CELL-BINDING SPECIFICITY OF MOUSE R-CADHERIN AND CHROMOSOMAL MAPPING OF THE GENE

R-cadherin was originally identified as a chicken cadherin expressed b y the retina. Here, we describe the identification of a mouse homologu e of R-cadherin. We isolated mouse cDNAs encoding a cadherin with 94% identity in amino acid sequence to the chicken R-cadherin, and defined this molecule as mouse R-cadherin. L cells transfected with the mouse R-cadherin cDNA acquired a cadherin-mediated cell-cell adhesiveness a s found for other cadherins. To examine the binding specificity of mou se R-cadherin, L cells expressing this cadherin (mRL) were mixed with L cells expressing chicken R-cadherin (cRL), mouse N-cadherin (mNL), m ouse E-cadherin (mEL) and mouse P-cadherin (mPL). While mRL cells rand omly intermixed with cRL cells, those cells aggregated separately from mEL or mPL cells. Mixing of mRL with mNL cells gave an intermediate r esult; that is, they formed both separate and chimeric aggregates, sug gesting that R- and N-cadherin can interact with each other although e ach has a preference to bind to its own type. Similar properties were previously found for chicken R-cadherin. Thus, the cell binding specif icity of R-cadherin is entirety conserved between the two species, sug gesting a conserved role for this protein in morphogenesis. We also lo cated the mouse R-cadherin gene to chromosome 2.