Exploring adipose biology in zebrafish

Adipose tissue plays a key role in metabolic homeostasis. Adipose tissue functions are associated with various pathological conditions including obesity, insulin resistance, and other metabolic complications. Understanding the normal regulation of adipose tissue formation and homeostasis is imperative to understanding the pathologies associated with a decrease or increase in adipose tissue. We have undertaken an unbiased forward genetic screening to identify novel genes that affect lipid storage in zebrafish adipose tissue. We aimed to clone and characterize gene(s) responsible for sans suet (sns) mutant. We utilized next generation sequencing analysis and obtained four candidate variants that may have genetic linkage with sns mutation. The targeted sequencing revealed that the candidate variant on chromosome 5 (hdr gene) was heterozygous in sns mutant fish. We hypothesize that the region near the hdr gene may have a stretch of a homozygous region that may be linked to sns phenotype. In addition, our goal was to develop transgenic reporter and molecular tools to manipulate gene function for the study of adipose biology in zebrafish. We aimed to create a transgenic reporter line that expresses mCherry exclusively in adipocytes. While testing the nuclease activity of Transcription Activator Like-Effector Nuclease (TALEN) in vivo, we found the inefficient introduction of double strand breaks in the predefined site of the genome. This result necessitates redesigning the genome engineering nuclease for efficient double strand breakage for successful knock-in.