The Experts below are selected from a list of 1218 Experts worldwide ranked by ideXlab platform
Lingling Cao - One of the best experts on this subject based on the ideXlab platform.
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Sporogenesis and development of gametophytes in an endangered plant, Tetracentron sinense Oliv
2016Co-Authors: Xiaohong Gan, Dan Xie, Lingling CaoAbstract:The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature Pollen grains are two-Celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinuCellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Signifi cantly, some striking features were fi rst found in T. sinense: (1) anther dehiscence occurs soon after the endothecium fi brously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-Celled Pollen grain; (3) a few Cellular events such as the vacuolization and the contraction and deformation of the Pollen Mother Cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense. Key words: Tetracentron sinense Oliv.; Sporogenesis; Development of gametophytes; Natural regeneration
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sporogenesis and development of gametophytes in an endangered plant tetracentron sinense oliv
Biological Research, 2012Co-Authors: Xiaohong Gan, Dan Xie, Lingling CaoAbstract:The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature Pollen grains are two-Celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinuCellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Significantly, some striking features were first found in T. sinense: (1) anther dehiscence occurs soon after the endothecium fibrously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-Celled Pollen grain; (3) a few Cellular events such as the vacuolization and the contraction and deformation of the Pollen Mother Cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense.
Olga Raskina - One of the best experts on this subject based on the ideXlab platform.
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Repetitive DNA in the Architecture, Repatterning, and Diversification of the Genome of Aegilops speltoides Tausch (Poaceae, Triticeae)
Frontiers Media S.A., 2018Co-Authors: Einat Zelinger, Yulia Pollak, Olga RaskinaAbstract:The genome’s adaptability to environmental changes, especially during rapid climatic fluctuations, underlies the existence and evolution of species. In the wild, genetic and epigenetic genomic changes are accompanied by significant alterations in the complex nuclear repetitive DNA fraction. Current intraspecific polymorphism of repetitive DNA is closely related to ongoing chromosomal rearrangements, which typically result from erroneous DNA repair and recombination. In this study, we addressed tandem repeat patterns and interaction/reshuffling both in Pollen Mother Cell (PMC) development and somatogenesis in the wild diploid cereal Aegilops speltoides, with a focus on genome repatterning and stabilization. Individual contrasting genotypes were investigated using the fluorescent in situ hybridization (FISH) approach by applying correlative fluorescence and electron microscopy. Species-specific Spelt1 and tribe-specific Spelt52 tandem repeats were used as the markers for monitoring somatic and meiotic chromosomal interactions and dynamics in somatic interphase nuclei. We found that, the number of tandem repeat clusters in nuclei is usually lower than the number on chromosomes due to the associations of clusters of the same type in common blocks. In addition, tightly associated Spelt1–Spelt52 clusters were revealed in different genotypes. The frequencies of nonhomologous/ectopic associations between tandem repeat clusters were revealed in a genotype-/population-specific manner. An increase in the number of tandem repeat clusters in the genome causes an increase in the frequencies of their associations. The distal/terminal regions of homologous chromosomes are separated in nuclear space, and nonhomologous chromosomes are often involved in somatic recombination as seen by frequently formed interchromosomal chromatin bridges. In both microgametogenesis and somatogenesis, inter- and intrachromosomal associations are likely to lead to DNA breaks during chromosome disjunction in the anaphase stage. Uncondensed/improperly packed DNA fibers, mainly in heterochromatic regions, were revealed in both the meiotic and somatic prophases that might be a result of broken associations. Altogether, the data obtained showed that intraorganismal dynamics of repetitive DNA under the conditions of natural out-crossing and artificial intraspecific hybridization mirrors the structural plasticity of the Ae. speltoides genome, which is interlinked with genetic diversity through the species distribution area in contrasting ecogeographical environments in and around the Fertile Crescent
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Presentation_1_Repetitive DNA in the Architecture, Repatterning, and Diversification of the Genome of Aegilops speltoides Tausch (Poaceae, Triticeae).pptx
2018Co-Authors: Yulia Pollak, Einat Zelinger, Olga RaskinaAbstract:The genome’s adaptability to environmental changes, especially during rapid climatic fluctuations, underlies the existence and evolution of species. In the wild, genetic and epigenetic genomic changes are accompanied by significant alterations in the complex nuclear repetitive DNA fraction. Current intraspecific polymorphism of repetitive DNA is closely related to ongoing chromosomal rearrangements, which typically result from erroneous DNA repair and recombination. In this study, we addressed tandem repeat patterns and interaction/reshuffling both in Pollen Mother Cell (PMC) development and somatogenesis in the wild diploid cereal Aegilops speltoides, with a focus on genome repatterning and stabilization. Individual contrasting genotypes were investigated using the fluorescent in situ hybridization (FISH) approach by applying correlative fluorescence and electron microscopy. Species-specific Spelt1 and tribe-specific Spelt52 tandem repeats were used as the markers for monitoring somatic and meiotic chromosomal interactions and dynamics in somatic interphase nuclei. We found that, the number of tandem repeat clusters in nuclei is usually lower than the number on chromosomes due to the associations of clusters of the same type in common blocks. In addition, tightly associated Spelt1–Spelt52 clusters were revealed in different genotypes. The frequencies of nonhomologous/ectopic associations between tandem repeat clusters were revealed in a genotype-/population-specific manner. An increase in the number of tandem repeat clusters in the genome causes an increase in the frequencies of their associations. The distal/terminal regions of homologous chromosomes are separated in nuclear space, and nonhomologous chromosomes are often involved in somatic recombination as seen by frequently formed interchromosomal chromatin bridges. In both microgametogenesis and somatogenesis, inter- and intrachromosomal associations are likely to lead to DNA breaks during chromosome disjunction in the anaphase stage. Uncondensed/improperly packed DNA fibers, mainly in heterochromatic regions, were revealed in both the meiotic and somatic prophases that might be a result of broken associations. Altogether, the data obtained showed that intraorganismal dynamics of repetitive DNA under the conditions of natural out-crossing and artificial intraspecific hybridization mirrors the structural plasticity of the Ae. speltoides genome, which is interlinked with genetic diversity through the species distribution area in contrasting ecogeographical environments in and around the Fertile Crescent.
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genotype and Cell specific dynamics of tandem repeat patterns in aegilops speltoides tausch poaceae triticeae
Cytogenetic and Genome Research, 2017Co-Authors: Olga RaskinaAbstract:In wild plant populations, chromosome rearrangements lead to the wide intraspecific polymorphisms in the abundance and patterns of highly repetitive DNA. However, despite the large amount of accumulated data, the impact of the complex repetitive DNA fraction on genome reorganization and functioning and the mechanisms balancing and maintaining the structural integrity of the genome are not fully understood. Homologous recombination is thought to play a key role in both genome reshuffling and stabilization, while the contribution of nonhomologous recombination seems to be undervalued. Here, tandem repeat patterns and dynamics during Pollen Mother Cell development were addressed, with a focus on the meiotic recombination that determines chromosome/genome repatterning and stabilization under cross-pollination and artificial hybridization in wild goatgrass, Aegilops speltoides. Native plants from contrasting allopatric populations and artificially created intraspecific hybrids were investigated using a FISH approach. Cytogenetic analysis uncovered a wide spectrum of genotype- and Cell-specific chromosomal rearrangements, suggesting intensive repatterning of both parental and hybrid genomes. The data obtained provide evidence that repetitive elements serve as overabundant and ubiquitous resources for maintaining chromosome architecture/genome integrity through homologous and nonhomologous recombination at the intraorganismal level, and genotype-specific repatterning underlies intrapopulation polymorphisms and intraspecific diversification in the wild.
Xiaohong Gan - One of the best experts on this subject based on the ideXlab platform.
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Sporogenesis and development of gametophytes in an endangered plant, Tetracentron sinense Oliv
2016Co-Authors: Xiaohong Gan, Dan Xie, Lingling CaoAbstract:The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature Pollen grains are two-Celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinuCellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Signifi cantly, some striking features were fi rst found in T. sinense: (1) anther dehiscence occurs soon after the endothecium fi brously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-Celled Pollen grain; (3) a few Cellular events such as the vacuolization and the contraction and deformation of the Pollen Mother Cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense. Key words: Tetracentron sinense Oliv.; Sporogenesis; Development of gametophytes; Natural regeneration
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sporogenesis and development of gametophytes in an endangered plant tetracentron sinense oliv
Biological Research, 2012Co-Authors: Xiaohong Gan, Dan Xie, Lingling CaoAbstract:The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature Pollen grains are two-Celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinuCellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Significantly, some striking features were first found in T. sinense: (1) anther dehiscence occurs soon after the endothecium fibrously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-Celled Pollen grain; (3) a few Cellular events such as the vacuolization and the contraction and deformation of the Pollen Mother Cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense.
Moju Cao - One of the best experts on this subject based on the ideXlab platform.
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RNA-seq raw data of PS-N_2_2
2017Co-Authors: Zhuofan Zhao, Yongming Liu, Bing Liang, Shuxian Guan, Hai Lan, Jing Wang, Moju CaoAbstract:File 2 of RNA-seq raw data of N48-2 biological replicate 2 spikelets at Pollen Mother Cell stage. Paired-end sequencing strategy was applied on the Illumina HiSeq 4000 sequencing platform.
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RNA-seq raw data of PS-N_3_1
2017Co-Authors: Zhuofan Zhao, Yongming Liu, Bing Liang, Shuxian Guan, Hai Lan, Jing Wang, Moju CaoAbstract:File 1 of RNA-seq raw data of N48-2 biological replicate 3 spikelets at Pollen Mother Cell stage. Paired-end sequencing strategy was applied on the Illumina HiSeq 4000 sequencing platform.
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Comparative transcriptome analysis of isonuclear-alloplasmic lines unmask key transcription factor genes and metabolic pathways involved in sterility of maize CMS-C
PeerJ Inc., 2017Co-Authors: Zhuofan Zhao, Yongming Liu, Bing Liang, Shuxian Guan, Hai Lan, Jing Wang, Moju CaoAbstract:Although C-type cytoplasmic male sterility (CMS-C) is one of the most attractive tools for maize hybrid seed production, the detailed regulation network of the male sterility remains unclear. In order to identify the CMS-C sterility associated genes and/or pathways, the comparison of the transcriptomes between the CMS-C line C48-2 and its isonuclear-alloplasmic maintainer line N48-2 at Pollen Mother Cell stage (PS), an early development stage of microspore, and mononuclear stage (MS), an abortive stage of microspore, were analyzed. 2,069 differentially expressed genes (DEGs) between the two stages were detected and thought to be essential for the spikelet development of N48-2. 453 of the 2,069 DEGs were differentially expressed at MS stage between the two lines and thought to be participated in the process or the causes of microspore abortion. Among the 453 DEGs, 385 (84.99%) genes were down-regulated and only 68 (15.01%) genes were up-regulated in C48-2 at MS stage. The dramatic decreased expression of the four DEGs encoding MYB transcription factors and the DEGs involved in “polyamine metabolic process”, “Cutin, suberine and wax biosynthesis”, “Fatty acid elongation”, “Biosynthesis of unsaturated fatty acids” and “Proline metabolism” might play an important role in the sterility of C48-2. This study will point out some directions for detailed molecular analysis and better understanding of sterility of CMS-C in maize
Weiwei Jin - One of the best experts on this subject based on the ideXlab platform.
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male sterile 28 encodes an argonaute family protein essential for male fertility in maize
Chromosome Research, 2021Co-Authors: Yumin Huang, Lingling Pan, Yue Zhao, Wei Huang, Weiwei JinAbstract:Male sterility is a common biological phenomenon in plants and is a useful trait for hybrid seed production. Normal tapetum development is essential for viable Pollen generation. Although many genes involved in tapetum differentiation and degradation have been isolated in maize, elements that regulate tapetum development during Pollen Mother Cell (PMC) meiosis are less studied. Here, we characterized a classical male-sterile mutant male sterile 28 (ms28) in maize. The ms28 mutant had a regular male meiosis process, while its tapetum Cells showed premature vacuolation at the early meiotic prophase stage. Using map-based cloning, we cloned the Ms28 gene and confirmed its role in male fertility in maize together with two allelic mutants. Ms28 encodes the ARGONAUTE (AGO) family protein ZmAGO5c, and its transcripts primarily accumulate in premeiosis anthers, with more intense signals in PMCs. Transcriptomic analysis revealed that genes related to anther development, Cell division, and reproductive structure development processes were differentially expressed between the ms28 mutant and its fertile siblings. Moreover, small RNA (sRNA) sequencing revealed that the small interfering RNA (siRNA) and microRNA (miRNA) abundances were obviously changed in ms28 meiotic anthers, which indicated that Ms28 may regulate tapetal Cell development through small RNA-mediated epigenetic regulatory pathways. Taken together, our results shed more light on the functional mechanisms of the early development of the tapetum for male fertility in maize.