Researchers from the Lawrence Berkeley National Laboratory published a study Monday that found an overlap between genetic factors in mice that are linked to body weight and motor coordination.
The study, published in the journal Scientific Reports, identified genes affecting body weight and motor performance in mice, shedding light on factors contributing to the onset of neurodegenerative disease in humans. Impaired motor performance in humans is a symptom of many neurodegenerative diseases such as Alzheimer’s and Parkinson’s, according to the study.
Researchers recorded the body weights of mice and tested their ability to balance on a rotarod — a rotating rod that spins — until the mice fell off at different speeds.
The researchers observed a wide variation in the mice’s performance on the rotarod, said Antoine Snijders, a biologist and research scientist in the Berkeley Lab. The study found a correlation between body weight and motor performance — heavier mice tended to perform worse on the rotarod, he said.
Berkeley Lab geneticist staff scientist Jian-Hua Mao, another researcher in the study, said one important aspect of the study was the subjects tested. Researchers used a genetically diverse set of mice — bred under a model called the Collaborative Cross — to represent the genetic diversity of humans with greater accuracy than typical test mice.
The study did not determine whether the genes control both body weight and rotarod performance, or if mice were heavier because of genes that limited their mobility or whether the body weight itself led to poorer motor performance.
Snijders said the researchers, using genetic linkage analysis, found 14 regions in the mouse genome associated with body weight and 45 genes associated with rotarod performance, seven of which overlapped.
They found that 103 mouse genes in regions that were associated with rotarod performance and body weight overlapped with 1,766 human genes associated with body weight and neurodegenerative diseases in humans. The researchers discovered that seven genes associated with Alzheimer’s disease were also present in regions of mice genes. They also found that 48 human genes associated with obesity had significant influence on the rotarod performance of mice.
The study brings scientists a step closer to understanding neurodegenerative diseases, Snijders said, adding that identifying susceptibility genes and understanding the mechanisms behind diseases will help scientists identify areas crucial for determining a cure.
“We have this overlap between genes that contribute to body weight and genes that control motor performance and those same genes seem to be in the human population contributing to obesity and neurodegenerative disease,” Snijders said.
Mao said scientists could improve future studies in their area by using the genetically diverse mice from the Collaborative Cross model or studying the human population directly.