Mapping transgene insertion sites reveals the α-Cre transgene expression in both developing retina and olfactory neurons

Yimeng Fan; Wenyue Chen; Ran Wei; Wei Qiang; Joel D Pearson; Tao Yu; Rod Bremner; Danian Chen

doi:10.1038/s42003-022-03379-9

Mapping transgene insertion sites reveals the α-Cre transgene expression in both developing retina and olfactory neurons

Commun Biol. 2022 May 3;5(1):411. doi: 10.1038/s42003-022-03379-9.

Authors

Yimeng Fan^#^{1

2}, Wenyue Chen^#^{1

2}, Ran Wei^#^{1

2}, Wei Qiang^{1

2}, Joel D Pearson³, Tao Yu³, Rod Bremner⁴, Danian Chen^{5

6

7}

Affiliations

¹ Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
² Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.
³ Lunenfeld-Tanenbaum Research Institute, Sinai Health System, and Departments of Ophthalmology and Visual Science, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
⁴ Lunenfeld-Tanenbaum Research Institute, Sinai Health System, and Departments of Ophthalmology and Visual Science, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. bremner@lunenfeld.ca.
⁵ Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China. danianchen2006@qq.com.
⁶ Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China. danianchen2006@qq.com.
⁷ Lunenfeld-Tanenbaum Research Institute, Sinai Health System, and Departments of Ophthalmology and Visual Science, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. danianchen2006@qq.com.

^# Contributed equally.

Abstract

The Tg(Pax6-cre,GFP)^2Pgr (α-Cre) mouse is a commonly used Cre line thought to be retinal-specific. Using targeted locus amplification (TLA), we mapped the insertion site of the transgene, and defined primers useful to deduce zygosity. Further analyses revealed four tandem copies of the transgene. The insertion site mapped to clusters of vomeronasal and olfactory receptor genes. Using R26R and Ai14 Cre reporter mice, we confirmed retinal Cre activity, but also detected expression in Gα₀⁺ olfactory neurons. Most α-Cre⁺ olfactory neurons do not express Pax6, implicating the influence of neighboring regulatory elements. RT-PCR and buried food pellet test did not detect any effects of the transgene on flanking genes in the nasal mucosa and retina. Together, these data precisely map α-Cre, show that it does not affect surrounding loci, but reveal previously unanticipated transgene expression in olfactory neurons. The α-Cre mouse can be a valuable tool in both retinal and olfactory research.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Integrases
Mice
Mice, Transgenic
Neurons*
Retina*
Transgenes

Substances

Cre recombinase
Integrases

Abstract

Publication types

MeSH terms

Substances

Grants and funding