Different origins of two corpora lutea recovered from a pregnant African elephant (Loxodonta africana).

Elephant ovaries contain multiple corpora lutea (CLs) throughout pregnancy. Two CLs (P-1 and P-2) collected from a pregnant African elephant were used to investigate their origin and physiological state in this study. The mRNA expressions of prolactin receptor, CYP11A and inhibin betaB subunit were higher in P-2 than in P-1, while LHCGR and inhibin betaA subunit mRNA were higher in P-1 than in P-2. Protein expression of cleaved caspase-3 was detected in P-1 but not in P-2. These results suggest different origins for the two CLs in this one pregnant elephant, and we also demonstrated the production of bioactive prolactin by the elephant placenta.