scholarly journals HAM Gene Family and Shoot Meristem Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuan Geng ◽  
Yun Zhou

Land plants develop highly diversified shoot architectures, all of which are derived from the pluripotent stem cells in shoot apical meristems (SAMs). As sustainable resources for continuous organ formation in the aboveground tissues, SAMs play an important role in determining plant yield and biomass production. In this review, we summarize recent advances in understanding one group of key regulators – the HAIRY MERISTEM (HAM) family GRAS domain proteins – in shoot meristems. We highlight the functions of HAM family members in dictating shoot stem cell initiation and proliferation, the signaling cascade that shapes HAM expression domains in shoot meristems, and the conservation and diversification of HAM family members in land plants. We also discuss future directions that potentially lead to a more comprehensive view of the HAM gene family and stem cell homeostasis in land plants.

Author(s):  
S. Tamir Rashid ◽  
Ludovic Vallier

Following Shinya Yamanaka's first report describing the reprogramming of fibroblasts into stem cells over three years ago, some sceptics initially drew analogies between this new field of research and the quasi-mystical practice of ‘alchemy’. Unlike the alchemist, however, stem cell researchers have rigorously tested and repeated experiments, proving their very own brand of cellular ‘alchemy’ to be a reality, with potentially massive implications for the study of human biology and clinical medicine. These investigations have resulted in an explosion of related publications and initiated the field of stem cell research known as ‘induced pluripotency’. In this review, we give an account of the historical development, current technologies and potential clinical applications of induced pluripotency and conclude with a perspective on the possible future directions for this dynamic field.


1989 ◽  
Vol 264 (12) ◽  
pp. 7046-7053 ◽  
Author(s):  
C M Giachelli ◽  
J Lin-Jones ◽  
C J Omiecinski

2021 ◽  
Vol 22 (9) ◽  
pp. 5011
Author(s):  
Daehwan Kim ◽  
Sangho Roh

Stem cell research is essential not only for the research and treatment of human diseases, but also for the genetic preservation and improvement of animals. Since embryonic stem cells (ESCs) were established in mice, substantial efforts have been made to establish true ESCs in many species. Although various culture conditions were used to establish ESCs in cattle, the capturing of true bovine ESCs (bESCs) has not been achieved. In this review, the difficulty of establishing bESCs with various culture conditions is described, and the characteristics of proprietary induced pluripotent stem cells and extended pluripotent stem cells are introduced. We conclude with a suggestion of a strategy for establishing true bESCs.


Author(s):  
Anja Trillhaase ◽  
Marlon Maertens ◽  
Zouhair Aherrahrou ◽  
Jeanette Erdmann

AbstractStem cell technology has been around for almost 30 years and in that time has grown into an enormous field. The stem cell technique progressed from the first successful isolation of mammalian embryonic stem cells (ESCs) in the 1990s, to the production of human induced-pluripotent stem cells (iPSCs) in the early 2000s, to finally culminate in the differentiation of pluripotent cells into highly specialized cell types, such as neurons, endothelial cells (ECs), cardiomyocytes, fibroblasts, and lung and intestinal cells, in the last decades. In recent times, we have attained a new height in stem cell research whereby we can produce 3D organoids derived from stem cells that more accurately mimic the in vivo environment. This review summarizes the development of stem cell research in the context of vascular research ranging from differentiation techniques of ECs and smooth muscle cells (SMCs) to the generation of vascularized 3D organoids. Furthermore, the different techniques are critically reviewed, and future applications of current 3D models are reported. Graphical abstract


2020 ◽  
Vol 31 (23) ◽  
pp. 2583-2596
Author(s):  
John M. Boyle ◽  
Kelsey M. Hennick ◽  
Samuel G. Regalado ◽  
Jacob M. Vogan ◽  
Xiaozhu Zhang ◽  
...  

To better understand telomere length set point control in human stem cells, we generated knockout stem cell lines for TPP1 and contrasted their phenotypes with those of homozygous TPP1 L104A mutant stem cells. This comparison reveals that TPP1 L104A is not a hypomorphic allele but formally establishes TPP1 L104 as a dissociation of function mutant.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiumei Miao ◽  
Lijing Zhang ◽  
Xiaowei Hu ◽  
Shuzhen Nan ◽  
Xiaolong Chen ◽  
...  

Abstract Background Linoleic acid is an important polyunsaturated fatty acid, required for all eukaryotes. Microsomal delta-12 (Δ12) oleate desaturase (FAD2) is a key enzyme for linoleic acid biosynthesis. Desert shrub Artemisia sphaerocephala is rich in linoleic acid, it has a large FAD2 gene family with twenty-six members. The aim of this work is to unveil the difference and potentially functionality of AsFAD2 family members. Results Full-length cDNAs of twenty-one AsFAD2 genes were obtained from A. sphaerocephala. The putative polypeptides encoded by AsFAD2 family genes showed a high level of sequence similarity and were relatively conserved during evolution. The motif composition was also relatively conservative. Quantitative real-time PCR analysis revealed that the AsFAD2–1 gene was strongly expressed in developing seeds, which may be closely associated with the high accumulating ability of linoleic acid in A. sphaerocephala seeds. Although different AsFAD2 family members showed diverse response to salt stress, the overall mRNA levels of the AsFAD2 family genes was stable. Transient expression of AsFAD2 genes in the Nicotiana benthamiana leaves revealed that the encoded proteins were all located in the endoplasmic reticulum. Heterologous expression in Saccharomyces cerevisiae suggested that only three AsFAD2 enzymes, AsFAD2–1, − 10, and − 23, were Δ12 oleate desaturases, which could convert oleic acid to linoleic acid, whereas AsFAD2–1 and AsFAD2–10 could also produce palmitolinoleic acid. Conclusions This research reported the cloning, expression studies, subcellular localization and functional identification of the large AsFAD2 gene family. These results should be helpful in understanding fatty acid biosynthesis in A. sphaerocephala, and has the potential to be applied in the study of plant fatty acids traits.


2015 ◽  
Vol 24 (3) ◽  
pp. 341-357 ◽  
Author(s):  
Michael Burns ◽  
Carolyn Baylor ◽  
Brian J. Dudgeon ◽  
Helene Starks ◽  
Kathryn Yorkston

PurposeThe purpose of this study was to explore the experiences of patients with aphasia, their family members, and physicians related to communication during medical interactions.MethodFace-to-face, semistructured interviews were conducted with 18 participants—6 patients with aphasia, 6 family members involved in patient care, and 6 practicing physicians. A qualitative description approach was used to collect and summarize narratives from participants' perspectives and experiences. Participants were asked about experiences with communication during medical interactions in which the family member accompanied the patient. Interviews were audio- and/or video-recorded, transcribed, and then coded to identify main themes.ResultsPatients and family members generally described their communication experiences as positive, yet all participants discussed challenges and frustrations. Three themes emerged: (a) patients and family members work as a team, (b) patients and family members want physicians to “just try” to communicate with the patient, and (c) physicians want to interact with patients but may not know how.ConclusionsParticipants discussed the need for successful accommodation, or changing how one communicates, to help facilitate the patients' increased understanding and ability to express themselves. Over- and underaccommodation with communication were commonly reported as problems. Speech-language pathologists have a role to play in helping to improve communication during medical interactions. Implications for current speech-language pathologist practice and future directions of research are discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takamasa Hirai ◽  
Ken Kono ◽  
Rumi Sawada ◽  
Takuya Kuroda ◽  
Satoshi Yasuda ◽  
...  

AbstractHighly sensitive detection of residual undifferentiated pluripotent stem cells is essential for the quality and safety of cell-processed therapeutic products derived from human induced pluripotent stem cells (hiPSCs). We previously reported the generation of an adenovirus (Ad) vector and adeno-associated virus vectors that possess a suicide gene, inducible Caspase 9 (iCasp9), which makes it possible to sensitively detect undifferentiated hiPSCs in cultures of hiPSC-derived cardiomyocytes. In this study, we investigated whether these vectors also allow for detection of undifferentiated hiPSCs in preparations of hiPSC-derived neural progenitor cells (hiPSC-NPCs), which have been expected to treat neurological disorders. To detect undifferentiated hiPSCs, the expression of pluripotent stem cell markers was determined by immunostaining and flow cytometry. Using immortalized NPCs as a model, the Ad vector was identified to be the most efficient among the vectors tested in detecting undifferentiated hiPSCs. Moreover, we found that the Ad vector killed most hiPSC-NPCs in an iCasp9-dependent manner, enabling flow cytometry to detect undifferentiated hiPSCs intermingled at a lower concentration (0.002%) than reported previously (0.1%). These data indicate that the Ad vector selectively eliminates hiPSC-NPCs, thus allowing for sensitive detection of hiPSCs. This cytotoxic viral vector could contribute to ensuring the quality and safety of hiPSCs-NPCs for therapeutic use.


2003 ◽  
Vol 116 (9) ◽  
pp. 1659-1666 ◽  
Author(s):  
R. Gross-Hardt

2021 ◽  
pp. 1-6
Author(s):  
Asuka Morizane ◽  
Jun Takahashi

Stem cell-based therapies for Parkinson’s disease are now being applied clinically. Notably, studies have shown that controlling the graft-induced immune response improves the results. In this mini-review, we concisely summarize current approaches used for this control. We focus on four modes of stem cell-based therapies: autologous transplantation, allogeneic transplantation with human leukocyte antigen-matching and allogeneic transplantation without, and finally the application of “universal” pluripotent stem cells. We also discuss immuno-suppressive treatments and the monitoring of immune reactions in the brain.


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