scholarly journals Efficient generation of zebrafish maternal-zygotic mutants through transplantation of ectopically induced and Cas9/gRNA targeted PGCs

2019 ◽  
Author(s):  
Fenghua Zhang ◽  
Xianmei Li ◽  
Mudan He ◽  
Ding Ye ◽  
Feng Xiong ◽  
...  

ABSTRACTThe CRISPR/Cas9 technology has been widely utilized for knocking out genes involved in various biological processes in zebrafish. Despite this technology is efficient for generating different mutations, one of the main drawbacks is low survival rates during embryogenesis when knocking out some embryonic lethal genes. To overcome this problem, we developed a novel strategy using a combination of CRISPR/Cas9 mediated gene knockout with primordial germ cells (PGCs) transplantation to facilitate and speed up the process of zebrafish mutant generation, particularly for embryonic lethal genes. First, we optimized the procedure for gRNA targeted PGCs transplantation (PGCT), by increasing the efficiencies of genome mutation in PGCs and induction of PGCs fates in donor embryos for PGCT. Second, the combined CRISPR/Cas9 with PGCT was utilized for generation of maternal zygotic (MZ) mutants of tcf7l1a (essential gene for head development), pou5f3 (essential gene for zygotic genome activation) and chd (essential gene for dorsal development) at F1 generation with high efficiency. Finally, we revealed some novel phenotypes in the maternal zygotic mutant of tcf7l1a and chd, while MZtcf7l1a showed elevated neural crest development, and MZchd have stronger ventralization than its zygotic counterparts. Therefore, this study presents an efficient and powerful method for generating MZ mutants of embryonic lethal genes in zebrafish.

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Elisa Dorantes-Acosta ◽  
Rosana Pelayo

Acute leukemias are the most common cancer in childhood and characterized by the uncontrolled production of hematopoietic precursor cells of the lymphoid or myeloid series within the bone marrow. Even when a relatively high efficiency of therapeutic agents has increased the overall survival rates in the last years, factors such as cell lineage switching and the rise of mixed lineages at relapses often change the prognosis of the illness. During lineage switching, conversions from lymphoblastic leukemia to myeloid leukemia, or vice versa, are recorded. The central mechanisms involved in these phenomena remain undefined, but recent studies suggest that lineage commitment of plastic hematopoietic progenitors may be multidirectional and reversible upon specific signals provided by both intrinsic and environmental cues. In this paper, we focus on the current knowledge about cell heterogeneity and the lineage switch resulting from leukemic cells plasticity. A number of hypothetical mechanisms that may inspire changes in cell fate decisions are highlighted. Understanding the plasticity of leukemia initiating cells might be fundamental to unravel the pathogenesis of lineage switch in acute leukemias and will illuminate the importance of a flexible hematopoietic development.


2021 ◽  
Author(s):  
Weidong Fei ◽  
Yunchun Zhao ◽  
Xiaodong Wu ◽  
Dongli Sun ◽  
Yao Yao ◽  
...  

Abstract The gestational trophoblastic tumor seriously endangers child productive needs and the health of women in childbearing age. Nanodrug-based therapy mediated by transporters provides novel strategy for the treatment of trophoblastic tumors. Focus on the overexpressed human equilibrative nucleoside transporter 1 (ENT1) on the membrane of choriocarcinoma cells (JEG-3), the cytarabine (Cy, a substrate of ENT1) grafted liposome (Cy-Lipo) was introduced for targeted delivery of methotrexate (Cy-Lipo@MTX) for choriocarcinoma therapy in this study. The ENT1 has high affinity for Cy-Lipo and can mediate the endocytosis of the designed nanovehicles into JEG-3 cells. The ENT1 protein maintains its transporting function through circulation and regeneration during endocytosis. Therefore, Cy-Lipo-based formulations achieved high tumor accumulation and retention in pharmacokinetic and distribution studies. More importantly, the designed Cy-lipid conjugation exhibited a synergistic therapeutic effect on choriocarcinoma. Finally, Cy-Lipo@MTX exerts an extremely powerful anti-choriocarcinoma effect with fewer side effects. This study suggests that the overexpressed ENT1 on choriocarcinoma cells holds a great potential to be a high-efficiency target for the rational design of active targeting nanotherapeutics.


2018 ◽  
Vol 6 (47) ◽  
pp. 24267-24276 ◽  
Author(s):  
Wenhong Peng ◽  
Guangjun Zhang ◽  
Lin Shao ◽  
Chao Ma ◽  
Bin Zhang ◽  
...  

A novel strategy is proposed to construct simple-structured SMAs using a weakly electron-deficient thiazolothiazole (TTz) core. The highest PCE of 8.77% is recorded for TTz1-based OSCs, which is the highest efficiency to date among non-fullerene OSCs with simple-structured SMAs.


2004 ◽  
Vol 5 (3) ◽  
pp. 219-226 ◽  
Author(s):  
Satoko Arai ◽  
Christina Minjares ◽  
Seiho Nagafuchi ◽  
Toru Miyazaki

The manipulation of a specific gene in NOD mice, the best animal model for insulin-dependent diabetes mellitus (IDDM), must allow for the precise characterization of the functional involvement of its encoded molecule in the pathogenesis of the disease. Although this has been attempted by the cross-breeding of NOD mice with many gene knockout mice originally created on the 129 or C57BL/6 strain background, the interpretation of the resulting phenotype(s) has often been confusing due to the possibility of a known or unknown disease susceptibility locus (e.g.,Iddlocus) cosegregating with the targeted gene from the diabetes-resistant strain. Therefore, it is important to generate mutant mice on a pure NOD background by using NOD-derived embryonic stem (ES) cells. By using the NOD ES cell line established by Nagafuchi and colleagues in 1999 (FEBSLett., 455, 101–104), the authors reexamined various conditions in the context of cell culture, DNA transfection, and blastocyst injection, and achieved a markedly improved transmission efficiency of these NOD ES cells into the mouse germ line. These modifications will enable gene targeting on a “pure” NOD background with high efficiency, and contribute to clarifying the physiological roles of a variety of genes in the disease course of IDDM.


RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40727-40733 ◽  
Author(s):  
Youzhi Cao ◽  
Qin Gao ◽  
Qiao Li ◽  
Xinbo Jing ◽  
Shufen Wang ◽  
...  

A novel strategy was applied for the preparation of MoS2/graphitic carbon nitride (g-C3N4) with porous morphology.


Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 407-411 ◽  
Author(s):  
Y. Tsunoda ◽  
T. Tokunaga ◽  
H. Imai ◽  
T. Uchida

We examined the developmental ability of enucleated eggs receiving embryonic nuclei and male primordial germ cells (PGCs) in the mouse. Reconstituted eggs developed into the blastocyst stage only when an earlier 2-cell nucleus was transplanted (36%) but very rarely if the donor nucleus was derived from a later 2-cell, 8-cell, or inner cell mass of a blastocyst (0–3%). 54–100%, 11–67%, 6–43% and 6–20% of enucleated eggs receiving male PGCs developed to 2-cell, 4-cell, 8-cell and blastocyst stage, respectively, in culture. The overall success rate when taking into account the total number of attempts at introducing germ cells was actually 0–6%. Live fetuses were not obtained after transfer of reconstituted eggs to recipients, although implantation sites were observed. The developmental ability of reconstituted eggs in relation to embryonic genome activation and genomic imprinting is discussed.


Genome ◽  
2006 ◽  
Vol 49 (11) ◽  
pp. 1416-1427 ◽  
Author(s):  
E.A. Silva ◽  
B.J. Lee ◽  
L.S. Caceres ◽  
D. Renouf ◽  
B.R. Vilay ◽  
...  

This report describes a novel strategy for isolating Drosophila mutants with conditional eye phenotypes that should be generally applicable for identifying genes required for cellular responses to specific drugs. To test the strategy, we screened 3 of the 5 major chromosome arms for hydroxyurea- and (or) caffeine-sensitive (huc) mutants, and isolated mutations affecting 5 different complementation groups. Most of these were represented by single alleles; however, we also isolated multiple alleles of huc29DE gene, an essential gene that is also associated with a nonconditional pupal lethal phenotype. We also identified huc95E mutants, which are extremely sensitive to caffeine. Although huc95E is a nonessential gene, mutant imaginal disc cells undergo caffeine-dependent apoptosis, and huc95E gene function is required for the viability of the organism when mutant larvae are exposed to levels of caffeine that controls can easily tolerate. We have mapped the cytological positions of huc29D and huc95E as a first step toward molecularly characterizing the relevant genes.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1149-1149
Author(s):  
Charlotte L Kaestner ◽  
Amin Sobh ◽  
Jianping Li ◽  
Alberto Riva ◽  
Richard Lynn Bennett ◽  
...  

Abstract Background: Acute Lymphoblastic Leukemia (ALL) is the most common childhood cancer and frequently infiltrates the central nervous system (CNS). CNS-directed therapy is currently limited to intrathecal and systemic high-dose methotrexate, or less commonly craniospinal irradiation, both of which are associated with substantial neurotoxicity. A lack of mechanistic understanding of the mechanisms of CNS infiltration presents an obstacle for the development of more specific and less toxic therapeutic approaches. We previously showed that ALL cells with a specific mutation (E1099K) in the histone methyltransferase NSD2 have aggressive CNS tropism by not only infiltrating the leptomeninges but also the brain parenchyma in murine xenografts models. Analysis of cBioPortal data shows that NSD2-E1099K is associated with a higher rate of testicular involvement in ALL also suggesting more aggressive infiltration behavior of the tumor. Accordingly, using gene editing to revert mutant NSD2 back to wild-type, we also showed that NSD2-E1099K cells have an enhanced ability to migrate and adhere in vitro. RNA-seq data on four NSD2-E1099K cell lines revealed genes that may play a role in ALL brain infiltration. However, it remains unknown which of those upregulated genes could be potential therapeutic targets against CNS leukemia. Aim: This study aims to Identify therapeutically targetable genes that are important for migration of NSD2-E1099K ALL cells Methods: Using a focused CRISPR-gene-knockout library of 5600 sgRNAs directed against 500 genes upregulated in NSD2-E1099K cells, we ascertained the necessity of the selected genes for migration in the RCH-ACV cell line. Candidate genes were evaluated for cellular dependency using a CRISPR-loss of function screen and the cancer dependency map portal. Overexpression of the candidate genes in NSD2-E1099K cell lines was confirmed with qPCR analysis. Candidate genes were validated by individual shRNA knockdown followed by migration and adhesion assays. Results: Our study identified genes whose knockout led to enhancement of migration and others whose knockout resulted in inhibition of migration. Protein Tyrosine Phosphatase Receptor Type G (PTPRG) was one of the top candidate genes whose knockout resulted in inhibition of migration. Dependency map analysis showed that PTPRG is not a commonly essential gene and a CRISPR-based-loss-of function screen performed in parallel to the migration screen confirmed that ALL cell survival is not dependent on PTPRG. We also found that PTPRG is overexpressed in multiple NSD2-E1099K ALL cell lines. Individual Knockdown of PTPRG in NSD2-E1099K ALL cell lines not only inhibited migration, but also led to a loss of adhesion ability to endothelial cells of the Blood Brain Barrier. Conclusions: Our findings implicate PTPRG as an important modulator of migration and adhesion in ALL cells and a potential therapeutic target for preventing ALL brain infiltration, especially in NSD2-E1099K ALL. Disclosures Licht: Epizyme: Research Funding.


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