STOCK S100a5^tm1.1Mom/MomJ

Stock number: 006709
Research areas: Neurobiology Research, Research Tools, Sensorineural Research

Description

This reporter null allele is valuable for mapping responses of specific olfactory receptors to specific odorants.

Detailed description

Expression of S100a5 is upregulated in olfactory sensory neurons in response to stimulation. This reporter null allele allows activity-dependent expression of GFP from the S100a5 locus such that when a specific olfactory sensory neuron is stimulated through its olfactory receptor that neuron can be detected by its GFP expression. This permits in vivo tracking of which olfactory receptor responds to which odorant. As expected from the lack of S100a5 transcript in vomeronasal sensory neurons, this allele does not drive GFP expression in vomeronasal sensory neurons. In their proof-of-concept paper McClintock et al. used this system to track eugenol response to olfactory sensory neurons expressing Olfr73, Olfr178, Olfr432, Olfr610, Olfr958, Olfr960, Olfr961, Olfr913, and Olfr1234 and muscone response to olfactory sensory neurons expressing Olfr74, Olfr235, Olfr816, and Olfr1440. When crossed with Cnga2^tm1Mom mice, which have odorant-evoked electrical activity ablated, the progeny null for CNGA2 have nearly undetectable GFP fluorescence from the S100a5 GFP reporter.

Development

The S100a5^tm1Mom mutation was generated in 129P2/OlaHsd derived E14 ES cells and the founder was bred to C57BL/6J. To excise the neomycin resistance sequence this line was bred with a mouse carrying Tg(EIIa-cre)C5379Lmgd, a transgene generated in FVB/N but having been backcrossed at least 10 times to C57BL/6J before this cross. The transgene was then bred out of the line and the mice were intercrossed to homozygosity. In 2007 sperm was cryopreserved from heterozygous males on this predominantly mixed B6;129P2 background.

Allele

Symbol: S100a5^tm1.1Mom
Name: targeted mutation 1.1, Peter Mombaerts
MGI accession ID: MGI:5605391
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: S100a5
Marker name: S100 calcium binding protein A5
Chromosome: 3
Strain of origin: 129P2/OlaHsd
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: GFP is expressed in olfactory sensory neurons.
Molecular note: The two coding exons and intervening intron were deleted and replaced with a tau-GFP reporter and a loxP flanked pgk-neo cassette, and a subsequent cross to a Tg(EIIa-cre)Lmgd bearing strain excised the neomycin selection casssette yielding a GFP reporter that gives activity-dependent fluorescent marking of olfactory sensory neurons