Mitochondrial Remodeling in Chicken Induced Pluripotent Stem-Like Cells

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

Induced pluripotent stem cells (iPSCs) were first generated by Yamanaka in 2006, revolutionizing research by overcoming limitations imposed by the use of embryonic stem cells. In terms of the conservation of endangered species, iPSC technology presents itself as a viable alternative for the manipulation of target genetics without compromising specimens. Although iPSCs have been successfully generated for various species, their application in nonmammalian species, particularly avian species, requires further in-depth investigation to cover the diversity of wild species at risk and their different protocol requirements. This study aims to provide an overview of the workflow for iPSC induction, comparing well-established protocols in humans and mice with the limited information available for avian species. Here, we discuss the somatic cell sources to be reprogrammed, genetic factors, delivery methods, enhancers, a brief history of achievements in avian iPSC derivation, the main approaches for iPSC characterization, and the future perspectives and challenges for the field. By examining the current protocols and state-of-the-art techniques employed in iPSC generation, we seek to contribute to the development of efficient and species-specific iPSC methodologies for at-risk avian species. The advancement of iPSC technology holds great promise for achieving in vitro germline competency and, consequently, addressing reproductive challenges in endangered species, providing valuable tools for basic research, bird genetic preservation and rescue, and the establishment of cryobanks for future conservation efforts.

A Bird's-Eye View of Endangered Species Conservation: Avian Genomics and Stem Cell Approaches for Green Peafowl (Pavo muticus)

Aves ranks among the top two classes for the highest number of endangered and extinct species in the kingdom Animalia. Notably, the IUCN Red List classified the green peafowl as endangered. This highlights promising strategies using genetics and reproductive technologies for avian wildlife conservation. These platforms provide the capacity to predict population trends and enable the practical breeding of such species. The conservation of endangered avian species is facilitated through the application of genomic data storage and analysis. Storing the sequence is a form of biobanking. An analysis of sequence can identify genetically distinct individuals for breeding. Here, we reviewed avian genomics and stem cell approaches which not only offer hope for saving endangered species, such as the green peafowl but also for other birds threatened with extinction.

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

The avian embryos growing outside the natural eggshell (ex ovo) were observed since the early 19th century, and since then chick embryonic structures have revealed reaching an in-depth view of external and internal anatomy, enabling us to understand conserved vertebrate development. However, the internal environment within an eggshell (in ovo) would still be the ideal place to perform various experiments to understand the nature of avian development and to apply other biotechnology techniques. With the advent of genetic manipulation and cell culture techniques, avian embryonic parts were dissected for explant culture to eventually generate expandable cell lines (in vitro cell culture). The expansion of embryonic cells allowed us to unravel the transcriptional network for understanding pluripotency and differentiation mechanism in the embryos and in combination with stem cell technology facilitated the applications of avian culture to the next levels in transgenesis and wildlife conservation. In this review, we provide a panoramic view of the relationship among different cultivation platforms from in ovo studies to ex ovo as well as in vitro culture of cell lines with recent advances in the stem cell fields.

Ascorbic acid and all-trans retinoic acid promote proliferation of chicken blastoderm cells (cBCs) by mediating DNA demethylation

Chicken blastoderm cells (cBCs) obtained from stage X (EG&K) embryos are easily available materials for the study of cell development. However, cBCs are not widely used because they are hard to maintain in long-term culture in vitro. To solve this problem, ascorbic acid (AA; also known as vitamin C (VC)) and all-trans retinoic acid (ATRA) were added into basic culture medium to promote cell growth. Results suggested that cultured cBCs possessed strongly proliferative activity and maintained their pluripotency on the support of chicken embryonic fibroblast (CEF) feeder. Moreover, when VC or/and ATRA was added, the number and area of cBC colonies increased significantly compared with the control group. The expression of pluripotency genes (Sox2 and Nanog) and cell cycle-regulated genes (CCND1 and CDK6) was upregulated obviously. Furthermore, results showed that 5hmC levels in VC and RA groups increased significantly by DNA dot blot and immunofluorescence staining. These results provide strong evidence that VC and ATRA induced DNA demethylation and enhanced 5hmC level. The level of H3K27me3 was raised, while the level of H3K9me2 was reduced by addition of VC and ATRA. Finally, the expression of Tet1 and Dnmt3b was upregulated remarkably. Therefore, these results indicated that VC and ATRA enhanced DNA demethylation and then promoted cBC survival and proliferation in vitro.

Current Issues and Technical Advances in Cultured Meat Production: A Review

As the global population grows, we need a stable protein supply to meet the demands. Although plant-derived protein sources are widely available, animal meat maintains its popularity as a high-quality and savory protein source. Recently, cultured meat, also known as in vitro meat, has been suggested as a meat analog produced through in vitro cell culture technology. Cultured meat has several advantages over conventional meat, such as environmental protection, disease prevention, and animal welfare. However, cultured meat manufacturing is an emerging technology; thus, its further and dynamic development would be pivotal. Commercialization of cultured meat to the public will take a long time but cultured meat undoubtedly will come to our table someday. Here, we discuss the social and economic aspects of cultured meat production as well as the recent technical advances in cultured meat technology.

Mitochondrial and Metabolic Dynamics of Endometrial Stromal Cells During the Endometrial Cycle

The endometrial cycle in response to hormonal stimulation is essential for implantation. The female has endometrium that repeats this cycle through about half of a lifetime. The cycle includes three phases, proliferative, secretory, and menstrual, and each phase has distinct characteristics. The endometrial stromal cells (EnSCs) in each phase also have specialized characteristics, including cell cycle, morphologies, and cellular metabolic state. So we hypothesized that the cells in each phase have unique mitochondrial morphologies because they are generally linked to cellular metabolic state. To investigate the metabolic characteristics in each phase, we investigated the mitochondrial morphologies by transmission electron microscopy, oxygen consumption rate (OCR), and intracellular adenosine triphosphate (ATP) production. The decidualized EnSCs have shorter mitochondria than those in the proliferative phase. Besides, they also displayed distinct intracellular structural characteristics compared with the proliferative phase, such as ribosome-rich endoplasmic reticulum and increased formation of vesicles. OCR and luminescent ATP detection assay revealed that the basal respiration and ATP production in the decidualized EnSCs were lower than those in the proliferative phase. Thus, we concluded that morphological and intracellular structural changes were induced during the decidualization. Moreover, the decreased mitochondrial length was shown to correlate with decreased dependency on oxidative phosphorylation and ATP concentration in EnSCs.

Induced pluripotent stem cells throughout the animal kingdom: Availability and applications

Up until the mid 2000s, the capacity to generate every cell of an organism was exclusive to embryonic stem cells. In 2006, researchers Takahashi and Yamanaka developed an alternative method of generating embryonic-like stem cells from adult cells, which they coined induced pluripotent stem cells (iPSCs). Such iPSCs possess most of the advantages of embryonic stem cells without the ethical stigma associated with derivation of the latter. The possibility of generating “custom-made” pluripotent cells, ideal for patient-specific disease models, alongside their possible applications in regenerative medicine and reproduction, has drawn a lot of attention to the field with numbers of iPSC studies published growing exponentially. IPSCs have now been generated for a wide variety of species, including but not limited to, mouse, human, primate, wild felines, bovines, equines, birds and rodents, some of which still lack well-established embryonic stem cell lines. The paucity of robust characterization of some of these iPSC lines as well as the residual expression of transgenes involved in the reprogramming process still hampers the use of such cells in species preservation or medical research, underscoring the requirement for further investigations. Here, we provide an extensive overview of iPSC generated from a broad range of animal species including their potential applications and limitations.