ORCID

https://orcid.org/0009-0008-9238-3825

Date of Award

Summer 2025

Language

English

Embargo Period

7-21-2025

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Biological Sciences

Program

Biology

Committee Members

Dr. Paolo Forni, Dr. ChangHwan Lee, Dr. Maxwell Turner, and Dr. Soma Dash

Subject Categories

Biology | Cell and Developmental Biology

Abstract

Neuronal migration is a vital process in embryonic development. In rodents, the very first neurons that originate from the olfactory placode migrate toward the developing brain as part of the migratory mass. This migratory mass includes Gonadotropin-releasing hormone-1 (GnRH-1) neurons, pioneer/terminal nerve (TN) neurons, and olfactory ensheathing cells—a type of glial cell.

Contactin-2 (Cntn2), also referred to as transiently expressed axonal surface glycoprotein-1 (TAG-1), belongs to the contactin family of proteins, which is part of the immunoglobulin superfamily of cell adhesion molecules. Cntn2 has been extensively utilized as a transient/stage-specific molecular marker for various neuronal populations, including commissural neurons of the spinal cord and motor neurons, sensory neurons emerging from the dorsal root ganglia as well as one of the few markers for TN neurons.

Currently, only a limited number of molecular markers are available to reliably label, trace, and manipulate early migratory neurons originating from the olfactory region. We recently reported Cntn2 expression in the TN via single-cell RNA sequencing of the developing olfactory system, pointing to the gene's significance as a suitable molecular marker or genetic entry point for investigating early neuronal migration in the nasal area.

Based on this, we designed an inducible Cntn2CreERT2 knock-in mouse line. This study characterizes the new mouse line and describes how this model can serve as a valuable tool for time-controlled conditional manipulation of developing neurons. This mouse provides faithful Cre-mediated recombination in the spinal cord, sensory neurons, and migratory neurons of the developing nose.

Using Cntn2 tracing, we found that despite being regarded as a terminal nerve marker, Cntn2 is expressed by both TN and GnRH-1 neurons. This provides important insights for developmental studies focused on investigating GnRH-1 neuronal migration.

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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