Population structure in diverse pepper (Capsicum spp.) accessions

BACKGROUND

Peppers, bell and chile, are a culturally and economically important worldwide. Domesticated Capsicum spp. are distributed globally and represent a complex of valuable genetic resources.

OBJECTIVES

Explore population structure and diversity in a collection of 467 peppers representing eight species, spanning the spectrum from highly domesticated to wild using 22,916 SNP markers distributed across the twelve chromosomes of pepper.

RESULTS

These species contained varied levels of genetic diversity, which also varied across chromosomes; the species also differ in the size of genetic bottlenecks they have experienced. We found that levels of diversity negatively correlate to levels of domestication, with the more diverse being the least domesticated.

Evolution of weedy giant ragweed (Ambrosia trifida): Multiple origins and gene expression variability facilitates weediness

Agricultural weeds may originate from wild populations, but the origination patterns and genetics underlying this transition remain largely unknown. Analysis of weedy-wild paired populations from independent locations may provide evidence to identify key genetic variation contributing to this adaptive shift. We performed genetic variation and expression analyses on transcriptome data from 67 giant ragweed samples collected from different locations in Ohio, Iowa, and Minnesota and found geographically separated weedy populations likely originated independently from their adjacent wild populations, but subsequent spreading of weedy populations also occurred locally. By using eight closely related weedy-wild paired populations, we identified thousands of unique transcripts in weedy populations that reflect shared or specific functions corresponding, respectively, to both convergently evolved and population-specific weediness processes. In addition, differential expression of specific groups of genes was detected between weedy and wild giant ragweed populations using gene expression diversity and gene co-expression network analyses. Our study suggests an integrated route of weedy giant ragweed origination, consisting of independent origination combined with the subsequent spreading of certain weedy populations, and provides several lines of evidence to support the hypothesis that gene expression variability plays a key role in the evolution of weedy species.

Genetic diversity, gene flow, and differentiation among wild, semiwild, and landrace chile pepper (Capsicum annuum) populations in Oaxaca, Mexico

PREMISE

Capsicum annuum (Solanaceae) was originally domesticated in Mexico, where wild (C. annuum var. glabriusculum) and cultivated (C. annuum var. annuum) chile pepper populations (>60 landraces) are common, and wild-resembling individuals (hereafter semiwild) grow spontaneously in anthropogenic environments. Here we analyze the role of elevation and domestication gradients in shaping the genetic diversity in C. annuum from the state of Oaxaca, Mexico.

METHODS

We collected samples of 341 individuals from 28 populations, corresponding to wild, semiwild (C. annuum var. glabriusculum) and cultivated C. annuum, and closely related species Capsicum frutescens and C. chinense. From the genetic variation of 10 simple sequence repeat (SSR) loci, we assessed the population genetic structure, inbreeding, and gene flow through variance distribution analyses, genetic clustering, and connectivity estimations.

RESULTS

Genetic diversity (H_E ) did not differ across domestication levels. However, inbreeding coefficients were higher in semiwild and cultivated chiles than in wild populations. We found evidence for gene flow between wild populations and cultivated landraces along the coast. Genetic structure analysis revealed strong differentiation between most highland and lowland landraces.

CONCLUSIONS

Gene flow between wild and domesticated populations may be mediated by backyards and smallholder farms, while mating systems may facilitate gene flow between landraces and semiwild populations. Domestication and elevation may overlap in their influence on genetic differentiation. Lowland Gui'ña dani clustered with highland landraces perhaps due to the social history of the Zapotec peoples. In situ conservation may play an important role in preserving semiwild populations and private alleles found in landraces.

Expression of AtWRI1 and AtDGAT1 during soybean embryo development influences oil and carbohydrate metabolism

Soybean oil is one of the most consumed vegetable oils worldwide. Genetic improvement of its concentration in seeds has been historically pursued due to its direct association with its market value. Engineering attempts aiming to increase soybean seed oil presented different degrees of success that varied with the genetic design and the specific variety considered. Understanding the embryo's responses to the genetic modifications introduced, is a critical step to successful approaches. In this work, the metabolic and transcriptional responses to AtWRI1 and AtDGAT1 expression in soybean seeds were evaluated. AtWRI1 is a master regulator of fatty acid (FA) biosynthesis, and AtDGAT1 encodes an enzyme catalysing the final and rate-limiting step of triacylglycerides biosynthesis. The events expressing these genes in the embryo did not show an increase in total FA content, but they responded with changes in the oil and carbohydrate composition. Transcriptomic studies revealed a down-regulation of genes putatively encoding for oil body packaging proteins, and a strong induction of genes annotated as lipases and FA biosynthesis inhibitors. Novel putative AtWRI1 targets, presenting an AW-box in the upstream region of the genes, were identified by comparison with an event that harbours only AtWRI1. Lastly, targeted metabolomics analysis showed that carbon from sugar phosphates could be used for FA competing pathways, such as starch and cell wall polysaccharides, contributing to the restriction in oil accumulation. These results allowed the identification of key cellular processes that need to be considered to break the embryo's natural restriction to uncontrolled seed lipid increase.

Novel Antimicrobial Topical Gel That Exhibits Inhibitory Effectiveness Toward Common Microbes in Wound Infection (P19-007-19)

Objectives

This research project focused on the inhibitory effectiveness of a novel antimicrobial gel (AMG) towards a panel of common microbes involved in wound infections.

Methods

A novel antimicrobial topical gel consisting of vitamin E TPGS (tocopherol polyethylene glycol succinate), ascorbyl palmitate, zinc aspartate, lavender oil and deionized distilled water was developed in our laboratory. Various in vitro techniques were used to determine the effectiveness of AMG on prokaryotic and eukaryotic microbes.

Results

In vitro experiments show that while AMG had varying inhibitory effects on both prokaryotic and eukaryotic microbes, there was a predilection for AMG to inhibit planktonic growth and biofilm formation of Staphylococcus species, most notably Methicillin Resistant Staphylococcus aureus (MRSA). The inhibitory effect of the AMK on planktonic growth was immediate with a four-fold reduction in growth, compared to controls, within 4 to 6 hrs of induction. Within 24 hrs S. aureus growth was minimal and complete inhibition of growth was achieved within 48 hrs. In an in vitro biofilm model, the AMG inhibited Staphylococcus biofilm attachment by 67% (density), 82% (mass) and 95% (viability). On pre-formed established biofilms, the AMG was able to inhibit 47% (density), 47% (mass) and 44% (viability) Staphylococcus biofilms. Antibiotic comparison experiments demonstrated that the MIC (minimum inhibitory concentration) of Mupirocin was <1% while the AMG was slightly elevated at <2%. However, thus far, Staphylococcus has not demonstrated resistance to AMG whereas it has become a troubling concern for Mupirocin. Fluorescent microscopy using LIVE/DEAD (SYTO9/propidium iodide) staining of Staphylococcus culture controls exhibited robust growth and viability while AMG treated Staphylococcus cultures showed sparse growth of non-viable cells. AMG has inhibitory activities against normal and methicillin resistant S. pseudintermedius which are prevalent in lick granulomas in canines.

Conclusions

AMG is nontoxic to humans and canines and demonstrates potential for use in wound infections as an alternative to commonly prescribed antibiotics without the unintended drug resistance seen with antibiotics. AMG is an effective treatment option, this far in vitro, for Staphylococcus infections that are particularly prone to biofilm growth.

Funding Sources

ETSU, Honors College, Student/Faculty Collaborative Research Grant.

Genetic Structure of Liriomyza trifolii (Diptera: Agromyzidae) Associated With Host Plants From Southeastern Mexico

Host-associated differentiation (HAD) has played a major role in insect diversification at both macroevolutionary and microevolutionary scales. This evolutionary process has been reported in insects associated with wild and domesticated plant species. In particular, domesticated species harbor large genetic and phenotypic diversity associated with traits of human interest, including variation in nutrition, phenology, fruit, and leaf shape. This diversity may alter selection regimes affecting insect evolution and host specialization. The genus Liriomyza includes highly polyphagous species that are characterized for living and feeding inside plant leaves. Ecological and genetic data suggest the presence of cryptic species within this genus. Moreover, there is evidence of HAD in a group of populations of Liriomyza trifolii (Burgess) associated with Capsicum annum L. (Solanaceae). In this work, we explored HAD in L. trifolii populations from southeastern Mexico, and inquire into differentiation specific to peppers based on cytochrome oxidase I. We also evaluated the relationship between the genetic structure of leafminers and the different types of C. annuum. Our main results did not support previous findings of specialization of L. trifolli on C. annuum. Nevertheless, we found a divergent group of haplotypes associated to Allium cepa (Aspargales: Amaryllidaceae) in sympatric condition to Physalis philadelphica Lam. (Solanales: Solanaceae) and C. annum, suggesting the presence of HAD, as well as significant genetic differentiation of L. trifolii associated to peppers from Oaxaca and Yucatán.

Genome-wide genotyping of a novel Mexican Chile Pepper collection illuminates the history of landrace differentiation after Capsicum annuum L. domestication

Studies of genetic diversity among phenotypically distinct crop landraces improve our understanding of fruit evolution and genome structure under domestication. Chile peppers (Capsicum spp. L.) are economically valuable and culturally important species, and extensive phenotypic variation among landraces exists in southern Mexico, a center of C. annuum diversity. We collected 103 chile pepper seed accessions from 22 named landraces across 27 locations in southern Mexico. We genotyped these accessions with genotyping by sequencing (GBS), yielding 32,623 filtered single-nucleotide polymorphisms. Afterward, we genotyped 32 additional C. annuum accessions from a global collection for comparison to the Mexican collection. Within the Mexican collection, genetic assignment analyses showed clear genetic differentiation between landraces and clarified the unique nature of the Tusta landrace. Further clustering analyses indicated that the largest fresh-use Chile de Agua and dry-use Costeño landraces were part of separate clades, indicating that these two landraces likely represent distinct populations. The global accessions showed considerable admixture and limited clustering, which may be due to the collapse of use-type divisions outside of Central America. The separation of the Mexican landraces in part by fruit morphology related to use highlights the relevance of this use-type morphological diversity for plant breeders and the utility of fruit development variation for evolutionary biologists.

Genetic Architecture of Soybean Yield and Agronomic Traits

Soybean is the world's leading source of vegetable protein and demand for its seed continues to grow. Breeders have successfully increased soybean yield, but the genetic architecture of yield and key agronomic traits is poorly understood. We developed a 40-mating soybean nested association mapping (NAM) population of 5,600 inbred lines that were characterized by single nucleotide polymorphism (SNP) markers and six agronomic traits in field trials in 22 environments. Analysis of the yield, agronomic, and SNP data revealed 23 significant marker-trait associations for yield, 19 for maturity, 15 for plant height, 17 for plant lodging, and 29 for seed mass. A higher frequency of estimated positive yield alleles was evident from elite founder parents than from exotic founders, although unique desirable alleles from the exotic group were identified, demonstrating the value of expanding the genetic base of US soybean breeding.

Genome-Wide Analysis of Grain Yield Stability and Environmental Interactions in a Multiparental Soybean Population

Genetic improvement toward optimized and stable agronomic performance of soybean genotypes is desirable for food security. Understanding how genotypes perform in different environmental conditions helps breeders develop sustainable cultivars adapted to target regions. Complex traits of importance are known to be controlled by a large number of genomic regions with small effects whose magnitude and direction are modulated by environmental factors. Knowledge of the constraints and undesirable effects resulting from genotype by environmental interactions is a key objective in improving selection procedures in soybean breeding programs. In this study, the genetic basis of soybean grain yield responsiveness to environmental factors was examined in a large soybean nested association population. For this, a genome-wide association to performance stability estimates generated from a Finlay-Wilkinson analysis and the inclusion of the interaction between marker genotypes and environmental factors was implemented. Genomic footprints were investigated by analysis and meta-analysis using a recently published multiparent model. Results indicated that specific soybean genomic regions were associated with stability, and that multiplicative interactions were present between environments and genetic background. Seven genomic regions in six chromosomes were identified as being associated with genotype-by-environment interactions. This study provides insight into genomic assisted breeding aimed at achieving a more stable agronomic performance of soybean, and documented opportunities to exploit genomic regions that were specifically associated with interactions involving environments and subpopulations.

Dissection of two soybean QTL conferring partial resistance to Phytophthora sojae through sequence and gene expression analysis

BACKGROUND

Phytophthora sojae is the primary pathogen of soybeans that are grown on poorly drained soils. Race-specific resistance to P. sojae in soybean is gene-for-gene, although in many areas of the US and worldwide there are populations that have adapted to the most commonly deployed resistance to P. sojae ( Rps) genes. Hence, this system has received increased attention towards identifying mechanisms and molecular markers associated with partial resistance to this pathogen. Several quantitative trait loci (QTL) have been identified in the soybean cultivar 'Conrad' that contributes to the expression of partial resistance to multiple P. sojae isolates.

RESULTS

In this study, two of the Conrad QTL on chromosome 19 were dissected through sequence and expression analysis of genes in both resistant (Conrad) and susceptible ('Sloan') genotypes. There were 1025 single nucleotide polymorphisms (SNPs) in 87 of 153 genes sequenced from Conrad and Sloan. There were 304 SNPs in 54 genes sequenced from Conrad compared to those from both Sloan and Williams 82, of which 11 genes had SNPs unique to Conrad. Eleven of 19 genes in these regions analyzed with qRT-PCR had significant differences in fold change of transcript abundance in response to infection with P. sojae in lines with QTL haplotype from the resistant parent compared to those with the susceptible parent haplotype. From these, 8 of the 11 genes had SNPs in the upstream, untranslated region, exon, intron, and/or downstream region. These 11 candidate genes encode proteins potentially involved in signal transduction, hormone-mediated pathways, plant cell structural modification, ubiquitination, and basal resistance.

CONCLUSIONS

These findings may indicate a complex defense network with multiple mechanisms underlying these two soybean QTL conferring resistance to P. sojae. SNP markers derived from these candidate genes can contribute to fine mapping of QTL and marker assisted breeding for resistance to P. sojae.

A gene encoding an abscisic acid biosynthetic enzyme (LsNCED4) collocates with the high temperature germination locus Htg6.1 in lettuce (Lactuca sp.)

Thermoinhibition, or failure of seeds to germinate when imbibed at warm temperatures, can be a significant problem in lettuce (Lactuca sativa L.) production. The reliability of stand establishment would be improved by increasing the ability of lettuce seeds to germinate at high temperatures. Genes encoding germination- or dormancy-related proteins were mapped in a recombinant inbred line population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. This revealed several candidate genes that are located in the genomic regions containing quantitative trait loci (QTLs) associated with temperature and light requirements for germination. In particular, LsNCED4, a temperature-regulated gene in the biosynthetic pathway for abscisic acid (ABA), a germination inhibitor, mapped to the center of a previously detected QTL for high temperature germination (Htg6.1) from UC96US23. Three sets of sister BC(3)S(2) near-isogenic lines (NILs) that were homozygous for the UC96US23 allele of LsNCED4 at Htg6.1 were developed by backcrossing to cv. Salinas and marker-assisted selection followed by selfing. The maximum temperature for germination of NIL seed lots with the UC96US23 allele at LsNCED4 was increased by 2-3°C when compared with sister NIL seed lots lacking the introgression. In addition, the expression of LsNCED4 was two- to threefold lower in the former NIL lines as compared to expression in the latter. Together, these data strongly implicate LsNCED4 as the candidate gene responsible for the Htg6.1 phenotype and indicate that decreased ABA biosynthesis at high imbibition temperatures is a major factor responsible for the increased germination thermotolerance of UC96US23 seeds.

Analyses of synteny between Arabidopsis thaliana and species in the Asteraceae reveal a complex network of small syntenic segments and major chromosomal rearrangements

Comparative genomic studies among highly divergent species have been problematic because reduced gene similarities make orthologous gene pairs difficult to identify and because colinearity is expected to be low with greater time since divergence from the last common ancestor. Nevertheless, synteny between divergent taxa in several lineages has been detected over short chromosomal segments. We have examined the level of synteny between the model species Arabidopsis thaliana and species in the Compositae, one of the largest and most diverse plant families. While macrosyntenic patterns covering large segments of the chromosomes are not evident, significant levels of local synteny are detected at a fine scale covering segments of 1-Mb regions of A. thaliana and regions of <5 cM in lettuce and sunflower. These syntenic patches are often not colinear, however, and form a network of regions that have likely evolved by duplications followed by differential gene loss.

Plant NBS-LRR proteins: adaptable guards

Plant nucleotide-binding site leucine-rich repeat (NBS-LRR) proteins are a large family involved in disease resistance; they may monitor the status of proteins targeted by pathogens.

The majority of disease resistance genes in plants encode nucleotide-binding site leucine-rich repeat (NBS-LRR) proteins. This large family is encoded by hundreds of diverse genes per genome and can be subdivided into the functionally distinct TIR-domain-containing (TNL) and CC-domain-containing (CNL) subfamilies. Their precise role in recognition is unknown; however, they are thought to monitor the status of plant proteins that are targeted by pathogen effectors.

Contextual control of long-term habituation in rats

This study examined contextual control of long-term habituation and whether such effects are dependent on the habituating response system. Habituation of the acoustic startle response transferred from the home cage to the testing context, whereas habituation of lick suppression was context specific (Experiments 1 and 2). Contextual control of habituation was demonstrated between 2 experimental contexts for lick suppression to a tone (Experiment 3) and bar-press suppression to a light (Experiment 4). Experiment 5 extinguished habituation of lick suppression and the orienting response to a tone with 27 exposures to the habituation context. Context specificity of both responses also was found. Previous failures to demonstrate contextual control of habituation may be due to the choice of response system and to less sensitive procedures to detect response recovery. The habituation mechanism for startle is independent from the process or processes that underlie habituation in other response systems, but the nature of these mechanisms is not yet known.

Contextual control of long-term habituation in rats

This study examined contextual control of long-term habituation and whether such effects are dependent on the habituating response system. Habituation of the acoustic startle response transferred from the home cage to the testing context, whereas habituation of lick suppression was context specific (Experiments 1 and 2). Contextual control of habituation was demonstrated between 2 experimental contexts for lick suppression to a tone (Experiment 3) and bar-press suppression to a light (Experiment 4). Experiment 5 extinguished habituation of lick suppression and the orienting response to a tone with 27 exposures to the habituation context. Context specificity of both responses also was found. Previous failures to demonstrate contextual control of habituation may be due to the choice of response system and to less sensitive procedures to detect response recovery. The habituation mechanism for startle is independent from the process or processes that underlie habituation in other response systems, but the nature of these mechanisms is not yet known.

Use of real-time confocal laser scanning microscopy to study immediate effects of photodynamic activation on photosensitized erythrocytes

With a view towards the design of systems capable of combining the use of chemotherapy and photodynamic therapy in the treatment of cancer and other disorders, it has been proposed that photosensitized erythrocytes might be employed as carriers/vehicles for agents such as cancer chemotherapeutics. In studying the light dependent release of entrapped agents from such a system, the efficacy of light induced release is usually studied by measuring release of an entrapped component into centrifugation supernatants following photoactivation. It has hitherto been extremely difficult to examine what occurs upon immediate irradiation at the microscopic level in real-time. In this study we demonstrate that, using real-time confocal laser scanning microscopy, it is possible to directly observe immediate short-term events occurring during direct irradiation with the visualizing beam. Following irradiation of photosensitized erythrocytes with the visualizing beam form the confocal scanning system, it was noticed that some from of cell-disruptive event occurred. In this study we demonstrate a dose dependent response between this relatively immediate, light induced disruptive event with respect to both irradiation exposure and photosensitizer concentration. We suggest that this system may provide a novel means of observing, at a microscopic level, events occurring in real-time during photodynamic therapy.

Studies on the biosorption of uranium by Talaromyces emersonii CBS 814.70 biomass

Residual biomass, produced by the thermophilic fungus, Talaromyces emersonii CBS 814.70, following growth on glucose-containing media, was examined for its ability to take up uranium from aqueous solution. It was found that the biomass had a relatively high observed biosorption capacity for the uranium (280 mg/g dry weight biomass). The calculated maximum biosorption capacity obtained by fitting the data to a Langmuir model was calculated to be 323 mg uranium/g dry weight biomass. Pretreatment of the biomass with either dilute HCl or NaOH brought about a significant decrease in biosorptive capacity for uranium. Studies on the effects of variation in temperature on the biosorptive capacity demonstrated no significant change in binding between 20 degrees C and 60 degrees C. However, a significant decrease in biosorptive capacity was observed at 5 degrees C. Binding of uranium to the biomass at all temperatures reached equilibrium within 2 min. While the routine binding assays were performed at pH 5.0, adjustment of the pH to 3.0 gave rise to a significant decrease in biosorption capacity by the biomass. The biosorptive capacity of the biomass for uranium was increased when extraction from solution in sea-water was examined.

Studies on the biosorption of uranium by Talaromyces emersonii CBS 814.70 biomass

Residual biomass, produced by the thermophilic fungus, Talaromyces emersonii CBS 814.70, following growth on glucose-containing media, was examined for its ability to take up uranium from aqueous solution. It was found that the biomass had a relatively high observed biosorption capacity for the uranium (280 mg/g dry weight biomass). The calculated maximum biosorption capacity obtained by fitting the data to a Langmuir model was calculated to be 323 mg uranium/g dry weight biomass. Pretreatment of the biomass with either dilute HCl or NaOH brought about a significant decrease in biosorptive capacity for uranium. Studies on the effects of variation in temperature on the biosorptive capacity demonstrated no significant change in binding between 20 degrees C and 60 degrees C. However, a significant decrease in biosorptive capacity was observed at 5 degrees C. Binding of uranium to the biomass at all temperatures reached equilibrium within 2 min. While the routine binding assays were performed at pH 5.0, adjustment of the pH to 3.0 gave rise to a significant decrease in biosorption capacity by the biomass. The biosorptive capacity of the biomass for uranium was increased when extraction from solution in sea-water was examined.

Encapsulation of the thrombolytic enzyme, brinase, in photosensitized erythrocytes: a novel thrombolytic system based on photodynamic activation

In order to circumvent many of the problems associated with the systemic administration of agents used in thrombolytic therapy, it was decided to investigate the possibility of using erythrocytes as carriers and delivery vehicles for these agents. The enzyme brinase, a fibrinolytic enzyme produced by Aspergillus oryzae, was loaded into rabbit erythrocytes using electroporation. The loading index for this enzyme was found to be 60% and incorporation appeared to be relatively stable over a period of 4 h. In order to facilitate the predetermined release of the loaded component from the erythrocytes, they were photosensitized using haematoporphyrin derivative (HPD) and release was demonstrated within 5 min of photoactivation. Inclusion of the loaded, photosensitized system into clotting blood and subsequent exposure to light demonstrated almost complete lysis of the clot. We believe that this system exhibits potential for use in thrombolytic therapy.

Methotrexate-loaded, photosensitized erythrocytes: a photo-activatable carrier/delivery system for use in cancer therapy

With a view towards the design of a system incorporating both the use of chemotherapeutics and photodynamic therapy for use in cancer treatment modalities, erythrocytes have been loaded with methotrexate and subsequently photosensitized by exposure to hematoporphyrin derivative. Loading of methotrexate into erythrocytes has been optimized by examining variations in electroporation conditions. Maximum loading indices observed were in the region of 64%. In order to obtain rapid pre-defined release of chemotherapeutic from the system, the erythrocytes were photosensitized. Light-dependent release of methotrexate from the system was examined. In addition, studies measuring the cytotoxic effects of light-activated release from the system using Hela cells as a target, suggested that decreases in cell viability following exposure to light resulted from the combined effects of chemotherapy and photoradiation therapy. Potential applications and advantages associated with this novel system are discussed.

Magnetically responsive photosensitizing reagents for possible use in photoradiation therapy

The ability of a magnetically responsive material to function as a carrier for photosensitizing agents for use in photoradiation therapy (PRT) has been examined in vitro. The photosensitizer has been attached to the magnetically responsive matrix (Dynabeads) by non-specific adsorption, Intralipid-mediated adsorption and poly-L-lysine mediated adsorption. In these studies, it has been demonstrated that conditions of attachment of photosensitizer to the matrix may be adapted in order to facilitate a diffuse or highly localized photo-toxic effect on target cells in vitro. The authors believe that this system may represent a novel approach to targeting photosensitizing agents to specific areas, thereby circumventing some of the problems associated with conventional photoradiation therapy (PRT), particularly in hollow organs.

The tumoricidal potential of extracorporeal shock wave therapy

A potential role of extracorporeal shock wave lithotripsy (E.S.W.L.), in the destruction of tumours has been proposed in recent literature. To examine further this potential, we have studied the effects of E.S.W.L. on the sarcoma-derived osteoblast-like cell line MG-63. An in-situ assay of cell viability was used to establish the cellular response to high energy shock wave therapy. A significant tumoricidal effect was confirmed when the cells were grown and tested in conventional monolayer phase. However cells grown in the three-dimensional matrix of alginate beads were significantly less vulnerable to extracorporeal shock wave therapy as earlier studies have suggested.