Physical Mutagens Research Articles

Genotyping by sequencing; a strategy for identification and mapping of induced mutation in newly developed wheat mutant lines.

Exposing genetic material with physical mutagens can create novel genetic resources capable of combating different stresses. High throughput GBS-DArTseq™ assay was deployed to estimate genetic diversity of 33 newly developed stable wheat mutants as compared to the wild type. The identified 1,57,608 PAVs markers were randomly distributed across wheat chromosomes and sub-genomes with the highest number detected on Chr-7D (2877) and Chr-7B (2711). The B sub-genome contained the most PAVs followed by D and A-sub genome. Among mutant lines, Pb-M-2061 and Pb-M-59 had the highest PAV count, while Pb-M-605 and Pb-M-196 had the lowest. A total of 7,910 PAVs were consistently present over all replicates, with 3,252 specifically present in mutants and absent in wild type. The maximum PAVs (1480) were found in Pb-M-1027 and Pb-M-1323 (656). Functional characterization revealed that out of 3,252, 1,238 were found in wheat transcriptome database that contained 152 characterized and 1,196 uncharacterized genes. COGs and GO-terms analysis linked many PAVs with pathways involving signaling, metabolism and defense. Maximum number of gene-containing PAVs were identified in Pb-M-1027, Pb-M-2302 and Pb-M-1323 which were involved in tolerance to diseases and abiotic stresses, improved photosynthetic efficiency, larger grain size, increased grain yield and harvest index pathways. This study provides valuable insights into the genetic diversity and potential agronomic benefits of PAVs in wheat mutant lines. These findings can help molecular geneticist and breeders for exploiting the induced genetic diversity for unravelling the genetic circuits as well as exploiting in wheat breeding for developing resilient cultivars.

Improvement of thermostable productivity ?-amylase from local isolate Bacillus licheniformis H14.

(28)Bacterial local isolates of Bacillus sp. were obtained from soil samples. Isolates were tested for thermostable alpha- amylase production on solid media; fifteen isolates were able to develop clear zone around the bacterial growth after floating the plates with iodine reagent (Lugol's solution). There were further tested in submerged culture which led to selection of Bacillus sp. H14since it was the most efficient .Microbial and biochemical tests showed that the local isolate Bacillus sp.H14was refered to the species B.licheniformis that signed as H14 was refered to the species B.licheniformis H14 .,To get ahigher yield of alpha – amylase(48.70unit/mg protein) production from the local isolate B.licheniformis H14 . This study used different mutation ways such as physical way by using the physical mutagen (ultraviolet light) and chemical way by using the chemical mutagen (nitrosoguanidine). Physical mutation results showed that the local isolate B.licheniformis HM14 get higher yield of alpha – amylase production(102.10 unit/mg protein) according to killing percentage (90%) while the chemical mutation results showed that the local isolate B.licheniformis HM4 get higher yield of alpha –amylase production(100.94 unit/mg protein) from the two mutant local isolates (HM14 and HM4)were the best carbon source starch (1.5%), peptone (1.5%) as nitrogen source, calcium chloride (0.02%), sodium chloride (0.05%), magnicium phosphate (0.05%), sodium di –hydrogen phosphate (0.16%), at initial pH (5) and inoculum size 1*108 cfu/ml at (50?C) For (72) hours, using shaking incubator at (150) rpm.

Effect of Gamma Irradiation and Ems on Germination and Survival of Okra (Abelmoschus esculentus L.) cv Arka Nikita

The present investigation was devised to observe different doses of chemical and physical mutagen on the germination and survival percentage of okra variety Arka Nikita. Seeds of okra variety Arka Nikita were treated with different doses of gamma rays and EMS. The experiment was laid out in Randomized Complete Block Design (RCBD) with thirteen treatments and three replications. It was clearly observed that germination and survival percentage decreased with increase in doses of gamma rays and EMS. Results revealed that among different treatments, treatment T1 (Control) recorded maximum germination (85) and survival per cent (98.82) and observed dose-dependent reduction in biological factors such as germination and survival, the LD50 values for gamma rays and EMS were 0.4% and 60 kR, respectively.

Overproduction Of Fibrinolysis Enzyme Produced By Mutant Pseudomonas Aeruginosa Compared To Wild Type Pseudomonas Aeruginosa

Objective: The aim of the study is to increase the production of fibrinolytic enzyme produced by pseudomonas aeruginosa after mutagenesis with physical mutagens compared to the wild type. Study design: Cross-sectional in descriptive study design and case–control in analytical study design. Backgrounds: P. aeruginosa is a ubiquitous gram-negative aerobe. Its opportunistic pathogen that infects patients with cystic fibrosis, burn, wounds, immunodeficiency, chronic obstructive pulmonary disorder (COPD), cancer. Fibrinolytic enzyme is a factor that lysis fibrin clots. This fibrinolytic factor has prospective use totreat cardiovascular diseases such as stroke and heart attack. Thrombotic disorders are the main cause of death world. Methodology: Study patients, specimens, collection of bacterial isolates. Plasma agar plate assay, Skim milk agar assay, Radial caseinolytic assay, Preparing magnetizing Water. Exposure P. aeruginosa to radioactive sources, lasers and magnetic water. Determination of optimal bacterial isolate for the fibrinolytic enzyme production. Results: Increased when P. aeruginosa were exposed to Na23 at an efficiency of 10 µci. Also exposed to 10 ml of magnetic water during 48 hr., then exposed to a cobalt radioactive source during 3 hr., another radioactive source is Cs137, Co60 and Sr90 in 1 hr. during 48 hours with exposure to laser and magnetized water. Conclusion: Conclude that the overproduction of fibrinolytic enzyme (clot-dissolving enzyme) increased when P. aeruginosa were exposed to Na23, Cs137, Co60 and Sr90 with exposed to laser and magnetized water in certain period.

Enhancing floral diversity: A review of mutation breeding techniques in flower crops

Flower crops encompass a wide range of ornamental annuals and perennials that are commercially cultivated for aesthetic appeal of their floral displays. Mutation induction has been used since the early 20th century to increase genetic diversity and develop new flower varieties with improved yield, quality, adaptation and market value. Mutation experiments have successfully created genetic variability and novel phenotypes in diverse floral species. Mutation breeding, which involves the induction of genetic variations via physical and chemical mutagens, has emerged as a vital technique for enhancing ornamental plant traits, such as flower color, shape, disease resistance and stress tolerance. It explores the types and applications of physical mutagens, such as gamma rays and ion beams and chemical mutagens, such as ethyl methane sulfonate (EMS) and sodium azide (SA). This review provides detailed insights into mutation breeding research conducted on major flower crops (e.g., rose, carnation, chrysanthemum and gerbera). This study also highlights achievements in the development of novel flower varieties, highlights the key challenges faced in mutation breeding programs and identifies gaps in research, particularly concerning the comparative efficacy of different mutagens, environmental impacts and genetic stability of mutated varieties. Furthermore, the impact of mutation breeding on the global flower market is discussed, emphasizing its role in expanding trait diversity, catering to niche markets and enhancing the commercial value of flower crops. Mutation breeding offers significant promise in the development of sustainable and climate-resilient ornamental crops that can meet the needs of emerging markets. This review serves as a valuable resource for students, scientists and breeders interested in leveraging mutation breeding for floral crop improvement.

Harnessing the Power of an Extensive EMS-Induced Sorghum Population for Rapid Crop Improvement.

Plant breeders leverage mutagenesis using chemical, biological, and physical mutagens to create novel trait variations. Many widely used sorghum genotypes have a narrow genetic base, which hinders improvements using classical breeding. Enhancing the diversity of the sorghum genome thus remains a key priority for sorghum breeders. To accelerate the genetic enhancement of sorghum, an extensive library comprised of seeds from 150,000 individual mutant plants of the Sorghum bicolor inbred line BTx623 was established using ethyl methanesulphonate (EMS) as a mutagen. The sorghum mutant library was bulked into 1498 pools (~100 seed heads per pool). In each pool, DNA was extracted from a subset of the seed and screened using the FIND-IT technology based on droplet digital PCR. All 43 nucleotide substitutions that were screened using FIND-IT were identified, demonstrating the potential to identify any EMS-derived mutation in an elite line of sorghum within days. This diverse library represents the largest collection of sorghum mutants ever conceived, estimated to cover 240% of all possible EMS-induced mutation points within the Sorghum genome. Using FIND-IT, the speed at which a specific desired EMS-derived mutation can be identified is a major upgrade to conventional reverse genetic techniques. Additionally, the ease at which valuable variants can be integrated into elite commercial lines is a far simpler and less expensive process compared to genome editing. Genomic variations in the library will have direct utility as a breeding resource for commercial sorghum applications, allowing enhanced adaptation to climate change and enhanced yield potential in marginal environments.

Genome-Wide Profile of Mutations Induced by Carbon Ion Beam Irradiation of Dehulled Rice Seeds.

As a physical mutagen, carbon ion beam (CIB) irradiation can induce high-frequency mutation, which is user-friendly and environment-friendly in plant breeding. In this study, we resequenced eight mutant lines which were screened out from the progeny of the CIB-irradiated dehulled rice seeds. Among these mutants, CIB induced 135,535 variations, which include single base substitutions (SBSs), and small insertion and deletion (InDels). SBSs are the most abundant mutation, and account for 88% of all variations. Single base conversion is the main type of SBS, and the average ratio of transition and transversion is 1.29, and more than half of the InDels are short-segmented mutation (1-2 bp). A total of 69.2% of the SBSs and InDels induced by CIBs occurred in intergenic regions on the genome. Surprisingly, the average mutation frequency in our study is 9.8 × 10-5/bp and much higher than that of the previous studies, which may result from the relatively high irradiation dosage and the dehulling of seeds for irradiation. By analyzing the mutation of every 1 Mb in the genome of each mutant strain, we found some unusual high-frequency (HF) mutation regions, where SBSs and InDels colocalized. This study revealed the mutation mechanism of dehulled rice seeds by CIB irradiation on the genome level, which will enrich our understanding of the mutation mechanism of CIB radiation and improve mutagenesis efficiency.

Induced Mutagenesis using Gamma Rays: Biological Features and Applications in Crop Improvement

Induced mutagenesis has emerged as an essential field of plant breeding to address global food security challenges, offering tools to enhance crop productivity, resistance, and nutritional value. Among the mutation induction tools, the physical mutagen such as gamma rays holds promise for efficient mutation induction. Gamma rays, a type of high-energy electromagnetic radiation, possess unique characteristics that enable them to penetrate plant tissues and induce genetic mutations. The biological effects are influenced by various factors, including the source, type of radiation, dose rate, absorbed dose, and the sensitivity of the tissues and organs. Gamma rays have been successfully applied to various plant species, producing novel superior mutants for cultivation. This paper explores the different aspects of gamma irradiation, including the radiation facilities, the biological effects of gamma rays on plant species, and the potential applications to generate genetic diversity and unlock desirable trait improvement in crop plants. The paper also showcases successful examples of high-yielding mutants developed through gamma-ray mutagenesis and their impact on agriculture. The potential approach of plant mutagenesis offers to address challenges for plant improvement for sustainable and resilient food production.

Gamma-rays induced genome wide stable mutations in cowpea deciphered through whole genome sequencing

Purpose Gamma rays are the most widely exploited physical mutagen in plant mutation breeding. They are known to be involved in the development of more than 60% of global cowpea (Vigna unguiculata (L.) Walp.) mutant varieties. Nevertheless, the nature and type of genome-wide mutations induced by gamma rays have not been studied in cowpea and therefore, the present investigation was undertaken. Materials and Methods Genomic DNAs from three stable gamma rays-induced mutants (large seed size, small seed size and disease resistant mutant) of cowpea cultivar ‘CPD103’ in M6 generation along with its progenitor were used for Illumina-based whole-genome resequencing. Results Gamma rays induced a relatively higher frequency (88.9%) of single base substitutions (SBSs) with an average transition to transversion ratio (Ti/Tv) of 3.51 in M6 generation. A > G transitions, including its complementary T > C transitions, predominated the transition mutations, while all four types of transversion mutations were detected with frequencies over 6.5%. Indels (small insertions and deletions) constituted about 11% of the total induced variations, wherein small insertions (6.3%) were relatively more prominent than small deletions (4.8%). Among the indels, single-base indels and, in particular, those involving A/T bases showed a preponderance, albeit indels of up to three bases were detected in low proportions. Distributed across all 11 chromosomes, only a fraction of SBSs (19.45%) and indels (20.2%) potentially altered the encoded amino acids/peptides. The inherent mutation rate induced by gamma rays in cowpea was observed to be in the order of 1.4 × 10−7 per base pair in M6 generation. Conclusion Gamma-rays with a greater tendency to induce SBSs and, to a lesser extent, indels could be efficiently and effectively exploited in cowpea mutation breeding.

Growth and yield performance of X-ray irradiated cucumber

Cucumber (Cucumis sativus L.) is a very important fruit which makes its demand and consumption continually on the increase all over the world. X-ray is an ionizing radiation and a physical mutagen with great potentials in creating artificial variability in crops. The employment of x-ray irradiation has been underutilized in plant mutagenesis, hence this study sought to determine its effect on the germination and agro-morphological traits of cucumber. Cucumber seeds were obtained from an agro-allied store and exposed to x-ray radiation from a source 70 KVA at a distance of 90cm and doses 10, 20, 30 and 40mAs. The field experiment was carried out in duplicate using a Randomized Complete Block Design (RCBD). Irradiated and unirradiated (control) seeds were sown directly on a total of ten prepared plots measuring 2.44 by 1.50 m. The result generated in this study show a positive shift at the higher doses (30 and 40 mAs) with reduced number of days to fruit maturity and increased number of fruits per plant when compared to the control and other doses. A strong positive correlation was observed among some traits studied, indicating the possibility of such traits being under the influence of the same gene and the ability to be inherited together. Zonata, a chlorophyll mutant was observed at 30 mAs indicating how successful the dose was in inducing beneficial mutation on the Cucumber. Higher doses of x-ray irradiation as used in this study is therefore recommended for the genetic improvement of other vegetable and under developed crops.

Germination, Physiochemical, and Morphology Changes of TR10 Rice Seeds Irradiated to Filtered and Unfiltered Neutron

In 2020, Sabah’s rice production was 117, 846 metric tonnes with a planted area of 40, 446 ha is relatively low compared to other states such as Selangor, which has 36,004 ha less planted area but can produce up to 159,535 metric tonnes more than Sabah. Low rice production in Sabah has contributed to the shortage of supply. Thus, new varieties could be needed that sufficiently produce yields that comparable to the efforts and cost of rice planting. One of the methods is producing new varieties that probably produce high yields using physical mutagen. From the literature available, gamma and neutrons were found to be the most common agents to increase rice production per unit planting area but used they were used separately. Theoretically, using fast neutron irradiation was found to produce a superior mutant. Thus, this paper aims to study the effect of rice seeds irradiated to both gamma and neutron simultaneous, and compare with neutron alone on the germination rates and physiochemical of rice seeds after the irradiations at different dosages. TR10 rice seeds were irradiated simultaneously to gamma and neutrons in the nuclear reactor core using Pneumatic Transfer System–PTS facility, while irradiation to neutrons alone was performed in a neutron chamber using Beam ports–BP facility at Nuclear Malaysia. The germination study shows a linear decrease as the irradiation doses increase in BP and fail to germinate in PTS. Yet, seeds irradiated in PTS showed no hazardous compounds and a remarkable increase in mineral content in seeds, particularly potassium and magnesium at 14 Gy. Similarly, to the shape of the starch granules in both facilities, the starch structure changes after being exposed to 14 Gy in PTS and 35 Gy in BP. As a result, seeds exposed to neutron alone induced considerably more inclusive effects and may raise growth performance and improve rice quality with optimal neutron dosage range from 7 to 14 Gy.

Effect of Chemical and Physical Mutagens on Leaf Morphological Changes in Horse Gram (Macrotyloma Uniflorum (Lam.)

Horse gram (Macrotyloma Uniflorum (Lam.) varieties viz., Phule Sakas and Man were mutated with EMS (ethyl methane sulphonate), SA (Sodium azide) and gamma rays (G), to determine the mutagenic potency in breeding programme. Considerable frequency of leaf changes carrying plants could be observed in both the varieties of Horse gram as a result of mutagenic treatments. The frequency of leaf change carrying plants revealed an enhancing feature with the gradual rise in concentration /dose of EMS, SA and Gamma rays in both the Horse gram varieties.

Impact of Gamma Irradiation on Biochemical and Physiological Characteristics of Black Rice

Rice (Oryza sativa L.) is a fruit caryopsis, well known for its high calorific value and presence of high antioxidant phytochemicals such as flavonoids and anthocyanins. Further exposure of crops to different doses of physical mutagens is useful to give insight into development of quality traits for plant breeding. So, the objective of the present study was to analyse the effects of gamma irradiation on black rice seeds that were exposed to different radiation doses and to evaluate the irradiation effect on physiological and biochemical characteristics of plants. Variations were observed among different doses from non-enzymatic antioxidant activities that showed the increasing flavonoids, phenolics and carotenoids accumulation from low to high doses. A high dose irradiation releases, high amount of H2O2 as compare to O2- indicating the involvement of enzymatic antioxidants as a defence mechanism. An inverse relation was shown between peroxidase and catalase enzyme and concentration of Superoxide dismutase also increased with increasing doses. To know the level of stress on cellular metabolism, total proline and malon dialdehyde accumulation was estimated and both showed positive results for increasing doses. In case of measurement of photosynthetic parameters, chlorophyll concentration increased from 50 Gy to 100 Gy and decreased from 150 Gy to 200 Gy due to peroxidation of membrane. Significant effect was not observed in the concentration of soluble sugar among various doses. Thus, the present study, was useful to isolating effective dose (50Gy, 100 Gy) that may contribute towards advancement of qualitative traits for future breeding purposes.

Evaluation of Induced Genetic Variability for Yield and Yield Contributing Traits in M4 Generation of Mungbean (Vigna radiata (L.) Wilczek)

The goal of the current study was to determine how much genetic variability there was for yield and traits that contributed to yield in two different mungbean varieties, WGG-42 and LGG-460, following the induction of mutations through chemicals (ethyl methane sulphonate and sodium azide) and physical (gamma rays) mutagens. In Rabi, 2018-19, in RBD with three replications in M4generation, fifty-five mutant lines selected from M3 progenies (36 in WGG-42 and 19 in LGG-460) were assessed alongside the two parents. Number of primary branches per plant, number of clusters per plant and number of pods per plant all showed high GCV and PCV. All the characters under study have high heritability. High heritability coupled with high genetic advance as per cent of mean was recorded for plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant, pod length and seed yield per plant indicating that the genetic variances for these characters are probably owing to their high additive gene effects. Our study indicates promising avenues for future mungbean breeding programs to enhance these characteristics.

Exploring the Effect of High-Energy Heavy Ion Beam on Rice Genome: Transposon Activation.

High-energy heavy ion beams are a new type of physical mutagen that can produce a wide range of phenotypic variations. In order to understand the mechanism of high-energy heavy ion beams, we resequenced the whole genome of individual plants with obvious phenotypic variations in rice. The sequence alignment results revealed a large number of SNPs and InDels, as well as genetic variations related to grain type and heading date. The distribution of SNP and InDel on chromosomes is random, but they often occur in the up/downstream regions and the intergenic region. Mutagenesis can cause changes in transposons such as Dasheng, mPing, Osr13 and RIRE2, affecting the stability of the genome. This study obtained the major gene mutation types, discovered differentially active transposons, screened out gene variants related to phenotype, and explored the mechanism of high-energy heavy ion beam radiation on rice genes.

A systematic review on physical mutagens in rice breeding in Southeast Asia.

In the 1920s, Lewis Stadler initiated the introduction of permanent improvements to the genetic makeup of irradiated plants. Since then, studies related to breeding mutations have grown, as efforts have been made to expand and improve crop productivity and quality. Stadler's discovery began with x-rays on corn and barley and later extended to the use of gamma-rays, thermal, and fast neutrons in crops. Radiation has since been shown to be an effective and unique method for increasing the genetic variability of species, including rice. Numerous systematic reviews have been conducted on the impact of physical mutagens on the production and grain quality of rice in Southeast Asia. However, the existing literature still lacks information on the type of radiation used, the rice planting materials used, the dosage of physical mutagens, and the differences in mutated characteristics. Therefore, this article aims to review existing literature on the use of physical mutagens in rice crops in Southeast Asian countries. Guided by the PRISMA Statement review method, 28 primary studies were identified through a systematic review of the Scopus, Science Direct, Emerald Insight, Multidisciplinary Digital Publishing, and MDPI journal databases published between 2016 and 2020. The results show that 96% of the articles used seeds as planting materials, and 80% of the articles focused on gamma-rays as a source of physical mutagens. The optimal dosage of gamma-rays applied was around 100 to 250 Gy to improve plant development, abiotic stress, biochemical properties, and nutritional and industrial quality of rice.

Effect of Gamma Irradiation on Growth Parameters of Vegetable Cowpea (Vigna unguiculata L. Walp)

Aim: The present investigation was carried out to study the effect of gamma irradiation on the growth parameters of cowpea variety Paiyur-1.Seeds were irradiated with physical mutagen viz., gamma irridation. The doses of radiation used were control, 50 Gy, 100 Gy, 150 Gy, 200 Gy, 250 Gy, 300 Gy, 350 Gy, and 400 Gy.Finding the LD50 and GR50 value for the physical mutagen dosages is the study's major goal. Cs137 is exposed to gamma radiation, and the observation were recorded in the M1 generation.
 Study Design: The regression method by applying Probit analysis based on rates of fatalities was utilised to estimate the Lethal Dose (LD50). Simple Linear Regression on the dose-response curve was adopted to evaluate the GR50 incorporating all of the vegetative parameters using R software.
 Place and Duration of Research: The study was carried out at Horticulture orchard, Department of Vegetable Science, Horticulture College and research Institute, Tamil Nadu Agricultural University, Coimbatore during 2022-2023.
 Methodology: In this study, the paiyur-1 variety of cowpea was sown with two replications, those mutagenized seeds were planted individually in germination paper using the roll towel method and dry seeds that weren't irradiated served as the control. To find the lethal dose 50 and to observe the shoot length, root length, germination percentage, mortality rate and seed vigour.
 Results: Among the 9 gamma irradiated treatments, 50Gy and 100 Gy exhibited superior germination percentages, despite the fact 50 Gy treated seeds were having appealing shoot length, root length, and plant height. The linear relationship have given that shoot length and root length are the two parameter that are highly susceptible to gamma irradiation than plant height and seed vigour.

Evaluation of Saccharomyces cerevisiae Improved Strains Potential in the Bioethanol Production from Bagasse

Plant biomass can be utilized to produce bioethanol, because they are abundantly available in nature. The cost of ethanol production from lignocellulosic materials is relatively high with low yield. But this can be solved by strain improvement processes. This study is aimed at evaluate bioethanol production potential of improved strains of Saccharomyces cerevisiae developed through random mutagenesis. Bagasse was hydrolysed with 1% NaOH and 1.0M H2SO4 respectively for five days. The hydrolysed bagasse was saccharified using Aspergillus niger isolated from soil samples. Saccharomyces cerevisiae isolated from locally produced wines; sorghum (burukutu) oil palm wine (emu) and raphia palm wine (oguro) with the highest ethanol production (5.0g/ml) were used, and then treated with physical mutagen (ultraviolet light) and chemical mutagens (Acridine dye, Bromo acetaldehyde, dithiothreitol, Ketoconazole and Nitrous acid) respectively to develop mutant with high ethanol producing efficiency under varied operational parameters. Three mutant strains of Saccharomyces cerevisiae namely;- SUV, SCD and SCK produced higher volumes of ethanol (7.5 g/ml, 9.8 g/ml, 11.2 g/ml respectively). SCD and SCK were able to grow at 25% ethanol concentration indicating that they had higher ethanol tolerance ability than the other strains. The optimum temperature and pH for ethanol production by all the strains were 350C and 6.0 respectively. The improved strains of Saccharomyces cerevisiae developed through random mutation techniques had produced more ethanol from the bagasse than the wild-type.

Replication stress causes delayed mitotic entry and chromosome 12 fragility at the ANKS1B large neuronal gene in human induced pluripotent stem cells.

Substantial background level of replication stress is a feature of embryonic and induced pluripotent stem cells (iPSCs), which can predispose to numerical and structural chromosomal instability, including recurrent aberrations of chromosome 12. In differentiated cells, replication stress-sensitive genomic regions, including common fragile sites, are widely mapped through mitotic chromosome break induction by mild aphidicolin treatment, an inhibitor of replicative polymerases. IPSCs exhibit lower apoptotic threshold and higher repair capacity hindering fragile site mapping. Caffeine potentiates genotoxic effects and abrogates G2/M checkpoint delay induced by chemical and physical mutagens. Using 5-ethynyl-2'-deoxyuridine (EdU) for replication labeling, we characterized the mitotic entry dynamics of asynchronous iPSCs exposed to aphidicolin and/or caffeine. Under the adjusted timing of replication stress exposure accounting revealed cell cycle delay, higher metaphase chromosome breakage rate was observed in iPSCs compared to primary lymphocytes. Using differential chromosome staining and subsequent locus-specific fluorescent in situ hybridization, we mapped the FRA12L fragile site spanning the large neuronal ANKS1B gene at 12q23.1, which may contribute to recurrent chromosome 12 missegregation and rearrangements in iPSCs. Publicly available data on the ANKS1B genetic alterations and their possible functional impact are reviewed. Our study provides the first evidence of common fragile site induction in iPSCs and reveals potential somatic instability of a clinically relevant gene during early human development and in vitro cell expansion.

Effect of Chemical and Physical Mutagens on Vegetative Growth and Flowering of Hibiscus Rosa-sinensis L Plant

Effect of Chemical and Physical Mutagens on Vegetative Growth and Flowering of Hibiscus Rosa-sinensis L Plant