Sexual Reproduction Research Articles

Genetic variation within the arctic-alpine Calamagrostis stricta (Poaceae) species complex in Europe

The Calamagrostis stricta (Poaceae) species complex is a circumpolar, boreo-arctic and montane taxon that includes numerous subspecies and varieties. The recent discovery of Calamagrostis lonana in the Alps calls for a thorough assessment of relationships within C. stricta. The main aim of our study was to elucidate the phylogenetic position, genetic structure and ploidy level of C. lonana, as compared to the other members of the C. stricta species complex from Central Europe to the Arctic. Fifteen populations of the C. stricta species complex were sampled across Central and Northern Europe, and their ploidy level was estimated using flow cytometry. Genetic variation was characterized using double digest RAD sequencing reads (ddRAD-seq) on a total of 115 individuals genotyped at 1157 single-nucleotide polymorphisms. Based on flow cytometric measurements, tetraploidy was observed in Arctic populations from Northern Europe and C. lonana in the Alps, in contrast to other populations exhibiting higher ploidy levels. Calamagrostis lonana was genetically closely related to the arctic C. stricta subsp. groenlandica, while C. stricta subsp. stricta formed a second genetic cluster across Central Europe. A third, very distinct genetic cluster was observed in the northern Svalbard archipelago. Despite lacking evidence of sexual reproduction, substantially more genetic diversity than expected under asexual reproduction was detected within populations in C. lonana and other taxa. The distribution and genetic structure of the C. stricta species complex has been shaped by major post-glacial environmental changes having affected cold regions and specifically highlights C. lonana as a valuable relict taxon for the Alps.

Morphological characteristics, developmental dynamics, and gene temporal expressions across various development stages of Aphis gossypii sexual female

BackgroundAphis gossypii (Hemiptera: Aphididae) is a worldwide polyphagous phloem-feeding agricultural pest, and it can produce offspring by sexual or asexual reproduction. Compared with dozens of generations by parthenogenesis, sexual reproduction is performed in only one generation within one year, and little is known about the sexual reproduction of A. gossypii. In this study, sexual females of A. gossypii were successfully obtained through a previously established induction platform, and the morphological characteristics, developmental dynamics, and temporal gene expression were examined. Subsequently, signaling pathways potentially involved in regulating the growth, development, and reproduction of sexual females were investigated.ResultsThe morphological observation showed that from the 1st instar nymph to adult, sexual females exhibited a gradually deepened body color, an enlarged body size, longer antennae with a blackened end, and obviously protruding cauda (in adulthood). The anatomy found that the ovaries of sexual females developed rapidly from the 2nd instar nymph, and the embedded oocytes matured in adulthood. In addition, time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns, in which gene expression levels in clusters 1, 5, and 8 peaked at the 2nd instar nymphal stage with the largest number of up-regulated genes, suggesting that the 2nd instar nymph was an important ovary development period. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O (FoxO) signaling pathway, highlighting their important role in sexual female adult development and reproduction.ConclusionThe morphological changes of the sexual female at each developmental stage were revealed for the first time. In addition, time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females. Overall, these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.

Beyond Asexual: Genomics-Driven Progress in Unveiling Sexual Reproduction in Cereal Rust Fungi.

Recent advances in genomics technologies have revolutionized our understanding of cereal rust fungi, providing unprecedented insights into the complexities of their sexual life cycle. Genomic approaches, including long-read sequencing, genome assembly, and haplotype phasing technologies, have revealed critical insights into mating systems, genetic diversity, virulence evolution, and host adaptation. Population genomics studies have uncovered diverse reproductive strategies across different cereal rust species and geographic regions, highlighting the interplay between sexual recombination and asexual reproduction. Transcriptomics have begun to unravel the gene expression networks driving sexual reproduction, while complementary omics approaches such as proteomics, and metabolomics offer potential insights into the underlying molecular processes. Despite this progress, many aspects of rust sexual reproduction remain elusive. Integrating multiple omics approaches with advanced cell biology techniques can help address these knowledge gaps, particularly in understanding sexual reproduction and its role in pathogen evolution. This comprehensive approach will be crucial for developing more targeted and resilient crop protection strategies, ultimately contributing to global food security.

Could the transcription factor AtnN coordinating the aspercryptin secondary metabolite gene cluster in Aspergillus nidulans be a global regulator?

Products of dormant secondary metabolite gene clusters of fungal genomes can be exploited for medical purposes as bioactive agents. These clusters can be switched on under oxidative stress and may endow fungi with a versatile chemical armory in a competitive niche. In Aspergillus nidulans, the aspercryptin gene cluster, including the synthase [atnA (AN7884)] and its transcription factor (atnN), was activated under menadione sodium bisulfite (MSB) treatment. In this study, we generated and phenotypically examined the gene deletion and overexpression mutants of atnN and studied the secondary metabolite production of the mutants. Overexpression of atnN significantly reduced the colony growth of surface cultures compared to the control. The ΔatnN gene deletion strain showed higher sensitivity to tert-butyl hydroperoxide (tBOOH), while the atnNOE strain was more resistant to MSB, Congo Red, and sorbitol. Interestingly, deletion of atnN decreased cleistothecia formation of A. nidulans. Manipulation of atnN affected the synthesis of several secondary metabolites, for example, the siderophore production of A. nidulans. The extracellular triacetylfusarinine C (TAFC) production decreased, while the intracellular ferricrocin (FC) concentration of the cultures increased in the atnNOE mutant cultivating A. nidulans in a complex medium containing 1% mycological peptone and 2% maltose. In Czapek-Dox Broth medium, increased asperthecin production was observed in the ΔatnN mutant. The mycotoxin sterigmatocystin synthesis elevated in the ΔatnN mutant, while reduced in the atnNOE mutant on minimal medium. Our study supports previous observations that secondary metabolite production is coordinated in a complex way, and the linkage of stress response, sexual reproduction, and secondary metabolite production can be governed by several transcription factors.

Environmental Modulators on the Development of the Raccoon Roundworm (Baylisascaris procyonis): Effects of Temperature on the Embryogenesis

Members of the Ascarididae family are common zoonotic pathogens in humans and play an economic role in domestic and livestock animal husbandry. This family includes the obligatorily parasitic nematodes of the genus Baylisascaris, with the raccoon roundworm Baylisascaris procyonis being the most well-known representative. B. procyonis uses the raccoon (Procyon lotor) as its primary host and can utilize a broad range of mammals as paratenic hosts. Sexual reproduction of the adult nematodes occurs in the small intestine. Eggs are excreted into the environment through feces, where they develop into the infectious stage under suitable conditions within a few days to weeks. Infection of primary and paratenic hosts occurs through the oral ingestion of these infectious eggs. Raccoons can also become infected by ingesting infected paratenic hosts. Humans serve as accidental hosts and can suffer significant damage to organ tissues, the visual system, and the central nervous system after ingesting infectious eggs. The aim of the study was to investigate the effects of ambient temperature on embryonic development and to document the morphological changes during embryogenesis. Live specimens were collected from the raccoon intestine and incubated. Single-celled eggs were collected during this process. The eggs were decorticated and then preserved. To test the effects of ambient temperature, the eggs were incubated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 38°C and monitored at 24-hour intervals for their developmental stages. Detailed photographic documentation of the developmental stages was conducted. An increase in ambient temperature led to a reduction in development time. The temperature range within which embryogenesis proceeded to the L1 larval stage was between 10°C and 30°C. Incubation at 5°C did not produce L1 larvae even after 11 months. Incubation at 35°C and 38°C resulted in the complete degeneration of the eggs before reaching the L1 larval stage.

Exposure to Pseudomonas spp. increases Anopheles gambiae insecticide resistance in a host-dependent manner

The microbiota of mosquitoes influences many aspects of their biology, including developmental processes, mating and sexual reproduction, immune functions, and refractoriness to pathogens. Here, we considered their role in resistance against insecticides. In particular, we assessed how larval infection of a permethrin-resistant and a sensitive colony of Anopheles gambiae by four strains belonging to three different Pseudomonas species affects several life history traits and the impact of the insecticide on adult mortality. Our data showed that all four Pseudomonas strains persisted in adults until death. The bacteria increased the likelihood that mosquitoes survived 24 h after exposure to permethrin by up to twofold. The impact of the bacteria depended on the bacterial strains and the mosquito colony: in the resistant colony, all bacteria increased survival by about twofold, while in the sensitive colony, only two of the four strains increased survival. The benefit concerning insecticide resistance came with little to no impact on the other traits (i.e., larval mortality, developmental time and adult longevity). Altogether, our results highlight the importance of considering environmental microbial exposure and mosquito microbial communities in epidemiological and vector-control studies, while also suggesting a possible role for Pseudomonas spp. as a symbiont in A. gambiae.

Recombination landscape and karyotypic variations revealed by linkage mapping in the grapevine downy mildew pathogen Plasmopara viticola.

Plasmopara viticola, the causal agent of grapevine downy mildew, is a biotrophic oomycete engaged in a tight coevolutionary relationship with its host. Rapid adaptation of the pathogen is favored by annual sexual reproduction that generates genotypic diversity. With the aim of studying the recombination landscape across the P. viticola genome, we generated 2 half-sibling F1 progenies (N = 189 and 162). Using targeted SNP sequencing, between 1,405 and 1,894 markers were included in parental linkage maps, and a consensus map was obtained by integrating 4,509 markers. The reference genome could be assembled into 17 pseudochromosomes, anchoring 88% of its physical length. We observed a strong collinearity between parental genomes and extensive synteny with the downy mildew Peronospora effusa. In the consensus map, the median recombination rate was 13.8 cM/Mb. The local recombination rate was highly variable along chromosomes, and recombination was suppressed in putative centromeric regions. Recombination rate was found negatively correlated with repeats' coverage and positively correlated with gene coverage. However, genes encoding secreted proteins and putative effectors were underrepresented in highly recombining regions. In both progenies, about 5% of the individuals presented karyotypic anomalies. Aneuploidies and triploidies almost exclusively originated from the male-transmitted chromosomes. Triploids resulted from fertilization by diploid gametes, but also from dispermy. Obligatory sexual reproduction each year may explain the lower level of karyotypic variation in P. viticola compared to other oomycetes. The linkage maps will be useful to guide future de novo chromosome-scale assemblies of P. viticola genomes and to perform forward genetics.

Transcription factor-dependent regulatory networks of sexual reproduction in Fusarium graminearum.

Transcription factors (TFs) involved in sexual reproduction in filamentous fungi have been characterized. However, we have little understanding of how these TFs synergize within regulatory networks resulting in sexual development. We investigated 13 TFs in Fusarium graminearum, whose knockouts exhibited abortive or arrested phenotypes during sexual development to elucidate the transcriptional regulatory cascade underlying the development of the sexual fruiting bodies. A Bayesian network of the TFs was inferred based on transcriptomic data from key stages of sexual development. We evaluated in silico knockout impacts to the networks of the developmental phenotypes among the TFs and guided knockout transcriptomics experiments to properly assess regulatory roles of genes with same developmental phenotypes. Additional transcriptome data were collected for the TF knockouts guided by the stage at which their phenotypes appeared and by the cognate in silico prediction. Global TF networks revealed that TFs within the mating-type locus (MAT genes) trigger a transcriptional cascade involving TFs that affected early stages of sexual development. Notably, PNA1, whose knockout mutants produced exceptionally small protoperithecia, was shown to be an upstream activator for MAT genes and several TFs essential for ascospore production. In addition, knockout mutants of SUB1 produced excessive numbers of protoperithecia, wherein MAT genes and pheromone-related genes exhibited dysregulated expression. We conclude that PNA1 and SUB1 play central and suppressive roles in initiating sexual reproduction, respectively. This comprehensive investigation contributes to our understanding of the transcriptional framework governing the multicellular body plan during sexual reproduction in F. graminearum.IMPORTANCEUnderstanding transcriptional regulation of sexual development is crucial to the elucidation of the complex reproductive biology in Fusarium graminearum. We performed gene knockouts on 13 transcription factors (TFs), demonstrating knockout phenotypes affecting distinct stages of sexual development. Using transcriptomic data across stages of sexual development, we inferred a Bayesian network of these TFs that guided experiments to assess the robustness of gene interactions using a systems biology approach. We discovered that the mating-type locus (MAT genes) initiates a transcriptional cascade, with PNA1 identified as an upstream activator essential for early sexual development and ascospore production. Conversely, SUB1 was found to play a suppressive role, with knockout mutants exhibiting excessive protoperithecia due to abnormally high expression of MAT and pheromone-related genes. These findings highlight the central roles of PNA1 and SUB1 in regulating other gene activity related to sexual reproduction, contributing to a deeper understanding of the mechanisms of the multiple TFs that regulate sexual development.

A Comprehensive Review of Plant Based Extracts for Preventing and Controlling Candida albicans

A common fungal pathogen Candida albicans can cause infections ranging from simple mucosal infections to serious systemic illnesses especially in people with weakened immune systems. Normally found in the human microbiome it turns harmful when the immune system is weakened. Its dimorphism—the capacity to transition between hyphal, and yeast forms—is a primary factor contributing to its pathogenicity, and is essential for both tissue penetration, and dissemination. This transition is crucial for tissue invasion, biofilm formation, and dissemination within the host. The infection mechanism involves adhesion to host cells, biofilm formation, epithelial invasion, and bloodstream dissemination. Furthermore, Candida albicans may use different carbon sources to adapt metabolically increasing its survival in a variety of host environments. Recent study revealed that Candida albicans possesses a parasexual cycle that allows for genetic diversity without requiring sexual reproduction. Plant-based remedies have become viable substitutes for conventional pharmaceutical antifungals with benefits including a decreased chance of drug resistance, fewer side effects, and cheaper expenses. Plant extracts offer several advantages, including a reduced likelihood of resistance development, fewer adverse side effects, and lower treatment costs. In particular, herbal medicines are emerging as safer, more sustainable options for managing C. albicans infections. As a result, plant based treatments are becoming increasingly recognized for their role in supporting antifungal therapy and enhancing overall treatment efficacy. In treating Candida albicans infections, herbal medicine is becoming more and more recognized as a useful tool due to its ability to offer safer, and more sustainable treatments. This pathogen can severely reduce crop yield and quality, posing a significant threat to global food security and agricultural economies, particularly in regions where these crops are staples. This review as an attempt to study their potential to address some of the limitations of current antifungal therapies, such as toxicity and resistance against C. albicans makes them an important area of research.

Dual roles of pear EARLY FLOWERING 4 -like genes in regulating flowering and leaf senescence

BackgroundFlowering is a critical agronomic trait in fruit tree cultivation, essential for sexual reproduction and fruit yield. Circadian clock system, governing processes such as flowering, growth, and hormone signaling, plays a key role in plant adaptability. While some clock-related genes influencing pear flowering have been studied, the role of the PbELF4 (EARLY FLOWERING 4) family remains largely unexplored.ResultsIn this study, we identified five ELF4 homologous genes within the pear (Pyrus bretschneideri) genome. Phylogenetic analysis delineated two distinct groups within the PbELF4 genes, with PbELF4a and PbELF4b clustering with AtELF4. Expression profiling across various pear tissues revealed diverse expression patterns. Diurnal rhythms of PbELF4 genes were discernible in pear leaves, suggesting potential regulatory roles. Ectopic overexpression of PbELF4a and PbELF4b in Arabidopsis significantly delayed flowering and suppressed the expression of flowering-related genes. Additionally, PbELF4b overexpression induced premature leaf senescence, evidenced by reduced chlorophyll content and increased expression of senescence-associated genes. Nuclear localization of PbELF4a and PbELF4b proteins was observed, and interaction assays revealed that PbELF4a interacted with PbELF3α.ConclusionsThese findings underscore the conserved function of PbELF4a and PbELF4b as negative regulators of flowering time, with PbELF4b also demonstrating a positive role in leaf senescence.

Bioinformatics analysis of the Microsporidia sp. MB genome: a malaria transmission-blocking symbiont of the Anopheles arabiensis mosquito

BackgroundThe use of microsporidia as a disease-transmission-blocking tool has garnered significant attention. Microsporidia sp. MB, known for its ability to block malaria development in mosquitoes, is an optimal candidate for supplementing malaria vector control methods. This symbiont, found in Anopheles mosquitoes, can be transmitted both vertically and horizontally with minimal effects on its mosquito host. Its genome, recently sequenced from An. arabiensis, comprises a compact 5.9 Mbp.ResultsHere, we analyze the Microsporidia sp. MB genome, highlighting its major genomic features, gene content, and protein function. The genome contains 2247 genes, predominantly encoding enzymes. Unlike other members of the Enterocytozoonida group, Microsporidia sp. MB has retained most of the genes in the glycolytic pathway. Genes involved in RNA interference (RNAi) were also identified, suggesting a mechanism for host immune suppression. Importantly, meiosis-related genes (MRG) were detected, indicating potential for sexual reproduction in this organism. Comparative analyses revealed similarities with its closest relative, Vittaforma corneae, despite key differences in host interactions.ConclusionThis study provides an in-depth analysis of the newly sequenced Microsporidia sp. MB genome, uncovering its unique adaptations for intracellular parasitism, including retention of essential metabolic pathways and RNAi machinery. The identification of MRGs suggests the possibility of sexual reproduction, offering insights into the symbiont’s evolutionary strategies. Establishing a reference genome for Microsporidia sp. MB sets the foundation for future studies on its role in malaria transmission dynamics and host-parasite interactions.

Chemically induced proximity reveals a Piezo-dependent meiotic checkpoint at the oocyte nuclear envelope.

Sexual reproduction relies on robust quality control during meiosis. Assembly of the synaptonemal complex between homologous chromosomes (synapsis) regulates meiotic recombination and is crucial for accurate chromosome segregation in most eukaryotes. Synapsis defects can trigger cell cycle delays and, in some cases, apoptosis. We developed and deployed a chemically induced proximity system to identify key elements of this quality control pathway in Caenorhabditis elegans. Persistence of the polo-like kinase PLK-2 at pairing centers-specialized chromosome regions that interact with the nuclear envelope-induced apoptosis of oocytes in response to phosphorylation and destabilization of the nuclear lamina. Unexpectedly, the Piezo1/PEZO-1 channel localized to the nuclear envelope and was required to transduce this signal to promote apoptosis in maturing oocytes.

Romeo and Juliet: a forbidden love story? A review of hybridization in keystone, aquatic megafauna

Hybridization, understood here as the sexual reproduction between individuals of different species, is relatively common in riverine, estuarine, and marine environments. Investigating hybridization in wild populations of aquatic megafauna species provides important insight into their biology, evolution, and conservation. Here, we conducted an extensive and systematic review of published reports of hybrids in keystone, aquatic megafauna, aiming to provide a clear summary of state-of-the-art and hybridization trends in this group. We selected 129 journal articles reporting 80 hybrids in aquatic megafauna. We included mammals (40.3 %), turtles (33.3 %), crocodilians (17.8 %), and elasmobranchs (8.5 %) that are widely distributed in oceans and continental waters. Our results showed a clear increase in reports of hybrids involving aquatic megafauna in recent years, possibly reflecting the improvement in molecular techniques. However, this increase could also be a consequence of translocation of organisms and habitat modification by humans, and may have a critical impact on conservation, particularly regarding already depleted populations. Hybridization has directly or indirectly facilitated the extinction of many species, but it has also played a crucial role in the evolution and adaptation of many others. To determine whether hybridization is a natural effect or a collateral effect of anthropic pressures we need to understand its implications on the conservation of aquatic megafauna.

Molecular Insights into the Reproductive Patterns and Genetic Structure of Wheat Stripe Rust in Ili, Xinjiang.

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a globally significant fungal disease that seriously threatens wheat yield, particularly in China. This study investigates the genetic structure and reproductive patterns of Pst populations in Ili, Xinjiang, using 12 pairs of Simple Sequence Repeat (SSR) molecular markers. Analyses of 79 Pst isolates from either spring or winter wheat areas in Ili revealed three primary genetic clusters, indicating notable differences between populations associated with spring and winter wheat. The STRUCTURE results, complemented by UPGMA and PCoA analyses, highlight significant genetic diversity within these populations, with evidence of genetic recombination and sexual reproduction in certain areas. Pst populations in Ili exhibit a mixed mode of reproduction, predominantly sexual in Qapqal and Xinyuan D and primarily asexual within the spring wheat populations. The gene flow analysis underscores extensive inter-population communication, which facilitates the spread and adaptation of the pathogen across diverse wheat-growing environments. This study marks the first documentation of sexual reproduction in Pst within Xinjiang, providing new insights into its spread and genetic variation. These findings suggest that sexual reproduction may play a role in the regional adaptation and evolution of Pst, impacting future management strategies for wheat stripe rust in Xinjiang and potentially in broader Central Asian contexts.

Juvenile and total reproductive values for sexual reproduction under any genetic system

Abstract Reproductive value (RV) is the expected contribution of genes by an individual or class of individuals to the gene pool in the distant future, and it plays a crucial role in understanding adaptation in long-term evolution. Class RVs are linked to the genetic system and to life history: for diploid genetics, Grafen derived expressions for relative RVs of female and male juveniles, and for the absolute RVs of all females and of all males. Subsequently, Gardner presented a derivation for relative RVs of juvenile females and males under haplodiploidy. Here we generalise these results to any genetic system for biparental sexual reproduction, such that RV is explicitly linked to parameters of the genetic system and life history. The earlier results by Grafen and Gardner arise as special cases. Finally, we derive expressions for absolute juvenile and total reproductive values of both sexes under any genetic system.

Variation in reproductive organ functionality among a population of tomato genotypes reveals the importance of pollen viability and fruit set in response to heat stress

ABSTRACT High temperature limit crop productivity as a consequence of global warming and climate change. In particular, high temperature interferes with sexual reproduction and thus fruit and seed formation in crops. In the present study, phenotypic evaluation of a tomato population, including 21 tomato genotypes, was carried out under high-temperature stress (35°C). Several reproductive and yield-related traits, including the number of inflorescences, number of flowers per inflorescence, pollen viability, fruit set, number of fruits per plant, and number of fruits per inflorescence, were investigated. Significant positive correlations between pollen viability and fruit set were observed (r = 0.83). Based on the obtained findings, the fruit set, pollen viability, number of fruits per plant, and number of fruits per inflorescence were recognized as markers for heat tolerance screening of tomato genotypes. These traits effectively separate tolerant and sensitive genotypes, which can be used in breeding program. At the same time, the number of inflorescences and the number of flowers per inflorescence did not separate between tolerant and sensitive genotypes. In conclusion, heat stress, through influencing pollen viability and fertilization, imposes its effects on reproductive organ development in tomato genotypes.

A review of potential biological controls for Ailanthus altissima

Abstract Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) (tree-of-heaven) is an invasive tree species first introduced to the United States in 1784. With high rates of sexual reproduction, rapid growth, and prolific vegetative sprouting, A. altissima is an aggressive competitor that reduces native plant diversity and is difficult to manage beyond small-scale infestations. In the United States, the issues associated with Ailanthus management were compounded by the 2014 arrival of Lycorma delicatula (spotted lanternfly). Lycorma delicatula coevolved with A. altissima, its primary host, in eastern Asia. Suppression of A. altissima is recommended as an important strategy to slow the spread of L. delicatula. Due to the inadequacy of traditional control methods to manage A. altissima, biological controls are desired. Several potential biological control agents have been proposed for A. altissima. This review discusses current research on several promising candidates, specifically a native fungus, Verticillium nonalfalfae Inderb. et al. (Hypocreales: Plectosphaerellaceae); a trunk-boring beetle, Eucryptorrhynchus brandti (Harold) (Coleoptera: Curculionidae: Cryptorrhynchinae); and an eriophyid mite, Aculops ailanthi (Lin-Fuping, Jin-Changle & Kuang-Haiya) (Arachnida: Eriphyidae). A list of other possible biological control agents is also provided. We discuss unanswered questions for each species, the limits of biological controls in this system, and call for further research on integrated pest management practices for managing A. altissima.

A Single‐Cell Atlas of Crab Ovary Provides New Insights Into Oogenesis in Crustaceans

AbstractOogenesis is crucial for sexual reproduction and provides the material basis for population continuation. Nonetheless, the identity of the cells involved, the nature of transformation, and underlying regulators of oogenesis in crustaceans remain elusive. Here, an atlas of the ovary is plotted via single‐nuclei RNA sequencing (snRNA‐seq) in the mud crab Scylla paramamosain, resulting in five cell types, including germ cells, somatic cells, and three follicle cell types identified, which in turn provides abundant candidate markers for them. Moreover, profiles of ligand‐receptor in different cells of the crab ovary indicate the roles of cell communication in oogenesis. Dozens of transcription factors in the trajectory from oogonia to oocytes as well as the key molecules/pathways in somatic cells and follicle cells relevant to oogenesis are screened, which is evolutionarily conserved and its underlying regulatory mechanism is subject to some modification across various phyla. The spatiotemporal expression patterns of seven markers are further verified and the RNAi confirms the essential roles of piwi and VgR in oogenesis. These data help to elucidate the mechanism underlying gametogenesis and the evolution of reproductive strategy in invertebrates.

Indirect effects of warming via phenology on reproductive success of alpine plants

Abstract Climate warming has induced pronounced shifts in the phenology of alpine plants worldwide, yet the impact of these changes on plant reproduction remains unclear, although phenology plays a vital role in reproduction. Based on a 7‐year field warming and altered precipitation experiment initiated in 2017, we measured three reproductive phenological events and seven reproductive traits of six dominant species, belonging to two flowering functional groups, to assess the effects of climate change on reproductive phenology and the reproductive consequence of changing the phenology in an alpine meadow on the eastern Tibetan Plateau from 2021 to 2023. Warming significantly advanced the start of flowering in early‐spring flowering (ESF) and mid‐summer flowering (MSF) plants, while the fruiting period of ESF plants remained stable. Furthermore, warming led to a decrease in the number of seeds and productivity of alpine plants, while seed size remained stable. Phenological changes regulate the reproductive success of alpine plants. Specifically, the start of flowering for ESF plants and the start of fruiting for MSF plants regulated the number of seeds and productivity of the two flowering functional groups, respectively. The increase in phenological niche overlap and intensification of interspecific competition, caused by different phenological responses of the flowering functional groups to warming, also are key factors contributing to the decline in seed production of alpine plants. Synthesis. These results demonstrate that the reproductive success of alpine plants would be decreased by earlier reproduction under climate warming, and alpine plants tend to maintain stable seed size in response to climate change. Our study emphasizes the important regulatory and indicative role of reproductive phenology in the sexual reproduction of alpine plants under future climate change.

Seed set by artificial pollination and seed storage under cryogenic, freezer and dry conditions in the medicinal plant Uncaria rhynchophylla

Abstract Uncaria rhynchophylla (Rubiaceae), a woody liana with significant medicinal value, has been used as a traditional Japanese and Chinese medicine. While effective seed production is required for breeding and efficient seedling production, the physiology of sexual reproduction remains largely unknown in this species. Therefore, we first observed the flowering behaviour, and next attempted artificial pollination using flowering individuals in a greenhouse. In this study it became clear that this species sets seeds by allogamy, but not by autogamy. The obtained seeds showed about a 90% germination rate. We also examined seed desiccation tolerance and storage conditions which are important to preserve the genetic resources. Seeds of this species were found to have a characteristic of the orthodox type, having high desiccation tolerance. Seeds after 6 months of storage at + 22, −20 and −160°C showed comparable germination rates to the seeds before storage.