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Plants (Basel, Switzerland) Jun 2023Doubled haploid (DH) technology is a tool used to develop large numbers of inbred lines and increase the rate of genetic gain by shortening the breeding cycles. However,...
Doubled haploid (DH) technology is a tool used to develop large numbers of inbred lines and increase the rate of genetic gain by shortening the breeding cycles. However, previous attempts to produce DH sunflower plants ( spp.) have resulted in limited success. In this research, we applied gamma-induced parthenogenesis to assist the production of DH sunflowers. The objectives of the study included (1) identifying optimal gamma ray doses for inducing DH sunflowers using two cytoplasmic male sterility (CMS) lines as female plants and two male pollinators with recognizable morphological markers, (2) selecting new male pollinators from wild sunflower varieties, and (3) testing the efficacy of the selected male pollinators using emasculated non-male sterile sunflower lines as female plants. In these experiments, pollen grains were irradiated with gamma ray doses ranging from 50 to 200 Gy. The optimal gamma ray dose for pollen grain irradiation and DH plant production was identified to be 100 Gy. In addition, a cultivated (G11/1440) and a wild-type (ANN1811) sunflower line can be used as common male pollinators for their distinctive morphological markers and wide capacity for DH induction by gamma-irradiated pollen grains.
PubMed: 37446990
DOI: 10.3390/plants12132430 -
BMC Biology Jul 2023Aphids are common crop pests. These insects reproduce by facultative parthenogenesis involving several rounds of clonal reproduction interspersed with an occasional...
BACKGROUND
Aphids are common crop pests. These insects reproduce by facultative parthenogenesis involving several rounds of clonal reproduction interspersed with an occasional sexual cycle. Furthermore, clonal aphids give birth to live young that are already pregnant. These qualities enable rapid population growth and have facilitated the colonisation of crops globally. In several cases, so-called "super clones" have come to dominate agricultural systems. However, the extent to which the sexual stage of the aphid life cycle has shaped global pest populations has remained unclear, as have the origins of successful lineages. Here, we used chromosome-scale genome assemblies to disentangle the evolution of two global pests of cereals-the English (Sitobion avenae) and Indian (Sitobion miscanthi) grain aphids.
RESULTS
Genome-wide divergence between S. avenae and S. miscanthi is low. Moreover, comparison of haplotype-resolved assemblies revealed that the S. miscanthi isolate used for genome sequencing is likely a hybrid, with one of its diploid genome copies closely related to S. avenae (~ 0.5% divergence) and the other substantially more divergent (> 1%). Population genomics analyses of UK and China grain aphids showed that S. avenae and S. miscanthi are part of a cryptic species complex with many highly differentiated lineages that predate the origins of agriculture. The complex consists of hybrid lineages that display a tangled history of hybridisation and genetic introgression.
CONCLUSIONS
Our analyses reveal that hybridisation has substantially contributed to grain aphid diversity, and hence, to the evolutionary potential of this important pest species. Furthermore, we propose that aphids are particularly well placed to exploit hybridisation events via the rapid propagation of live-born "frozen hybrids" via asexual reproduction, increasing the likelihood of hybrid lineage formation.
Topics: Animals; Aphids; Poaceae; Reproduction, Asexual; Reproduction; Genomics
PubMed: 37443008
DOI: 10.1186/s12915-023-01649-4 -
Frontiers in Cellular and Infection... 2023The bacterial endosymbiont, spp. induce thelytokous parthenogenesis in certain parasitoid wasps, such as the egg parasitoid wasps spp. To complete the cycle of...
INTRODUCTION
The bacterial endosymbiont, spp. induce thelytokous parthenogenesis in certain parasitoid wasps, such as the egg parasitoid wasps spp. To complete the cycle of vertical transmission, displays efficient transovarial transmission by targeting the reproductive tissues and often exhibits strong tissue-specific tropism in their host.
METHOD
The present study aimed to describe the basic distribution patterns that occur during the development of -infected, thelytokous , and . We used fluorescence hybridization (FISH) to investigate signal dynamics during early embryogenesis (from 30 to 120 min). titers and distributions from the embryo to adult stages of after early embryogenesis were detected by absolute quantitative polymerase chain reaction (AQ-PCR) and FISH. The symmetry ratios (SR) of the signals were calculated using the SR odds ratios in the anterior and posterior parts of the host. The SR was determined to describe tropism during early embryogenesis and various developmental stages of .
RESULTS
was concentrated in the posterior part of the embryo during early embryogenesis and the various developmental stages of both and . density increased with the number of nuclei and the initial mitotic division frequency during early embryogenesis. The total titer increased with postembryogenesis development in both and . However, the densities relative to body size were significantly lower at the adult and pupal stages than they were at the embryonic stage.
DISCUSSION
The present work revealed that posterior concentration during early host embryogenesis determined localization in adult wasps. By this mechanism, exhibits efficient vertical transmission across generations by depositing only female -infected offspring. The results of this study describe the dynamics of during the development of their host. The findings of this investigation helped clarify tropism in wasps.
Topics: Animals; Female; Wasps; Wolbachia; In Situ Hybridization, Fluorescence; Embryonic Development; Parthenogenesis
PubMed: 37424778
DOI: 10.3389/fcimb.2023.1198428 -
Journal of Experimental Botany Aug 2023The word 'fruit' is derived from the latin 'fructus' which itself is said to be derived from 'frui', which means to enjoy. Along those lines, I hope this year's...
The word 'fruit' is derived from the latin 'fructus' which itself is said to be derived from 'frui', which means to enjoy. Along those lines, I hope this year's Flowering Newsletter brings a lot of joy, because fruits and seeds feature in multiple articles.
Topics: Apomixis; Seeds; Fruit
PubMed: 37419454
DOI: 10.1093/jxb/erad258 -
Ecology and Evolution Jul 2023Reconstruction of species histories is a central aspect of evolutionary biology. Patterns of genetic variation within and among populations can be leveraged to elucidate...
Reconstruction of species histories is a central aspect of evolutionary biology. Patterns of genetic variation within and among populations can be leveraged to elucidate evolutionary processes and demographic histories. However, interpreting genetic signatures and unraveling the contributing processes can be challenging, in particular for non-model organisms with complex reproductive modes and genome organization. One way forward is the combined consideration of patterns revealed by different molecular markers (nuclear vs. mitochondrial) and types of variants (common vs. rare) that differ in their age, mode, and rate of evolution. Here, we applied this approach to RNAseq data generated for (Archaeognatha), an Alpine jumping bristletail considered parthenogenetic and triploid. We generated de novo transcriptome and mitochondrial assemblies to obtain high-density data to investigate patterns of mitochondrial and common and rare nuclear variation in 17 individuals sampled from all known populations. We find that the different variant types capture distinct aspects of the evolutionary history and discuss the observed patterns in the context of parthenogenesis, polyploidy, and survival during glaciation. This study highlights the potential of different variant types to gain insights into evolutionary scenarios even from challenging but often available data and the suitability of and the genus as a study system for the evolution of sexual strategies and polyploidization during environmental change. We also emphasize the need for further research which will be stimulated and facilitated by these newly generated resources and insights.
PubMed: 37404697
DOI: 10.1002/ece3.10227 -
Genome Biology and Evolution Jul 2023Cyclical parthenogenesis, where females can engage in sexual or asexual reproduction depending on environmental conditions, represents a novel reproductive phenotype...
Cyclical parthenogenesis, where females can engage in sexual or asexual reproduction depending on environmental conditions, represents a novel reproductive phenotype that emerged during eukaryotic evolution. The fact that environmental conditions can trigger cyclical parthenogens to engage in distinct reproductive modes strongly suggests that gene expression plays a key role in the origin of cyclical parthenogenesis. However, the genetic basis underlying cyclical parthenogenesis remains understudied. In this study, we characterize the female transcriptomic signature of sexual versus asexual reproduction in the cyclically parthenogenetic microcrustacean Daphnia pulex and Daphnia pulicaria. Our analyses of differentially expressed genes (DEGs), pathway enrichment, and gene ontology (GO) term enrichment clearly show that compared with sexual reproduction, the asexual reproductive stage is characterized by both the underregulation of meiosis and cell cycle genes and the upregulation of metabolic genes. The consensus set of DEGs that this study identifies within the meiotic, cell cycle, and metabolic pathways serves as candidate genes for future studies investigating how the two reproductive cycles in cyclical parthenogenesis are mediated at a molecular level. Furthermore, our analyses identify some cases of divergent expression among gene family members (e.g., doublesex and NOTCH2) associated with asexual or sexual reproductive stage, suggesting potential functional divergence among gene family members.
Topics: Parthenogenesis; Transcriptome; Reproduction, Asexual; Male; Female; Animals; Daphnia; Gene Expression Profiling
PubMed: 37392457
DOI: 10.1093/gbe/evad122 -
Experimental & Applied Acarology Aug 2023Unsustainable soil management is one of the drivers of soil degradation, but impact assessment requires the development of indicators. Oribatids might be considered as...
Unsustainable soil management is one of the drivers of soil degradation, but impact assessment requires the development of indicators. Oribatids might be considered as early indicators of disturbances due to the stability of their community. The aim of this study was to investigate the feasibility of oribatids as bioindicators of sustainable agricultural practices. Under a dry Mediterranean climate, three fertilization experiments - two under a two-crop rotation system and one under maize monoculture and established 12 years earlier - were sampled 3× for oribatid identification during the last annual cropping cycle. The hypothesis was that different nutrient and crop managements affect the number of oribatid species and individuals present, and these parameters could be used as indicators of soil degradation. In total, 18 oribatid species were identified, and 1974 adult individuals were recovered. Maximum abundance was found prior to sowing. Pig slurry (PS) vs. control, and dairy cattle manure (CM) vs. mineral fertilization increased oribatid abundance. This increase was evident when the average applied rates with PS were ca. 2 Mg of organic matter (OM) ha yr, or higher than ca. 4 Mg OM ha yr for CM. When the preceding crop was wheat and PS or CM were used, Oribatula (Zygoribatula) excavata (which reproduces sexually) predominated. In maize monoculture fertilized with CM, Tectocepheus sarekensis and Acrotritia ardua americana (which can reproduce through parthenogenesis) prevailed vs. Oribatula, which indicated a heavily disturbed soil. Under this specific Mediterranean environment, the predominance of certain parthenogenic oribatid species and the number of individuals provide advanced warning on soil degradation.
Topics: Cattle; Animals; Swine; Mites; Soil; Agriculture; Fertilization; Crop Production
PubMed: 37338638
DOI: 10.1007/s10493-023-00812-4 -
International Journal of Molecular... May 2023The infamous "master manipulators"-intracellular bacteria of the genus -infect a broad range of phylogenetically diverse invertebrate hosts in terrestrial ecosystems....
The infamous "master manipulators"-intracellular bacteria of the genus -infect a broad range of phylogenetically diverse invertebrate hosts in terrestrial ecosystems. has an important impact on the ecology and evolution of their host with documented effects including induced parthenogenesis, male killing, feminization, and cytoplasmic incompatibility. Nonetheless, data on infections in non-terrestrial invertebrates are scarce. Sampling bias and methodological limitations are some of the reasons limiting the detection of these bacteria in aquatic organisms. In this study, we present a new metagenetic method for detecting the co-occurrence of different strains in freshwater invertebrates host species, i.e., freshwater Arthropoda (Crustacea), Mollusca (Bivalvia), and water bears (Tardigrada) by applying NGS primers designed by us and a Python script that allows the identification of target sequences from the microbiome communities. We also compare the results obtained using the commonly applied NGS primers and the Sanger sequencing approach. Finally, we describe three supergroups of : (i) a new supergroup V identified in Crustacea and Bivalvia hosts; (ii) supergroup A identified in Crustacea, Bivalvia, and Eutardigrada hosts, and (iii) supergroup E infection in the Crustacea host microbiome community.
Topics: Animals; Male; Wolbachia; Phylogeny; Ecosystem; Arthropods; Bacteria; Crustacea; Symbiosis
PubMed: 37298356
DOI: 10.3390/ijms24119400 -
Annual Review of Microbiology Sep 2023Among endosymbiotic bacteria living within eukaryotic cells, is exceptionally widespread, particularly in arthropods. Inherited through the female germline, it has... (Review)
Review
Among endosymbiotic bacteria living within eukaryotic cells, is exceptionally widespread, particularly in arthropods. Inherited through the female germline, it has evolved ways to increase the fraction of bacterially infected offspring by inducing parthenogenesis, feminization, male killing, or, most commonly, cytoplasmic incompatibility (CI). In CI, infection of males causes embryonic lethality unless they mate with similarly infected females, creating a relative reproductive advantage for infected females. A set of related bicistronic operons encodes the CI-inducing factors. The downstream gene encodes a deubiquitylase or nuclease and is responsible for CI induction by males, while the upstream product when expressed in females binds its sperm-introduced cognate partner and rescues viability. Both toxin-antidote and host-modification mechanisms have been proposed to explain CI. Interestingly, male killing by either or endosymbionts involves deubiquitylases as well. Interference with the host ubiquitin system may therefore be a common theme among endosymbiont-mediated reproductive alterations.
Topics: Female; Male; Humans; Wolbachia; Semen; Reproduction; Cytoplasm; Molecular Biology; Symbiosis
PubMed: 37285552
DOI: 10.1146/annurev-micro-041020-024616 -
Biology Letters Jun 2023Over the past two decades, there has been an astounding growth in the documentation of vertebrate facultative parthenogenesis (FP). This unusual reproductive mode has...
Over the past two decades, there has been an astounding growth in the documentation of vertebrate facultative parthenogenesis (FP). This unusual reproductive mode has been documented in birds, non-avian reptiles-specifically lizards and snakes-and elasmobranch fishes. Part of this growth among vertebrate taxa is attributable to awareness of the phenomenon itself and advances in molecular genetics/genomics and bioinformatics, and as such our understanding has developed considerably. Nonetheless, questions remain as to its occurrence outside of these vertebrate lineages, most notably in Chelonia (turtles) and Crocodylia (crocodiles, alligators and gharials). The latter group is particularly interesting because unlike all previously documented cases of FP in vertebrates, crocodilians lack sex chromosomes and sex determination is controlled by temperature. Here, using whole-genome sequencing data, we provide, to our knowledge, the first evidence of FP in a crocodilian, the American crocodile, . The data support terminal fusion automixis as the reproductive mechanism; a finding which suggests a common evolutionary origin of FP across reptiles, crocodilians and birds. With FP now documented in the two main branches of extant archosaurs, this discovery offers tantalizing insights into the possible reproductive capabilities of the extinct archosaurian relatives of crocodilians and birds, notably members of Pterosauria and Dinosauria.
Topics: Animals; Alligators and Crocodiles; Biological Evolution; Genomics; Dinosaurs; Turtles; Birds; Parthenogenesis
PubMed: 37282490
DOI: 10.1098/rsbl.2023.0129