scholarly journals Environment-conditioned male fertility of HD-ZIP IV transcription factor mutant ocl4: impact on 21-nt phasiRNA accumulation in pre-meiotic maize anthers

2020 ◽  
Author(s):  
Pranjal Yadava ◽  
Saleh Tamim ◽  
Han Zhang ◽  
Chong Teng ◽  
Xue Zhou ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Outer Cell ◽  
Small Interfering Rnas ◽  
Male Sterile ◽  
Layer 4 ◽  
Hybrid Seeds ◽  
Growing Conditions ◽  
Key Steps ◽  
Outer Cell Layer ◽  
Favorable Conditions

AbstractEnvironment-conditioned genic male sterility is a key strategy used to produce hybrid seeds efficiently in many crops, with the exception of maize. The underlying molecular mechanisms of environment-conditioned sterility are poorly understood. Here, we report a derivative line of the male sterile outer cell layer 4 (ocl4) mutant of maize, in which fertility was restored and perpetuated over several generations, under warm growing conditions. Conditionally fertile ocl4 anthers exhibit the anatomical abnormality of a partially duplicated endothecial layer, just like their sterile counterparts. We profiled the dynamics of phased, small interfering RNAs (phasiRNAs) during pre-meiotic development in fully sterile and various grades of semi-fertile ocl4 anthers. We found that the biogenesis of 21-nt phasiRNAs is largely dependent on Ocl4 at three key steps: (1) production of PHAS precursor transcripts, (2) expression of miR2118 that modulates precursor processing, and (3) accumulation of 21-nt phasiRNAs. We propose that 21-nt reproductive phasiRNAs buffer development under unfavorable environmental conditions and are dispensable under favorable conditions.

scholarly journals Epigenetic memory effects in forest trees: a victory of “Michurinian biology”?

2017 ◽  
Vol 63 (4) ◽  
pp. 173-179 ◽  
Author(s):  
Dušan Gömöry ◽  
Matúš Hrivnák ◽  
Diana Krajmerová ◽  
Roman Longauer
Keyword(s):  
Molecular Mechanisms ◽  
Cytosine Methylation ◽  
Epigenetic Inheritance ◽  
Memory Effects ◽  
Forest Trees ◽  
Small Interfering Rnas ◽  
Adaptation To Climate Change ◽  
Growth Environment ◽  
Micro Rnas ◽  
Covalent Modifications

AbstractThe study reviews trait inheritance, which is in contradiction with the rules of Mendelian genetics, and which was object of controversies among biologists (sometimes with grave political consequences) in the USSR and Sovietcontrolled countries in the 1930s-1960s. “Carryover” or “memory” effects of the climate, to which maternal trees are exposed during seed development, on phenological behavior and other adaptively relevant traits of their offspring in conifers are mentioned; similar effects are associated with the germination and early growth environment. Molecular mechanisms underlying these effects include covalent modifications of DNA or DNA-associated proteins (cytosine methylation, various types of histone modifications), micro-RNAs and small interfering RNAs. Tools for the identification of these modifications are reviewed with a focus on cytosine methylation, along with an overview of the hitherto knowledge on the occurrence of DNA modifications in forest trees. The practical implications of epigenetic inheritance in forest trees are discussed with the focus on the adaptation to climate change and legislation on forest reproductive materials.

Embryonic development of the heart

Development ◽  
1969 ◽  
Vol 22 (3) ◽  
pp. 333-348
Author(s):  
Francis J. Manasek
Keyword(s):  
Cell Layer ◽  
Embryonic Heart ◽  
Outer Cell ◽  
Chick Embryos ◽  
Myocardial Wall ◽  
Undifferentiated Cells ◽  
Epicardial Layer ◽  
Outer Cell Layer ◽  
Heart Wall

The mature heart may be thought of as consisting of three layers, endocardium, myocardium, and an outer investing tissue called the epicardium. During early formation of the tubular heart of chick embryos, at about the 8-somite stage, two tissue layers become clearly discernible with the light microscope: the endocardium and the developing myocardial wall. The outer epicardial layer does not appear until later in development. It is generally accepted that embryonic heart wall or ‘epimyocardium’ is composed of muscle and undifferentiated cells. As its name implies, the epimyocardium is thought to give rise to myocardium and epicardium. Kurkiewicz (1909) suggested that the epicardium was not an epimyocardial derivative but rather is formed from cells originating in the sinus venosus region, which migrate over the surface of the heart. Nevertheless, it has become generally accepted that the outer cell layer of the embryonic heart wall differentiates in situ to give rise to the definitive visceral epicardium (Patten, 1953).

scholarly journals Comparative transcriptome analysis indicates that a core transcriptional network mediates isonuclear alloplasmic male sterility in wheat (Triticum aestivum L.)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zihan Liu ◽  
Sha Li ◽  
Wei Li ◽  
Qi Liu ◽  
Lingli Zhang ◽  
...  
Keyword(s):  
Male Sterility ◽  
Candidate Genes ◽  
Transcriptome Analysis ◽  
Molecular Mechanisms ◽  
Interaction Mechanism ◽  
Outer Wall ◽  
Comparative Transcriptome ◽  
Male Sterile ◽  
Comparative Transcriptome Analysis ◽  
The Impact

Abstract Background Cytoplasmic male sterility (CMS) plays a crucial role in the utilization of heterosis and various types of CMS often have different abortion mechanisms. Therefore, it is important to understand the molecular mechanisms related to anther abortion in wheat, which remain unclear at present. Results In this study, five isonuclear alloplasmic male sterile lines (IAMSLs) and their maintainer were investigated. Cytological analysis indicated that the abortion type was identical in IAMSLs, typical and stainable abortion, and the key abortive period was in the binucleate stage. Most of the 1,281 core shared differentially expressed genes identified by transcriptome sequencing compared with the maintainer in the vital abortive stage were involved in the metabolism of sugars, oxidative phosphorylation, phenylpropane biosynthesis, and phosphatidylinositol signaling, and they were downregulated in the IAMSLs. Key candidate genes encoding chalcone--flavonone isomerase, pectinesterase, and UDP-glucose pyrophosphorylase were screened and identified. Moreover, further verification elucidated that due to the impact of downregulated genes in these pathways, the male sterile anthers were deficient in sugar and energy, with excessive accumulations of ROS, blocked sporopollenin synthesis, and abnormal tapetum degradation. Conclusions Through comparative transcriptome analysis, an intriguing core transcriptome-mediated male-sterility network was proposed and constructed for wheat and inferred that the downregulation of genes in important pathways may ultimately stunt the formation of the pollen outer wall in IAMSLs. These findings provide insights for predicting the functions of the candidate genes, and the comprehensive analysis of our results was helpful for studying the abortive interaction mechanism in CMS wheat.

Cellular and Molecular Mechanisms for the Bone Response to Mechanical Loading

2001 ◽  
Vol 11 (s1) ◽  
pp. S128-S136 ◽  
Author(s):  
Susan A. Bloomfield
Keyword(s):  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Interstitial Fluid Flow ◽  
Effector Cells ◽  
Bone Response ◽  
Osteogenic Response ◽  
Mechanical Signal ◽  
Endocrine Factors ◽  
Key Steps

To define the cellular and molecular mechanisms for the osteogenic response of bone to increased loading, several key steps must be defined: sensing of the mechanical signal by cells in bone, transduction of the mechanical signal to a biochemical one, and transmission of that biochemical signal to effector cells. Osteocytes are likely to serve as sensors of loading, probably via interstitial fluid flow produced during loading. Evidence is presented for the role of integrins, the cell’s actin cytoskeleton, G proteins, and various intracellular signaling pathways in transducing that mechanical signal to a biochemical one. Nitric oxide, prostaglandins, and insulin-like growth factors all play important roles in these pathways. There is growing evidence for modulation of these mechanotransduction steps by endocrine factors, particularly parathyroid hormone and estrogen. The efficiency of this process is also impaired in the aged animal, yet what remains undefined is at what step mechanotransduction is affected.

scholarly journals TIE2 Associates with Caveolae and Regulates Caveolin-1 To Promote Their Nuclear Translocation

2017 ◽  
Vol 37 (21) ◽  
Author(s):  
Mohammad B. Hossain ◽  
Rehnuma Shifat ◽  
Jingyi Li ◽  
Xuemei Luo ◽  
Kenneth R. Hess ◽  
...  
Keyword(s):  
Dna Repair ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Subcellular Fractionation ◽  
Tyrosine Kinase Receptor ◽  
Histone H4 ◽  
Small Interfering Rnas ◽  
Caveolin 1

ABSTRACT DNA repair pathways are aberrant in cancer, enabling tumor cells to survive standard therapies—chemotherapy and radiotherapy. Our group previously reported that, upon irradiation, the membrane-bound tyrosine kinase receptor TIE2 translocates into the nucleus and phosphorylates histone H4 at Tyr51, recruiting ABL1 to the DNA repair complexes that participate in the nonhomologous end-joining pathway. However, no specific molecular mechanisms of TIE2 endocytosis have been reported. Here, we show that irradiation or ligand-induced TIE2 trafficking is dependent on caveolin-1, the main component of caveolae. Subcellular fractionation and confocal microscopy demonstrated TIE2/caveolin-1 complexes in the nucleus, and using inhibitor or small interfering RNAs (siRNAs) against caveolin-1 or Tie2 inhibited their trafficking. TIE2 was found in caveolae and directly phosphorylated caveolin-1 at Tyr14 in vitro and in vivo. This modification regulated the generation of TIE2/caveolin-1 complexes and was essential for TIE2/caveolin-1 nuclear translocation. Our data further demonstrate that the combination of TIE2 and caveolin-1 inhibitors resulted in significant radiosensitization of malignant glioma cells, which will guide the development of combinatorial treatment with radiotherapy for patients with glioblastoma.

Potential of wild common bean for seed yield improvement of cultivars in the tropics

1995 ◽  
Vol 75 (4) ◽  
pp. 807-813 ◽  
Author(s):  
Shree P. Singh ◽  
Albeiro Molina ◽  
Paul Gepts
Keyword(s):  
Common Bean ◽  
Seed Yield ◽  
Seed Weight ◽  
Hybrid Population ◽  
Test Environment ◽  
Yield Improvement ◽  
Days To Maturity ◽  
Growing Conditions ◽  
Favorable Conditions ◽  
Wild Beans

Thirty nine wild or weedy common bean (Phaseolus vulgaris L.) accessions, representing the two extremes of geographical range of distribution and domestication of cultigens in the Americas, were crossed to a high-yielding, small-seeded cultivar, ICA Pijao. The resulting F1, F2, and F3 population bulks, along with ICA Pijao, were evaluated for seed yield, days to maturity, and 100-seed weight under favorable growing conditions at two locations in Colombia. The F3 and F4 bulks were tested separately under soil-fertility and moisture stresses. Thirty random F5-derived F8 lines from the highest yielding population involving both Andean and Middle American wild beans, along with the parents and a control cultivar, were also evaluated for 2 yr, under favorable conditions. No F1 hybrid, population bulk, or F5-derived F8 line significantly outyielded ICA Pijao in any test environment. The mean yield of F1 hybrids, population bulks, and F5-derived F8 lines involving wild and weedy beans of Middle America was higher than that involving Andean South American wild beans. Heritability for seed yield, seed weight, and days to maturity, as well as gains from selection were comparable to those obtained in crosses among cultivars. The small seed of the progenies and the positive correlation between seed size and seed yield suggest that alternative mating schemes that increase the recovery of progenies with a cultivated phenotype should be investigated. Until this research is done, it would be premature to draw conclusions about the yield improvement potential of wild beans. Key words:Phaseolus vulgaris, common bean (wild), yield, heterosis, heritability, selection gain

scholarly journals The YopD Translocator of Yersinia pseudotuberculosis Is a Multifunctional Protein Comprised of Discrete Domains

2004 ◽  
Vol 186 (13) ◽  
pp. 4110-4123 ◽  
Author(s):  
Jan Olsson ◽  
Petra J. Edqvist ◽  
Jeanette E. Bröms ◽  
Åke Forsberg ◽  
Hans Wolf-Watz ◽  
...  
Keyword(s):  
Pore Formation ◽  
Molecular Mechanisms ◽  
Yersinia Pseudotuberculosis ◽  
Regulatory Control ◽  
Multifunctional Protein ◽  
Target Cell Membrane ◽  
Discrete Domains ◽  
Key Steps ◽  
Mutagenesis Study ◽  
Insight Into

ABSTRACT To establish an infection, Yersinia pseudotuberculosis utilizes a plasmid-encoded type III translocon to microinject several anti-host Yop effectors into the cytosol of target eukaryotic cells. YopD has been implicated in several key steps during Yop effector translocation, including maintenance of yop regulatory control and pore formation in the target cell membrane through which effectors traverse. These functions are mediated, in part, by an interaction with the cognate chaperone, LcrH. To gain insight into the complex molecular mechanisms of YopD function, we performed a systematic mutagenesis study to search for discrete functional domains. We highlighted amino acids beyond the first three N-terminal residues that are dispensable for YopD secretion and confirmed that an interaction between YopD and LcrH is essential for maintenance of yop regulatory control. In addition, discrete domains within YopD that are essential for both pore formation and translocation of Yop effectors were identified. Significantly, other domains were found to be important for effector microinjection but not for pore formation. Therefore, YopD is clearly essential for several discrete steps during efficient Yop effector translocation. Recognition of this modular YopD domain structure provides important insights into the function of YopD.

scholarly journals Small RNA molecules in the regulation of spermatogenesis

Reproduction ◽  
2009 ◽  
Vol 137 (6) ◽  
pp. 901-911 ◽  
Author(s):  
Zuping He ◽  
Maria Kokkinaki ◽  
Disha Pant ◽  
G Ian Gallicano ◽  
Martin Dym
Keyword(s):  
Small Rna ◽  
Small Rnas ◽  
Molecular Mechanisms ◽  
Small Interfering Rnas ◽  
Rna Molecules ◽  
Open Questions ◽  
Complex Process ◽  
Potential Applications ◽  
Pachytene Spermatocytes ◽  
Mitotic Proliferation

Small RNA molecules (small RNAs), including small interfering RNAs (siRNAs), microRNAs (miRNAs), and piwi-interacting RNAs (piRNAs), have recently emerged as important regulators of gene expression at the post-transcriptional or translation level. Significant progress has recently been made utilizing small RNAs in elucidating the molecular mechanisms regulating spermatogenesis. Spermatogenesis is a complex process that involves the division and eventual differentiation of spermatogonial stem cells into mature spermatozoa. The process of spermatogenesis is composed of several phases: mitotic proliferation of spermatogonia to produce spermatocytes; two meiotic divisions of spermatocytes to generate haploid round spermatids; and spermiogenesis, the final phase that involves the maturation of early-round spermatids into elongated mature spermatids. A number of miRNAs are expressed abundantly in male germ cells throughout spermatogenesis, while piRNAs are only present in pachytene spermatocytes and round spermatids. In this review, we first address the synthesis, mechanisms of action, and functions of siRNA, miRNA, and piRNA, and then we focus on the recent advancements in defining the small RNAs in the regulation of spermatogenesis. Concerns pertaining to the use of siRNAs in exploring spermatogenesis mechanisms and open questions in miRNAs and piRNAs in this field are highlighted. The potential applications of small RNAs to male contraception and treatment for male infertility and testicular cancer are also discussed.

scholarly journals EFFECTS OF GROWING CONDITIONS ON CROSSING SUCCESS IN DIFFERENT POTATO(Solanum tuberosum L.)CROSSES

AGROFOR ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Güngör YILMAZ ◽  
Ahmet KINAY ◽  
Nejdet KANDEMİR ◽  
Şaziye DÖKÜLEN
Keyword(s):  
Solanum Tuberosum ◽  
High Altitude ◽  
Open Field ◽  
Seed Production ◽  
Solanum Tuberosum L ◽  
Hybrid Seeds ◽  
Low Altitude ◽  
Growing Conditions ◽  
Number Of Seeds ◽  
Made In

This study was carried out to determine the effect of growing conditions underdifferent altitudes on seed production in different potato crosses in Tokat Provinceof Turkey in 2015. Plants were grown and crosses were made in open field or nethouse in Tokat location (altitude 600 m asl.), open field or net house in Artovalocation (altitude 1200 m asl.), or controlled polycarbonate greenhouse. Fifteendifferent crosses were made between 12 parent cultivars. Production of hybridpotato seed was considered “crossing success”. Results showed that parentcultivars and cross combinations affected crossing success and no seeds wereproduced from some combinations while some combinations produced abundantseeds. The highest number of seeds were produced in controlled polycarbonategreenhouse, whereas very low amount of seeds were produced under low altitude(600 m asl.) open field conditions. Polycarbonate greenhouse produced 47.3% ofall seeds, while low altitude net house produced 19.8%, high altitude open fieldproduced 15.8%, high altitude net house produced 13.6% and low altitude openfield produced 3.5%. It was concluded that for a high crossing success, potatocrossing should be made by controlled polycarbonate greenhouse conditions and 23C0 day / 17 C0 night temperatures produced more hybrid seeds.

scholarly journals Transcriptome profiling provides insights into the molecular mechanisms of maize kernel and silk development

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ting Li ◽  
Yapeng Wang ◽  
Yaqin Shi ◽  
Xiaonan Gou ◽  
Bingpeng Yang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Transcriptome Profiling ◽  
Maize Yield ◽  
Abnormal Development ◽  
Maize Kernel ◽  
Yield Determination ◽  
Maize Yields ◽  
Transcript Profiles ◽  
Key Steps ◽  
Maize Kernels

Abstract Background Maize kernel filling, which is closely related to the process of double fertilization and is sensitive to a variety of environmental conditions, is an important component of maize yield determination. Silk is an important tissue of maize ears that can discriminate pollen and conduct pollination. Therefore, investigating the molecular mechanisms of kernel development and silk senescence will provide important information for improving the pollination rate to obtain high maize yields. Results In this study, transcript profiles were determined in an elite maize inbred line (KA105) to investigate the molecular mechanisms functioning in self-pollinated and unpollinated maize kernels and silks. A total of 5285 and 3225 differentially expressed transcripts (DETs) were identified between self-pollinated and unpollinated maize in a kernel group and a silk group, respectively. We found that a large number of genes involved in key steps in the biosynthesis of endosperm storage compounds were upregulated after pollination in kernels, and that abnormal development and senescence appeared in unpollinated kernels (KUP). We also identified several genes with functions in the maintenance of silk structure that were highly expressed in silk. Further investigation suggested that the expression of autophagy-related genes and senescence-related genes is prevalent in maize kernels and silks. In addition, pollination significantly altered the expression levels of senescence-related and autophagy-related genes in maize kernels and silks. Notably, we identified some specific genes and transcription factors (TFs) that are highly expressed in single tissues. Conclusions Our results provide novel insights into the potential regulatory mechanisms of self-pollinated and unpollinated maize kernels and silks.

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