Mitochondrial Remodeling in Chicken Induced Pluripotent Stem-Like Cells

Abstract

Chicken pluripotent stem cells (PSCs), such as embryonic stem cells and blastoderm cells, have been used to study development and differentiation in chicken. However, chicken PSCs are not widely used because they are hard to maintain in long-term culture. Recent reports suggest that chicken somatic cells can be reprogrammed to pluripotent state by defined factors to form induced pluripotent stem cells (iPSCs). These chicken iPSCs showed pluripotent differentiation potential and could be maintained in long-term culture. However, intracytoplasmic remodeling during reprogramming of chicken cells remains largely unknown. In this study, we generated chicken iPS-like cells (ciPSLCs) from chicken embryonic fibroblasts using a retroviral expression system encoding human reprogramming factors. These ciPSLCs could be maintained for more than 10 passages and expressed the endogenous chicken pluripotency markers, cNonog and cSox2. Moreover, the ciPSLCs showed higher nucleus to cytoplasm ratio and contained globular mitochondria with immature cristae. This morphology was similar to that of mammalian PSCs, but different from that of avian somatic cells, which showed lower nucleus to cytoplasm ratio and mature mitochondria. These results suggest that intracytoplasmic organelles in differentiated somatic cells could be successfully remodeled into the pluripotent state during reprogramming in chicken.

Avian iPSC Derivation to Recover Threatened Wild Species: A Comprehensive Review in Light of Well-Established Protocols

“…Choi et al, in 2016, shed light on the structural changes that occur within chicken cells during the process of reprogramming, providing insights into the cellular mechanisms involved in iPSC generation and pluripotency acquisition. Through electron microscopy, it was observed that intracytoplasmic organelles in differentiated somatic cells underwent remodeling during cell reprogramming and that ciPSCs exhibited a higher nucleus-tocytoplasm ratio and contained globular mitochondria with immature cristae [111].…”

Avian Embryonic Culture: A Perspective of In Ovo to Ex Ovo and In Vitro Studies

“…The discovery of chick ESCs and blastodermal cell culture emphasizes the conserved network regulating pluripotency required at least leukemia inhibitory factor (LIF) ( Etches et al, 1997 ; Pain et al, 1996 ), a cytokine used to culture naïve mouse ESCs and iPSCs ( Niwa et al, 1998 ; Takahashi and Yamanaka, 2006 ). In addition, basic fibroblast growth factor (bFGF), a cytokine used to cultivate primed human ESCs/iPSCs ( Thomson et al, 1998 ; Takahashi et al, 2007 ), is required in several avian ESCs/iPSCs studies ( Pain et al, 1996 ; van de Lavoir et al, 2006 ; Whyte et al, 2015 ; Choi et al, 2016 ; Katayama et al, 2018 ). Thus, this suggests that pluripotent stem cells from avian species exhibit some bias in a naïve-primed direction which could depend on other culture supplements.…”

Pluripotency in avian species

“…Somatic cell reprogramming appears to be far more difficult to achieve in non-mammalian species. Few studies, using human and mouse transcription factors as reprogramming genes reported the derivation and characterization of iPS-like cells in chicken (designated ciPS cells) (Choi et al, 2016;Yu et al, 2014;Lu et al, 2015;Rosselo et al, 2013). By using chicken genes, iPS-like cells were also generated.…”