Exon 4 was floxed by insertion of a single upstream loxP site and a downstream floxed neo cassette. The neo cassette was subsequently removed by transient expression of cre recombinase in correctly targeted ES cells, leaving exon 4 flanked by loxP sites. (J:80690)
Legend:
cx: complex: > 1 genome feature ot: other: hemizygous, indeterminate,... (F): Female
(M): Male
N: normal phenotype
(#): related diseases count