Project description:Efforts to implement effective assisted reproductive technologies (ART) to extricate the northern white rhinoceros (NWR; Ceratotherium simum cottoni) from extinction, could be unconventionally offset from studies carried out using the southern white rhinoceros (Ceratotherium simum simum) as a relative model species. The bi-directional communication and critical transport of regulatory molecules controlling follicular growth and oocyte development are in part mediated through extracellular vesicles (EVs), which encompass a highly conserved and advanced paracrine signaling mechanism important in shuttling unique cargo such as microRNAs (miRNAs). In this study, critical miRNAs for follicular development were identified, proposing novel approaches using EV-mediated miRNA to possibly improve the in vitro technologies outcome in a multitude of species.
Project description:In this study, we performed bulk RNA-seq of pluripotent stem cells (PSCs) and induced pre-somitic mesoderm (PSM) cells of six different mammalian species. The species studied are: mouse (Mus musculus), marmoset (Callithrix jacchus), rabbit (Oryctolagus cuniculus), human (Homo sapiens), cattle (Bos taurus) and southern white rhinoceros (Ceratotherium simum). We used mouse ESCs, marmoset iPSCs, rabbit ESCs, human iPSCs, bovine ESCs and rhinoceros ESCs to induce PSM-like cells from these species following protocols already described. PSC samples were extracted under maintenance conditions. PSM samples were extracted on the day when the differentiation efficiency was higher based on the percentage of cells expressing the PSM marker TBX6. We used identical culture conditions when extracting the induced PSM cells to minimize the effect of external factors on our results. Two replicates per each cell type and species were collected for a total of 24 samples. We compared the expression levels of more than 10,000 orthologous protein-coding genes across the six species. With this, we determined that the species-specific segmentation clock periods might be derived from species-specific gene expression profiles controlling basic biological processes.
Project description:In vivo-collected granulosa cells (GC) from the southern white rhinoceros (SWR) provide a non-invasive assessment of the developmental status of oocytes prior to in vitro culture, which will aid in the development of assisted reproductive technologies (ART). Our study aimed to investigate gene expression in SWR granulosa cells (GC), collected in vivo and gain preliminary insight into the transcriptional activity occurring within the cells during various stages of oocyte development. It was hypothesized there would be similarities between the SWR GC transcriptome and cattle and humans, two species for which well-annotated genomes are available and ART are commonly used. GC were collected from SWR following ovum pickup (OPU) and pooled from all aspirated follicles. Total RNA was isolated, libraries prepared and sequencing performed using an Illumina NextSeq 500. Reads were aligned and annotated to CerSimCot1.0. Databases for cattle and human were acquired for comparison. This study identified 37,407 transcripts present in GC of SWR. It was determined that cattle and human transcriptomes are valuable resources with a homology of 45% with the SWR. In conclusion, these data provide preliminary, novel insights into the transcriptional activity of GC in the SWR that can be used to enhance ART in this species.
