Expression of SR‐BI (Scavenger Receptor Class B Type I) in turtle (Chrysemys picta) tissues and other nonmammalian vertebrates

In this study, the tissue distribution of the expression of an HDL-receptor (SR-BI; Scavenger Receptor Class B Type I) was investigated in the turtle using an antiserum to murine SR-BI. Several turtle tissues including liver, heart, small intestine, kidney, oviduct, ovary, and testis were shown to express an 82 kDa membrane protein. In addition, SR-BI expression in livers of other nonmammalian species such as the chicken, frog, goldfish, shark, and skate is also reported. Ovarian SR-BI expression varies seasonally in the turtle as do plasma levels of apoA-I and cholesterol ester. It is possible that changing levels of SR-BI, the receptor for apoA-I, is physiologically relevant to the demands of the turtle ovarian cycle and cholesterol distribution.