Tex. Spec. Dist. Code § 1084.053
(a) A person may not be elected or appointed to an elected position on the board unless the person is:
(b) In addition to the requirements prescribed by Subsection (a), a person is not eligible to serve as a director if the person:
(2) directly or in conjunction with another person or entity has an ownership interest in another business or entity that:
(c) Subsection (b) does not apply to:
(1) an ownership or investment interest in publicly available shares of a registered investment company, such as a mutual fund, that owns publicly traded equity securities or debt obligations issued by:
Added by Acts 2009, 81st Leg., R.S., Ch. 1139 (H.B. 2619), Sec. 1.01, eff. April 1, 2011.