Ultrastructural Characteristics of Three Undifferentiated Mouse Embryonic Stem Cell Lines and Their Differentiated Three-Dimensional Derivatives: A Comparative Study

Abstract

The fine structures of mouse embryonic stem cells (mESCs) grown as colonies and differentiated in three-dimensional (3D) culture as embryoid bodies (EBs) were analyzed by transmission electron microscopy. Undifferentiated mESCs expressed markers that proved their pluripotency. Differentiated EBs expressed different differentiation marker proteins from the three germ layers. The ultrastructure of mESCs revealed the presence of microvilli on the cell surfaces, large and deep infolded nuclei, low cytoplasm-to-nuclear ratios, frequent lipid droplets, nonprominent Golgi apparatus, and smooth endoplasmic reticulum. In addition, we found prominent juvenile mitochondria and free ribosomes-rich cytoplasm in mESCs. Ultrastructure of the differentiated mESCs as EBs showed different cell arrangements, which indicate the different stages of EB development and differentiation. The morphologies of BALB/c and 129 W9.5 EBs were very similar at day 4, whereas C57BL/6 EBs were distinct from the others at day 4. This finding suggested that differentiation of EBs from different cell lines occurs in the same pattern but not at the same rate. Conversely, the ultrastructure results of BALB/c and 129 W9.5 ESCs revealed differentiating features, such as the dilated profile of a rough endoplasmic reticulum. In addition, we found low expression levels of undifferentiated markers on the outer cells of BALB/c and 129 W9.5 mESC colonies, which suggests a faster differentiation potential.

Ultrastructural comparison of porcine putative embryonic stem cells derived by <i>in vitro</i> fertilization and somatic cell nuclear transfer

“…Compared with PFFs and IVF-pESCs, SCNT-pESCs had more microvilli on their surfaces, which suggests that they have high absorption and secretory activity, resulting in an increase in cell surface area. Microvilli indicate highly metabolic activity and have also been observed in mESCs, mouse EBs and hESCs [ 25 , 26 , 27 ].…”

“…TEM techniques can provide useful information about the functionality of cells. The ultrastructural characteristics of mouse ESCs (mESCs) [ 25 ], nonhuman primate ESCs [ 1 ] and human ESCs (hESCs) [ 26 ], as well as embryoid bodies (EBs) derived from mESC lines [ 27 , 28 ], have been reported. Moreover, Talbot et al reported the ultrastructure of porcine blastocysts [ 29 ].…”

Ultrastructural heterogeneity of the mitochondrial population in rat embryonic and induced pluripotent stem cells

“…Probably, the same effect takes place in rat cells because they are constantly cultured with 2i. Mouse pluripotent stem cells are not reported to contain glycogen (Alharbi et al, 2014; Baharvand & Matthaei, 2003; Lai & Bu, 2016; Suldina et al, 2018). That cells are usually grown with supplementation of LIF and BMP4, as we did in our work elsewhere (Suldina et al, 2018).…”

“…On the other hand, Baharvand and Matthaei (2003) described mitochondria in mouse ESCs as rounded or ovoid with tubular and lamellar structure but almost always enlarged. Alharbi et al (2014) documented the variability of mitochondrial morphology in nonisogenic mouse ESC lines: these cells often contain small mitochondria with thin cristae, while large mitochondria with developed cristae are rarely observed. We previously characterized the diversity of mitochondrial morphology in isogenic mouse ESCs (Suldina et al, 2018).…”

Structure and ultrastructure of neurospheres spontaneously generated in culture from sheep ovarian cortical cells.

“…Light cells placed at the outer sheet of the neurospheres (LFCs and LPCs), beared abundant microvilli at their apical membrane. The presence of apical microvilli is a characteristic feature of embryonic stem cells [58,59,60], epithelial cells of embryoid bodies [61], and neuroepithelial and neural progenitor cells during neurogenesis [62], but it has been reported to be a rare finding in neurospheres [12].…”