Molecular remodelling of members of the relaxin family during primate evolution

Abstract

The members of the relaxin family include the two hormones relaxin and the structurally closely related relaxin-like factor (RLF). Relaxin displays high sequence variability within and between taxonomic groups among land animals. Widely regarded as a hormone of the female reproductive tract, relaxin is expressed in the ovary and at the feto-maternal interface [1]. Known as a marker of human postpubertal testicular Leydig cells in various species [2–4], RLF is essential for the development of the Gubernaculum testis. Male RLF -/- mice are infertile due to impaired testicular descent resulting in cryptorchidism [5, 6]. Strepsirrhini, which includes the Afro-Asian loris and the Malagasy lemurs, are assumed to have diverged from other primates about 65 Million years ago (Myr) and have developed independently for over 60 Myr [7]. To study the dynamics in the molecular remodelling of both members of the relaxin family during primate evolution, we have cloned the cDNA sequences of the preprorelaxins and RLF in the African lorisiform Galago crassicaudatus (Gcr) and of preprorelaxin in the Malagasy lemur Varecia variegata (Vva) which is phylogenetically regarded plesiomorphic to all Malagasy lemurs [8].