Mapping and targeting ofC1ql1-expressing cells in the mouse

Abstract

AbstractThe C1Q complement protein C1QL1 is highly conserved in mammals where it is expressed in various tissues including the brain. This secreted protein interacts with Brain-specific Angiogenesis Inhibitor 3, BAI3/ADGRB3, and controls synapse formation and maintenance.C1ql1is expressed in the inferior olivary neurons that send projections to cerebellar Purkinje cells, but its expression in the rest of the brain is less documented. To mapC1ql1expression and enable the specific targeting ofC1ql1-expressing cells, we characterized a knockin mouse model expressing the Cre recombinase under the control ofC1ql1regulatory sequences. We characterized the capacity for Cre-driven recombination in the brain and mapped Cre expression in various neuron types using reporter mouse lines. Using an intersectional strategy with viral particle injections, we show that this mouse line can be used to target specific afferents of Purkinje cells. AsC1ql1is also expressed in other regions of the brain, as well as in other tissues such as adrenal glands, placenta, colon and testis, our mouse model is a useful tool to targetC1ql1-expressing cells in a broad variety of tissues.