Overview

About This Module

This module is the genomics component of the larger Electric Fish Module at the Neural Systems & Behavior course at MBL. The broader module examines weakly electric fish from the perspective of sensorimotor integration, electrosensory physiology, and hormonal modulation of behavior.

In this component of our work, we’ll focus on a specific question: how does 11-ketotestosterone (11-KT) reshape gene expression across the electrosensory system at single-cell resolution? Androgens like 11-KT are known to lengthen the electric organ discharge (EOD) waveform in mormyrids, an effect with broad consequences for electric communication and electroreception. But which cell types respond, which genes are affected, and are the sensory and motor arms of the system are coordinately regulated?

The lesson progresses in four stages:

  1. Experimental foundation — You will prepare 11-KT/cocoa butter implants, perform IP implantation surgery on live fish, and record EOD waveforms over multiple days to confirm the hormone treatment is working before any tissue is collected.

  2. EOD data analysis — Using R, you will load raw JSON waveform files, visualize and measure EOD duration changes, and build tidy datasets for statistical comparison across treatment groups.

  3. snRNA-seq QC and normalization — We will learn the basisc of working with snRNAseq data in R, including various QC metrics as well as how to identify cell types.

  4. Differential expression — Finally, we will identify genes and cell types that respond to 11-KT, then cross-validate your findings against a published study (Losilla & Gallant 2025).

By the end of the module you will have a reproducible snRNA-seq workflow applicable to any tissue where cell-type resolution matters!

See the Schedule for the day-by-day plan, and Setup for getting your R environment set up!