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Insects Jun 2024The skin beetle is regularly found beyond North America where it originated. The larvae cause considerable concern in museums, as they damage hides or furs in addition...
The skin beetle is regularly found beyond North America where it originated. The larvae cause considerable concern in museums, as they damage hides or furs in addition to being a special source of damage to collections of dried plants in herbaria or collections of insects and other zoological specimens. arrived in Europe in the mid-20th century and was associated mostly with stored food products, but over time, it has become recognised as a museum pest. Although it is still uncommon and may only be observed in a small fraction of museums, when the insect is found in large numbers, it can cause problems. Catches from blunder traps in Austrian museums and from an online database in the UK were used to track changing concern over the insect. As a single female beetle can continue to reproduce because the species is parthenogenetic, its presence can persist over long periods of time. Although small populations in museums are typically found in the adult form, the larval forms are more common where a site is infested by high numbers, perhaps because the larvae and adults must range more widely for food. Although can be controlled using pesticides, it is also possible to kill the larvae within infested materials through freezing or anoxia.
PubMed: 38921120
DOI: 10.3390/insects15060405 -
Cell Death Discovery Jun 2024Despite the advances in the understanding of reproductive physiology, the mechanisms underlying ovarian aging are still not deciphered. Recent research found an...
Despite the advances in the understanding of reproductive physiology, the mechanisms underlying ovarian aging are still not deciphered. Recent research found an association between impaired ATM-mediated DNA double-strand break (DSB) repair mechanisms and oocyte aging. However, direct evidence connecting ATM-mediated pathway function decline and impaired oocyte quality is lacking. The objective of this study was to determine the role of ATM-mediated DNA DSB repair in the maintenance of oocyte quality in a mouse oocyte knockdown model. Gene interference, in vitro culture, parthenogenesis coupled with genotoxicity assay approaches, as well as molecular cytogenetic analyses based upon next-generation sequencing, were used to test the hypothesis that intact ATM function is critical in the maintenance of oocyte quality. We found that ATM knockdown impaired oocyte quality, resulting in poor embryo development. ATM knockdown significantly lowered or blocked the progression of meiosis in vitro, as well as retarding and reducing embryo cleavage after parthenogenesis. After ATM knockdown, all embryos were of poor quality, and none reached the blastocyst stage. ATM knockdown was also associated with an increased aneuploidy rate compared to controls. Finally, ATM knockdown increased the sensitivity of the oocytes to a genotoxic active metabolite of cyclophosphamide, with increased formation of DNA DSBs, reduced survival, and earlier apoptotic death compared to controls. These findings suggest a key role for ATM in maintaining oocyte quality and resistance to genotoxic stress, and that the previously observed age-induced decline in oocyte ATM function may be a prime factor contributing to oocyte aging.
PubMed: 38914566
DOI: 10.1038/s41420-024-02041-z -
PLoS Genetics Jun 2024Tardigrades are small aquatic invertebrates known for their remarkable tolerance to diverse extreme stresses. To elucidate the in vivo mechanisms underlying this...
Tardigrades are small aquatic invertebrates known for their remarkable tolerance to diverse extreme stresses. To elucidate the in vivo mechanisms underlying this extraordinary resilience, methods for genetically manipulating tardigrades have long been desired. Despite our prior success in somatic cell gene editing by microinjecting Cas9 ribonucleoproteins (RNPs) into the body cavity of tardigrades, the generation of gene-edited individuals remained elusive. In this study, employing an extremotolerant parthenogenetic tardigrade species, Ramazzottius varieornatus, we established conditions that led to the generation of gene-edited tardigrade individuals. Drawing inspiration from the direct parental CRISPR (DIPA-CRISPR) technique employed in several insects, we simply injected a concentrated Cas9 RNP solution into the body cavity of parental females shortly before their initial oviposition. This approach yielded gene-edited G0 progeny. Notably, only a single allele was predominantly detected at the target locus for each G0 individual, indicative of homozygous mutations. By co-injecting single-stranded oligodeoxynucleotides (ssODNs) with Cas9 RNPs, we achieved the generation of homozygously knocked-in G0 progeny, and these edited alleles were inherited by G1/G2 progeny. This is the first example of heritable gene editing in the entire phylum of Tardigrada. This establishment of a straightforward method for generating homozygous knockout/knock-in individuals not only facilitates in vivo analyses of the molecular mechanisms underpinning extreme tolerance, but also opens up avenues for exploring various topics, including Evo-Devo, in tardigrades.
Topics: Animals; Tardigrada; CRISPR-Cas Systems; Gene Editing; Parthenogenesis; Homozygote; Female; Gene Knock-In Techniques; Gene Knockout Techniques; Alleles
PubMed: 38870088
DOI: 10.1371/journal.pgen.1011298 -
Journal of Evolutionary Biology Jun 2024Oak gall wasps typically exhibit a life cycle with one sexual and one asexual generation each year. These wasps can carry various endosymbionts, one of which is the...
Oak gall wasps typically exhibit a life cycle with one sexual and one asexual generation each year. These wasps can carry various endosymbionts, one of which is the maternally inherited bacterium Wolbachia that can induce several reproductive manipulations on its host. Cytoplasmic incompatibility (CI) has been described as the most prominent of these manipulations. CI leads to embryonic mortality in the hosts' offspring when infected males mate with either uninfected females or with females that harbour different Wolbachia strains. It has been hypothesized that Wolbachia can induce CI in oak gall wasps. To address this hypothesis, we derived a mathematical model to investigate the spread of a bacterial infection in naive populations and to determine the plausibility of CI occurrence. To validate our model, we used published data from Wolbachia-infected Belonocnema treatae populations in two approaches. Our first approach uses measurements of infection frequencies and maternal transmission in the sexual generation. For the second approach, we extended the model to compare predictions to estimates of mtDNA-haplotypes, which, like Wolbachia, are maternally inherited, and can therefore be associated with the infection. Both approaches indicate that CI is present in these populations. Our model can be generalized to investigate the occurrence of CI not only for oak gall wasps but also for other species.
PubMed: 38869236
DOI: 10.1093/jeb/voae077 -
ELife Jun 2024Facultative parthenogenesis (FP) has historically been regarded as rare in vertebrates, but in recent years incidences have been reported in a growing list of fish,...
Facultative parthenogenesis (FP) has historically been regarded as rare in vertebrates, but in recent years incidences have been reported in a growing list of fish, reptile, and bird species. Despite the increasing interest in the phenomenon, the underlying mechanism and evolutionary implications have remained unclear. A common finding across many incidences of FP is either a high degree of homozygosity at microsatellite loci or low levels of heterozygosity detected in next-generation sequencing data. This has led to the proposal that second polar body fusion following the meiotic divisions restores diploidy and thereby mimics fertilization. Here, we show that FP occurring in the gonochoristic species and results in genome-wide homozygosity, an observation inconsistent with polar body fusion as the underlying mechanism of restoration. Instead, a high-quality reference genome for and analysis of whole-genome sequencing from multiple FP and control animals reveals that a post-meiotic mechanism gives rise to homozygous animals from haploid, unfertilized oocytes. Contrary to the widely held belief that females need to be isolated from males to undergo FP, females housed with conspecific and heterospecific males produced unfertilized eggs that underwent spontaneous development. In addition, offspring arising from both fertilized eggs and parthenogenetic development were observed to arise from a single clutch. Strikingly, our data support a mechanism for facultative parthenogenesis that removes all heterozygosity in a single generation. Complete homozygosity exposes the genetic load and explains the high rate of congenital malformations and embryonic mortality associated with FP in many species. Conversely, for animals that develop normally, FP could potentially exert strong purifying selection as all lethal recessive alleles are purged in a single generation.
Topics: Animals; Parthenogenesis; Female; Lizards; Male; Meiosis; Homozygote
PubMed: 38847388
DOI: 10.7554/eLife.97035 -
Animal Science Journal = Nihon Chikusan... 2024Prolonged exposure of bisphenol A (BPA) has adverse effects on in vitro maturation (IVM) of oocytes, but treatment with tauroursodeoxycholic acid (TUDCA) can improve the...
Prolonged exposure of bisphenol A (BPA) has adverse effects on in vitro maturation (IVM) of oocytes, but treatment with tauroursodeoxycholic acid (TUDCA) can improve the IVM and development of embryos. The purpose of this study was to investigate the effects of BPA and both BPA and TUDCA on IVM and parthenogenetic development of embryos. The results showed that BPA treatment adverse effects on the cumulus expansion index, survival rate, polar body rate, mitochondrial distribution of the oocytes after maturation culture, and that it also decreased the cleavage rate and blastocyst rate of embryos after parthenogenetic develpoment. In addition, BPA treatment upregulated expression of genes related to endoplasmic reticulum stress and apoptosis and increased the intracellular reactive oxygen species (ROS) level, while it decreased expression of genes related to cumulus expansion. However, the supplementation of TUDCA relieved these adverse effects of BPA except polar body rate, blastocyst rate, and expression of BCL2 and PTGS1. In conclusion, the supplementation of TUDCA can partly attenuate the negative effects of BPA on IVM and parthenogenetic development of embryos, possibly by modification of the expression of genes related to endoplasmic reticulum stress, apoptosis and cumulus expansion, intracellular ROS level, and mitochondrial distribution.
Topics: Animals; Phenols; Taurochenodeoxycholic Acid; Oocytes; Parthenogenesis; Benzhydryl Compounds; Reactive Oxygen Species; In Vitro Oocyte Maturation Techniques; Apoptosis; Embryonic Development; Swine; Endoplasmic Reticulum Stress; Female; Gene Expression; Blastocyst; Mitochondria
PubMed: 38845341
DOI: 10.1111/asj.13966 -
Plant Reproduction Jun 2024The DNA methylation status at an epigenetic quantitative trait locus in the Arabidopsis chromosome 2 is linked to the formation of apomictic-like endosperms. Seed...
The DNA methylation status at an epigenetic quantitative trait locus in the Arabidopsis chromosome 2 is linked to the formation of apomictic-like endosperms. Seed development in most angiosperms is coupled to fertilization of the maternal gametes by two sperm cells. However, apomictic species can reproduce asexually via seeds. This trait is of great agricultural interest, as it would fix complex genotypes and allow for pollen-independent seed production. However, engineering full apomixis requires three independent processes: apomeiosis, parthenogenesis and autonomous endosperm development. While the first two have been successfully engineered in some crops, the formation of autonomous endosperms remains a challenge. Although it is known that this trait is under epigenetic control, such as of DNA methylation, the underlying mechanisms remain mostly undiscovered. Here, using epigenetic recombinant inbred lines, we identified an epigenetic quantitative trait locus in the Arabidopsis chromosome 2, which correlates with permissiveness for the formation of asexual seeds: hypomethylation at this genomic region allows the formation of larger autonomous endosperms. Importantly, the methylation at this locus only correlates with asexual seed size, and not to the size of sexual seeds or that of other organs. With this, we aim to show that screening for epialleles is a promising strategy to uncover loci underlying relevant traits and could pave the way to identifying genes necessary for the engineering of apomixis.
PubMed: 38836892
DOI: 10.1007/s00497-024-00504-y -
Current Biology : CB Jun 2024The Wolbachia strain that infects the parasitoid wasp Encarsia formosa induces female-producing parthenogenesis. A new study shows that a Wolbachia-encoded gene has...
The Wolbachia strain that infects the parasitoid wasp Encarsia formosa induces female-producing parthenogenesis. A new study shows that a Wolbachia-encoded gene has replaced the use of the ancestral wasp homologue that normally controls sexual reproduction, resulting in parthenogenesis.
Topics: Wolbachia; Parthenogenesis; Animals; Wasps; Female; Reproduction
PubMed: 38834030
DOI: 10.1016/j.cub.2024.04.076 -
Reproduction in Domestic Animals =... Jun 2024This study examines the impact of Notoginsenoside R1 (NGR1), a compound from Panax notoginseng, on the maturation of porcine oocytes and their embryonic development,...
This study examines the impact of Notoginsenoside R1 (NGR1), a compound from Panax notoginseng, on the maturation of porcine oocytes and their embryonic development, focusing on its effects on antioxidant levels and mitochondrial function. This study demonstrates that supplementing in vitro maturation (IVM) medium with NGR1 significantly enhances several biochemical parameters. These include elevated levels of glutathione (GSH), nuclear factor erythrocyte 2-related factor 2 (NRF2) and mRNA expression of catalase (CAT) and GPX. Concurrently, we observed a decrease in reactive oxygen species (ROS) levels and an increase in JC-1 immunofluorescence, mitochondrial distribution, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) and nuclear NRF2 mRNA levels. Additionally, there was an increase in ATP production and lipid droplets (LDs) immunofluorescence. These biochemical improvements correlate with enhanced embryonic outcomes, including a higher blastocyst rate, increased total cell count, enhanced proliferative capacity and elevated octamer-binding transcription factor 4 (Oct4) and superoxide dismutase 2 (Sod2) gene expression. Furthermore, NGR1 supplementation resulted in decreased apoptosis, reduced caspase 3 (Cas3) and BCL2-Associated X (Bax) mRNA levels and decreased glucose-regulated protein 78 kD (GRP78) immunofluorescence in porcine oocytes undergoing in vitro maturation. These findings suggest that NGR1 plays a crucial role in promoting porcine oocyte maturation and subsequent embryonic development by providing antioxidant levels and mitochondrial protection.
Topics: Animals; Antioxidants; Ginsenosides; In Vitro Oocyte Maturation Techniques; Mitochondria; Embryonic Development; Oocytes; Female; Swine; Reactive Oxygen Species; Embryo Culture Techniques
PubMed: 38828566
DOI: 10.1111/rda.14631 -
Journal of Integrative Plant Biology May 2024Parthenogenesis, the development of unfertilized egg cells into embryos, is a key component of apomixis. AtBBM (BABY BOOM), a crucial regulator of embryogenesis in...
Parthenogenesis, the development of unfertilized egg cells into embryos, is a key component of apomixis. AtBBM (BABY BOOM), a crucial regulator of embryogenesis in Arabidopsis, possesses the capacity to shift nutritional growth toward reproductive growth. However, the mechanisms underlying AtBBM-induced parthenogenesis remain largely unexplored in dicot plants. Our findings revealed that in order to uphold the order of sexual reproduction, the embryo-specific promoter activity of AtBBM as well as repressors that inhibit its expression in egg cells combine to limiting its ability to induce parthenogenesis. Notably, AtRKD5, a RWP-RK domain-containing (RKD) transcription factor, binds to the 3' end of AtBBM and is identified as one of the inhibitory factors for AtBBM expression in the egg cell. In the atrkd5 mutant, we successfully achieved enhanced ectopic expression of AtBBM in egg cells, resulting in the generation of haploid offspring via parthenogenesis at a rate of 0.28%. Furthermore, by introducing chimeric Arabidopsis and rice BBM genes into the egg cell, we achieved a significant 4.6-fold enhancement in haploid induction through the atdmp8/9 mutant. These findings lay a strong foundation for further exploration of the BBM-mediated parthenogenesis mechanism and the improvement of haploid breeding efficiency mediated by the dmp8/9 mutant.
PubMed: 38818961
DOI: 10.1111/jipb.13678