Search Results (78)

Efficient in vitro regeneration remains a major constraint in the genetic transformation, genome editing, and molecular breeding of wheat (Triticum aestivum L.), largely due to strong genotype-dependent recalcitrance and limited activation of developmental programs required for somatic embryogenesis. Plant regeneration relies on extensive transcriptional reprogramming and epigenetic remodeling orchestrated by morphogenic regulators that modulate meristem identity, as well as cellular pluri- and totipotency. In this review, we synthesize current molecular knowledge on key transcription factors (BBM, WUS/WUS2, GRF-GIF, WOX, LAX1, SERK, WIND1/ERF115) and signaling peptides (CLE/CLV-WUS module, phytosulfokine/PSK) that regulate embryogenic competence in monocot cereals, with emphasis on their orthologs and functional relevance in wheat. We highlight how controlled expression of these morphogenic genes, promoter engineering, and transient or excisable induction systems can significantly enhance regeneration capacity, reduce chimerism in CRISPR-Cas-edited plants, and facilitate genotype-independent transformation. We also discuss epigenetic and metabolic constraints underlying wheat recalcitrance and their potential modulation to improve culture responsiveness. By integrating evidence from wheat, rice, maize, and barley, we outline conserved gene-regulatory networks that reinitiate totipotency and propose strategies to accelerate doubled haploid production and speed-breeding pipelines. Collectively, morphogenic factors emerge as central molecular tools for overcoming regeneration bottlenecks and enabling next-generation wheat improvement. The objective of this review is to synthesize and critically evaluate current molecular knowledge on morphogenic regulators controlling in vitro regeneration in wheat (Triticum aestivum L.), with particular emphasis on their roles in genetic transformation and genome editing. Full article

Generation of state-of-the-art highly productive cabbage genotypes (Brassica oleracea convar. capitata (L.) Alef.) with improved agronomic traits is attainable using modern biotechnological approaches. However, capitata cabbage is relatively recalcitrant to de novo shoot organogenesis from callus tissue, especially with loss of somatic cell totipotency during genetic transformation. An effective and rapid protocol for in vitro indirect shoot organogenesis from hypocotyl and cotyledon explants derived from 6-day-old aseptic donor seedlings of Russian cabbage genotypes (the DH line as well as cvs. Podarok and Parus) has been developed. In order to obtain standardized donor explants, aseptic cabbage seeds were germinated under dim light conditions (30–40 µmol m⁻² s⁻¹) with a 16 h light/8 h dark photoperiod. Multiple indirect shoot organogenesis (1.47–4.93 shoots per explant) from both cotyledonary leaves and hypocotyl segments with a frequency of 55.2–89.1% was achieved through 45 days of culture on the 0.7% agar-solidified (w/v) Murashige and Skoog (MS) basal medium containing 2 mg/L 6-benzylaminopurine (6-BAP), 0.02 mg/L 1-naphthalene acetic acid (NAA), and 5 mg/L AgNO₃. The regenerants were successfully rooted on an MS basal medium (69.2%) without plant growth regulators (PGRs), as well as supplemented with 0.5 mg/L NAA (86.8%). Subsequently, in vitro rooted cabbage plantlets were adapted to soil conditions with an efficiency of 85%. This rapid protocol, allowing for the performance of a full cycle from in vitro seed germination to growing adapted plantlets under ex vitro conditions over 95 days, can be successfully applied to induce an indirect shoot formation in various cabbage genotypes, and it is recommended to produce transgenic plants with improved quality traits and productivity. Full article

The metabolic hyperactivity of tumor cells demands a substantial amount of energy and molecules to build new cells and expand the tumor, diverting these resources from healthy cells. Amino acids (AAs) are the only totipotent and essential molecules for protein construction. Previous in vitro studies in human and murine cancer cells, along with in vivo studies in mice, have shown that an excess of essential amino acids (EAAs) exerts an inhibitory effect on tumor proliferation by promoting apoptosis and autophagy. In this study, both in vitro and in vivo, we evaluated whether a mixture based on EAA can influence the development of human colon cancer (HCT116). To this end, in vitro, we assessed the proliferation of HCT116 cells treated with a special mix of EAA. In vivo, immunosuppressed athymic nude mice, injected with HCT116 cells subcutaneously (s.c.) or intraperitoneally (i.p.), were given a modified EAAs-rich diet (EAARD) compared to the standard laboratory diet (StD). In vitro data showed that the EAA mix impairs cancer growth by inducing apoptosis and autophagy. In vivo, the results demonstrated that EAARD-fed mice developed s.c. tumors significantly smaller than those of StD-fed mice (total mass 3.24 vs. 6.09 g, respectively). Mice injected i.p. and fed with EAARD showed a smaller and more limited number of intra-peritoneal tumors than StD-fed mice (total mass 0.79 vs. 4.77 g, respectively). EAAs prevents the growth of HCT116 cells by inducing autophagy and apoptosis, increasing endoplasmic reticulum stress, and inhibiting inflammation and neo-vascularization. In addition, the EAARD-fed mice, maintained muscle mass and white and brown adipose tissues. A diet with an excess of EAAs affects the survival and proliferative capacity of human colon cancer cells, maintaining anabolic stimuli in muscular cells. Full article

Embryogenesis and tumorigenesis share several key biological characteristics, such as rapid cell proliferation, high plasticity, and immune evasion. This similarity indicates that developmental pathways can be hijacked, leading to the formation of malignant cell states. With regard to this, cancer can be regarded as a stem cell disease. On the contrary, a fetus, in many ways, has similar characteristics to the “ideal tumor”, such as immune evasion and rapid growth. Therefore, deciphering the molecular mechanisms beneath these phenomena will help us to understand the embryonic origins of cancer. This review discusses the relationship between embryogenesis and tumorigenesis, highlighting the potential roles played by DUX4. DUX4 is involved in the activation of the zygote genome and then facilitates the establishment of totipotency in pre-implantation embryos, whereas the misexpression of DUX4 is associated with different types of cancer. Taken together, this indicates that DUX4 performs analogous functions in these two processes and connects embryogenesis and tumorigenesis. Through examining DUX4, this review underscores the importance of developmental mechanisms in cancer biology, suggesting that the insights gained from studying embryonic processes may provide novel therapeutic strategies. As we continue to explore the complex relationship between cancer and embryogenesis, elucidating the role of DUX4 in linking these two processes will be critical for developing targeted therapies that exploit developmental pathways. Full article

Callus browning is a significant problem that hinders plant tissue regeneration in Paeonia ostii “Fengdan” by causing cell death and inhibiting growth. However, the molecular mechanism underlying callus browning in P. ostii remains unclear. In this study, we investigated the metabolites and potential regulatory genes involved in callus browning of P. ostii using metabolomic and transcriptomic analyses. We found a significant accumulation of phenolic compounds in the browned callus, represented by flavonoid compounds. Notably, the accumulations of luteotin and disomentin were higher in browning calli compared to non-browning calli. Transcriptomic analysis identified that candidate genes associated with flavonoid biosynthesis, including flavonoid 3-hydroxylase (PoF3H) and flavone synthase II (PoFNSII), were highly expressed in the browned callus of P. ostii “Fengdan”. Weighted gene co-expression network analysis (WGCNA) further highlighted that polyphenol oxidase (PoPPO) which encoded polyphenol oxidase, together with flavonoid biosynthesis-related genes such as flavanone 3-hydroxylase (PoF3H) and flavonone Synthase II (PoFNSII), as well as cellular totipotency-related genes wuschel-related homeobox 4 (PoWOX4), were involved in callus browning. Based on these findings, we proposed the molecular mechanism by which flavonoid accumulation, polyphenol oxidation, and cellular totipotency pathways contribute to callus browning in P. ostii. Our study provides new insights into the molecular mechanism underlying callus browning and offers the foundations to facilitate the establishment of an efficient plant tissue regeneration system in P. ostii. Full article

Discourses on human embryo experimentation often refer to monozygotic twinning and individuation. A criterion to establish regulations that guide human embryo research proposes that individuation is achieved once the embryo ceases to have the potential for dividing into two or more viable entities at about 15 days of gestational age. This standard is based on an updated version of a developmental model initially proposed by George Corner. A fundamental problem with this approach is the model’s lack of sufficient evidence to explain adequately human embryo twinning and, consequently, to serve as a basis to establish appropriate ethical guidelines for embryo experimentation. In addition, subsequent formulations of Corner’s model added an extension of blastomere totipotency to different moments of gestation, without a proper scientific basis. The model is also challenged by monozygotic twinnings that result in placental and amniotic arrangements incompatible with Corner’s framework. Investigations into the physiology of fertilisation and of the zygote suggest that individuation may occur at a very early stage. An alternative description of monozygotic twinning may explain better sesquizygotic twinning events and serve to re-evaluate the individuation criterion. The study aims to investigate deficiencies in the embryology of this model and assess their ethical implications. Full article

Background and Clinical Significance: Head and neck teratomas are embryonal tumors that develop when totipotent germ cells escape the developmental control of primary organizers and form a more-or-less organoid mass in which tissues from all three germ layers (ectoderm, endoderm, and mesoderm) can be identified. Mature teratomas may either transit into germ cell or non-germ cell malignancies or remain histologically mature with the possibility of growing, thus inducing certain complications when reaching a large size. This article aims to investigate a very rare case of a 6-year-old child who exhibited a recurrent intraoral mass with multiple conflicting biopsies. Case Presentation: A 6-year-old male patient was referred to the postgraduate clinic of the Department of Oral Medicine/Pathology, Dental School, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece, because his pediatric dentist noticed an exophytic, intraoral mass, distal to tooth #75 during a routine checkup. The first histopathological examination showed a gingival tumor, classified as a small round blue cell tumor, with greater similarity to adamantinoma-like Ewing sarcoma (ALES) and less to synovial sarcoma. The second pathologist examined the same tissue specimen and suggested the extremely rare presence of an immature malignant teratoma. Following chemotherapy, the rest of the teratoma with the adjacent tooth #75 was removed, and the histopathological examination showed a mature teratoma. Conclusions: This case illustrates the crucial role of the dentist, and in this case of the pediatric dentist, to promptly diagnose the underlying disease. Genetic screening may assist in detecting high-risk populations. In such complex histopathological cases, the importance of cooperating with experienced oral and maxillofacial pathologists is highlighted. We describe a rare case of intraoral malignant teratoma, and an extended literature review revealed that our case is the first ever reported. Full article

Lactating oocytes consume a lot of energy during maturation, a large part of which comes from lipid metabolism. PPARγ is a key regulator of lipid metabolism. In this study, rosiglitazone (RSG), an activator of PPARγ, was added to a mature medium to investigate its effects on the levels of spindle and the chromosome arrangement, lipid deposition, reactive oxygen species (ROS), and glutathione (GSH) levels, oocyte secretion factors, apoptosis and lipid metabolism-related gene expression, and subsequent embryonic development during the maturation of sheep oocytes. The oocyte secretion factor affects gene expression related to apoptosis and lipid metabolism and subsequent embryonic development. The results showed that the proportion of spindle and normal chromosome arrangements increased in the 5 μM RSG treatment group, the lipid content increased after cell maturation, the ROS level decreased, and the GSH level increased. The expressions of oocyte secretion factor (GDF9 and BMP15), anti-apoptosis gene (BCL2), and lipid metabolism-related genes (ACAA1, CPT1A, PLIN2) were increased in the 5 μM treatment group. Finally, the development of blastocysts was examined. After the oocytes were treated with 5 μM RSG, the blastocyst rate and the gene expression of the totipotency gene (OCT4) were increased. It was concluded that increasing PPARγ activity during ovine oocyte maturation could promote lipid metabolism, reduce oxidative stress, and improve the ovine oocyte maturation rate and subsequent embryo development. Full article

The regeneration of plant somatic cells is a prerequisite for their biological breeding. Identification of key genes controlling embryogenic callus (EC) differentiation and investigation of the genetic mechanism of cell fate determination are important for improving plant variety. In this study, we used the maize inbred line KN5585 and its gene-edited mutants Zmprx19-1, Zmprx19-2 and Zmprx19-3 as plant materials. Three somatic regeneration-related traits, the embryogenic callus induction rate (EIR), green callus rate (GCR) and plantlet regeneration rate (PRR), were identified by tissue culture of immature embryos. Additionally, the ECs at different differentiation stages (0 d, 5 d, 10 d and 15 d) were subjected to RNA-seq, and comparative transcriptome analyses were performed. The results showed that the somatic regeneration traits of the mutants were all highly significantly lower than those of the wild type (p < 0.01). The PRR value of KN5585 was 75.25%, while the highest PRR of the mutants was only 15.08%, indicating that knockdown of ZmPRX19 inhibited EC regeneration. Transcriptome sequencing yielded a total of 200.30 Gb of clean data from 24 libraries, with an average of 6.53 Gb of clean data per library. Mutant and wild-type gene expression data were compared separately at four differentiation stages, and 689 common differentially expressed genes (DEGs) were screened. WGCNA was used to classify these genes into nine modules, which were subsequently subjected to GO and KEGG enrichment analyses. In total, 40, 23, 17 and 5 genes were significantly (q < 0.05) enriched in plant hormone signal transduction, the MAPK signaling pathway-plant, phenylpropanoid biosynthesis and photosynthesis, respectively. Moreover, protein–protein interaction (PPI) network analysis revealed five MAPKKK17_18 hub nodes involved in the MAPK pathway-plant, which may be the key genes controlling plantlet differentiation from ECs. The above results provide a basis for the final elucidation of the molecular mechanism of plant somatic regeneration. Full article

Flatworms are known for their remarkable regenerative ability, one which depends on totipotent cells known as germinative cells in cestodes. Depletion of germinative cells with hydroxyurea (HU) affects the regeneration of the parasite. Here, we studied the reduction and recovery of germinative cells in T. crassiceps cysticerci after HU treatment (25 mM and 40 mM of HU for 6 days) through in vitro assays. Viability and morphological changes were evaluated. The recovery of cysticerci’s mobility and morphology was evaluated at 3 and 6 days, after 6 days of treatment. The number of proliferative cells was evaluated using EdU. Our results show morphological changes in the size, shape, and number of evaginated cysticerci at the 40 mM dose. The mobility of cysticerci was lower after 6 days of HU treatment at both concentrations. On days 3 and 6 of recovery after 25 mM of HU treatment, a partial recovery of the proliferative cells was observed. Proteomic and Gene Ontology analyses identified modifications in protein groups related to DNA binding, DNA damage, glycolytic enzymes, cytoskeleton, skeletal muscle, and RNA binding. Full article

The generation of mature gametes and competent embryos in vitro from pluripotent stem cells has been successfully achieved in a few species, mainly in mice, with recent advances in humans and scarce preliminary reports in other domestic species. These biotechnologies are very attractive as they facilitate the understanding of developmental mechanisms and stages that are generally inaccessible during early embryogenesis, thus enabling advanced reproductive technologies and contributing to the generation of animals of high genetic merit in a short period. Studies on the production of in vitro embryos in pigs and cattle are currently used as study models for humans since they present more similar characteristics when compared to rodents in both the initial embryo development and adult life. This review discusses the most relevant biotechnologies used in veterinary medicine, focusing on the generation of germ-cell-like cells in vitro through the acquisition of totipotent status and the production of embryos in vitro from pluripotent stem cells, thus highlighting the main uses of pluripotent stem cells in livestock species and reproductive medicine. Full article

Background: The primary co-occurrence of gonadal and extragonadal central nervous system (CNS) germ cell tumors (GCTs) has rarely been reported in the literature, and a common opinion on the underlying etiopathogenetic mechanism is lacking. Objective: We aim to investigate the pathophysiological mechanisms and genetic pathways underlying the primary co-occurrence of gonadal and CNS GCTs. Methods: We reviewed data from 29 consecutive patients with a diagnosis of CNS GCT, evaluated in our Hospital over the past 23 years, and searched for those who had at least a primary gonadal co-occurrence of GCT. A systematic review of the literature according to the PRISMA guidelines was also conducted. For a comprehensive and detailed search, PubMed, Ovid MEDLINE, and Ovid EMBASE databases have been consulted. Boolean operators and MeSH terms were used to find studies. Only articles published between 2000 and 2023 were considered. Results: Including our Institutional case report, a total of 7 patients with both testicular NGGCTs and CNS GCTs were identified (5 patients with metachronous tumors and patients with synchronous presentation). The average age at tumor diagnosis was 17 years. The cerebral histotypes reported were mixed GCTs (3 cases; 43%), pure germinomas (3 cases, 43%), and one yolk sac tumor (14%). Two out of seven cases (29%) were syndromic, one suffering from Down Syndrome and the other from Testicular Dysgenesis Syndrome. Regarding the etiology and molecular mechanism of GCT development, several gene mutations have been reported in the literature. Particularly, genetic alterations in the MAPK and/or PI3K/AKT/mTOR pathway, together with mutations of the KIT gene, have been shown to guarantee survival and transformation of mismigrated totipotent primordial germ cells, while suppressor genes allow their resistance against apoptotic death. Aberrant chromosomes have also been reported to be responsible for oncogenic transformation. It is also known that CNS and testicular GCTs share some genetic/epigenetic profiles. Conclusions: The primary co-occurrence of testicular NGGCT and extragonadal CNS GCTs is extremely rare. Genetic factors seem to play a paramount role in their etiopathogenesis. Additional research is needed to elucidate molecular mechanisms of oncogenesis in such patients. Full article

Oocytes are efficient at reprogramming terminally differentiated cells to a totipotent state. Nuclear transfer techniques can exploit this property to produce cloned animals. However, the overall efficiency is low. The use of umbilical cord mesenchymal stem cells (UC-MSCs) as donor nuclei may increase blastocyst rates, but the exact reasons for this remain unexplored. A single-cell transcriptomic approach was used to map the transcriptome profiles of eight-cell embryos that were in vitro-fertilized and handmade-cloned using umbilical cord mesenchymal stem cells and fibroblasts as nuclear donors. Differences were examined at the chromatin level, the level of differentially expressed genes, the level of histone modifications and the level of DNA methylation. This research provides critical information regarding the use of UC-MSCs as a preferred donor nucleus for nuclear transfer techniques. It also offers unique insights into the mechanism of cellular reprogramming. Full article

Camelina is an oil seed crop that is enjoying increasing interest because it has a particularly valuable fatty acid profile, is modest regarding its water and nutrient requirements, and is comparatively resilient to abiotic and biotic stress factors. The regeneration of plants from cells accessible to genetic manipulation is an essential prerequisite for the generation of genetically engineered plants, be it by transgenesis or genome editing. Here, immature embryos were used on the assumption that their incomplete differentiation was associated with totipotency. In culture, regenerative structures appeared adventitiously at the embryos’ hypocotyls. For this, the application of auxin- or cytokinin-type growth regulators was essential. The formation of regenerative structures was most efficient when indole-3-acetic acid was added to the induction medium at 1 mg/L, zygotic embryos of the medium walking stick stage were used, and their hypocotyls were stimulated by pricking to a wound response. Histological examinations revealed that the formation of adventitious shoots was initiated by locally activated cell division and proliferation in the epidermis and the outer cortex of the hypocotyl. While the regeneration of plants was established in principle using the experimental line Cam139, the method proved to be similarly applicable to the current cultivar Ligena, and hence it constitutes a vital basis for future genetic engineering approaches. Full article