Exploring the function of long non-coding RNA in the development of bovine early embryos

Abstract

Now recognised as part of the cellular transcriptome, the function of long non-coding (lnc) RNA remains unclear. Previously, we found that some lncRNA molecules in bovine embryos are highly responsive to culture conditions. In view of a recent demonstration that lncRNA may play a role in regulating important functions, such as maintenance of pluripotency, modification of epigenetic marks and activation of transcription, we sought evidence of its involvement in embryogenesis. Among the numerous catalogued lncRNA molecules found in oocytes and early embryos of cattle, three candidates chosen for further characterisation were found unexpectedly in the cytoplasmic compartment rather than in the nucleus. Transcriptomic survey of subcellular fractions found these candidates also associated with polyribosomes and one of them spanning transzonal projections between cumulus cells and the oocyte. Knocking down this transcript in matured oocytes increased developmental rates, leading to larger blastocysts. Transcriptome and methylome analyses of these blastocysts showed concordant data for a subset of four genes, including at least one known to be important for blastocyst survival. Functional characterisation of the roles played by lncRNA in supporting early development remains elusive. Our results suggest that some lncRNAs play a role in translation control of target mRNA. This would be important for managing the maternal reserves within which is embedded the embryonic program, especially before embryonic genome activation.

Long noncoding RNA 2193 regulates meiosis through global epigenetic modification and cytoskeleton organization in pig oocytes

“…We, therefore, selected lncRNA2193 based on its relatively high abundance (the first selection criterion). The second criterion we adopted was longer than 600nt in length and had single‐copy in the genome, to avoid the interference from other small RNAs and repeated elements (Caballero et al, 2014). The third criterion was based on the association of predicted candidate targets with the meiotic event ( Bubr1, Mad2, c‐mos, Cdk1 , and Ccnb1 ), which are known to be vital for oocyte meiosis through the spindle checkpoint, MAPK and MPF signal pathways (Gebauer & Richter, 1997; J. Li et al, 2018; Shimoi, Tomita, Kataoka, & Kameyama, 2019; Touati et al, 2015; Wei, Greaney, Zhou, & Homer, 2018).…”

Long non‐coding RNA regulation of reproduction and development

“…lncRNAs associated with preimplantation development have been characterized by RNA‐seq of zygotes and other preimplantation stages of development (Paranjpe et al, ; Yan et al, ; Caballero et al, ; Zhang et al, ; Hamazaki et al, ). By comparing lncRNA profiles of the zygotes with those of its parental gametes, it is possible to identify lncRNAs arising immediately after zygote activation.…”

Mining long noncoding RNA in livestock

“…Caballero et al . () described the expression and intracellular location of three lncRNAs in bovine oocytes and early stages of embryo development. These lncRNAs were found to be clearly located in the cytoplasm and partially associated with polyribosomes, indicating a role in translation regulation.…”