On Thursday evening, lab officials told a small group of Ellsworth officials and residents that they expect to start work in June on converting the former Lowe’s building into a mouse vivarium, where they will breed research mice that they sell to biomedical scientists around the world. Lab officials told about 40 people at the meeting that they expect the renovation of the 140,000-square-foot building to take 18 months and to have their first research mouse in the facility by Jan. 1, 2018.