Behavioral Differences Between the Wildtype and Genomic Screen Homeobox 1 Mutant Zebrafish

Andrew Booher*, Oliver Cook, Alexandra Rose Schmidt and Sadie A Bergeron, Department of Biology, West Virginia University, Morgantown, WV, 26505

Field (Broad Category): Biology (Biological & Biochemical Sciences) 

Student’s Major: Biology 

The genomic screen homeobox 1 (gsx1) gene encodes a transcription factor and is expressed by 10 hours post fertilization in some of the earliest born neurons in the zebrafish brain. Juvenile and adult gsx1 mutant zebrafish exhibit variable behavioral patterns. These mutants have been carefully compared to their nonmutant siblings to quantify the significant behavioral differences between the genotypes. Tanks with 4 individuals of each genotype (gsx1+/+ and gsx1-/-) were constructed. Videos were recorded for 3 or 5 minutes, without and with food respectively, and behavior was manually quantified for numerous parameters. The tanks are measured into three equal zones to assess overall swim patterns and tank position, and fish-to-fish distance is used to quantify shoaling behavior. Response to the addition of food in feeding trials is measured by fish position in the tank before and after food introduction. Additionally, the length and bouts of repetitive swimming behavior into the side or corner of the tank are also recorded. We also assessed spawning behavior by crossing different genotypes and counting the number of fertilized eggs produced. We have found that gsx1 mutants exhibit behavior that is more isolated and independent in nature. They lack the ability or drive to travel to the top of the tank when food is added and have more frequent bouts of repetitive swimming behavior. When crossed with non-mutant genotypes they do not produce fertilized eggs. Together these results show a degradation in social behaviors as a result of mutating gsx1. 

Funding: West Virginia University Department of Biology 

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course