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Zygote (Cambridge, England) Dec 2023Klotho is a protein that plays different functions in female fertility. We have previously reported that klotho protein supplementation during maturation improves...
Klotho is a protein that plays different functions in female fertility. We have previously reported that klotho protein supplementation during maturation improves porcine embryo development, while klotho knockout for somatic cell cloning completely blocks full-term pregnancy . However, the effects of the microinjection of klotho protein or klotho knockdown dual vector in porcine embryos at different time points and the specific molecular mechanisms remain largely unknown. In this study, we injected the preassembled cas9 + sgRNA dual vector, for klotho knockdown, into the cytoplasm of the germinal vesicle stage of oocytes and into porcine embryos after 6-h parthenogenetic activation. Similarly, the klotho protein was inserted into the cytoplasm of germinal vesicle stage oocytes and porcine embryos after 6-h parthenogenetic activation. Compared with the controls, the microinjection of klotho dual vector markedly decreased the blastocyst formation rates in germinal vesicle stage oocytes and activated embryos. However, the efficiency of blastocyst formation when klotho protein was inserted before maturation was significantly higher than that after klotho protein insertion into parthenogenetically activated embryos. These results indicated that klotho knockdown may impair embryo development into blastocyst irrespective of injection timing. In addition, klotho protein injection timing in pig embryos may be an important factor for regulating embryo development.
Topics: Pregnancy; Animals; Female; Swine; RNA, Guide, CRISPR-Cas Systems; Oocytes; Blastocyst; Embryonic Development; Parthenogenesis
PubMed: 37905414
DOI: 10.1017/S096719942300045X -
Heredity Feb 2024From concatenated chromosomes to polyploidization, large-scale genome changes are known to occur in parthenogenetic animals. Here, we report mosaic aneuploidy in larval...
From concatenated chromosomes to polyploidization, large-scale genome changes are known to occur in parthenogenetic animals. Here, we report mosaic aneuploidy in larval brains of facultatively parthenogenetic Drosophila. We identified a background of aneuploidy in D. mercatorum strains and found increased levels of aneuploidy in the larval brain tissue of animals arising parthenogenetically versus those arising from sexual reproduction. There is also intra-individual variation in germline-derived aneuploidy within the same strain. To determine if this is a general feature of facultative parthenogenesis in drosophilids, we compared sexually reproduced and parthenogenetic offspring from an engineered facultative parthenogenetic strain of D. melanogaster. In addition to germline-derived aneuploidy, this revealed somatic aneuploidy that increased by up to fourfold in parthenogens compared to sexually reproduced offspring. Therefore, the genetic combination identified in D. mercatorum that causes facultative parthenogenesis in D. melanogaster results in aneuploidy, which indicates that the loss of mitotic control resulting in parthenogenesis causes subsequent genome variation within the parthenogenetic offspring. Our findings challenge the assumption that parthenogenetic offspring are near genetic replicas of their mothers.
Topics: Animals; Drosophila; Drosophila melanogaster; Reproduction; Sexual Behavior, Animal; Parthenogenesis
PubMed: 38017115
DOI: 10.1038/s41437-023-00664-z -
The New Phytologist Mar 2024In planta haploid induction (HI), which reduces the chromosome number in the progeny after fertilization, has garnered increasing attention for its significant potential... (Review)
Review
In planta haploid induction (HI), which reduces the chromosome number in the progeny after fertilization, has garnered increasing attention for its significant potential in crop breeding and genetic research. Despite the identification of several natural and synthetic HI systems in different plant species, the molecular and cellular mechanisms underlying these HI systems remain largely unknown. This review synthesizes the current understanding of HI systems in plants (with a focus on genes and molecular mechanisms involved), including the molecular and cellular interactions which orchestrate the HI process. As most HI systems can function across taxonomic boundaries, we particularly discuss the evidence for conserved mechanisms underlying the process. These include mechanisms involved in preserving chromosomal integrity, centromere function, gamete communication and/or fusion, and maintenance of karyogamy. While significant discoveries and advances on haploid inducer systems have arisen over the past decades, we underscore gaps in understanding and deliberate on directions for further research for a more comprehensive understanding of in vivo HI processes in plants.
Topics: Haploidy; Plant Breeding; Plants; Centromere
PubMed: 38180262
DOI: 10.1111/nph.19523 -
Studies in Health Technology and... Nov 2023The growth and development of early mammalian embryos mainly take place in the fallopian tube, which not only provides nutrients for embryonic growth and development but...
The growth and development of early mammalian embryos mainly take place in the fallopian tube, which not only provides nutrients for embryonic growth and development but also offers suitable mechanical conditions. The embryo culture system established in assisted reproductive technology mainly simulates the environment in which oocytes and embryos grow and develop in vivo. However, current in vitro embryo culture is mainly static and cannot completely mimic the mechanical environment in which embryos grow and develop in vivo. Therefore, to more accurately simulate the mechanical environment of embryos in the fallopian tube, we have developed a dynamic culture device to investigate the effects of mechanical stimulation on the in vitro maturation of immature oocytes and their parthenogenetic developmental potential. Immature mice oocytes were subjected to in vitro maturation by static culture and vibration (3 Hz, 6 Hz) with tilting for 15∼16 hours. The maturation of oocytes was observed after the culture period. The mature oocytes were activated by parthenogenesis and the rate of embryo compaction and formation of parthenogenetic blastocysts was analyzed. The results showed that using 3 Hz vibration and tilting can significantly improve the parthenogenetic development potential of immature mice oocytes.
Topics: Female; Animals; Mice; Vibration; Embryonic Development; Parthenogenesis; Oocytes; Blastocyst; Mammals
PubMed: 38007729
DOI: 10.3233/SHTI230828 -
Proceedings. Biological Sciences Sep 2023Obligately parthenogenetic species are expected to be short lived since the lack of sex and recombination should translate into a slower adaptation rate and increased...
Obligately parthenogenetic species are expected to be short lived since the lack of sex and recombination should translate into a slower adaptation rate and increased accumulation of deleterious alleles. Some, however, are thought to have been reproducing without males for millions of years. It is not clear how these old parthenogens can escape the predicted long-term costs of parthenogenesis, but an obvious explanation is cryptic sex. In this study, we screen for signatures of cryptic sex in eight populations of four parthenogenetic species of stick insects, some estimated to be older than 1 Myr. Low genotype diversity, homozygosity of individuals and high linkage disequilibrium (LD) unaffected by marker distances support exclusively parthenogenetic reproduction in six populations. However, in two populations (namely, of the species and ) we find strong evidence for cryptic sex, most likely mediated by rare males. These populations had comparatively high genotype diversities, lower LD, and a clear LD decay with genetic distance. Rare sex in species that are otherwise largely parthenogenetic could help explain the unusual success of parthenogenesis in the genus and raises the question whether episodes of rare sex are in fact the simplest explanation for the persistence of many old parthenogens in nature.
Topics: Humans; Male; Animals; Female; Alleles; Genotype; Linkage Disequilibrium; Parthenogenesis; Insecta
PubMed: 37727092
DOI: 10.1098/rspb.2023.0404 -
Biomolecules May 2024Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop's biology, mostly the genetic... (Review)
Review
Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop's biology, mostly the genetic heterozygosity of autotetraploid cultivars and the intricacies of the reproductive system. Novel site-directed genetic modification techniques provide opportunities for designing climate-smart cultivars, but they also pose new possibilities (and challenges) for breeding potato. As potato species show a remarkable reproductive diversity, and their ovules have a propensity to develop apomixis-like phenotypes, tinkering with reproductive genes in potato is opening new frontiers in potato breeding. Developing diploid varieties instead of tetraploid ones has been proposed as an alternative way to fill the gap in genetic gain, that is being achieved by using gene-edited self-compatible genotypes and inbred lines to exploit hybrid seed technology. In a similar way, modulating the formation of unreduced gametes and synthesizing apomixis in diploid or tetraploid potatoes may help to reinforce the transition to a diploid hybrid crop or enhance introgression schemes and fix highly heterozygous genotypes in tetraploid varieties. In any case, the induction of apomixis-like phenotypes will shorten the time and costs of developing new varieties by allowing the multi-generational propagation through true seeds. In this review, we summarize the current knowledge on potato reproductive phenotypes and underlying genes, discuss the advantages and disadvantages of using potato's natural variability to modulate reproductive steps during seed formation, and consider strategies to synthesize apomixis. However, before we can fully modulate the reproductive phenotypes, we need to understand the genetic basis of such diversity. Finally, we visualize an active, central role for genebanks in this endeavor by phenotyping properly genotyped genebank accessions and new introductions to provide scientists and breeders with reliable data and resources for developing innovations to exploit market opportunities.
Topics: Solanum tuberosum; Plant Breeding; Apomixis; Reproduction; Genes, Plant; Phenotype; Tetraploidy; Genotype
PubMed: 38927018
DOI: 10.3390/biom14060614 -
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 -
Current Biology : CB Feb 2024Brown algae are the only group of heterokont protists exhibiting complex multicellularity. Since their origin, brown algae have adapted to various marine habitats,...
Brown algae are the only group of heterokont protists exhibiting complex multicellularity. Since their origin, brown algae have adapted to various marine habitats, evolving diverse thallus morphologies and gamete types. However, the evolutionary processes behind these transitions remain unclear due to a lack of a robust phylogenetic framework and problems with time estimation. To address these issues, we employed plastid genome data from 138 species, including heterokont algae, red algae, and other red-derived algae. Based on a robust phylogeny and new interpretations of algal fossils, we estimated the geological times for brown algal origin and diversification. The results reveal that brown algae first evolved true multicellularity, with plasmodesmata and reproductive cell differentiation, during the late Ordovician Period (ca. 450 Ma), coinciding with a major diversification of marine fauna (the Great Ordovician Biodiversification Event) and a proliferation of multicellular green algae. Despite its early Paleozoic origin, the diversification of major orders within this brown algal clade accelerated only during the Mesozoic Era, coincident with both Pangea rifting and the diversification of other heterokont algae (e.g., diatoms), coccolithophores, and dinoflagellates, with their red algal-derived plastids. The transition from ancestral isogamy to oogamy was followed by three simultaneous reappearances of isogamy during the Cretaceous Period. These are concordant with a positive character correlation between parthenogenesis and isogamy. Our new brown algal timeline, combined with a knowledge of past environmental conditions, shed new light on brown algal diversification and the intertwined evolution of multicellularity and sexual reproduction.
Topics: Phylogeny; Eukaryota; Plants; Rhodophyta; Plastids; Phaeophyceae; Evolution, Molecular
PubMed: 38262417
DOI: 10.1016/j.cub.2023.12.069 -
Reproduction in Domestic Animals =... Apr 2024Mangiferin (MGN) is primarily found in the fruits, leaves, and bark of plants of the Anacardiaceae family, including mangoes. MGN exhibits various pharmacological...
Mangiferin (MGN) is primarily found in the fruits, leaves, and bark of plants of the Anacardiaceae family, including mangoes. MGN exhibits various pharmacological effects, such as protection of the liver and gallbladder, anti-lipid peroxidation, and cancer prevention. This study aimed to investigate the effects of MGN supplementation during in vitro culture (IVC) on the antioxidant capacity of early porcine embryos and the underlying mechanisms involved. Porcine parthenotes in the IVC medium were exposed to different concentrations of MGN (0, 0.01, 0.1, and 1 μM). The addition of 0.1 μM MGN significantly increased the blastocyst formation rate of porcine embryos while reducing the apoptotic index and autophagy. Furthermore, the expression of antioxidation-related (SOD2, GPX1, NRF2, UCHL1), cell pluripotency (SOX2, NANOG), and mitochondria-related (TFAM, PGC1α) genes was upregulated. In contrast, the expression of apoptosis-related (CAS3, BAX) and autophagy-related (LC3B, ATG5) genes decreased after MGN supplementation. These findings suggest that MGN improves early porcine embryonic development by reducing oxidative stress-related genes.
Topics: Animals; Oxidative Stress; Embryonic Development; Xanthones; Embryo Culture Techniques; Apoptosis; Antioxidants; Autophagy; Swine; Blastocyst; Female; Gene Expression Regulation, Developmental; Parthenogenesis
PubMed: 38646981
DOI: 10.1111/rda.14565 -
Molecular Plant Jan 2024
Topics: Apomixis; Crops, Agricultural; Seeds
PubMed: 38105558
DOI: 10.1016/j.molp.2023.12.010