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International Journal of Reproductive... May 2023Parthenogenesis (PG) is a rare phenomenon occurring in humans, and understanding this may help us develop an explanation for such occurrences. Moreover, it may help... (Review)
Review
Parthenogenesis (PG) is a rare phenomenon occurring in humans, and understanding this may help us develop an explanation for such occurrences. Moreover, it may help reveal the cause of idiopathic ovarian teratoma (OT). We aim to explain the occurrence of PG and OT in humans based on a new hypothesis. Previous literature has been searched through relevant scientific websites and international journals on the causes and mechanisms of PG and OT in humans. The previous literature on human PG was sparse and mostly contained case reports. It appears that human PG is not as rare as previously reported but may occur spontaneously, resulting in OT formation. The difference between PG and sexual reproduction is that PG has no embryonic diversity. The biopsied embryonic samples in the PG correspond exclusively to those of the maternal side. Spontaneous PG in humans often degrades or leads to formation of OT. The cause and mechanism of spontaneous PG remain unclear in the available literature. Here, we hypothesized that in some cases the secondary oocyte and first polar body enclosed in the zona pellucida may fuse together to form a single cell that restores the diploid number of chromosomes and initiates cell division to form PG. It may go unnoticed or be represented by the OT. Future studies are recommended to investigate this hypothesis.
PubMed: 37260553
DOI: 10.18502/ijrm.v21i4.13267 -
TAG. Theoretical and Applied Genetics.... May 2023Apomixis is an asexual mode of reproduction through seeds where progeny are clones of the mother plants. Naturally apomictic modes of reproduction are found in hundreds... (Review)
Review
Apomixis is an asexual mode of reproduction through seeds where progeny are clones of the mother plants. Naturally apomictic modes of reproduction are found in hundreds of plant genera distributed across more than 30 plant families, but are absent in major crop plants. Apomixis has the potential to be a breakthrough technology by allowing the propagation through seed of any genotype, including F1 hybrids. Here, we have summarized the recent progress toward synthetic apomixis, where combining targeted modifications of both the meiosis and fertilization processes leads to the production of clonal seeds at high frequencies. Despite some remaining challenges, the technology has approached a level of maturity that allows its consideration for application in the field.
Topics: Apomixis; Crops, Agricultural; Seeds; Reproduction; Genotype
PubMed: 37199785
DOI: 10.1007/s00122-023-04357-3 -
BMC Genomics May 2023The genus Daphnia switches its reproductive mode from subitaneous egg production to resting egg production in response to environmental stimuli. Although this life...
BACKGROUND
The genus Daphnia switches its reproductive mode from subitaneous egg production to resting egg production in response to environmental stimuli. Although this life history trait is essential for surviving unsuitable environments, the molecular mechanism of resting egg production is little understood. In this study, we examined genes related to induction of resting egg production using two genotypes of panarctic Daphnia pulex, the JPN1 and JPN2 lineages, which differ genetically in the frequency of resting egg production. We reared these genotypes under high and low food levels. At the high food level, individuals of both genotypes continually produced subitaneous eggs, whereas at the low food level, only the JPN2 genotype produced resting eggs. Then, we performed RNA-seq analysis on specimens of three instars, including before and after egg production.
RESULTS
These results showed that expressed genes differed significantly between individuals grown under high and low food levels and among individuals of different instars and genotypes. Among these differentially expressed genes (DEGs), we found 16 that changed expression level before resting egg production. Some of these genes showed high-level expression only before resting egg production and one gene was an ortholog of bubblegum (bgm), which is reportedly up-regulated before diapause in bumblebees. According to gene ontology (GO) enrichment analysis, one GO term annotated as long-chain fatty acid biosynthetic process was enriched among these 16 genes. In addition, GO terms related to glycometabolism were enriched among down-regulated genes of individuals holding resting eggs, compared to those before resting egg production.
CONCLUSIONS
We found candidate genes highly expressed only before resting egg production. Although functions of candidate genes found in this study have not been reported previously in Daphnia, catabolism of long-chain fatty acids and metabolism of glycerates are related to diapause in other organisms. Thus, it is highly probable that candidate genes identified in this study are related to the molecular mechanism regulating resting egg production in Daphnia.
Topics: Animals; Daphnia; Reproduction; Genotype; Sequence Analysis, RNA; Daphnia pulex
PubMed: 37198540
DOI: 10.1186/s12864-023-09369-3 -
Biomolecules Mar 2023In bacteria, polymers of inorganic phosphates, particularly linear polyphosphate, are used as alternative phosphate donors for adenosine triphosphate production. A...
In bacteria, polymers of inorganic phosphates, particularly linear polyphosphate, are used as alternative phosphate donors for adenosine triphosphate production. A six-chain form of sodium metaphosphate, sodium hexametaphosphate (SHMP), is believed to have no physiological functions in mammalian cells. In this study, we explored the possible effects of SHMP on mammalian cells, using mouse oocytes, which are useful for observing various spatiotemporal intracellular changes. Fertilization-competent oocytes were isolated from the oviducts of superovulated mice and cultured in an SHMP-containing medium. In the absence of co-incubation with sperm, SHMP-treated oocytes frequently formed pronuclei and developed into two-cell embryos owing to the increase in calcium concentration in the cytoplasm. We discovered an intriguing role for SHMP as an initiator of calcium rise in mouse oocytes, presumably in a wide variety of mammalian cells.
Topics: Male; Animals; Mice; Calcium; Calcium Signaling; Semen; Polyphosphates; Mammals
PubMed: 37189325
DOI: 10.3390/biom13040577 -
International Journal of Molecular... May 2023has been shown to induce thelytokous parthenogenesis in species, which have been widely used as biological control agents around the world. Little is known about the...
has been shown to induce thelytokous parthenogenesis in species, which have been widely used as biological control agents around the world. Little is known about the changes of bacterial community after restoring arrhenotokous or bisexual reproduction in the . Here, we investigate the emergence of males of through curing experiments (antibiotics and high temperature), crossing experiments, and high-throughput 16S ribosomal RNA sequencing (rRNA-seq). The results of curing experiments showed that both antibiotics and high temperatures could cause the thelytokous to produce male offspring. was dominant in the thelytokous bacterial community with 99.01% relative abundance. With the relative abundance of being depleted by antibiotics, the diversity and relative content of other endosymbiotic bacteria increased, and the reproductive mode reverted from thelytoky to arrhenotoky in . Although antibiotics did not eliminate in , sulfadiazine showed an advantage in restoring entirely arrhenotokous and successive bisexual reproduction. This study was the first to demonstrate the bacterial communities in parthenogenetic before and after antibiotics or high-temperature treatment. Our findings supported the hypothesis that titer-dependence drives a reproduction switch in between thelytoky and arrhenotoky.
Topics: Animals; Male; Hymenoptera; Anti-Bacterial Agents; Temperature; Wolbachia; Parthenogenesis; Wasps
PubMed: 37176154
DOI: 10.3390/ijms24098448 -
Journal of Experimental Botany Aug 2023Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In... (Review)
Review
Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In sexually-reproducing flowering plants, it generally develops after fertilization. However, autonomous endosperm (AE) formation (i.e. independent of fertilization) is also possible. Recent findings of AE loci/ genes and aberrant imprinting in native apomicts, together with a successful initiation of parthenogenesis in rice and lettuce, have enhanced our understanding of the mechanisms bridging sexual and apomictic seed formation. However, the mechanisms driving AE development are not well understood. This review presents novel aspects related to AE development in sexual and asexual plants underlying stress conditions as the primary trigger for AE. Both application of hormones to unfertilized ovules and mutations that impair epigenetic regulation lead to AE development in sexual Arabidopsis thaliana, which may point to a common pathway for both phenomena. Apomictic-like AE development under experimental conditions can take place due to auxin-dependent gene expression and/or DNA methylation.
Topics: Humans; Endosperm; Epigenesis, Genetic; Asteraceae; Seeds; Reproduction; Arabidopsis
PubMed: 37155961
DOI: 10.1093/jxb/erad168 -
Genes Apr 2023The genus Mill. (sea lavenders) includes species with sexual and apomixis reproductive strategies, although the genes involved in these processes are unknown. To...
The genus Mill. (sea lavenders) includes species with sexual and apomixis reproductive strategies, although the genes involved in these processes are unknown. To explore the mechanisms beyond these reproduction modes, transcriptome profiling of sexual, male sterile, and facultative apomictic species was carried out using ovules from different developmental stages. In total, 15,166 unigenes were found to be differentially expressed with apomictic vs. sexual reproduction, of which 4275 were uniquely annotated using an database, with different regulations according to each stage and/or species compared. Gene ontology (GO) enrichment analysis indicated that genes related to tubulin, actin, the ubiquitin degradation process, reactive oxygen species scavenging, hormone signaling such as the ethylene signaling pathway and gibberellic acid-dependent signal, and transcription factors were found among differentially expressed genes (DEGs) between apomictic and sexual plants. We found that 24% of uniquely annotated DEGs were likely to be implicated in flower development, male sterility, pollen formation, pollen-stigma interactions, and pollen tube formation. The present study identifies candidate genes that are highly associated with distinct reproductive modes and sheds light on the molecular mechanisms of apomixis expression in sp.
Topics: Apomixis; Plumbaginaceae; Ovule; Gene Expression Profiling; Reproduction; Arabidopsis
PubMed: 37107659
DOI: 10.3390/genes14040901 -
Current Biology : CB Apr 2023Wang and Underwood introduce apomixis in plants.
Wang and Underwood introduce apomixis in plants.
Topics: Apomixis; Plants; Seeds
PubMed: 37098328
DOI: 10.1016/j.cub.2023.01.051 -
Current Zoology Apr 2023Despite numerous works devoted to hybrid origin of parthenogenesis in reptiles, the causes of hybridization between different species, resulting in the origin of... (Review)
Review
Despite numerous works devoted to hybrid origin of parthenogenesis in reptiles, the causes of hybridization between different species, resulting in the origin of parthenogenetic forms, remain uncertain. Recent studies demonstrate that sexual species considered parental to parthenogenetic rock lizards ( spp.) avoid interspecific mating in the secondary overlap areas. A specific combination of environmental factors during last glaciation period was critical for ectotherms, which led to a change in their distribution and sex ratio. Biased population structure (e.g., male bias) and limited available distributional range favored the deviation of reproductive behavior when species switched to interspecific mates. To date, at least 7 diploid parthenogenetic species of rock lizards (, Lacertidae) originated through interspecific hybridization in the past. The cytogenetic specifics of meiosis, in particular the weak checkpoints of prophase I, may have allowed the formation of hybrid karyotypes in rock lizards. Hybridization and polyploidization are 2 important evolutionary forces in the genus . At present, throughout backcrossing between parthenogenetic and parental species, the triploid and tetraploid hybrid individuals appear annually, but no triploid species found among spp. on current stage of evolution. The speciation by hybridization with the long-term stage of diploid parthenogenetic species, non-distorted meiosis, together with the high ecological plasticity of Caucasian rock lizards provide us with a new model for considering the pathways and persistence of the evolution of parthenogenesis in vertebrates.
PubMed: 37091994
DOI: 10.1093/cz/zoac036 -
Animals : An Open Access Journal From... Mar 2023This study evaluated the effect of various growth factors and hormones in an in vitro growth (IVG) medium on the in vitro maturation (IVM) and developmental competence...
This study evaluated the effect of various growth factors and hormones in an in vitro growth (IVG) medium on the in vitro maturation (IVM) and developmental competence of oocytes derived from small antral follicles (SAFs) in pigs. Cumulus-oocyte complexes (COCs) derived from SAFs were either untreated or treated with epidermal growth factor (EGF), insulin-like factor-1 (IGF-1), insulin, or growth hormone (GH) for 2 days of IVG. Following IVG, COCs were cultured for maturation, and IVM oocytes were induced for parthenogenesis (PA). During IVG, the nuclear maturation of oocytes was significantly increased by the insulin treatment compared to other treatments. Moreover, the insulin treatment significantly increased blastocyst formation after PA relative to the No-IVG, control, EGF, and GH treatments. The cumulus expansion score after IVG-IVM was significantly higher in the insulin group than in the other groups. The glutathione (GSH) contents in IVM oocytes were increased through treatment with IGF, insulin, and GH compared to those of No-IVG oocytes. The level of reactive oxygen species (ROS) in IVM oocytes in all treatment groups was significantly lower after IVG culture than in the No-IVG group. The maturation-promoting factor (MPF) activity after IVM in the insulin-treated oocytes was significantly higher than that of the oocytes treated with EGF, IGF-1, and GH. In conclusion, this study demonstrates that insulin treatment during IVG culture improves the maturational and developmental competence of oocytes derived from SAFs in pigs through its effect on cumulus cell expansion and cytoplasmic microenvironments, such as GSH, ROS, and MPF activity.
PubMed: 37048462
DOI: 10.3390/ani13071206