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It is unknown whether transient transgenerational epigenetic responses to environmental challenges affect the process of evolution, which typically unfolds over many generations. Here, we show that in C. elegans, inherited small RNAs control genetic variation by regulating the crucial decision of whether to self-fertilize or outcross. We found that under stressful temperatures, younger hermaphrodites secrete a male-attracting pheromone. Attractiveness transmits transgenerationally to unstressed progeny via heritable small RNAs and the Argonaute Heritable RNAi Deficient-1 (HRDE-1). We identified an endogenous small interfering RNA pathway, enriched in endo-siRNAs that target sperm genes, that transgenerationally regulates sexual attraction, male prevalence, and outcrossing rates. Multigenerational mating competition experiments and mathematical simulations revealed that over generations, animals that inherit attractiveness mate more and their alleles spread in the population. We propose that the sperm serves as a "stress-sensor" that, via small RNA inheritance, promotes outcrossing in challenging environments when increasing genetic variation is advantageous.

Background The characterization of major resistance genes (R genes) in the potato remains an important task for molecular breeding. However, R genes are rapidly evolving and frequently occur in genomes as clusters with complex structures, and their precise mapping and identification are complicated and time consuming. Results Comparative analysis of root transcriptomes of Solanum phureja genotypes with contrasting resistance to Globodera rostochiensis revealed a number of differentially expressed genes. However, compiling a list of candidate R genes for further segregation analysis was hampered by their scarce annotation. Nevertheless, combination of transcriptomic analysis with data on predicted potato NBS-LRR-encoding genes considerably improved the quality of the results and provided a reasonable number of candidate genes that provide S. phureja with strong resistance to the potato golden cyst nematode. Conclusion Combination of comparative analyses of tissue-specific transcriptomes in resistant and susceptible genotypes may be used as an approach for the rapid identification of candidate potato R genes for co-segregation analysis and may be used in parallel with more sophisticated studies based on genome resequencing. Electronic supplementary material The online version of this article (10.1186/s12870-017-1193-1) contains supplementary material, which is available to authorized users.

It is unknown whether the activity of the nervous system can be inherited. In Caenorhabditis elegans nematodes, parental responses can transmit heritable small RNAs that regulate gene expression transgenerationally. In this study, we show that a neuronal process can impact the next generations. Neurons-specific synthesis of RDE-4-dependent small RNAs regulates germline amplified endogenous small interfering RNAs (siRNAs) and germline gene expression for multiple generations. Further, the production of small RNAs in neurons controls the chemotaxis behavior of the progeny for at least three generations via the germline Argonaute HRDE-1. Among the targets of these small RNAs, we identified the conserved gene saeg-2, which is transgenerationally downregulated in the germline. Silencing of saeg-2 following neuronal small RNA biogenesis is required for chemotaxis under stress. Thus, we propose a small-RNA-based mechanism for communication of neuronal processes transgenerationally.

Summary Experiences trigger transgenerational small RNA-based responses in C. elegans nematodes. Dedicated machinery ensures that heritable effects are reset, but how the responses segregate in the population is unknown. We show that isogenic individuals differ dramatically in the persistence of transgenerational responses. By examining lineages of more than 20,000 worms, three principles emerge: (1) The silencing each mother initiates is distributed evenly among her descendants; heritable RNAi dissipates but is uniform in every generation. (2) Differences between lineages arise because the mothers that initiate heritable responses stochastically assume different “inheritance states” that determine the progeny’s fate. (3) The likelihood that an RNAi response would continue to be inherited increases the more generations it lasts. The inheritance states are determined by HSF-1, which regulates silencing factors and, accordingly, small RNA levels. We found that, based on the parents’ inheritance state, the descendants’ developmental rate in response to stress can be predicted., Graphical Abstract, Highlights • Segregation of inherited small RNA responses follows three simple principles • Mothers stochastically assume inheritance states that determine the progeny’s fate • HSF-1 defines the states and regulates silencing factors and small RNA levels • The mothers’ inheritance state can predict the progeny’s response to stress, Transgenerational RNAi responses in C.elegans exhibit distinct segregation patterns described by three simple rules.

Summary In C. elegans nematodes, components of liquid-like germ granules were shown to be required for transgenerational small RNA inheritance. Surprisingly, we show here that mutants with defective germ granules can nevertheless inherit potent small RNA-based silencing responses, but some of the mutants lose this ability after many generations of homozygosity. Animals mutated in pptr-1, which is required for stabilization of P granules in the early embryo, display extraordinarily strong heritable RNAi responses, lasting for tens of generations. Intriguingly, the RNAi capacity of descendants derived from mutants defective in the core germ granule proteins MEG-3 and MEG-4 is determined by the genotype of the ancestors and changes transgenerationally. Further, whether the meg-3/4 mutant alleles were present in the paternal or maternal lineages leads to different transgenerational consequences. Small RNA inheritance, rather than maternal contribution of the germ granules themselves, mediates the transgenerational defects in RNAi of meg-3/4 mutants and their progeny. Accordingly, germ granule defects lead to heritable genome-wide mis-expression of endogenous small RNAs. Upon disruption of germ granules, hrde-1 mutants can inherit RNAi, although HRDE-1 was previously thought to be absolutely required for RNAi inheritance. We propose that germ granules sort and shape the RNA pool, and that small RNA inheritance maintains this activity for multiple generations., Graphical Abstract, Highlights • Disrupting germ granules leads to deviations from Mendelian inheritance • The gene silencing capacity of germ granule mutants changes transgenerationally • Paternal and maternal lineages transmit distinct germ granule-dependent small RNAs • Ancestral germ granules determine the small RNA pools of future generations, RNA-rich germ granules are highly conserved and required for germline functions. Lev et al. show that ancestral germ granules shape the gene silencing capacity and small RNA pools of future generations. Altering germ granules in paternal and maternal lineages generates distinct transgenerational dynamics that deviate from Mendelian inheritance.

It has been previously reported that pretreatment with exogenous heat shock protein 70 (Hsp70) is able to protect cells and animals from the deleterious effects of bacterial lipopolysaccharide (LPS) produced by Gram-negative bacteria. However, the effects of Hsp70 pretreatment on lipoteichoic acid (LTA) challenge resulted from Gram-positive bacteria infection have not been fully elucidated. In this study, we demonstrated that preconditioning with human recombinant Hsp70 ameliorates various manifestations of systematic inflammation, including reactive oxygen species, TNFα, and CD11b/CD18 adhesion receptor expression induction observed in different myeloid cells after LTA addition. Therefore, exogenous Hsp70 may provide a mechanism for controlling excessive inflammatory responses after macrophage activation. Furthermore, in a rat model of LTA-induced sepsis, we demonstrated that prophylactic administration of exogenous human Hsp70 significantly exacerbated numerous homeostatic and hemodynamic disturbances induced by LTA challenge and partially normalized the coagulation system and multiple biochemical blood parameters, including albumin and bilirubin concentrations, which were severely disturbed after LTA injections. Importantly, prophylactic intravenous injection of Hsp70 before LTA challenge significantly reduced mortality rates. Thus, exogenous mammalian Hsp70 may serve as a powerful cellular defense agent against the deleterious effects of bacterial pathogens, such as LTA and LPS. Taken together, our findings reveal novel functions of this protein and establish exogenous Hsp70 as a promising pharmacological agent for the prophylactic treatment of various types of sepsis.

Interspecific somatic hybrids between commercial cultivars of potato Solanum tuberosum L. Agave and Delikat and the wild diploid species Solanum cardiophyllum Lindl. (cph) were produced by protoplast electrofusion. The hybrid nature of the regenerated plants was confirmed by flow cytometry, simple sequence repeat (SSR), amplified fragment length polymorphism (AFLP), microsatellite-anchored fragment length polymorphism (MFLP) markers and morphological analysis. Somatic hybrids were assessed for their resistance to Colorado potato beetle (CPB) using a laboratory bioassay, to Potato virus Y (PVY) by mechanical inoculation and field trials, and foliage blight in a greenhouse and by field trials. Twenty-four and 26 somatic hybrids of cph + cv. Agave or cph + cv. Delikat, respectively, showed no symptoms of infection with PVY, of which 3 and 12, respectively, were also resistant to foliage blight. One hybrid of cph + Agave performed best in CPB and PVY resistance tests. Of the somatic hybrids that were evaluated for their morphology and tuber yield in the field for 3 years, four did not differ significantly in tuber yield from the parental and standard cultivars. Progeny of hybrids was obtained by pollinating them with pollen from a cultivar, selfing or cross-pollination. The results confirm that protoplast electrofusion can be used to transfer the CPB, PVY and late blight resistance of cph into somatic hybrids. These resistant somatic hybrids can be used in pre-breeding studies, molecular characterization and for increasing the genetic diversity available for potato breeding by marker-assisted combinatorial introgression into the potato gene pool.

Solanum tarnii, a wild diploid, tuber-bearing Mexican species belonging to the series Pinnatisecta is highly resistant to Potato virus Y (PVY) and Colorado potato beetle and shows a strong hypersensitive reaction to Phytophthora infestans. Therefore, it could be a potential source of resistance to pathogens for potato breeders. S. tarnii (2n = 2x = 24) is reproductively isolated from tetraploid Solanum tuberosum and hence difficult to include in potato breeding programmes. In this study, interspecific somatic hybrids were produced for the first time by protoplast electrofusion of the cells of potato cv. Delikat (Solanum tuberosum L.) and Solanum tarnii. The hybrid nature of the regenerants was confirmed by simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers and by morphological analysis and flow cytometry. Selected somatic hybrids were successfully backcrossed with cv. Delikat. Parental lines, primary somatic hybrids and BC1 progeny were assessed for resistance to PVY by mechanical inoculation, grafting and exposure to viruliferous aphid vectors in the field, and resistance to late blight (P. infestans) by detached leaflet and whole tuber tests. The somatic hybrids showed no symptoms of viral infection and most of them displayed high levels of resistance to foliage blight. The BC1 progenies were highly resistant to PVY and a few were resistant to foliage blight. Selected hybrids and BC1 clones were evaluated in the field for tuber quality and tuber yield. Some BC1 clones produced yields of good quality tubers. The results confirm that both the resistance to PVY and to late blight of S. tarnii is expressed in somatic hybrids, and PVY resistance is transferred to BC1 progeny, whereas blight resistance is harder to transfer. Somatic hybridization again proved to be a valuable tool for producing pre-breeding material with increased genetic diversity.

The purpose of this study was to elucidate the mechanism of action of the Helix lucorum hemocyanin (HlH), b-HlH-h, and RvH2-g hemocyanins as potential agents against bladder cancer.We evaluated the viability of 647-V, T-24, and CAL-29 bladder cancer cell lines after treatment with the tested hemocyanins. The cell viability was measured at 72 hrs with MTT and WST-1 assays. Acridine orange/propidium iodide double staining was used to discriminate between apoptotic and necrotic cells. Gene expression profiling of the 168 genes from human inflammatory cytokines and signal transduction pathways were performed on the tumor cells before and after hemocyanins' treatment.The results showed decreased survival of cancer cells in the presence of HlH and two functional units: b-HlH-h and RvH2-g. Acridine orange/propidium iodide double staining revealed that the decreased viability was due to apoptosis. The gene expression data showed upregulation of genes involved in the apoptosis as well as of the immune system activation, and downregulation of the CCL2, CCL17, CCL21, CXCL1, and ABCF1 genes.The present study is the first to report gene expression in human cells under the influence of hemocyanins. The mechanism of antitumor activity of the HlH, b-HlH-h, and RvH2-g hemocyanins includes induction of apoptosis. In addition to the antiproliferative effect, downregulation of the genes with metastatic potential was observed. Together with the already known immunogenic effect, these findings support further studies on hemocyanins as potential therapeutic agents against bladder cancer.

As an extension of our studies on the antitumour properties of various hemocyanins, we sought to compare the antiproliferative effects of hemocyanins derived from two snail species: Helix lucorum (HlH) and Helix aspersa (HaH). This is the first report on the antitumour effects of HaH. We hypothesized that HaH has antitumour effects not only against bladder cancer, as previously shown with other hemocyanins, but also on other cancer cell lines. The antiproliferative properties of the mentioned hemocyanins were investigated in vitro on the following human cell lines: bladder cancer (CAL-29 and T-24), ovarian cancer (FraWü), acute monocytic leukemia (THP-1), prostate cancer (DU-145), glioma cancer (LN-18), and Burkitt’s lymphoma (Daudi). The properties of HaH were compared to those of HlH, keyhole limpet hemocyanin (KLH), and two positive controls (doxorubicin and mitomycin C). An antiproliferative effect of the total molecule and one structural subunit of HaH, bc-HaH, against both bladder cancer cell lines, T-24 and CAL-29, was observed. The cytotoxic effect of HaH ranged between 15% and 60% among the other tested cell lines. The endotoxin contamination did not affect the efficacy of HaH. Therefore, HlH and HaH could be appropriate for more detailed investigations of their use as antitumour agents for the studied cancers.

International audience; The Cryptochrome/Photolyase Family (CPF) represents an ancient group of widely distributed UV-A/blue-light sensitive proteins sharing common structures and chromophores. During the course of evolution, different CPFs acquired distinct functions in DNA repair, light perception and circadian clock regulation. Previous phylogenetic analyses of the CPF have allowed reconstruction of the evolution and distribution of the different CPF super-classes in the tree of life. However, so far only limited information is available from the CPF orthologs in aquatic organisms that evolved in environments harboring great diversity of life forms and showing peculiar light distribution and rhythms. To gain new insights into the evolutionary and functional relationships within the CPF family, we performed a detailed study of CPF members from marine (diatoms, sea urchin and annelid) and freshwater organisms (teleost) that populate diverse habitats and exhibit different life strategies. In particular, we first extended the CPF family phylogeny by including genes from aquatic organisms representative of several branches of the tree of life. Our analysis identifies four major super-classes of CPF proteins and importantly singles out the presence of a plant-like CRY in diatoms and in metazoans. Moreover, we show a dynamic evolution of Cpf genes in eukaryotes with various events of gene duplication coupled to functional diversification and gene loss, which have shaped the complex array of Cpf genes in extant aquatic organisms. Second, we uncover clear rhythmic diurnal expression patterns and light-dependent regulation for the majority of the analyzed Cpf genes in our reference species. Our analyses reconstruct the molecular evolution of the CPF family in eukaryotes and provide a solid foundation for a systematic characterization of novel light activated proteins in aquatic environments. (C) 2014 Published by Elsevier B.V.

Platynereis dumerilii is a marine polychaete and an established model system for studies of evolution and development. Platynereis is also a re-emerging model for studying the molecular basis of circalunar reproductive timing: a biological phenomenon observed in many marine species. While gene expression studies have provided new insight into patterns of gene regulation, a lack of reverse genetic tools has so far limited the depth of functional analyses in this species. To address this need, we established customized transcriptional activator-like effector nucleases (TALENs) as a tool to engineer targeted modifications in Platynereis genes. By adapting a workflow of TALEN construction protocols and mutation screening approaches for use in Platynereis, we engineered frameshift mutations in three endogenous Platynereis genes. We confirmed that such mutations are heritable, demonstrating that TALENs can be used to generate homozygous knockout lines in P. dumerilii. This is the first use of TALENs for generating genetic knockout mutations in an annelid model. These tools not only open the door for detailed in vivo functional analyses, but also can facilitate further technical development, such as targeted genome editing.

The human and mouse genes for the neuropeptide Y 4 receptor have been isolated, sequenced, and shown to contain no introns within the coding region of the gene. Nonisotopic in situ hybridization and interspecific mouse backcross mapping have localized the genes to human chromosome 10ql1.2 and mouse chromosome 14. Five nucleotide variants, which do not alter the protein sequence, have been identified within the coding region of the human receptor gene. The human Y 4 subtype is most closely related to the Y 1 -receptor subtype (42%), suggesting that it evolved from an ancestral Y 1 -like receptor via an RNA-mediated transpositional event.

The gene for titin, a 4MDa myofibrillar protein, was analysed in golden hamster DNAs from different sources, using human cDNA probes and PCR. In the DNA from the BHK-21-Bi subline of baby hamster kidney cells, extended sequences coding for Z-line associated domains mere missing, indicating a deletion that renders titin non-functional. These sequences were present in the original BHK-21 line and in hamster DNAs. Our finding shows that, due to the absence of selective pressure on a gene's function, genomic deterioration can occur in a permanent cell line and can lead to a loss of overlapping DNA stretches in both autosomes. (C) 1997 Federation of European Biochemical Societies.