**Cell Progeny in the Olfactory Bulb after Targeting Specific Progenitors with Di**ff**erent UbC-StarTrack Approaches**

#### **Rebeca Sánchez-González, María Figueres-Oñate** †**, Ana Cristina Ojalvo-Sanz and Laura <sup>L</sup>ópez-Mascaraque \***

Department of Molecular, Cellular and Development Neurobiology, Instituto Cajal-CSIC, 28002 Madrid, Spain; rebeca@cajal.csic.es (R.S.-G.); maria.figueres@gen.mpg.de (M.F.-O.); anacris23@cajal.csic.es (A.C.O.-S.)

**\*** Correspondence: mascaraque@cajal.csic.es

† Present address: Max Planck Research Unit for Neurogenetics, Frankfurt am Main, 60438 Frankfurt, Germany.

Received: 30 January 2020; Accepted: 11 March 2020; Published: 13 March 2020

**Abstract:** The large phenotypic variation in the olfactory bulb may be related to heterogeneity in the progenitor cells. Accordingly, the progeny of subventricular zone (SVZ) progenitor cells that are destined for the olfactory bulb is of particular interest, specifically as there are many facets of these progenitors and their molecular profiles remain unknown. Using modified StarTrack genetic tracing strategies, specific SVZ progenitor cells were targeted in E12 mice embryos, and the cell fate of these neural progenitors was determined in the adult olfactory bulb. This study defined the distribution and the phenotypic diversity of olfactory bulb interneurons from specific SVZ-progenitor cells, focusing on their spatial pallial origin, heterogeneity, and genetic profile.

**Keywords:** Olfactory interneuron; heterogeneity; StarTrack; development; neural progenitor cell; cell fate; in utero electroporation
