IOWA CITY — Democrat Janelle Rettig of Iowa City said she will run for re-election to the Johnson County Board of Supervisors.Rettig, 52, is finishing up her second full term as a supervisor. She first was appointed to the five-member board in 2009.Rettig joins Supervisor Mike Carberry in running for re-election to the only two board seats on the ballot this fall.“I thought ‘OK, what is it that I still what to get done?’ and the list of things I still want to get done is substantial enough,’ Rettig said in her announcement Sunday.