scholarly journals Can We Use Gene-Editing to Induce Apomixis in Sexual Plants?

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 781 ◽  
Author(s):  
Armin Scheben ◽  
Diego Hojsgaard
Keyword(s):  
Gene Editing ◽  
Endosperm Development ◽  
Egg Cell ◽  
Epigenetic Changes ◽  
Molecular Models ◽  
Specific Expression ◽  
Natural Genetic Variation ◽  
Limited Success ◽  
Substantial Progress ◽  
Hybrid Seeds

Apomixis, the asexual formation of seeds, is a potentially valuable agricultural trait. Inducing apomixis in sexual crop plants would, for example, allow breeders to fix heterosis in hybrid seeds and rapidly generate doubled haploid crop lines. Molecular models explain the emergence of functional apomixis, i.e., apomeiosis + parthenogenesis + endosperm development, as resulting from a combination of genetic or epigenetic changes that coordinate altered molecular and developmental steps to form clonal seeds. Apomixis-like features and synthetic clonal seeds have been induced with limited success in the sexual plants rice and maize by using gene editing to mutate genes related to meiosis and fertility or via egg-cell specific expression of embryogenesis genes. Inducing functional apomixis and increasing the penetrance of apomictic seed production will be important for commercial deployment of the trait. Optimizing the induction of apomixis with gene editing strategies that use known targets as well as identifying alternative targets will be possible by better understanding natural genetic variation in apomictic species. With the growing availability of genomic data and precise gene editing tools, we are making substantial progress towards engineering apomictic crops.

scholarly journals Cell-Selective Regulation of CFTR Gene Expression: Relevance to Gene Editing Therapeutics

Genes ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 235 ◽  
Author(s):  
Hannah Swahn ◽  
Ann Harris
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Gene Editing ◽  
Genetic Diseases ◽  
3D Structure ◽  
Three Dimensional ◽  
Cell Types ◽  
Regulatory Elements ◽  
Cftr Gene ◽  
Specific Expression

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is an attractive target for gene editing approaches, which may yield novel therapeutic approaches for genetic diseases such as cystic fibrosis (CF). However, for gene editing to be effective, aspects of the three-dimensional (3D) structure and cis-regulatory elements governing the dynamic expression of CFTR need to be considered. In this review, we focus on the higher order chromatin organization required for normal CFTR locus function, together with the complex mechanisms controlling expression of the gene in different cell types impaired by CF pathology. Across all cells, the CFTR locus is organized into an invariant topologically associated domain (TAD) established by the architectural proteins CCCTC-binding factor (CTCF) and cohesin complex. Additional insulator elements within the TAD also recruit these factors. Although the CFTR promoter is required for basal levels of expression, cis-regulatory elements (CREs) in intergenic and intronic regions are crucial for cell-specific and temporal coordination of CFTR transcription. These CREs are recruited to the promoter through chromatin looping mechanisms and enhance cell-type-specific expression. These features of the CFTR locus should be considered when designing gene-editing approaches, since failure to recognize their importance may disrupt gene expression and reduce the efficacy of therapies.

scholarly journals Epigenetic Regulation of Plant Gametophyte Development

2019 ◽  
Vol 20 (12) ◽  
pp. 3051 ◽  
Author(s):  
Vasily V. Ashapkin ◽  
Lyudmila I. Kutueva ◽  
Nadezhda I. Aleksandrushkina ◽  
Boris F. Vanyushin
Keyword(s):  
Mother Cell ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Endosperm Development ◽  
Epigenetic Changes ◽  
Gametophyte Development ◽  
Daughter Cells ◽  
Second Stage ◽  
Somatic Tissues ◽  
Mother Cells

Unlike in animals, the reproductive lineage cells in plants differentiate from within somatic tissues late in development to produce a specific haploid generation of the life cycle—male and female gametophytes. In flowering plants, the male gametophyte develops within the anthers and the female gametophyte—within the ovule. Both gametophytes consist of only a few cells. There are two major stages of gametophyte development—meiotic and post-meiotic. In the first stage, sporocyte mother cells differentiate within the anther (pollen mother cell) and the ovule (megaspore mother cell). These sporocyte mother cells undergo two meiotic divisions to produce four haploid daughter cells—male spores (microspores) and female spores (megaspores). In the second stage, the haploid spore cells undergo few asymmetric haploid mitotic divisions to produce the 3-cell male or 7-cell female gametophyte. Both stages of gametophyte development involve extensive epigenetic reprogramming, including siRNA dependent changes in DNA methylation and chromatin restructuring. This intricate mosaic of epigenetic changes determines, to a great extent, embryo and endosperm development in the future sporophyte generation.

scholarly journals GENOMICS AND EPIGENOMICS IN MAIZE HYBRID KERNEL

2018 ◽  
Vol 49 (6) ◽  
Author(s):  
Elsahookie & et al.
Keyword(s):  
Noncoding Rna ◽  
Endosperm Development ◽  
Imprinted Genes ◽  
Specific Expression ◽  
Protein Coding ◽  
Maize Hybrid ◽  
Preferential Expression ◽  
Protein Coding Genes ◽  
Stage Of Development ◽  
Intergenic Regions

The endosperm in cereals supplies nutrients to the developing kernel and seedling, and it is the primary tissue that gene imprinting occurs. Developing maize (Zea mays L.) endosperms were analysed for allelic gene expression in both reciprocal crosses of inbreds B73 and Mo17. A high-throughput transcriptome sequencing in kernels at 0, 3 up to 15 DAP of both reciprocals were performed, and found a gradual increased paternal transcript expression in 3 and 5 DAP kernels. Meanwhile, in 7 DAP endosperm, most of genes tested gave the ratio 2:1 maternal: paternal, suggesting that paternal genes are almost fully activated at 7 DAP. There were 300 PEGs and 499 MEGs identified across endosperm development stages. A 63 genes out of 116, 234 exhibited parent-specific expression were identified at 7, 10 and 15 DAP. Most of paternally expressed genes was at 7 DAP due to deviation of paternal alleles expression at this stage of development. Imprinted genes in terms of relative expression of maternal and paternal alleles differed at least five folds in both crosses. A total of 179 (1.6%) protein coding genes expressed in the endosperm were imprinted, 68 of them showed maternal preferential expression and 111 paternal expression, besides 38 long noncoding RNA were found imprinted and transcribed in either sense or antisense direction from intronic regions of normal protein coding genes or from intergenic regions. Imprinted genes showed clustering around the genome. A total of 21 imprinted  genes in the maize hybrid endosperm had differentially methylated regions (DMRs). All DMRs were found to be hypomethylated in maternal alleles and hypermethylated in paternal alleles. These results confirm a complex mechanism controlling endosperm in maize in imprinting, auxin activity, and development regulation. Studying F2 kernels on F1 plants may shed a new light on controlling kernel number weight in unit of area.

CRISPR/Cas system research has advanced significantly in biological sciences.There are still many challenges to effective delivery before efficient gene editing may be achieved

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Plant Breeding ◽  
Rapid Growth ◽  
Gene Editing ◽  
Life Sciences ◽  
Great Promise ◽  
System Research ◽  
Efficient Gene ◽  
Effective Delivery ◽  
Agricultural Applications ◽  
Substantial Progress

The CRISPR/Cas system's discovery and execution offer great promise for the treatment of human illnesses and the revolutionization of plant breeding. Despite the fact that CRISPR/Cas system research is well advanced in the life sciences community, there are still considerable barriers to effective delivery that must be overcome before effective gene editing can be achieved. Consider characteristics like specificity, efficacy, and controlled expression while deciding on a plan. Due to the discovery of innovative delivery systems, many of the shortcomings of the CRISPR/Cas system's translatability have been addressed. Because of the rapid growth of delivery mechanisms, a successful translation of CRISPR/Cas technology into medical and agricultural applications is vital, and substantial progress is predicted.

scholarly journals A pipeline for rapidly generating genetically engineered mouse models of pancreatic cancer using in vivo CRISPRCas9 mediated somatic recombination

2018 ◽  
Author(s):  
Noboru Ideno ◽  
Hiroshi Yamaguchi ◽  
Takashi Okumara ◽  
Jonathon Huang ◽  
Mitchel J. Brun ◽  
...  
Keyword(s):  
Mouse Models ◽  
Mouse Strain ◽  
Gene Editing ◽  
High Efficiency ◽  
Intraepithelial Neoplasia ◽  
Genetically Engineered ◽  
Ductal Adenocarcinoma ◽  
Specific Expression ◽  
Genetically Engineered Mouse Models

ABSTRACTGenetically engineered mouse models (GEMMs) that recapitulate the major genetic drivers in pancreatic ductal adenocarcinoma (PDAC) have provided unprecedented insights into the pathogenesis of this lethal neoplasm. Nonetheless, generating an autochthonous model is an expensive, time consuming and labor intensive process, particularly when tissue specific expression or deletion of compound alleles are involved. In addition, many of the current PDAC GEMMs cause embryonic, pancreas-wide activation or loss of driver alleles, neither of which reflects the cognate human disease scenario. The advent of CRISPR/Cas9 based gene editing can potentially circumvent many of the aforementioned shortcomings of conventional breeding schema, but ensuring the efficiency of gene editing in vivo remains a challenge. Here we have developed a pipeline for generating PDAC GEMMs of complex genotypes with high efficiency using a single “workhorse” mouse strain expressing Cas9 in the adult pancreas under a p48 promoter. Using adeno-associated virus (AAV) mediated delivery of multiplexed guide RNAs (sgRNAs) to the adult murine pancreas of p48-Cre; LSL-Cas9 mice, we confirm our ability to express an oncogenic KrasG12D allele through homology-directed repair (HDR), in conjunction with CRISPR-induced disruption of cooperating alleles (Trp53, Lkb1 and Arid1A). The resulting GEMMs demonstrate a spectrum of precursor lesions (pancreatic intraepithelial neoplasia [PanIN] or Intraductal papillary mucinous neoplasm [IPMN] with eventual progression to PDAC. Next generation sequencing of the resulting murine PDAC confirms HDR of oncogenic KrasG12D allele at the endogenous locus, and insertion deletion (“indel”) and frameshift mutations of targeted tumor suppressor alleles. By using a single “workhorse” mouse strain and optimal AAV serotype for in vivo gene editing with combination of driver alleles, we have created a facile autochthonous platform for interrogation of the PDAC genome.

scholarly journals The ancestral C. elegans cuticle suppresses rol-1

2020 ◽  
Author(s):  
Luke M. Noble ◽  
Asif Miah ◽  
Taniya Kaur ◽  
Matthew V. Rockman
Keyword(s):  
Genetic Variation ◽  
Caenorhabditis Elegans ◽  
Comparative Genomics ◽  
Linkage Mapping ◽  
Genetic Background ◽  
Gene Editing ◽  
Wild Strain ◽  
Collagen Gene ◽  
Natural Genetic Variation ◽  
C Elegans

ABSTRACTGenetic background commonly modifies the effects of mutations. We discovered that worms mutant for the canonical rol-1 gene, identified by Brenner in 1974, do not roll in the genetic background of the wild strain CB4856. Using linkage mapping, association analysis and gene editing, we determined that N2 carries an insertion in the collagen gene col-182 that acts as a recessive enhancer of rol-1 rolling. From population and comparative genomics, we infer the insertion is derived in N2 and related laboratory lines, likely arising during the domestication of Caenorhabditis elegans, and breaking a conserved protein. The ancestral version of col-182 also modifies the phenotypes of four other classical cuticle mutant alleles, and the effects of natural genetic variation on worm shape and locomotion. These results underscore the importance of genetic background and the serendipity of Brenner’s choice of strain.

scholarly journals DNA METHYLTRANSFERASE 3 (MET3) is regulated by Polycomb Group complex during Arabidopsis endosperm development

2021 ◽  
Author(s):  
Louis Tirot ◽  
pauline E jullien
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Dna Methyltransferase ◽  
Plant Reproduction ◽  
Endosperm Development ◽  
Polycomb Group ◽  
Epigenetic Changes ◽  
Expression Bias ◽  
Transcriptional Changes ◽  
Polycomb Complex

Complex epigenetic changes occur during plant reproduction. These regulations ensure the proper transmission of epigenetic information as well as allowing for zygotic totipotency. In Arabidopsis, the main DNA methyltransferase is called MET1 and is responsible for methylating cytosine in the CG context. The Arabidopsis genome encodes for three additional reproduction-specific homologs of MET1, namely MET2a, MET2b and MET3. In this paper, we show that the DNA methyltransferase MET3 is expressed in the seed endosperm and its expression is further restricted to the chalazal endosperm. MET3 is biallelically expressed in the endosperm but displays a paternal expression bias. We found that MET3 expression is regulated by the Polycomb complex proteins FIE and MSI1. Seed development is not impaired in met3 mutant, and we could not observe significant transcriptional changes in met3 mutant. Interestingly, we found that MET3 regulates gene expression in a Polycomb mutant background suggesting a further complexification of the interplay between H3K27me3 and DNA methylation in the seed endosperm.

scholarly journals Recent Advances in the Application of CRISPR/Cas9 Gene Editing System in Poultry Species

2021 ◽  
Vol 12 ◽  
Author(s):  
Collins N. Khwatenge ◽  
Samuel N. Nahashon
Keyword(s):  
Gene Editing ◽  
Epigenetic Modification ◽  
Wide Spectrum ◽  
Poultry Production ◽  
Poultry Industry ◽  
Genetic Characteristics ◽  
Genetics Research ◽  
Recent Advances ◽  
Substantial Progress ◽  
The Many

CRISPR/Cas9 system genome editing is revolutionizing genetics research in a wide spectrum of animal models in the genetic era. Among these animals, is the poultry species. CRISPR technology is the newest and most advanced gene-editing tool that allows researchers to modify and alter gene functions for transcriptional regulation, gene targeting, epigenetic modification, gene therapy, and drug delivery in the animal genome. The applicability of the CRISPR/Cas9 system in gene editing and modification of genomes in the avian species is still emerging. Up to date, substantial progress in using CRISPR/Cas9 technology has been made in only two poultry species (chicken and quail), with chicken taking the lead. There have been major recent advances in the modification of the avian genome through their germ cell lineages. In the poultry industry, breeders and producers can utilize CRISPR-mediated approaches to enhance the many required genetic variations towards the poultry population that are absent in a given poultry flock. Thus, CRISPR allows the benefit of accessing genetic characteristics that cannot otherwise be used for poultry production. Therefore CRISPR/Cas9 becomes a very powerful and robust tool for editing genes that allow for the introduction or regulation of genetic information in poultry genomes. However, the CRISPR/Cas9 technology has several limitations that need to be addressed to enhance its use in the poultry industry. This review evaluates and provides a summary of recent advances in applying CRISPR/Cas9 gene editing technology in poultry research and explores its potential use in advancing poultry breeding and production with a major focus on chicken and quail. This could aid future advancements in the use of CRISPR technology to improve poultry production.

A Gene Block Causing Cross-Incompatibility Hidden in Wild and Cultivated Rice

Genetics ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 343-352 ◽  
Author(s):  
Kazuki Matsubara ◽  
Yoshio Sano ◽  
Keyword(s):  
Recombinant Inbred Lines ◽  
Wild Strain ◽  
Endosperm Development ◽  
Oryza Rufipogon ◽  
Chromosome 6 ◽  
Isogenic Line ◽  
Cultivated Rice ◽  
Gene Block ◽  
Hybrid Seeds ◽  
Dominant Suppressor

AbstractUnidirectional cross-incompatibility was detected in advanced generations of backcrossing between wild (Oryza rufipogon) and cultivated (O. sativa) rice strains. The near-isogenic line (NIL) of T65wx (Japonica type) carrying an alien segment of chromosome 6 from a wild strain gave a reduced seed setting only when crossed with T65wx as the male. Cytological observations showed that abortion of hybrid seeds occurred as a consequence of a failure of early endosperm development followed by abnormalities in embryo development. The genetic basis of cross-incompatibility reactions in the female and male was investigated by testcrosses using recombinant inbred lines (RILs) that were established through dissecting the introgressed segments of wild and cultivated (Indica type) strains. The results revealed that the crossin-compatibility reaction was controlled by Cif in the female and by cim in the male. When the female plant with Cif was crossed with the male plant with cim, a failure of early endosperm development was observed in the hybrid zygotes. Among cultivars of O. sativa, cim was distributed predominantly in the Japonica type but not in the Indica type. In addition, a dominant suppressor, Su-Cif, which changes the reaction in the female from incompatible to compatible was proposed to present near the centromere of chromosome 6 of the Indica type. Further, the death of young F1 zygotes was controlled by the parental genotypes rather than by the genotype of the hybrid zygote itself since all three genes acted sporophytically, which strongly suggests an involvement of parent-of-origin effects. We discuss the results in relation to the origin of a crossing barrier as well as their maintenance within the primary gene pool.

Early seed development in hexaploid triticale

1973 ◽  
Vol 51 (12) ◽  
pp. 2291-2300 ◽  
Author(s):  
P. J. Kaltsikes
Keyword(s):  
Endosperm Development ◽  
The Other ◽  
Appreciable Amount ◽  
Egg Cell ◽  
Hexaploid Triticale ◽  
Dna Amount ◽  
Primary Endosperm Nucleus ◽  
Mitotic Abnormalities ◽  
Embryo Cells ◽  
Early Seed Development

The development of the embryo, endosperm, and antipodals was studied in five hexaploid triticale lines. The egg cell was fertilized 10–15 h after pollination. The first division of the zygote occurred 15–20 h later. Ninety-six hours after pollination there was a twofold difference among the lines in the number of embryo cells, which ranged from 17 to 31. The polar nuclei were fertilized 4–5 h after pollination and the first division of the primary endosperm nucleus took place 2–3 h later. At 60 h the lines examined fell into two groups with respect to endosperm development: one group included 6A190 and 6A250, both raw amphiploids, which had 1032 and 486 endosperm nuclei, respectively; and another which included Rosner, Armadillo 458, and 6517, all products of artificial selection, with 209, 201, and 98 endosperm nuclei, respectively. The first five or six endosperm divisions were highly synchronized while later a gradient was established. Cellularization of endosperm was first observed 96 h after pollination. No appreciable amount of mitotic abnormalities was observed in the endosperm nuclei. In all lines examined endosperm nuclei were found with DNA amount exceeding 6C.The number of antipodals, some of which were highly endopolyploid (up to 256C), ranged from 10 to 30 within and among lines. Disintegration of the antipodals began about 3 days after pollination in 6A190, at 4 days in Rosner, and at 5 days in the other lines. The rate of endosperm development and especially the disintegration of the antipodal complement seemed to be positively related with the amount of seed shrivelling observed in the lines studied.

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