No member of any board of education of a seven-director district, any portion of which is located in a first class county, shall hold any office or employment of profit from the board while a member thereof. No member of any board of education of a seven-director district, any portion of which is located in a county of the second, third or fourth class, shall, except as provided in sections 105.450 to 105.458, hold any office or employment of profit from the board while a member thereof. The secretary and treasurer, if not members of the board, may receive reasonable compensation for their services.