Proteomics of Galápagos marine iguanas links function of femoral gland proteins to the immune system

ABSTRACT: Communication between individuals via molecules, termed chemosignaling, is widespread among animal and plant species. However, we lack knowledge on the specific functions of the substances involved for most of such systems. The femoral gland is an organ secreting a waxy substance, which is involved in chemical communication in lizards. While the lipids and volatile substances secreted by the femoral glands have been investigated in several biochemical studies, the protein composition and functions of secretions are completely unknown. Applying a proteomic approach, we provide the first attempt to comprehensively characterize the protein composition of femoral gland secretions from the Galápagos marine iguana. Using samples from several organs, the marine iguana proteome was assembled by next generation sequencing and mass spectrometry, resulting in 7,513 proteins; 4305 proteins were present in the femoral gland, including keratins, small serum proteins and fatty acid-binding proteins. Surprisingly, no proteins with obvious roles in partner recognition or inter-species communication could be identified. However, we found several proteins with direct associations to the innate immune system, such as lysozyme C, antileukoproteinase (ALP), pulmonary surfactant protein (SFTPD) and galectin (LGALS1), suggesting the femoral glands function as an important barrier to infection. The identification of previously unrecognized effective anti-microbial peptides from the femoral gland show similar activities against E.coli and B. subtilis compared to oncocin. This proteomics dataset is a valuable resource for future functional protein analysis and demonstrates that femoral glands secretions covers also functions of the innate immune system.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Amblyrhynchus Cristatus

TISSUE(S): Heart, Brain, Semen, Lung, Skin, Muscle, Blood

SUBMITTER: Frederik Tellkamp  

LAB HEAD: Marcus Krüger

PROVIDER: PXD018909 | Pride | 2020-06-29

REPOSITORIES: Pride