# Neural substrates of bower building behavior in Lake Malawi cichlid fish

> **NIH NIH F32** · GEORGIA INSTITUTE OF TECHNOLOGY · 2020 · $11,241

## Abstract

PROJECT SUMMARY:
Understanding how variation in conserved genes and neural systems gives rise to variation in
cognition and behavior is a fundamental goal of behavioral neuroscience. The unique genetic and
behavioral features of Lake Malawi bower-building cichlids position them as a powerful species
system for advancing this goal. Bower-building is a complex natural behavior in which males
construct species-specific courtship structures in the sand. Bower-building behavior recruits
conserved brain regions, such as the putative homologue of the mammalian hippocampus, that
regulate social and spatial learning, memory, and behavior across species. Specific bower
structures, such as crater-like “pits” and mountain-like “castles,” have repeatedly evolved in
dozens of closely-related species. The unusually high degree of genetic similarity between
species enables intercrossing of pit-digging and castle-building lineages in the laboratory,
producing pit-castle hybrids. Remarkably, first generation (F1) pit-castle hybrids express both
parental behaviors in sequence, first digging a pit and then building a castle. Phased expression
of parental behaviors in F1 hybrids is associated with a unique pattern of gene regulation in the
brain, whereby parental “pit” alleles are upregulated during pit-digging, and parental “castle”
alleles are upregulated during castle-building (allele-specific expression; ASE). Such “context-
specific ASE” is a novel neurogenetic mechanism that may regulate neural and behavioral
plasticity. The primary objectives of the proposed research are to (1) develop automated video
and depth sensing systems to measure bower-building behavior for weeks at a time, (2)
characterize several dimensions of bower-building behavior, (3) investigate the neural basis of
species differences in bower-building behavior, and (4) investigate context-specific ASE in the
brain during pit-digging and castle-building in F1 hybrids. The proposed research will integrate
innovative technologies, next-generation sequencing approaches, and the strengths of a non-
traditional species system to advance the field of behavioral neuroscience. More specifically,
these experiments will generate fundamental knowledge about the neurogenetic basis of natural
complex behavioral variation and a novel neurogenetic mechanism that may contribute to neural
plasticity.

## Key facts

- **NIH application ID:** 10137412
- **Project number:** 3F32GM128346-01A1S1
- **Recipient organization:** GEORGIA INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** Zachary V Johnson
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $11,241
- **Award type:** 3
- **Project period:** 2019-04-01 → 2020-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10137412

## Citation

> US National Institutes of Health, RePORTER application 10137412, Neural substrates of bower building behavior in Lake Malawi cichlid fish (3F32GM128346-01A1S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10137412. Licensed CC0.

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