Generation Progeny Research Articles

Genetic diversity and response to selection for yield and component traits in selected F4 and F5 progenies of oat

The present study was planned to record the response to selection and extent of genetic diversity in selected F4 and F5 generation progenies, which were derived from seven crosses of oats. The F4 and F5 progenies were evaluated in randomized block design over three replications during Rabi, 2019-20 and Rabi, 2020-21, respectively at the Experimental Farm of Fodder Section, CSKHPKV, Palampur. The utmost response to selection was depicted by grain yield per plant, fresh fodder yield per plant, biological yield per plant, harvest index, leaves per plant and plant height in most of the crosses. Hence, improvement through selection could be based on these traits. PCA studies revealed that the first five components accounted for more than 80% of the total variance among the progenies. Four PC in F4 and five PC in F5 generation possess eigen values > 1. The first principal component, i.e., PC1 accounted for the maximum proportion of total variability in the set of all variables, i.e., 36.97% and 30.29% in both F4 and F5 generations, respectively. The dendrogram showed that 34 genotypes of oat were grouped into three clusters in F4 generation and 33 genotypes from F5 into eight clusters. On the basis of divergence and cluster mean studies, it was suggested that maximum heterosis and good recombinants could be obtained in crosses between progenies of clusters II and III from F4 generation and clusters I, V, VII from F5 generation.

Comparative study of seed germination, phenology, and reproductive fitness in Melilotus sulcatus populations from Israel

BackgroundMelilotus sulcatus (Fabaceae) is an annual weed species prevalent in the Mediterranean Basin and Asia, characterized by a hard seed coat, indicating physical seed dormancy and long seed-bank longevity. This weed exhibits high phenotypic plasticity, thriving across various climatic regions in Israel. This study investigates seed germination of M. sulcatus populations under different temperatures. Moreover, we have studied the phenology, and reproductive biology of M. sulcatus populations in a common garden experiment. Seeds of M. sulcatus were collected from onion fields at Kibbutz Grofit located in the hyper-arid Southern Arava region, with ~ 30 mm average annual rainfall, and from Kibbutz Yifat, in the Jezreel Valley, where annual rainfall is 450–650 mm. Progeny generations were grown in pollen-proof cages at Newe Ya’ar Research Center also located at the Jezreel Valley.ResultsDifferences in seed area and average weight were observed among populations and generations, with field populations producing heavier seeds compared to progeny populations. The optimal temperature (T0) for seed germination varied among populations, with the highest T0 recorded for the Grofit field population (23.40℃) collected at the warm site and the lowest for the Yifat field population (17.67℃) collected at the cold site, while the two progeny populations showed similar T0 values. Phenology and reproductive biology were tested using seeds of the two field populations. Despite the vigorous growth of the Grofit population, there were no significant differences in average final weight (4.59 g for Grofit and 4.23 g for Yifat) and height (51.8 cm for Grofit and 50.3 cm for Yifat) between populations. Grofit progeny plants exhibited a statistically significantly higher number of seeds per pod, combined with larger seed area and average weight.ConclusionsOverall, our findings underscore the adaptive strategies employed by M. sulcatus populations in response to their environment. Vigorous plant growth, a higher number of seeds per pod, and larger seed area and average weight were observed in individuals from the Grofit population compared to the Yifat population. The greater fitness of Grofit population, originated from hyper-arid conditions, highlights the significant impact of environmental factors on species adaptation.

The SARS-CoV-2 antibody-dependent enhancement façade.

Antibody-dependent enhancement (ADE) is an immunological paradox whereby sensitization following a primary viral infection results in the subsequent enhancement of a similar secondary infection. This idiosyncratic immune response has been established in dengue virus infections, driven by four antigenically related serotypes co-circulating in endemic regions. Several coronaviruses exhibit antibody-mediated mechanisms of viral entry, which has led to speculation of an ADE capacity for SARS-CoV-2, though in vivo and epidemiological evidence do not currently support this phenomenon. Three distinct antibody-dependent mechanisms for SARS-CoV-2 entry have recently been demonstrated: 1. FcR-dependent, 2. ACE2-FcR-interdependent, and 3. FcR-independent. These mechanisms of viral entry may be dependent on SARS-CoV-2 antibody specificity; antibodies targeting the receptor binding domain (RBD) typically result in Fc-dependent and ACE2-FcR-interdependent entry, whereas antibodies targeting the N-terminal domain can induce a conformational change to the RBD that optimizes ACE2-receptor binding domain interactions independent of Fc receptors. Whether these antibody-dependent entry mechanisms of SARS-CoV-2 result in the generation of infectious progenies and enhancement of infection has not been robustly demonstrated. Furthermore, ADE of SARS-CoV-2 mediated by antigenic seniority remains a theoretical concern, as no evidence suggests that SARS-CoV-2 imprinting blunts a subsequent immune response, contributing to severe COVID-19 disease.

Anastatus japonicus Ashmead, a potential biological control agent of Riptortus pedestris (Fabricius)

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) is a significant pest of soybean production in China. While biological control would be a desirable means to manage this pest, little research on the use of parasitoids against R. pedestris has been done. In this study, for the parasitoid Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae), we measured the parasitism rate in R. pedestris, the emergence rate of parasitoid progeny, and mortality of eggs from host-feeding. Parasitoids of different ages were assessed against R. pedestris eggs of various ages under laboratory conditions. In addition, the development and longevity of A. japonicus reared on R. pedestris egg were also measured. We found the maximum parasitism rate of A. japonicus was 54.6% on R. pedestris egg. And the maximum emergence rate of A. japonicus was 50.0% from all offered R. pedestris eggs. Mortality from parasitoid host-feeding was 43.8% when 1-day-old R. pedestris eggs were offered to 6-day-old A. japonicus parasitoids. For older eggs, parasitism rates were lower, making 1-day old eggs the optimal host age for use in mass rearing. Longevity of the offspring (F1) generation of A. japonicus were 10 (males) and 23 (females) days. The developmental times of the F1 offspring were 21.9 (males) and 21.7 (females) days. The parasitism rate and the rate of mortality due to host feeding caused by parasitoid progeny (F1) generation were 56.3, and 43.8%, respectively. Among all the eggs parasitized not subjected to host feeding, 98.5% yielded adult parasitoids. Among all emerging A. japonicus, the sex ratio (as % female) in the F2 generation was 45%, which was significantly higher than that in the first generation (F1) (18%). These results suggest that A. japonicus could be a potential biological control agent for use against R. pedestris.

Sublethal and transgenerational effects of tetraniliprole on the tomato pinworm Phthorimaea (=Tuta) absoluta (Lepidoptera: Gelechiidae)

Invasive pest species of economic importance often require intensive pesticide use, leading to recurrent problems of pesticide resistance. Such is the case with the tomato pinworm, Phthorimaea (=Tuta) absoluta (Meyrick) (Lepidoptera: Gelechiidae), requiring the use of new insecticidal compounds for their management. Tetraniliprole, a novel insecticide effective against lepidopteran, coleopteran, and dipteran pests, is a potential alternative against the tomato pinworm. This study investigates the sublethal effects of tetraniliprole on the development and reproduction of the parental (F0) and progeny (F1) generations of P. absoluta while exploring the underlying mechanisms. Sublethal tetraniliprole exposure extended larval duration and reduced pupation rate, emergence rate, hatchability, and fecundity in both the F0 and F1 of P. absoluta. Additionally, the life-table parameters of the F1 generation were significantly altered, with decreases in net reproductive rate (R0) and increases in the mean generation time (T), leading to decreases in the intrinsic rate of population growth (r). The relative fitness of F1 insects exposed to tetraniloprole was reduced compared to unexposed insects (0.63 and 0.49, respectively). Furthermore, the mRNA expression levels of reproduction-related genes such as TaVg and TaVgR were down-regulated in the tetraniliprole-exposed insects. Finally, insect exposure to tetraniloprole increases the activity of the antioxidant enzymes such as glutathione S-transferase (GSTs), catalase (CAT), and superoxide dismutase (SOD). Taken together, these findings suggest that sublethal concentrations of tetraniloprole adversely affect both the development and reproduction of P. absoluta, providing a foundation for optimizing pest control strategies.

Modeling long-term, stage-structured dynamics of Tribolium castaneum (Coleoptera: Tenebrionidae) at food facilities with and without two types of long-lasting insecticide-incorporated netting.

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a cosmopolitan and destructive external-infesting pest at many food facilities. The use of deltamethrin- and α-cypermethrin-incorporated long-lasting insecticide-incorporated netting (LLIN) has shown incredible promise for the management of stored product insects. However, it is unknown how LLIN deployed within food facilities may affect the long-term population dynamics of T. castaneum compared to populations where no LLIN is present. Exposure to LLIN has been shown to affect mortality in the current generation and decrease progeny production in the subsequent generation. Thus, we modeled the long-term population dynamics of T. castaneum at food facilities over 15 generations by incorporating realistic estimates for mortality and progeny reduction after contact with LLIN compared to baseline growth by the species. We parameterized the model with estimates from the literature and used a four-stage structured population (eggs, larvae, pupae, and adults). The model was implemented using the package popbio in R. Our models suggest that deploying LLIN led to significant population reductions based on the estimates of mortality and progeny reduction from prior work, whereas the baseline model exhibited exponential population growth. In addition, there were differences in the frequencies of each life stage under each scenario modeled. As a result, it appears deploying LLIN may contribute to the local extirpation of T. castaneum within as few as 15 generations. Our work contributes to a growing literature about the effectiveness of incorporating LLIN into existing pest management programs for managing stored product insects in food facilities.

Genetic Variation in Growth Characteristics and Wood Properties of Ficus variegata Blume First Generation Progeny Trials in Indonesia

Genetic Variation in Growth Characteristics and Wood Properties of Ficus variegata Blume First Generation Progeny Trials in Indonesia

A Fusarium verticillioides MAT1-2 Strain near Isogenic to the Sequenced FGSC7600 Strain for Producing Homozygous Multigene Mutants.

Fungal genetic systems ideally combine molecular tools for genome manipulation and a sexual reproduction system to create an informative assortment of combinations of genomic modifications. When employing the sexual cycle to generate multi-mutants, the background genotype variations in the parents may result in progeny phenotypic variation obscuring the effects of combined mutations. Here, to mitigate this variation in Fusarium verticillioides, we generated a MAT1-2 strain that was near isogenic to the sequenced wild-type MAT1-1 strain, FGSC7600. This was accomplished by crossing FGSC7600 with the divergent wild-type MAT1-2 strain FGSC7603 followed by six sequential backcrosses (e.g., six generations) of MAT1-2 progeny to FGSC7600. We sequenced each generation and mapped recombination events. The parental cross involved twenty-six crossovers on nine of the eleven chromosomes. The dispensable chromosome 12, found in FGSC7603 but lacking in FGSC7600, was not present in the progeny post generation five. Inheritance of complete chromosomes without crossover was frequently observed. A deletion of approximately 140 kilobases, containing 54 predicted genes on chromosome 4, occurred in generation 4 and was retained in generation 5 indicating that these genes are dispensable for growth and both asexual and sexual reproduction. The final MAT1-2 strain TMRU10/35 is about 93% identical to FGSC7600. TMRU10/35 is available from the Fungal Genetics Stock Center as FGSC27326 and from the ARS Culture Collection as NRRL64809.

Folate-mediated transgenerational inheritance of sperm DNA methylation patterns correlate with spinal axon regeneration

ABSTRACT In mammals, the molecular mechanisms underlying transgenerational inheritance of phenotypic traits in serial generations of progeny after ancestral environmental exposures, without variation in DNA sequence, remain elusive. We’ve recently described transmission of a beneficial trait in rats and mice, in which F0 supplementation of methyl donors, including folic acid, generates enhanced axon regeneration after sharp spinal cord injury in untreated F1 to F3 progeny linked to differential DNA methylation levels in spinal cord tissue. To test whether the transgenerational effect of folic acid is transmitted via the germline, we performed whole-genome methylation sequencing on sperm DNA from F0 mice treated with either folic acid or vehicle control, and their F1, F2, and F3 untreated progeny. Transgenerational differentially methylated regions (DMRs) are observed in each consecutive generation and distinguish folic acid from untreated lineages, predominate outside of CpG islands and in regions of the genome that regulate gene expression, including promoters, and overlap at both the differentially methylated position (DMP) and gene levels. These findings indicate that molecular changes between generations are caused by ancestral folate supplementation. In addition, 29,719 DMPs exhibit serial increases or decreases in DNA methylation levels in successive generations of untreated offspring, correlating with a serial increase in the phenotype across generations, consistent with a ‘wash-in’ effect. Sibship-specific DMPs annotate to genes that participate in axon- and synapse-related pathways.

Parent-offspring regression and intergeneration correlation analysis in powdery mildew resistance derived F4 and F5 generations of oat

The present investigation was undertaken to determine the intergeneration correlation and parent-offspring regression in F4 and F5 generations of seven different oat crosses which were grown during Rabi 2019-20 and 2020-21, respectively, at Experimental Farm of Fodder Section, CSKHPKV, Palampur. Correlation studies revealed a negative correlation between crude protein yield per plant with grain yield per plant in F5 generation and a positive correlation between fresh fodder yield per plant and dry matter yield per plant in both generations, revealing crude protein yield as major forage yield component. F4 generation progenies showed highly significant and positive values of intergeneration correlation and regression with F5 generation progenies for grain yield per plant, crude protein yield per plant, harvest index and number of tillers per plant in most of the crosses, which indicated that the performance of plants on the basis of these traits is a reliable indicator of their performance in subsequent generations. Narrow sense heritability increased with the advancement of generation from F4 to F5, indicating the additivity of gene effects for the traits such as grain yield per plant, 100-grain weight, harvest index and crude protein yield per plant. Two progenies P4-5-2 -5 and P4-5-2-8 of the cross HJ-8 × JPO-46 were resistant to powdery mildew disease in F5 generation and the number of resistant plants was more in F5 generation over F4 generation which showed the efficiency of selection for resistance to powdery mildew.

Highs and Lows in Calicivirus Reverse Genetics.

In virology, the term reverse genetics refers to a set of methodologies in which changes are introduced into the viral genome and their effects on the generation of infectious viral progeny and their phenotypic features are assessed. Reverse genetics emerged thanks to advances in recombinant DNA technology, which made the isolation, cloning, and modification of genes through mutagenesis possible. Most virus reverse genetics studies depend on our capacity to rescue an infectious wild-type virus progeny from cell cultures transfected with an "infectious clone". This infectious clone generally consists of a circular DNA plasmid containing a functional copy of the full-length viral genome, under the control of an appropriate polymerase promoter. For most DNA viruses, reverse genetics systems are very straightforward since DNA virus genomes are relatively easy to handle and modify and are also (with few notable exceptions) infectious per se. This is not true for RNA viruses, whose genomes need to be reverse-transcribed into cDNA before any modification can be performed. Establishing reverse genetics systems for members of the Caliciviridae has proven exceptionally challenging due to the low number of members of this family that propagate in cell culture. Despite the early successful rescue of calicivirus from a genome-length cDNA more than two decades ago, reverse genetics methods are not routine procedures that can be easily extrapolated to other members of the family. Reports of calicivirus reverse genetics systems have been few and far between. In this review, we discuss the main pitfalls, failures, and delays behind the generation of several successful calicivirus infectious clones.

Original Research Article Genetic Diversity and Association Analysis for Agronomic and Yield Related Traits in Interspecific Progenies of Pigeonpea (Cajanus cajan)

The limited genetic diversity in existing cultivars emphasizes the need for incorporating potential exotics and wild relatives in breeding programs. This study focussed on assessing genetic variation and correlations among yield traits in F8 and F9 progenies resulting from nine interspecific crosses, involving three cultivated parental lines and three wild species. Results indicate significant genotypic variation for all traits studied. Phenotypic and genotypic coefficients of variation varied across agronomic parameters. Heritability estimates ranged from 22.61% (Primary branches plant-1) to 89.35% (Days to maturity) for different traits, emphasizing the potential for selection in breeding programs. Positive correlations were observed among various traits in both progeny generations, providing insights into the interplay of genetic factors influencing pigeon pea traits. The cluster analysis revealed that, 54 interspecific cross derived lines with three parents were grouped into four clusters, indicating the greater diversity among the lines for the selection of yield related traits for pigeonpea crop improvement.

Serine deamination by human serine racemase synergizes with antibiotics to curtail the replication of Chlamydia trachomatis

The obligate intracellular bacterium, Chlamydia trachomatis, has evolved to depend on its human host for many metabolites, including most amino acids and three of the four nucleotides. Given this, it is not surprising that depletion of a single amino acid in the host cell growth medium blocks chlamydial replication. Paradoxically, supra-normal levels of some amino acids also block productive replication of Chlamydia. Here, we have determined how elevated serine levels, generated by exogenous supplementation, impede chlamydial inclusion development and reduce the generation of infectious progeny. Our findings reveal that human serine racemase, which is broadly expressed in multiple tissues, potentiates the anti-chlamydial effect of elevated serine concentrations. In addition to reversibly converting l-serine to d-serine, serine racemase also deaminates serine via β-elimination. We have determined that d-serine does not directly impact Chlamydia; rather, ammonia generated by serine deamination limits the productive chlamydial replication. Our findings imply that ammonia produced within host cells can traverse the chlamydial inclusion membrane. Further, this property of serine deaminase can be exploited to sensitize Chlamydia to concentrations of doxycycline that are otherwise not bactericidal. Because exogenously elevated levels of serine can be tolerated over extended periods, the broad expression pattern of serine racemase indicates it to be a host enzyme whose activity can be directed against multiple intracellular bacterial pathogens. From a therapeutic perspective, demonstrating host metabolism can be skewed to generate an anti-bacterial metabolite that synergizes with antibiotics, we believe our results provide a new approach to target intracellular pathogens.

Guardians of wheat: Unleashing transgenerational immune priming with Trichoderma against spot blotch

Plants encounter various biotic stresses in their natural habitat, prompting the exploration of innovative protective measures to bolster their immune defences against pathogens. An effective strategy involves priming plant immunity, conferring enduring and comprehensive protection. Defence priming, characterized by heightened responsiveness to attackers following prior stress exposure, intriguingly manifests transgenerationally, transmitting the memory of priming to subsequent plant generations. In our investigation, we delved into the phenomenon of transgenerational immune priming (TGIP) in wheat facilitated by Trichoderma, spanning from the parental generation (G0) to the grand progeny (G2) generation. Successful establishment of transgenerational priming in the G2 generation was achieved by initially priming the G0 generation of wheat with Trichoderma. To assess priming inheritance, seeds from the G1 generation were collected, and both primed and non-primed wheat plants' grand progeny (G2 generation) were cultivated in soil. Subsequent evaluation encompassed the disease phenotype, biochemical parameters, and yield-related traits of the G2 generation wheat when confronted with Bipolaris sorokiniana, the causal agent of spot blotch disease. Our analysis revealed that the G2 generation of primed wheat displayed superior protection against spot blotch compared to non-primed wheat. Biochemical studies indicated no activation of defensive responses in the absence of disease pressure in G2 wheat plants. However, upon pathogen challenge, the grand progeny of primed wheat exhibited a robust defence response, surpassing that of non-primed wheat. This targeted defence response enabled efficient resource utilization and mitigated yield penalties. Furthermore, under biotic stress conditions, the grand progeny of primed wheat exhibited enhanced yield parameters compared to non-primed wheat. Our findings provide conclusive evidence that Trichoderma-mediated priming against B. sorokiniana can be inherited successfully from the parental (G0) generation to the grand progeny (G2) generation of wheat. This study represents the initial documentation of Trichoderma-mediated TGIP in wheat against B. sorokiniana, holding significant promise for sustainable agriculture by offering an environmentally friendly alternative to chemical pesticides.

HO-CR and HOLL-CR: new forms of winter oilseed rape (Brassica napus L.) with altered fatty acid composition and resistance to selected pathotypes of Plasmodiophora brassicae (clubroot)

The priority in oilseed rape (Brassica napus L.) research and breeding programs worldwide is to combine different features to develop cultivars tailored to specific applications of this crop. In this study, forms with a modified fatty acid composition of seed oil were successfully combined with a source of resistance to Plasmodiophora brassicae Wor., a harmful protist-causing clubroot. Three HO-type recombinants in F6–F12 generations with oleic acid content of 80.2–82.1% and one HOLL-type F6 inbred mutant recombinant (HOmut × LLmut), with a high oleic acid content (80.9%) and reduced linolenic acid content (2.3%), were crossed with the cultivar Tosca, resistant to several pathotypes of P. brassicae. The work involved genotyping with the use of DNA markers specific for allelic variants of desaturase genes responsible for the synthesis of oleic and linolenic fatty acids, CAPS (FAD2 desaturase, C18:1), and SNaPshot (FAD3 desaturase, C18:3), respectively. Of 350 progenies in the F3 generation, 192 (55%) were selected for further studies. Among them, 80 HO (≥ 72%) lines were identified, 10 of which showed resistance to at least one up to four P. brassicae pathotypes. Thirty lines in the selected progeny contained high oleic acid and less than 5% linolenic acid; eight of them belonged to the HOLL type conferring resistance to at least one pathotype. Two HO lines and two HOLL lines were resistant to four pathotypes. The resulting HO-CR and HOLL-CR inbred lines with altered seed oil fatty acid composition and resistance to P. brassicae represent unique oilseed rape material with the desired combination of valuable traits.

Potential for Using Four Plant Essential Oils to Protect Stored Products Against <i>Tribolium castaneum</i> (Herbst) (Coleoptera: Tenebrionidae)

Food products that are kept in storage, such as grains, cereals, and processed foods, can sustain serious damage from stored-product insects. This study examined the effects of four essential oils (EOs) extracted from sweet violet (Viola odorata L.), parsley (Petroselinum crispum L.), neroli (Citrus aurantium amara), and marjoram (Origanum majorana) against red flour beetles Tribolium castaneum (L.) in terms of contact and fumigant toxicities, repellency, and antifeedant properties. The EOs of O. majorana and V. odorata had the highest contact toxicities against T. castaneum adults, with LC50 of 5,313 mg/L and 5,512 mg/L, respectively. The EO of V. odorata showed the highest fumigant toxicity against adults of T. castaneum with an LC50 of 491 mg/L after 48 hours of exposure. All tested EOs exhibited a repulsive effect against adults of T. castaneum. Rejection of the tested EOs increased with increasing concentrations and time of exposure, except for O. majorana. The lowest concentration of EOs extracted from P. crispum and O. majorana demonstrated feeding stimulatory effects over control, but C. aurantium showed the highest feeding deterrence index (FDI) value against adults of T. castaneum. The phagostimulant activity of O. majorana and P. crispum decreased linearly as the applied concentration of the EOs increased. The application of EOs resulted in a significant decrease in the number of emerged adults of new generation progeny (F1); the reduction in F1 exhibited a dose-dependent relationship. These findings highlight the prospective application of plant EOs as biocontrol agents against adults of T. castaneum.

Thiamethoxam-Induced Intergenerational Sublethal Effects on the Life History and Feeding Behavior of Rhopalosiphum padi

Thiamethoxam, a second-generation neonicotinoid insecticide is widely used for controlling sap-sucking insect pests including Rhopalosiphum padi. The current study aimed to investigate the life-history parameters and feeding behavior of R. padi following treatments with sublethal concentrations of thiamethoxam. The lethal concentration 50 (LC50) value of thiamethoxam against adult R. padi was 11.458 mg L−1 after 48 h exposure. The sublethal concentrations of thiamethoxam (LC5 and LC10) significantly decreased the adult longevity, fecundity, and reproductive days in the directly exposed aphids (F0 generation). In the progeny R. padi (F1), the developmental durations and total prereproductive period (TPRP) were decreased while the adult longevity, fecundity, and reproductive days (RPd) were increased at both thiamethoxam concentrations. The demographic parameters including the net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were prolonged only at the LC5 of thiamethoxam. The EPG results indicated that the sublethal concentrations of thiamethoxam increases the total duration of non-probing (Np) while reducing the total duration of E2 in directly exposed aphids (F0). Interestingly, the E2 were significantly increased in the progeny generation (F1) descending from previously exposed parental aphids (F0). Overall, this study showed that thiamethoxam exhibited high toxicity against directly exposed individuals (F0), while inducing intergenerational hormetic effects on the progeny generation (F1) of R. padi. These findings provided crucial details about thiamethoxam-induced hormetic effects that might be useful in managing resurgences of this key pest.

Revealing novel insights on how oral supplementation with collagen peptides may prevent hair loss: Lessons from the human hair follicle organ culture

Dietary supplementation with bioactive collagen peptides (CPs) may be a helpful adjuvant strategy in reducing the excessive hair shedding and thinning associated with aging or patterned hair loss. However, the underlying biological effects of CPs on hair follicle (HF) function have not yet been characterized. Excessive hair loss occurs when HFs exit the growth phase (anagen) prematurely due to, among other factors, impaired epithelial HF stem cell (eHFSC) activities. The aims of this study were to investigate the response of human HFs to peptides from the two most popular CP sources, i.e. marine and bovine collagens, which were previously in vitro-digested to mimic gastrointestinal breakdown, in one of the most clinically-relevant ex vivo HF models. Both types of collagens reduced the proliferation of pluripotent K15+ eHFSCs and enhanced the generation of K19+ and/or CD34+ stem cell progenies. In addition, bovine CPs significantly increased K15+ cells in the bulge and marine CPs significantly maintained HFs longer in anagen. Our results suggest that both marine and bovine CPs may help to prevent hair loss and maintain healthy hair by preserving eHFSCs and/or improving the generation of SC progenies. This data invites the further exploration of other CPs for the prevention of excessive hair shedding.

Hormetic effects of thiamethoxam on Schizaphis graminum: demographics and feeding behavior

In agroecosystems, insects contend with chemical insecticides often encountered at sublethal concentrations. Insects’ exposure to these mild stresses may induce hormetic effects, which has consequences for managing insect pests. In this study, we used an electrical penetration graph (EPG) technique to investigate the feeding behavior and an age-stage, two-sex life table approach to estimate the sublethal effects of thiamethoxam on greenbug, Schizaphis graminum. The LC5 and LC10 of thiamethoxam significantly decreased longevity and fecundity of directly exposed adult aphids (F0). However, the adult longevity, fecundity, and reproductive days (RPd)—indicating the number of days in which the females produce offspring – in the progeny generation (F1) exhibited significant increase when parental aphids (F0) were treated with LC5 of the active ingredient. Subsequently, key demographic parameters such as intrinsic rate of increase (r) and net reproductive rate (R0) significantly increased at LC5 treatment. EPG recordings showed that total durations of non-probing (Np), intercellular stylet pathway (C), and salivary secretion into the sieve element (E1) were significantly increased, while mean duration of probing (Pr) and total duration of phloem sap ingestion and concurrent salivation (E2) were decreased in F0 adults exposed to LC5 and LC10. Interestingly, in the F1 generation, total duration of Np was significantly decreased while total duration of E2 was increased in LC5 treatment. Taken together, our results showed that an LC5 of thiamethoxam induces intergenerational hormetic effects on the demographic parameters and feeding behavior of F1 individuals of S. graminum. These findings have important implications on chemical control against S. graminum and highlight the need for a deeper understanding of the ecological consequences of such exposures within pest management strategies across the agricultural landscapes.

Transcriptome analysis of polyploid giant cancer cells and their progeny reveals a functional role for p21 in polyploidization and depolyploidization

Polyploid giant cancer cells (PGCC) are frequently detected in tumors and are increasingly recognized for their roles in chromosomal instability and associated genome evolution that leads to cancer recurrence. We previously reported that therapy stress promotes polyploidy, and that acid ceramidase plays a role in depolyploidization. In this study, we used an RNA-seq approach to gain a better understanding of the underlying transcriptomic changes that occur as cancer cells progress through polyploidization and depolyploidization. Our results revealed gene signatures that are associated with disease-free and/or overall survival in several cancers and identified the cell cycle inhibitor CDKN1A/p21 as the major hub in PGCC and early progeny. Increased expression of p21 in PGCC was limited to the cytoplasm. We previously demonstrated that the sphingolipid enzyme acid ceramidase is dispensable for polyploidization upon therapy stress but plays a crucial role in depolyploidization. The current study demonstrates that treatment of cells with ceramide is not sufficient for p53-independent induction of p21 and that knockdown of acid ceramidase, which hydrolyzes ceramide, does not interfere with upregulation of p21. In contrast, blocking the expression of p21 with UC2288 prevented the induction of acid ceramidase and inhibited both the formation of PGCC from parental cells as well as the generation of progeny from PGCC. Taken together, our data suggest that p21 functions upstream of acid ceramidase and plays an important role in polyploidization and depolyploidization.