Department of Biological Sciences

School of Natural Sciences and Mathematics

Faculty Profile: Robert Marsh

A quick scan of the book shelf of Robert Marsh, Ph.D., associate professor and associate head of the Department of Molecular and Cell Biology and chairman of the Undergraduate Education Committee in biology, reveals titles such as Recombinant DNA, Protein Sequence Analysis and Cross Linking for Better Results.

This kind of information taken out of context could make Marsh appear to be the kind of scientist with plans to change the world by merging DNA to create, ultimately, an improved product, a super race.

Now breathe a collective sigh of relief. For those of you who might not be ready to bring in the clones – or any other mutant animals – Marsh directs his genetic manipulations on plants.

“Most people in biology have their interests in animals and from the molecular standpoint, that’s where my research interests lie as well. But I think that plants always attracted me a little more. Maybe it’s because you can put them in one place and they’ll stay there,” Marsh said dryly. “I wouldn’t be happy without some work with plants to augment the molecular research with an animal-relevant system.”

Sitting in his office, one sees – perhaps after the bookshelf – two large window frames – each roughly 4-feet-by-8-feet – filled halfway to the ceiling with glass jars capped with aluminum foil that show glimpses of green growth inside.

“I have my windows here. They cycle annually between nearly empty and full of mason jars, in which I have orchid seedlings. What you see there is the result of about a 20-year breeding program. It represents an attempt to produce commercially viable cut flower and potted plants using a genus from Mexico that has not had much work done on it in the past, but offers lots of potential,” Marsh said.

“There are about 15 species of the genus, called Barkeria. It is related to the big, showy Cattleya orchids that used to be the big corsage orchids years ago,” he said.

If at first you don't succeed...

Marsh is something of an expert on orchids. His research has led him to believe that some pretty good money will be made someday if these Mexican orchids can be developed and commercialized.

“The first 10 years of hybridization produced some pretty good results, but it came to a sterile dead-end. The offspring were female fertile but male sterile, and you can’t get very far that way,” he said laughingly.

“So, I had to go back to the drawing board, pick up new parents and repeat the breeding with alternate species.”

“I didn’t ever want to make crosses where I didn’t have the very best parents,” he continued. “Fortunately, I was able to put my hands on really good stock and that has formed the nucleus for the breeding.

“Now in the past few years there have been several awards to the crosses and the progeny of the crosses, both to me and to other growers. They’ve been tried and grown successfully in California, so we have some commercial experience in growing as well as hobbyist experience. I would say that is one of the things that I’m happiest about, in terms of the results. And it represents classic biology.”

While Marsh’s quest to build the perfect orchid comes with an economic incentive, it’s largely a side venture compared with all he does for the university.

“My main research in the laboratory has dealt with understanding how the nuclear structure is put together inside cells,” Marsh explained.

“We used to think that there is an underlying matrix of proteins to which the chromosomes are attached for gene expression, for regulation, for organization, replication, and so forth,” Marsh said. “And that’s been a hard thing to get a handle on and prove, ‘Here are the matrix proteins and this is what they form and this is how they interact with the chromosomes.’

“It’s been a controversial area, and the dust really hasn’t fully settled. But it seems that there are connecting, underlying elements in the nucleus,” Marsh revealed. “Maybe not as pervasive within the nuclei as to form a fibrous network, but the DNA is constrained in loops with protein paper clips holding the strands of DNA to allow for regulation, expression, etc.

“In studying that, we have actually gone off on a tangent that has become our main object of study in the last five years. And that was the discovery of the enzyme transglutaminase -- in the model organism that we are using, the slime mold Physarum.

“Transglutaminase,” Marsh continued, “has the function of linking two separate proteins together through a covalent bond. A specific type of covalent bond called an isopeptide bond.

“This is something that occurs when blood clots, to stabilize the clot. It occurs in your organs, in the extracellular matrix that the cells are embedded in to help give your organs their shape and structural stability. It’s one of the factors that link the molecules of your hair together to give it form and texture.

“It would be analogous to glue, in fact, the bonds this enzyme makes,” he said.

Mapping out courses of action

In addition to his research, Marsh enjoys shaping policy when it comes to the biology curricula in his role as chairman of the Undergraduate Education Committee.

“Two of my major roles are interacting with undergraduate advisors and crafting and moving undergraduate majors' programs along within the department,” Marsh said.

“In 2001 we added a major in molecular biology, and, this year, developed two streamlined double majors pairing molecular biology with business administration or crime and justice studies. Theses possibilities mirror double majors with biology that were developed earlier.

“The department also has a fast track to the D.O. degree in conjunction with the School of Osteopathic Medicine in Fort Worth. We are always on the lookout for ways to better serve our undergraduates," Marsh said.

  • Updated: February 6, 2006
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