A fragment of mouse Smc1b promoter located between positions -283 and -12 from the translation start codon was inserted in between the AseI and AgeI sites of pEGFP-C1 (Takara Bio Inc.). Several founder mice were generated but line numbers were not available. The pound symbol (#) is used when no line is specified and/or lines are pooled. Cre activities analyzed by crossing to YFP reporter strain showed reporter activities only in testis, not in spleen, kidney, and other control organs; testis section staining showed YFP only in spermatocytes. (J:153803)