scholarly journals Impact of Spontaneous Haploid Genome Doubling in Maize Breeding

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 369 ◽  
Author(s):  
Nicholas A. Boerman ◽  
Ursula K. Frei ◽  
Thomas Lübberstedt
Keyword(s):  
Genome Editing ◽  
Male Fertility ◽  
Gene Pyramiding ◽  
Haploid Genome ◽  
Systematic Design ◽  
Maize Breeding ◽  
Genome Doubling ◽  
New Methodologies ◽  
Marker Assisted Backcrossing ◽  
The Impact

Doubled haploid (DH) technology has changed the maize-breeding landscape in recent years. Traditionally, DH production requires the use of chemical doubling agents to induce haploid genome doubling and, subsequently, male fertility. These chemicals can be harmful to humans and the plants themselves, and typically result in a doubling rate of 10%–30%. Spontaneous genome doubling and male fertility of maize haploids, without using chemical doubling agents, have been observed to a limited extent, for nearly 70 years. Rates of spontaneous haploid genome doubling (SHGD) have ranged from less than 5% to greater than 50%. Recently, there has been increased interest to forgo chemical treatment and instead utilize this natural method of doubling. Genetic-mapping studies comprising worldwide germplasm have been conducted. Of particular interest has been the detection of large-effect quantitative trait loci (QTL) affecting SHGD. Having a single large-effect QTL with an additive nature provides flexibility for the method of introgression, such as marker-assisted backcrossing, marker-assisted gene pyramiding, and systematic design. Moreover, it allows implementation of new methodologies, such as haploid-inducer mediated genome editing (HI-edit) and promotion of alleles by genome editing. We believe the use of SHGD can further enhance the impact of DH technology in maize.

Genetic Dissection of Haploid Male Fertility in Maize (Zea mays L.)

2018 ◽  
Author(s):  
Jiwei Yang ◽  
Haochuan Li ◽  
Yanzhi Qu ◽  
Qiong Chen ◽  
Jihua Tang ◽  
...  
Keyword(s):  
Male Fertility ◽  
Genetic Basis ◽  
Mapping Population ◽  
Transgressive Segregation ◽  
Haploid Genome ◽  
Genetic Dissection ◽  
Genome Doubling ◽  
Haploid Male ◽  
Female Donor ◽  
Simple Sequence

AbstractHaploid genome doubling is a key limiting step of haploid breeding in maize. Spontaneous restoration of haploid male fertility (HMF) provides a method by which costs can be saved and which does not require the use of toxic chemicals, in contrast to the artificial doubling process. To reveal the genetic basis of HMF, haploids were obtained from the offspring of 285 F2:3 families, derived from the cross Zheng58× K22. The F2:3 families were used as female donor and YHI-1 as the male inducer line. The rates of HMF from each family line were evaluated at two field sites over two planting seasons. Quantitative trait loci (QTL) for HMF were identified using a genetic linkage map containing 157 simple sequence repeat (SSR) markers. QTL for HMF displayed incomplete dominance. Transgressive segregation of haploids from F2:3 families was observed relative to haploids derived from the two parents of the mapping population. A total of nine QTL were detected, which were distributed on chromosomes 1, 3, 4, 7, and 8. Three QTL, qHMF3b, qHMF7a, and qHMF7b were detected in both locations, respectively. In our mapping population, HMF was controlled by three major QTL. These QTL could be useful to predict the ability of spontaneous haploid genome doubling in related breeding materials, and to accelerate the haploid breeding process by introgression or aggregation of those QTL.

scholarly journals Usefulness of Adapted Exotic Maize Lines Developed By Doubled Haploid and Single Seed Descent Methods

2021 ◽  
Author(s):  
Iara Goncalves Santos ◽  
Anderson L. Verzegnazzi ◽  
Jode Edwards ◽  
Ursula K. Frei ◽  
Nicholas Boerman ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
Genetic Variance ◽  
Agronomic Traits ◽  
Inbred Lines ◽  
Snp Markers ◽  
Haploid Genome ◽  
Genome Doubling ◽  
The Impact ◽  
Elite Germplasm

Abstract Adapted exotic maize (Zea mays L.) germplasm, such as BS39, provides a unique opportunity for broadening the genetic base of U.S. Corn Belt germplasm. In vivo doubled haploid (DH) technology has been used to efficiently exploit exotic germplasm. It can help to purge deleterious recessive alleles. The objectives of this study were to determine the usefulness of BS39-derived inbred lines using both SSD and DH methods, to determine the impact of spontaneous as compared to artificial haploid genome doubling on genetic variance among BS39-derived DH lines, and to identify SNP markers associated with agronomic traits among BS39 inbreds monitored at testcross level. We developed two sets of inbred lines directly from BS39 by DH and SSD methods, named BS39_DH and BS39_SSD. Additionally, two sets were derived from a cross between BS39 and A427 (SHGD donor) by DH and SSD methods, named BS39×A427_DH and BS39×A427_SSD, respectively. Grain yield, moisture, plant height, ear height, stalk lodging, and root lodging were measured to estimate genetic parameters. For genome-wide association (GWAS) analysis, inbred lines were genotyped using Genotype-by-Sequencing (GBS) and Diversity Array Technology Sequencing (DArTSeq). Some BS39-derived inbred lines performed better than elite germplasm inbreds and all sets showed significant genetic variance. The presence of spontaneous haploid genome doubling genes did not affect performance of inbred lines. Five SNPs were significant and three of them located within genes related to plant development or abiotic stresses. These results demonstrate the potential of BS39 to add novel alleles to temperate elite germplasm.

scholarly journals The Impact of Bone on the Biology of Aging

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 740-740
Author(s):  
Gerard Karsenty
Keyword(s):  
Muscle Function ◽  
Male Fertility ◽  
Leydig Cells ◽  
Memory Loss ◽  
Age Related ◽  
Systematic Exploration ◽  
Biology Of Aging ◽  
The Impact ◽  
The Brain ◽  
Regulate Energy Metabolism

Abstract We hypothesized that bone may secrete hormones that regulate energy metabolism and reproduction. Testing this hypothesis revealed that the osteoblast-specific secreted protein osteocalcin is a hormone regulating glucose homeostasis and male fertility by signaling through a GPCR, Gprc6a, expressed in pancreatic β bells and Leydig cells of the testes. The systematic exploration of osteocalcin biology, revealed that it regulates an unexpectedly large spectrum of physiological functions in the brain and peripheral organs and that it has most features of an antigeromic molecule. As will be presented at the meeting, this body of work suggests that harnessing osteocalcin for therapeutic purposes may be beneficial in the treatment of age-related diseases such as depression, age-related memory loss and the decline in muscle function seen in sarcopenia.

scholarly journals The Impact of Climate Change on the Resistance of Rice Near-Isogenic Lines with Resistance Genes Against Brown Planthopper

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yun-Hung Kuang ◽  
Yu-Fu Fang ◽  
Shau-Ching Lin ◽  
Shin-Fu Tsai ◽  
Zhi-Wei Yang ◽  
...  
Keyword(s):  
Climate Change ◽  
Resistance Genes ◽  
Environmental Changes ◽  
Gene Pyramiding ◽  
Brown Planthopper ◽  
Inhibitory Effect ◽  
Near Isogenic Lines ◽  
Impact Of Climate Change ◽  
Isogenic Lines ◽  
The Impact

Abstract Background The impact of climate change on insect resistance genes is elusive. Hence, we investigated the responses of rice near-isogenic lines (NILs) that carry resistance genes against brown planthopper (BPH) under different environmental conditions. Results We tested these NILs under three environmental settings (the atmospheric temperature with corresponding carbon dioxide at the ambient, year 2050 and year 2100) based on the Intergovernmental Panel on Climate Change prediction. Comparing between different environments, two of nine NILs that carried a single BPH-resistant gene maintained their resistance under the environmental changes, whereas two of three NILs showed gene pyramiding with two maintained BPH resistance genes despite the environmental changes. In addition, two NILs (NIL-BPH17 and NIL-BPH20) were examined in their antibiosis and antixenosis effects under these environmental changes. BPH showed different responses to these two NILs, where the inhibitory effect of NIL-BPH17 on the BPH growth and development was unaffected, while NIL-BPH20 may have lost its resistance during the environmental changes. Conclusion Our results indicate that BPH resistance genes could be affected by climate change. NIL-BPH17 has a strong inhibitory effect on BPH feeding on phloem and would be unaffected by environmental changes, while NIL-BPH20 would lose its ability during the environmental changes.

Major locus for spontaneous haploid genome doubling detected by a case–control GWAS in exotic maize germplasm

2021 ◽  
Author(s):  
Anderson Luiz Verzegnazzi ◽  
Iara Gonçalves dos Santos ◽  
Matheus Dalsente Krause ◽  
Matthew Hufford ◽  
Ursula Karoline Frei ◽  
...  
Keyword(s):  
Case Control ◽  
Haploid Genome ◽  
Major Locus ◽  
Genome Doubling ◽  
Maize Germplasm

Publics, Scientists and the State: Mapping the Global Human Genome Editing Controversy

2021 ◽  
pp. 1-28
Author(s):  
Ya-Wen Lei
Keyword(s):  
Public Sphere ◽  
Human Genome ◽  
Genome Editing ◽  
Scientific Research ◽  
Theoretical Framework ◽  
The State ◽  
Scientific Controversies ◽  
Chinese State ◽  
National Expert ◽  
The Impact

Abstract Literature on scientific controversies has inadequately attended to the impact of globalization and, more specifically, the emergence of China as a leader in scientific research. To bridge this gap in the literature, this article develops a theoretical framework to analyse global scientific controversies surrounding research in China. The framework highlights the existence of four overlapping discursive arenas: China's national public sphere and national expert sphere, the transnational public sphere and the transnational expert sphere. It then examines the struggles over inclusion/exclusion and publicity within these spheres as well as the within- and across-sphere effects of such struggles. Empirically, the article analyses the human genome editing controversy surrounding research conducted by scientists in China between 2015 and 2019. It shows how elite scientists negotiated expert–public relationships within and across the national and transnational expert spheres, how unexpected disruption at the nexus of the four spheres disrupted expert–public relationships as envisioned by elite experts, and how the Chinese state intervened to redraw the boundary between openness and secrecy at both national and transnational levels.

scholarly journals Human Genetic Diversity Alters Therapeutic Gene Editing Off-Target Outcomes

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3993-3993
Author(s):  
Linda Yingqi Lin ◽  
Samuele Cancellieri ◽  
Jing Zeng ◽  
Francesco Masillo ◽  
My Anh Nguyen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Clinical Trials ◽  
Genome Editing ◽  
Gene Editing ◽  
Conflicts Of Interest ◽  
African Ancestry ◽  
Great Promise ◽  
Personal Genome ◽  
Hematopoietic Stem ◽  
The Impact

Abstract CRISPR gene editing holds great promise to modify somatic genomes to ameliorate disease. In silico prediction of homologous sites coupled with biochemical evaluation of possible genomic off-targets may predict genotoxicity risk of individual gene editing reagents. However, standard computational and biochemical methods focus on reference genomes and do not consider the impact of genetic diversity on off-target potential. Here we developed a web application called CRISPRme that explicitly and efficiently integrates human genetic variant datasets with orthogonal genomic annotations to predict and prioritize off-target sites at scale. The method considers both single-nucleotide variants (SNVs) and indels, accounts for bona fide haplotypes, accepts spacer:protospacer mismatches and bulges, and is suitable for personal genome analyses. We tested the tool with a guide RNA (gRNA) targeting the BCL11A erythroid enhancer that has shown therapeutic promise in clinical trials for sickle cell disease (SCD) and β-thalassemia (Frangoul et al. NEJM 2021). We find that the top predicted off-target site is produced by a non-reference allele common in African-ancestry populations (rs114518452, minor allele frequency (MAF) = 4.5%) that introduces a protospacer adjacent motif (PAM) for SpCas9. We validate that SpCas9 generates indels (~9.6% frequency) and chr2 pericentric inversions in a strictly allele-specific manner in edited CD34+ hematopoietic stem/progenitor cells (HSPCs), although a high-fidelity Cas9 variant mitigates this off-target. This report illustrates how population and private genetic variants should be considered as modifiers of genome editing outcomes. We expect that variant-aware off-target assessment will be required for therapeutic genome editing efforts going forward, including both ongoing and future clinical trials, and we provide a powerful approach for comprehensive off-target prediction. CRISPRme is available at crisprme.di.univr.it. Disclosures No relevant conflicts of interest to declare.

scholarly journals The impact of nutrition and lifestyle on male fertility

2020 ◽  
Vol 92 (2) ◽  
Author(s):  
Mahmoud Benatta ◽  
Redha Kettache ◽  
Noor Buchholz ◽  
Alberto Trinchieri
Keyword(s):  
Male Fertility ◽  
Negative Impact ◽  
Relevant Literature ◽  
Water Disinfection ◽  
Semen Parameters ◽  
Cochrane Central Register ◽  
Central Register ◽  
Newcastle Ottawa Scale ◽  
Molecular Components ◽  
The Impact

Background and aims: Male unexplained infertility has long been suspected to result from environmental, lifestyle and nutritional factors. However, the literature on the subject is still scarce, and clinical studies providing robust evidence are even scarcer. In addition, some similar studies come to different conclusions. Dietary pattern can influence spermatogenesis by its content of fatty acids and antioxidants. Yet, in an age of industrialized mass food production, human bodies become more exposed to the ingestion of xenobiotics, as well as chemicals used for production, preservation, transportation and taste enhancement of foods. We attempted in this paper to collect the available evidence to date on the effect of nutritional components on male fertility. Material and methods: A systematic search of the relevant literature published in PubMed, ScienceDirect and Cochrane Central Register of Controlled Trials Database was conducted. Literature was evaluated according to the Newcastle-Ottawa- Scale. Results: Epidemiological observations are concordant in demonstrating an association of low-quality sperm parameters with higher intake of red meat, processed and organ meat and fullfat dairy. On the contrary, better semen parameters were observed in subjects consuming a healthy diet, rich in fruit, vegetables, whole grains and fish. Evidences of the negative impact on male fertility of by-products of water disinfection, accumulation in food chain of persistent organochlorine pollutants, pesticides, phthalates from food and water containers and hormones used in breeding cattle have been reported. Clinical trials of the effects of micronutrients on semen parameters and outcomes of assisted fertilization are encouraging, although optimal modality of treatment should be established. Conclusions: Although quality of evidence should be ameliorated, it emerges that environmental factors can influence male fertility. Some nutrients may enhance fertility whereas others will worsen it. With diagnostic analysis on a molecular or even sub-molecular level, new interactions with micronutrients or molecular components of our daily ingested foods and leisure drugs may lead to a better understanding of so far suspected but as yet unexplained effects on male spermatogenesis and fertility.

scholarly journals The Impact of Zinc Oxide Nanoparticles on Male (In)Fertility

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 849 ◽  
Author(s):  
Ana Rita Pinho ◽  
Sandra Rebelo ◽  
Maria de Lourdes Pereira
Keyword(s):  
Zinc Oxide ◽  
Reproductive System ◽  
Male Fertility ◽  
Zinc Oxide Nanoparticles ◽  
Engineered Nanoparticles ◽  
Male Reproductive System ◽  
Oxide Nanoparticles ◽  
Exceptional Set ◽  
Zno Nps ◽  
The Impact

Zinc oxide nanoparticles (ZnO NPs) are among nanoscale materials, attracting increasing attention owing to their exceptional set of characteristics, which makes these engineered nanoparticles a great option for improving the quality and effectiveness of diagnosis and treatment. The capacity of ZnO NPs to induce reactive oxygen species (ROS) production, DNA damage, and apoptosis represents a promise for their use in both cancer therapy and microbial treatment. However, their intrinsic toxicity together with their easy entrance and accumulation in organism have raised some concerns regarding the biomedical use of these NPs. Several studies have reported that ZnO NPs might induce cytotoxic effects on the male reproductive system, compromising male fertility. Despite some advances in this area, the knowledge of the effects of ZnO NPs on male fertility is still scarce. Overall, a brief outline of the major ZnO NPs biomedical applications and promises in terms of diagnostic and therapeutic use will also be explored. Further, this review intends to discuss the effect of ZnO NPs exposure on the male reproductive system and speculate their effects on male (in)fertility.

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