Asymmetric variation in DNA methylation during domestication and de-domestication of rice.

Hundreds of plant species have been domesticated to feed human civilization, while some crops have undergone de-domestication into agricultural weeds, threatening global food security. To understand the genetic and epigenetic basis of crop domestication and de-domestication, we generated DNA methylomes from 95 accessions of wild rice (Oryza rufipogon L.), cultivated rice (Oryza sativa L.) and weedy rice (O. sativa f. spontanea). We detected a significant decrease in DNA methylation over the course of rice domestication but observed an unexpected increase in DNA methylation through de-domestication. Notably, DNA methylation changes occurred in distinct genomic regions for these 2 opposite stages. Variation in DNA methylation altered the expression of nearby and distal genes through affecting chromatin accessibility, histone modifications, transcription factor binding, and the formation of chromatin loops, which may contribute to morphological changes during domestication and de-domestication of rice. These insights into population epigenomics underlying rice domestication and de-domestication provide resources and tools for epigenetic breeding and sustainable agriculture.

EVLncRNAs 3.0: an updated comprehensive database for manually curated functional long non-coding RNAs validated by low-throughput experiments.

Long noncoding RNAs (lncRNAs) have emerged as crucial regulators across diverse biological processes and diseases. While high-throughput sequencing has enabled lncRNA discovery, functional characterization remains limited. The EVLncRNAs database is the first and exclusive repository for all experimentally validated functional lncRNAs from various species. After previous releases in 2018 and 2021, this update marks a major expansion through exhaustive manual curation of nearly 25 000 publications from 15 May 2020, to 15 May 2023. It incorporates substantial growth across all categories: a 154% increase in functional lncRNAs, 160% in associated diseases, 186% in lncRNA-disease associations, 235% in interactions, 138% in structures, 234% in circular RNAs, 235% in resistant lncRNAs and 4724% in exosomal lncRNAs. More importantly, it incorporated additional information include functional classifications, detailed interaction pathways, homologous lncRNAs, lncRNA locations, COVID-19, phase-separation and organoid-related lncRNAs. The web interface was substantially improved for browsing, visualization, and searching. ChatGPT was tested for information extraction and functional overview with its limitation noted. EVLncRNAs 3.0 represents the most extensive curated resource of experimentally validated functional lncRNAs and will serve as an indispensable platform for unravelling emerging lncRNA functions. The updated database is freely available at https://www.sdklab-biophysics-dzu.net/EVLncRNAs3/.

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure-Activity Relationship.

Natural polysaccharides are macromolecular substances with great potential owing to their wide biological activity and low toxicity. However, not all polysaccharides have significant pharmacodynamic activity; hence, appropriate chemical modification methods can be selected according to the unique structural characteristics of polysaccharides to assist in enhancing and promoting the presentation of their biological activities. This review summarizes research progress on modified polysaccharides, including common chemical modification methods, the change in biological activity following modification, and the factors affecting the biological activity of chemically modified polysaccharides. At the same time, the difficulties and challenges associated with the structural modification of natural polysaccharides are also outlined in this review. Thus, research on polysaccharide structure modification is critical for improving the development and utilization of sugar products.

Nuclear import receptors and hnRNPK mediates nuclear import and stress granule localization of SIRLOIN.

The majority of lncRNAs and a small fraction of mRNAs localize in the cell nucleus to exert their functions. A SIRLOIN RNA motif was previously reported to drive its nuclear localization by the RNA-binding protein hnRNPK. However, the underlying mechanism remains unclear. Here, we report crystal structures of hnRNPK in complex with SIRLOIN, and with the nuclear import receptor (NIR) Impα1, respectively. The protein hnRNPK bound to SIRLOIN with multiple weak interactions, and interacted Impα1 using an independent high-affinity site. Forming a complex with hnRNPK and Impα1 was essential for the nuclear import and stress granule localization of SIRLOIN in semi-permeabilized cells. Nuclear import of SIRLOIN enhanced with increasing NIR concentrations, but its stress granule localization peaked at a low NIR concentration. Collectively, we propose a mechanism of SIRLOIN localization, in which NIRs functioned as drivers/regulators, and hnRNPK as an adaptor.

Negative cooperativity between Gemin2 and RNA provides insights into RNA selection and the SMN complex's release in snRNP assembly.

The assembly of snRNP cores, in which seven Sm proteins, D1/D2/F/E/G/D3/B, form a ring around the nonameric Sm site of snRNAs, is the early step of spliceosome formation and essential to eukaryotes. It is mediated by the PMRT5 and SMN complexes sequentially in vivo. SMN deficiency causes neurodegenerative disease spinal muscular atrophy (SMA). How the SMN complex assembles snRNP cores is largely unknown, especially how the SMN complex achieves high RNA assembly specificity and how it is released. Here we show, using crystallographic and biochemical approaches, that Gemin2 of the SMN complex enhances RNA specificity of SmD1/D2/F/E/G via a negative cooperativity between Gemin2 and RNA in binding SmD1/D2/F/E/G. Gemin2, independent of its N-tail, constrains the horseshoe-shaped SmD1/D2/F/E/G from outside in a physiologically relevant, narrow state, enabling high RNA specificity. Moreover, the assembly of RNAs inside widens SmD1/D2/F/E/G, causes the release of Gemin2/SMN allosterically and allows SmD3/B to join. The assembly of SmD3/B further facilitates the release of Gemin2/SMN. This is the first to show negative cooperativity in snRNP assembly, which provides insights into RNA selection and the SMN complex's release. These findings reveal a basic mechanism of snRNP core assembly and facilitate pathogenesis studies of SMA.

Identification and allele mining of new candidate genes underlying rice grain weight and grain shape by genome-wide association study.

BACKGROUND: Grain weight and grain shape are important agronomic traits that affect the grain yield potential and grain quality of rice. Both grain weight and grain shape are controlled by multiple genes. The 3,000 Rice Genomes Project (3 K RGP) greatly facilitates the discovery of agriculturally important genetic variants and germplasm resources for grain weight and grain shape. RESULTS: Abundant natural variations and distinct phenotic differentiation among the subgroups in grain weight and grain shape were observed in a large population of 2,453 accessions from the 3 K RGP. A total of 21 stable quantitative trait nucleotides (QTNs) for the four traits were consistently identified in at least two of 3-year trials by genome-wide association study (GWAS), including six new QTNs (qTGW3.1, qTGW9, qTGW11, qGL4/qRLW4, qGL10, and qRLW1) for grain weight and grain shape. We further predicted seven candidate genes (Os03g0186600, Os09g0544400, Os11g0163600, Os04g0580700, Os10g0399700, Os10g0400100 and Os01g0171000) for the six new QTNs by high-density association and gene-based haplotype analyses. The favorable haplotypes of the seven candidate genes and five previously cloned genes in elite accessions with high TGW and RLW are also provided. CONCLUSIONS: Our results deepen the understanding of the genetic basis of grain weight and grain shape in rice and provide valuable information for improving rice grain yield and grain quality through molecular breeding.

Metagenomic insights into soil microbial communities involved in carbon cycling along an elevation climosequences.

Diversity and community composition of soil microorganisms along the elevation climosequences have been widely studied, while the microbial metabolic potential, particularly in regard to carbon (C) cycling, remains unclear. Here, a metagenomic analysis of C related genes along five elevations ranging from 767 to 4190 m at Mount Kilimanjaro was analysed to evaluate the microbial organic C transformation capacities in various ecosystems. The highest gene abundances for decomposition of moderate mineralizable compounds, i.e. carbohydrate esters, chitin and pectin were found at the mid-elevations with hump-shaped pattern, where the genes for decompositions of recalcitrant C (i.e. lignin) and easily mineralizable C (i.e. starch) showed the opposite trend (i.e. U-shaped pattern), due to high soil pH and seasonality in both low and high elevations. Notably, the gene abundances for the decompositions of starch, carbohydrate esters, chitin and lignin had positive relationships with corresponding C compounds, indicating the consistent responses of microbial functional profiles and metabolites to elevation climosequences. Understanding of adaptation of microbial communities, potential function and metabolites to elevation climosequences and their influencing factors provided a new insight for the regulation of terrestrial C storage.

Plant Diversity Enhances Soil Fungal Diversity and Microbial Resistance to Plant Invasion.

Interactions and feedbacks between aboveground and belowground biomes are fundamental in controlling ecosystem functions and stability. However, the relationship between plant diversity and soil microbial diversity is elusive. Moreover, it remains unknown whether plant diversity loss will cause the stability of soil microbial communities to deteriorate. To shed light on these questions, we conducted a pot-based experiment to manipulate the plant richness gradient (1, 2, 4, or 8 species) and plant [Symphyotrichum subulatum (Michx.) G. L. Nesom] invasion status. We found that, in the noninvasion treatment, soil fungal diversity significantly and positively correlated with plant diversity, while the relationship between bacterial and plant diversity was not significant. Under plant invasion conditions, the coupling of plant-fungal alpha diversity relationship was enhanced, but the plant-fungal beta diversity relationship was decoupled. We also found significant positive relationships between plant diversity and soil microbial resistance. The observed positive relationships were determined by turnover (species substitution) and nestedness (species loss) processes for bacterial and fungal communities, respectively. Our study demonstrated that plant diversity enhanced soil fungal diversity and microbial resistance in response to plant invasion. This study expands our knowledge about the aboveground-belowground diversity relationship and the diversity-stability relationship.IMPORTANCE Our study newly showed that plant invasion significantly altered relationships between aboveground and belowground diversity. Specifically, plant richness indirectly promoted soil fungal richness through the increase of soil total carbon (TC) without plant invasion, while plant richness had a direct positive effect on soil fungal richness under plant invasion conditions. Our study highlights the effect of plant diversity on soil fungal diversity, especially under plant invasion conditions, and the plant diversity effect on microbial resistance in response to plant invasion. These novel findings add important knowledge about the aboveground-belowground diversity relationship and the diversity-stability relationship.

Functional redundancy and specific taxa modulate the contribution of prokaryotic diversity and composition to multifunctionality.

Observational and experimental evidence has revealed the functional importance of microbial diversity. However, the effects of microbial diversity loss on ecosystem functions are not consistent across studies, which are probably tempered by microbial functional redundancy, specific taxa and functions evaluated. Here we conducted diversity manipulation experiments in two independent soils with distinct prokaryotic communities, and investigated how the initial community traits (e.g., distinct functional redundancy and taxonomic composition) modulate the contribution of prokaryotic diversity loss and composition shift to eight ecosystem functions related to soil nutrient cycling. We found that diversity loss impaired three functions (potential nitrification rate, N2 -fixation activity and phosphatase) and multifunctionality only in the communities with low functional redundancy, but all examined functions were unaffected in the communities with high functional redundancy. All significantly affected functions belonged to specialized functions, while the broad function (soil basal respiration) was unaffected. Moreover, prokaryotic composition explained more functional variation than diversity, which was ascribed to the crucial role of specific taxa that influence particular functions. Taken together, this study provides empirical evidence for identifying the mechanism underlying the ecosystem response to changes in microbial community, with implications for improving the prediction of ecosystem process models and managing microbial communities to promote ecosystem services.

Global proteome response to Pb(II) toxicity in poplar using SWATH-MS-based quantitative proteomics investigation.

Lead (Pb) toxicity is a growing serious environmental pollution that threatens human health and crop productivity. Poplar, as an important economic and ecological forest species, has the characteristics of fasting growth and accumulating heavy metals, which is a powerful model plant for phytoremediation. Here, a novel label-free quantitative proteomic platform of SWATH-MS was applied to detect proteome changes in poplar seedling roots following Pb treatment. In total 4388 unique proteins were identified and quantified, among which 542 proteins showed significant abundance changes upon Pb(II) exposure. Functional categorizations revealed that differentially expressed proteins (DEPs) primarily distributed in specialized biological processes. Particularly, lignin and flavonoid biosynthesis pathway were strongly activated upon Pb exposure, implicating their potential roles for Pb detoxification in poplar. Furthermore, hemicellulose and pectin related cell wall proteins exhibited increased abundances, where may function as a sequestration reservoir to reduce Pb toxicity in cytoplasm. Simultaneously, up-regulation of glutathione metabolism may serve as a protective role for Pb-induced oxidative damages in poplar. Further correlation investigation revealed an extra layer of post-transcriptional regulation during Pb response in poplar. Overall, our work represents multiply potential regulators in mediating Pb tolerance in poplar, providing molecular targets and strategies for phytoremediation.

Genome-Wide Association Study on Resistance to Rice Black-Streaked Dwarf Disease Caused by Rice black-streaked dwarf virus.

Rice black-streaked dwarf disease caused by Rice black-streaked dwarf virus (RBSDV) is one of the most destructive viral diseases of rice. Thus, it is imperative that resistant rice germplasms are screened for novel RBSDV-resistant genes. RBSDV resistance of a diverse global collection comprising 1,953 rice accessions was evaluated under natural conditions across 3 years. The average disease incidences of the Xian/indica (XI) subgroup were significantly lower than those of the Geng/japonica (GJ) subgroup. Interestingly, most XI-1A accessions in the Xian subgroup were significantly more susceptible than XI-1B accessions, even though XI-1A and XI-1B have a close phylogenetic relationship. Four Xian accessions stably and highly resistant to RBSDV were consistently identified in 2 years. Ten genomic regions (GRs) with 147 single nucleotide polymorphisms associated with RBSDV resistance were detected by a single-locus genome-wide association study (GWAS), of which five were repeatedly identified in a multilocus GWAS. Two previously reported GRs, grRBSDV-6.1 and grRBSDV-6.3, which were repeatedly detected as stably and highly associated with RBSDV resistance, contained 17 and seven genes, respectively, with significant differences of resistance among haplotypes. Haplotype analyses of the candidate genes LOC_Os06g03150 in grRBSDV-6.1 and LOC_Os06g31190 in grRBSDV-6.3 suggested that the former gene is mainly associated with the differentiation of resistance within the Xian subgroup and the latter gene mainly explains the difference in the resistance between Xian and Geng. Another three novel resistance GRs (grRBSDV-1.1, grRBSDV-7.1, and grRBSDV-9.1) were identified. Our findings may enhance the application of disease-resistant rice germplasms for breeding RBSDV-resistant varieties.

Contrasting patterns and drivers of soil bacterial and fungal diversity across a mountain gradient.

Microbial elevational diversity patterns have been extensively studied, but their shaping mechanisms remain to be explored. Here, we examined soil bacterial and fungal diversity and community compositions across a 3.4 km elevational gradient (consists of five elevations) on Mt. Kilimanjaro located in East Africa. Bacteria and fungi had different diversity patterns across this extensive mountain gradient-bacterial diversity had a U shaped pattern while fungal diversity monotonically decreased. Random forest analysis revealed that pH (12.61% importance) was the most important factor affecting bacterial diversity, whereas mean annual temperature (9.84% importance) had the largest impact on fungal diversity, which was consistent with results obtained from mixed-effects model. Meanwhile, the diversity patterns and drivers of those diversity patterns differ among taxonomic groups (phyla/classes) within bacterial or fungal communities. Taken together, our study demonstrated that bacterial and fungal diversity and community composition responded differently to climate and edaphic properties along an extensive mountain gradient, and suggests that the elevational diversity patterns across microbial groups are determined by distinct environmental variables. These findings enhanced our understanding of the formation and maintenance of microbial diversity along elevation, as well as microbial responses to climate change in montane ecosystems.

The determination of trace free acid content in lithium-ion battery electrolytes by coulometric titration in non-aqueous media.

A new quantitative analysis method was proposed, aiming at resolving the difficulty encountered in accurately determining the trace content of a free acid in lithium-ion battery electrolytes in the past 30 years. The presented method overcame the three restrictive factors of lithium-ion battery electrolytes, namely, poor thermal stability, the formation of hydrofluoric acid with water and difficulty in the accurate determination of trace free acids. The free acid in lithium-ion battery electrolytes was directly titrated with ethoxide ions generated through the electrolyzation of a 0.50 mol L-1 LiCl ethanol solution. The content of free acid was obtained according to the Faraday's law, and the whole determination process could be completed in 5 minutes. The relative standard deviation was below 2.0% when the content of free acid was 2.0 µg and above. The detection limit was 1.0 µg and the recovery rate was 99.5%-102.5%. In this method, free acid determination was not affected by temperature change and the existence of a small amount of water. Thus, this study provides a simple, fast and accurate analytical method with a lower detection limit for free acid in the lithium-ion battery industry and comprehensively improves the quality of lithium-ion battery electrolytes and the performance of lithium-ion battery products.

Ectomycorrhizal fungi inoculation alleviates simulated acid rain effects on soil ammonia oxidizers and denitrifiers in Masson pine forest.

Acid rain can cause severe effects on soil biota and nutrient biogeochemical cycles in the forest ecosystem, but how plant-symbiotic ectomycorrhizal fungi will modulate the effects remains unknown. Here, we conducted a full factorial field experiment in a Masson pine forest by simultaneously controlling the acidity of the simulated rain (pH 5.6 vs. pH 3.5) and the ectomycorrhizal fungi Pisolithus tinctorius inoculation (non-inoculation vs. inoculation), to investigate the effects on ammonia oxidizers and denitrifiers. After 10 months, compared with the control (rain pH 5.6, and non-inoculation), simulated acid rain (pH 3.5) reduced soil nutrient content, decreased archaeal amoA gene abundance and inhibited denitrification enzyme activity. Also, simulated acid rain altered the community compositions of all the examined functional genes (archaeal amoA, bacterial amoA, nirK, nirS and nosZ). However, inoculation with ectomycorrhizal fungi under acid rain stress recovered soil nutrient content, archaeal amoA gene abundance and denitrification enzyme activity to levels comparable to the control, suggesting that ectomycorrhizal fungi inoculation ameliorates simulated acid rain effects. Taken together, ectomycorrhizal fungi inoculation - potentially through improving soil substrate availability - could alleviate the deleterious effects of acid rain on nitrogen cycling microbes in forest soils.

Electrochemical Detection of Circulating Tumor Cells Based on DNA Generated Electrochemical Current and Rolling Circle Amplification.

Circulating tumor cells (CTCs) are important indicators for tumor diagnosis and tumor metastasis. However, the extremely low levels of CTCs in peripheral blood challenges the precise detection of CTCs. Herein, we report DNA generated electrochemical current combined with rolling circle amplification (RCA) as well as magnetic nanospheres for highly efficient magnetic capture and ultrasensitive detection of CTCs. The antiepithelial cell adhesion molecule (EpCAM) antibody-modified magnetic nanospheres were used to capture and enrich CTCs. The following binding of an aptamer onto the CTC surface and the subsequent RCA assembled a significant amount of DNA molecules onto the electrode. The reaction of the DNA molecules with molybdate can then form redox molybdophosphate and produce an electrochemical current. Using the breast cancer cell MCF-7 as a model, the sensor displays good performances toward detection of MCF-7 that was spiked into peripheral blood. The signal amplification strategy integrated with a magnetic nanosphere platform exhibits good performance in the efficient capture and detection of CTCs, which may find wide potential in cancer diagnostics and therapeutics.

Polycytosine DNA Electric-Current-Generated Immunosensor for Electrochemical Detection of Human Epidermal Growth Factor Receptor 2 (HER2).

A polycytosine DNA-based immunosensor for electrochemical detection was developed and tested for detection of human epidermal growth factor receptor 2 (HER2), a breast cancer biomarker. We utilized gold nanoparticles (AuNPs) as supporting matrix to immobilize polycytosine DNA sequence (dC20) for electrochemical current generation and anti-HER2 antibodies. In the presence of target HER2, a sandwiched immunocomplex forms between a peptide specific to HER2 immobilized on the gold electrode and the anti-HER2 antibodies on the AuNPs. The HER2 captured by the sensor is detected because of the reaction of the dC20 phosphate backbone with molybdate, forming redox molybdophosphate precipitate that generates an electrochemical current on the surface of the electrode. The assay is sensitive: the calculated limit of detection of HER2 was as low as 0.5 pg/mL and the detection was linear to HER2 from 1 pg/mL to 1 ng/mL. The sensor's specificity is high, and there is no cross reactivity with several potential interferents, such as human IgG, human IgA, p53, carcinoembryonic antigen, and protein kinase. The sensor's performance with HER2 in clinical serum samples is similar to the performance of commercial ELISA assays. The configuration of polycytosine DNA as electrochemical current generating label and anti-HER2 antibodies on AuNPs is versatile and can be reconfigured to detect low levels of different analytes, or made more sensitive by amplifying the DNA to produce more phosphate to react with Na2MoO4.

Runx1 promotes satellite cell proliferation during ischemia - Induced muscle regeneration.

RUNX1 is a transcription factor that is not expressed in uninjured muscles, but can be detected in denervated muscles, suggesting a role of RUNX1 in muscle's response to injury. However, the role of RUNX1 in muscle's response to ischemia has not been reported. Our study showed that Runx1 is up regulated in skeletal muscle during ischemia reperfusion induced injury. Over-expression of Runx1 in C2C12 cells inhibits myogenic differentiation, but promotes proliferation of myoblasts. Consistent with these findings, we found that Runx1 expression was decreased in differentiated satellite cells. Our results indicate that Runx1 regulates muscle regeneration by promoting proliferation of satellite cells.

Carbonaceous Nanomaterials Have Higher Effects on Soybean Rhizosphere Prokaryotic Communities During the Reproductive Growth Phase than During Vegetative Growth.

Carbonaceous nanomaterials (CNMs) can affect agricultural soil prokaryotic communities, but how the effects vary with the crop growth stage is unknown. To investigate this, soybean plants were cultivated in soils amended with 0, 0.1, 100, or 1000 mg kg-1 of carbon black, multiwalled carbon nanotubes (MWCNTs), or graphene. Soil prokaryotic communities were analyzed by Illumina sequencing at day 0 and at the soybean vegetative and reproductive stages. The sequencing data were functionally annotated using the functional annotation of prokaryotic taxa (FAPROTAX) database. The prokaryotic communities were unaffected at day 0 and were altered at the plant vegetative stage only by 0.1 mg kg-1 MWCNTs. However, at the reproductive stage, when pods were filling, most treatments (except 1000 mg kg-1 MWCNTs) altered the prokaryotic community composition, including functional groups associated with C, N, and S cycling. The lower doses of CNMs, which were previously shown to be less agglomerated and thus more bioavailable in soil relative to the higher doses, were more effective toward both overall communities and individual functional groups. Taken together, prokaryotic communities in the soybean rhizosphere can be significantly phylogenetically and functionally altered in response to bioavailable CNMs, especially when soybean plants are actively directing resources to seed production.

Hydroxyapatite nanoparticle based fluorometric turn-on determination of dipicolinic acid, a biomarker of bacterial spores.

Hydroxyapatite nanoparticles (HAP-NPs) were rendered fluorescence by doping with Eu(III) ion. The resulting fluorescent NPs are shown to be viable probes for sensitive and selective determination of dipicolinic acid (DPA), a major constituent of bacterial spores as used in bioterrorism. It is found that the addition of DPA to solutions of such HAP-NPs result in an enhancement of fluorescence due to the coordination of DPA with the Eu(III) dopant. The assay allows DPA to be detected in the 0.1 to 40 µM concentration range and with a 77 nM detection limit. The assay was applied to the detection of spores of Bacillus subtilis. The attractive properties of the probe make it a promising candidate for used in rapid detection of pathogenic bacterial spores. Graphical abstract Fluorescent hydroxyapatite nanoparticles (HAP-NPs) are shown to be a viable probe for detection of dipicolinic acid, a major constituent of bacterial spores. The red asterisks represent the fluorescence intensity of the HAP-NPs.

Immunoelectrochemical detection of the human epidermal growth factor receptor 2 (HER2) via gold nanoparticle-based rolling circle amplification.

The authors describe an adapted rolling circle amplification (RCA) method for the determination of human epidermal growth factor receptor 2 (HER2). This method (which is termed immunoRCA) combines an immunoreaction with DNA based signal amplification. Gold nanoparticles (AuNPs) were loaded with antibodies against HER2 and DNA, and then fulfill the functions of recognizing HER2 and achieving signal amplification. The DNA serves as a primer to trigger RCA. This results in formation of a long DNA containing hundreds of copies of circular DNA sequence on the electrode surface. Then, molybdate is added which reacts with the phosphate group of the long DNA to generate the redox-active molybdophosphate. This, in turn, results in an increased current and, thus, in strongly increased sensitivity of the immunoassay. A linear response is linear relationship between the change of current intensity and the logarithm of the concentration in the range from 1 to 200 pg·mL-1 of HER2, and the detection limit is 90 fg·mL-1 (at an S/N ratio of 3). The method was applied to the determination of HER2 in breast cancer patients serum samples, and the results correlated well with those obtained by an ELISA. The method was further successfully applied to the determination of HER2 in HER2-expressed mouse breast cancer 4 T1 cells. Conceivably, this strategy may be adapted to other DNA amplification methods and also may be used for the determination of other proteins and biomarkers by using the appropriate antibodies. Graphical abstract Schematic presentation of an adapted rolling circle amplification (RCA) strategy for the electrochemical detection of human epidermal growth factor receptor 2 (HER2), termed "immunoRCA" utilizing gold nanoparticles (AuNPs). Ab stands for antibody, Phi29 is an E.coli DNA polymerase, dNTP represents deoxynucleotides, and SWV stands for square wave voltammetry.