Project description:Chemical communication in elephants has been studied in detail both at the chemical and at the behavioural levels. Several pheromones have been identified, and their specific effects on the sexual behaviour of both the African and the Asian elephants have been accurately documented. This work is focused on the characterization of OBP1 through ligand-binding studies and analysis of post-translational modifications (PTMs). First, we have performed a proteomic analysis of a crude extract of the trunk wash obtained from the African elephant, and have found OBP1 as the main component, together with minor amounts of a OBP1 isoform and the von Ebner's gland (VEG) protein. Proteomic analysis of OBP1 revealed the occurrence of a variable degree of O-glycosylation, phosphorylation and acetylation in this protein. To specifically assay OBP1 spectra of binding, we have then expressed the African elephant protein in Pichia pastoris, which showed PTMs very similar to the natural counterpart. At functional level, we have found that recombinant OBP1 from the African elephant is able to bind the sex pheromone (Z)-7-dodecenyl acetate with strong affinity and some structurally related esters with lower strength.
Project description:The African elephant (Loxodonta africana) is experiencing serious challenges to optimal reproduction in captivity. The physiological and molecular basis of this impaired fertility remains unknown. A functional link between nutritional status, body condition score and fertility is well established in humans and many other species, where adipose tissue production of the hormone leptin has emerged as a crucial reproductive regulator. This report forms the basis for future studies to address the effect of nutrient composition and body condition on captive and wild elephants.
Project description:The identity of most functional elements in the mammalian genome and the phenotypes they impact are unclear. Here, we perform a genome-wide comparative analysis of patterns of accelerated evolution in species with highly distinctive traits to discover candidate functional elements for clinically important phenotypes. We identify accelerated regions (ARs) in the elephant, hibernating bat, orca, dolphin, naked mole rat and thirteen-lined ground squirrel lineages in mammalian conserved regions, uncovering ~33,000 elements that bind hundreds of different regulatory proteins in humans and mice. ARs in the elephant, the largest land mammal, are uniquely enriched at elephant DNA damage response genes and changed conserved regulatory sites. The genomic hotspot for elephant ARs is the E3 ligase subunit of the Fanconi Anemia Complex, a master regulator of DNA repair. Additionally, ARs in the six species are associated with specific human clinical phenotypes that have apparent concordance with overt traits in each species.
Project description:Background Methylation of CG dinucleotides constitutes a critical system of epigenetic memory in bony vertebrates, where it modulates gene expression and suppresses transposon activity. The genomes of studied vertebrates are pervasively hypermethylated, with the exception of regulatory elements such as transcription start sites (TSSs), where the presence of methylation is associated with gene silencing. This system is not found in the sparsely methylated genomes of invertebrates, and establishing how it arose during early vertebrate evolution is impeded by a paucity of epigenetic data from basal vertebrates. Methods We perform whole-genome bisulfite sequencing to generate the first genome-wide methylation profiles of a cartilaginous fish, the elephant shark Callorhinchus milii. Employing these to determine the elephant shark methylome structure and its relationship with expression, we compare this with higher vertebrates and an invertebrate chordate using published methylation and transcriptome data. Results Like higher vertebrates, the majority of elephant shark CG sites are highly methylated, and methylation is abundant across the genome rather than patterned in the mosaic configuration of invertebrates. This global hypermethylation includes transposable elements and the bodies of genes at all expression levels. Significantly, we document an inverse relationship between TSS methylation and expression in the elephant shark, supporting the presence of the repressive regulatory architecture shared by higher vertebrates. Conclusions Our demonstration that methylation patterns in a cartilaginous fish are characteristic of higher vertebrates imply the conservation of this epigenetic modification system across jawed vertebrates separated by 465 million years of evolution. In addition, these findings position the elephant shark as a valuable model to explore the evolutionary history and function of vertebrate methylation.
2017-03-24 | GSE96683 | GEO
Project description:Data corresponding to publication titled "Livestock exposure, seasonal diet shifts, and age influence wild African savanna elephant gut microbiomes"