With a breakthrough discovery, researchers from the University of Oregon and Ohio State University have found a link between mutant zebrafish and Fraser syndrome.
In a recent study conducted at the UO’s Institute of Neuroscience, Jared Coffin Talbot,@@checked@@ a postdoctoral researcher at Ohio State University who received his doctorate from the UO, and UO biology professors Charles Kimmel and John H. Postlethwait@@both checked@@ found the same gene in mutant zebrafish is in Fraser syndrome.
Fraser syndrome causes many different malformations, ranging from partial webbing of fingers and/or toes, kidney abnormalities, genital malformations, complete fusion of the eyes and/or malformations of the inner and outer ear that can result in deafness. Fraser syndrome can be inherited as an autosomal recessive genetic trait.
“I started out at the U of O studying a general question,” Talbot said, “‘What genes control the development of facial skeleton?’”
He said, “To find these genes that are important to facial skeleton, the Kimmel Lab mutated zebrafish and looked for mutants that affected facial skeleton.”@@why zebra fish?@@
The researchers focused on the endodermal pouch (known as p1), near the ears in the mutant zebrafish with the FRAS1 gene; this pouch is the equivalent to the Eustachian tube found in human ears. In researching the endodermal pouch, the researchers found that it was closely related to the hearing structure defect in Fraser syndrome that causes deafness.
“We learned that the mutant gene responsible for these defects was FRAS1,” Talbot said. “When the human gene FRAS1 is mutated, it cause a severe disease called Fraser syndrome.”
He said that in some of the mutant fish, some of the skeletal elements that form during or near the late p1 stage don’t form properly. Due to malformation in the late p1 stage, where skeletal elements would normally be separated, the elements become fused together in the further stages. He and his other researchers propose that in normal development this late p1 stage holds apart the skeletal elements.
“Specifically, we learned that zebrafish FRAS1 acts in tissues homologous to the human middle ear canal to sculpt tissues homologous to the human middle ear,” he said.
Meaning that the tissues in the zebra fish FRAS1 acts the same the sculpting tissue in the human middle ear. @@what?@@
To the researchers’ knowledge, no research has been conducted on the shape of the middle ear bones in Fraser syndrome.
Although their research is more focused on the ear malformations and the loss of hearing, the research could also provide more insight into the other defects such as the webbing of fingers/toes, kidney abnormalities, genital malformations and the fusion of the eyelids. Talbot, Kimmel and Postlethwait controlled the genetic and environmental factors and found that both lead to varying skeletal defects.
“I hope that my work has provided information that will be useful to this process,” Talbot said.