more complicated genome, such as that of a mouse, the process can require six months to a year.

"We have developed methods that enable one laboratory researcher to mutate 100 Dictyostelium genes within a month," Dr. Kuspa says. "That's not possible with mammals."

Kuspa's team of researchers is analyzing the genetic information on three of the Dictyostelium chromosomes. The other three chromosomes are being studied by collaborators at the Sanger Centre in Cambridge, England, and the Institute for Molecular Biotechnology in Jena, Germany. The project is expected to be completed within three years.

The Dictyostelium research is being conducted at Baylor's Human Genome Sequencing Center, where scientists are studying some of the 100,000 genes and 3 billion base pairs that make up the human genome.

"We expect that approximately 1,000 genes in Dictyostelium will be comparable to genes in humans for which there is little functional information," Dr. Kuspa says. "What we learn about mutations of those genes might help us understand what causes certain diseases in humans." Dr. Kuspa's research is funded by the National Institute of Child Health and Human Development.

- B.J. ALMOND

---

©2006 Texas Medical Center

---

E-Mail: tmc-info@tmc.edu
URL: http://www.tmc.edu/tmcnews/10_01_99/page_09.html