The retirement system created and established in this article shall be closed and no new members accepted in the system after June 30, 2005. Notwithstanding the provisions of sections seven and eight of this article, all persons who are regularly employed for full-time service as a member or an employee whose initial employment commences after June 30, 2005, shall become a member of the state Teachers' Retirement System created and established in article seven-a of this chapter: Provided, That any person rehired after June 30, 2005, shall become a member of the Teachers' Defined Contribution Retirement System created and established in this article, or of the Teachers Retirement System created and established in article seven-a of this chapter, depending upon which system he or she last contributed to while he or she was employed with an employer mandating membership and contributions to one of those plans: Provided, however, That a rehired person who thereby becomes a member of the Teachers' Defined Contribution Retirement System may become a member of the Teachers Retirement System within the applicable time periods and upon meeting the requirements provided in article seven-d of this chapter: Provided further, That any person rehired after December 31, 2007, who did not have at least $1 in the Teachers Defined Contribution Retirement System on December 31, 2007, and for whom the Teachers Defined Contribution Retirement System was the system to which he or she last contributed while employed by an employer who required membership and contributions to one of the two teachers retirement plans, shall, within ten days of returning to employment, affirmatively choose to reenter the Teachers Defined Contribution Retirement System or to become a contributing member of the Teachers Retirement System. Those rehired prior to July 1, 2008, and who did not have at least $1 in the Teachers Defined Contribution Retirement System on December 31, 2007, as determined by the Consolidated Public Retirement Board, shall be permitted to voluntarily elect to transfer effective August 1, 2008, upon written request to the Consolidated Public Retirement Board received no later than July 15, 2008.