Research Paper Volume 11, Issue 18 pp 8015—8034

Circular RNA profiling in the oocyte and cumulus cells reveals that circARMC4 is essential for porcine oocyte maturation

Figure 1. Characteristics of circRNAs expressed in porcine cumulus cells and oocytes. (A) Schematic illustration of experimental designs identifying circRNAs expressed in cumulus cells or oocytes before and after maturation. Premature COCs, cumulus cells before maturation (termed GCC), mature COCs, and cumulus cells after maturation (termed MCC) were collected respectively for RNA-seq. Of note, circRNAs expressed in the GCC were subtracted from these identical circRNAs expressed in the premature COCs to identify circRNAs expressed in GV oocytes, which are termed GV oocyte. Similarly, circRNAs expressed in MCC were subtracted from these identical circRNAs expressed in the mature COCs to identify circRNAs expressed in MII oocytes, which are termed MII oocyte. COCs, cumulus-oocyte complexes; GV, germinal vesicle; MII, metaphase II; IVM, in vitro maturation. Red dashed insets show cumulus cells before and after oocyte maturation at high magnification. (B) Chromosome distribution of circRNAs. Chromosome distribution of total circRNAs expressed in cumulus cells or oocytes was shown in the upper panel and bottom panel, respectively. (C) Genomic location of circRNAs. Genomic distribution of total circRNAs expressed in cumulus cells or oocytes was shown in the left panel and right panel, respectively. (D) GC enrichment of circRNAs and mRNAs. GC content of total circRNAs and mRNAs expressed in cumulus cells or oocytes was separately shown in the left panel and right panel.