Creepy-Crawly Critters

Friend or Foe?

In the world of cutting-edge medical research, roundworms, mice, rats, and fruit flies are star performers. Model genetic organisms such as the roundworm C. elegans and the fruit fly Drosophila share many biological properties with humans but are less complicated genetically, have a short life cycle, are easy to maintain in a laboratory setting, and lend themselves to detailed genetic mapping.

A Balm for Every Wound

The recent discovery of wound-healing genes in Drosophila by a team of UC San Diego biologists may hold clues for treating human skin ailments, such as psoriasis, eczema, and severe dry skin. Another application might be to build a better bandage—containing compounds to promote wound healing.

The researchers identified eight genes never before thought to play a role in wound healing that are called into action near the areas where wounds occur. Many of the same genes that regulate biological processes in the hard exoskeleton, or cuticle, of the fruit fly also control processes in human skin. The next step is to see whether the eight genes identified by the researchers play a comparable role in humans.

Combating Cholera

The worst cholera epidemic in recent history, which occurred after the 2010 earthquake in Haiti, killed more than seventy-nine hundred people and hospitalized hundreds of thousands more. Working with fruit flies, mice, and cultured human intestinal cells, biologists at UC San Diego identified an underlying biochemical mechanism that makes the cholera toxin so deadly. They discovered that the toxin reduces the delivery of proteins to molecular junctions that normally hold intestinal cells together. These findings could guide the development of new anticholera therapies.

Checking Nerve Cell Quality

Horizontal gaze palsy with progressive scoliosis (HGPPS) affects vision and causes an abnormal curvature of the spine. People with this condition are unable to move their eyes from side to side. The disorder is associated with the defective production of a neuron’s protein guidance receiver, which disrupts the transmission of signals from the brain to the eye.

Biologists at UC San Diego recently discovered a “quality check” system for neurons in the laboratory roundworm C. elegans that uses two proteins to squelch the signals from defective neurons and marks them for either repair or destruction. This finding and subsequent research could provide clues to treatment for HGPPS and other neurodevelopment disorders.

The quality-check system consists of two parts: a protein cleaning machine containing the protein EBAX-1, and a protein assembly helper called heat-shock protein 90 (hsp90). The research team showed that the defective human protein associated with HGPPS can interact with EBAX-1 proteins. Further studies are planned to investigate the action of EBAX-1.

Appropriate Technology

While C. elegans is a researcher’s best friend, intestinal roundworms are a devastating fact of life in the world’s poorest countries. Developing and delivering expensive anti-roundworm treatments is not a practical solution.

In 2013, the Bill and Melinda Gates Foundation awarded a two-year, $1 million grant to UC San Diego biology professor Raffi Aroian to explore an alternative approach. Aroian’s idea is to develop strains of bacteria possessing a crystalline protein that is toxic to parasitic roundworms. The bacteria could be easily consumed in yogurt and soybean dishes.

Biology's Big Picture

UC San Diego life sciences are seventh best among top research universities around the world, according to the 2013 Academic Ranking of World Universities by Shanghai Jiao Tong University. Research teams in the Division of Biological Sciences continue to make breakthroughs that hold promise for solving some of the world’s the most perplexing and urgent issues, from developing new treatments for cancer and diabetes to removing toxic waste from the environment, from protecting the world’s food supply to exploring the diseases of aging and the brain, from creating sustainable biofuels to maintaining the planet’s biodiversity.