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Plant Disease Apr 2024Hylocereus megalanthus (family Cactaceae), commonly known as bird's nest fruit (Yanwo fruit), was a new tropical plant cultivated commercially in south China because of...
Hylocereus megalanthus (family Cactaceae), commonly known as bird's nest fruit (Yanwo fruit), was a new tropical plant cultivated commercially in south China because of its high nutritional content and sweet taste. In August 2023, damping-off disease of approximately 60% of seedlings was observed at a nursery in Zhanjiang, Guangdong Province (E110°17'46″ N21°9'2″). Stems of infected seedlings exhibited symptoms of water-soaked tissue which caused collapse at the base of the stem and sloughing of necrotic root cortex tissue was observed (Figure 1). White aerial mycelia were visible on the surface of the stem and soil at a high relative humidity. Diseased tissues about 0.5 cm2 were taken from the infected roots and stems, surface disinfected with 75% ethanol and 3% hydrogen peroxide solution, each for 1 min, subsequently rinsed in sterile water, and placed on potato dextrose agar (PDA). Plates were incubated at 25 to 28℃ in the dark for 3 days. Coenocytic hyphae grew from all infected roots and stems. Hyphal tip transfers were completed twice, and twelve isolates with the same morphological characteristics were obtained. The colony growth on PDA was ample. Main hyphae are up to 9.5 µm wide. Sporangia were terminal, inflated, branched or unbranched. Encysted zoospores were 7.5 µm in diameter. Oogonia were terminal, globose, smooth and of 16.8 to 27.4 µm (average 21.5 µm) diameter. Oospores were typically spherical, thick-walled, yellowish, 19.7 to 26.3 µm (average 21.1 µm) diameter, wall 1 to 2 µm thick. Antheridia were mostly intercalary, sometimes terminal, broadly sac-shaped, 15.0×19.0 µm (Figure 2). The morphological features were very similar to those of Pythium spp. (Toporek and Keinath 2021). For further identification, the LSU and ITS regions of isolate CCAS-YWGCD (stored in Agricultural Culture Collection of China, ACCC 35633) were amplified and sequenced with using primer pairs LROR/LR7 and ITS1/ITS4, respectively (Gao et al. 2017; White et al. 1990). The resulting sequences were deposited in GenBank (ITS: OR775664; LSU: OR775667). BLASTn results showed 100% sequence similarity with reference sequences of Pythium aphanidermatum (AY598622 for ITS and HQ665084 for LSU). Phylogenetic tree generated from maximum likelihood analysis based on combined LSU and ITS sequence data with MEGA 10.1.8, clustered the oomycete in P. aphanidermatum clade with 100% bootstrap support (Figure 3). Therefore, the oomycete was identified as P. aphanidermatum. To confirm Koch's postulates, six three-month-old seedlings of H. megalanthus (height about 15 cm) were transplanted to 15 cm pots. Six-mm-diameter mycelial plugs obtained from 7-day-old cultures at 25℃ in the dark were buried adjacent to the stem of three unwounded healthy seedlings. Another three seedlings inoculated with PDA agar served as controls. The plants were covered with plastic bags, kept at about 30℃, and watered regularly to keep the soil moisture content high. All inoculated seedlings exhibited symptoms of stems rot and damping-off, Symptoms did not develop on the control seedlings. P. aphanidermatum by morphological and molecular analysis was reisolated from the stems. P. aphanidermatum had been reported worldwide causing disease in many agricultural crops (Qi et al. 2021; Kim et al. 2020), but this is the first report causing damping-off of H. megalanthus seedling in China as well as worldwide, and this disease should be monitored in nursery seedlings.
PubMed: 38654536
DOI: 10.1094/PDIS-01-24-0204-PDN -
Fungal Systematics and Evolution Dec 2022During a survey of gardens in Shiraz County, Iran, aimed at identifying oomycetes associated with roots of ornamental trees, a species of with distinctive morphological...
During a survey of gardens in Shiraz County, Iran, aimed at identifying oomycetes associated with roots of ornamental trees, a species of with distinctive morphological characters separating it from other known species in this genus was recovered from conifers and occasionally from a sp. Five isolates of this species were characterised. Phylogenetic analyses of nuclear (ITS and ) and mitochondrial ( and ) loci using Bayesian inference and maximum likelihood analyses as well as their distinct morphological and cultural characteristics ( abundant production of chlamydospores; globose, ellipsoid to ovoid sporangia; amorphous oogonia with a smooth wall; paragynous to rarely hypogynous antheridia and 1-5 antheridia per oogonium; mostly plerotic oospores) revealed that these isolates belong to a new species grouping in the phylogenetic clade G of . This paper formally describes . as a new species and compares it with other phylogenetically related and already known species, including , , and . Salmaninezhad F, Aloi F, Pane A, Mostowfizadeh-Ghalamfarsa R, Cacciola SO (2022). ., associated with conifers and spp. : 127-137. doi: 10.3114/fuse.2022.10.05.
PubMed: 36741557
DOI: 10.3114/fuse.2022.10.05 -
Methods in Molecular Biology (Clifton,... 2024In all organisms with sexual reproduction, sperm and oocytes derive from embryonic precursors termed primordial germ cells (PGCs) which pass on genetic information to...
In all organisms with sexual reproduction, sperm and oocytes derive from embryonic precursors termed primordial germ cells (PGCs) which pass on genetic information to subsequent generations. Studies aimed to unravel PGC development at molecular level in mammals can be traced at the early 1980s and were hampered by the difficulty in obtaining both sufficient quantities and purity of PGCs. For many laboratories, the isolation and purification methods of PGCs at different stages from embryos are the most shortcut and affordable tool to study many aspects of their development at cellular and molecular levels. In the present chapter, I focus on immunomagnetic cell sorting (MACS) and fluorescence-activated cell sorting (FACS) methods used in my laboratory for the purification of mouse PGCs from 10.5 to 12.5 dpc embryos before their differentiation in oogonia/oocytes in female and prospermatogonia in male.
Topics: Animals; Male; Female; Mice; Semen; Germ Cells; Immunomagnetic Separation; Cell Differentiation; Flow Cytometry; Mammals
PubMed: 38351442
DOI: 10.1007/978-1-0716-3698-5_1 -
Tissue & Cell Aug 2018The morphological and cytological changes of oogenesis and ovarian development were described in the freshwater crab Sinopotamon henanense through macroscopic and...
The morphological and cytological changes of oogenesis and ovarian development were described in the freshwater crab Sinopotamon henanense through macroscopic and microscopic examinations. Serial histological dissections of the ovaries demonstrated that oocyte development was asynchronous. Oogenesis was divided into four distinct stages including six phases: oogonium stage, the first phase (OI) and the second phase (OII) comprising the previtellogenic stage, the third phase (OIII), the fourth phase (OIV) and the fifth phase (OV), comprising the vitellogenic stage and the sixth phase representing the mature stage. Furthermore, examining and analyzing the gonadosomatic indices showed that the developmental cycle of the ovary was closely related to season, and indicated that the breeding season of S. henanense was between May and June. Ovarian development was classified into six stages: proliferation stage, small growth stage, large growth stage, pre-maturation stage, mature stage and spawning stage. Ovaries varied in size and color during each developmental stage, which were closely related to the status and proportions of oogonia and primary oocytes. Although there were cases that oocytes at two or more phases were present at each stage, ovary developmental stages were substantially different. These results provide an important base for studies of the regulatory mechanisms of oogenesis in this compared to other brachyuran species, and will be useful for the aquaculture of S. henanense and related species.
Topics: Animals; Brachyura; Female; Oogenesis; Ovary
PubMed: 30060825
DOI: 10.1016/j.tice.2018.05.009 -
Journal of Fish Biology Jul 2022To characterize the female reproductive biology of the endangered species Steindachneridion parahybae in captivity, the authors used the concentration of gonadal...
To characterize the female reproductive biology of the endangered species Steindachneridion parahybae in captivity, the authors used the concentration of gonadal steroids and the oocyte development during the annual reproductive cycle (RC) and after artificial induced spawning (AIS) until 48 h. Three stages of gonadal maturation were identified, based on morphological and physiological features: early maturation or previtellogenic (PRV) oocyte, advanced maturation or vitellogenic (VTG) oocyte and regression (REG) or follicular atresia. They identified and characterized the following stages of germ cells: oogonia, perinucleolar and cortical alveoli, and VTG and atretic oocytes during RC. The oestradiol levels were higher in PRV than those in VTG and REG during the RC, whereas androgens showed higher levels of oestradiol in VTG than those in PRV and REG. The progestogen levels remained unchanged during the whole RC. The final oocyte maturation (FOM) was achieved after AIS and postovulatory follicles (POF) were identified. Plasma concentration of progestogens (17α,20β-dihydroxy-pregnen-3-one and 17α-hydroxyprogesterone) increased considerably after AIS, remaining high up to 6 h after AIS, and progressively decreased over time after AIS. During RC, the lack of FOM and POFs reveals that captivity negatively impacts S. parahybae reproduction. Nonetheless, the VTG stage of oocytes, reached during RC, is suitable for ovulation induction with artificial hormone manipulation, enabling the reproduction of this species in captivity and being essential for the success of fish farming and/or fish conservation programmes (conservationist aquaculture).
Topics: Animals; Catfishes; Estradiol; Female; Follicular Atresia; Oocytes; Reproduction
PubMed: 35460078
DOI: 10.1111/jfb.15070 -
Fish Physiology and Biochemistry Apr 2018We investigated the feasibility of cryopreservation of spermatogonia and oogonia in the critically endangered cyprinid honmoroko Gnathopogon caerulescens using...
We investigated the feasibility of cryopreservation of spermatogonia and oogonia in the critically endangered cyprinid honmoroko Gnathopogon caerulescens using slow-cooling (freezing) and rapid-cooling (vitrification) methods. Initially, we examined the testicular cell toxicities and glass-forming properties of the five cryoprotectants: ethylene glycol (EG), glycerol (GC), dimethyl sulfoxide (DMSO), propylene glycol (PG), and 1,3-butylene glycol (BG), and we determined cryoprotectant concentrations that are suitable for freezing and vitrification solutions, respectively. Subsequently, we prepared the freezing solutions of EG, GC, DMSO, PG, and BG at 3, 2, 3, 2, and 2 M and vitrification solutions at 7, 6, 5, 5, and 4 M, respectively. Following the cryopreservation of the testicular cells mainly containing early-stage spermatogenic cells (e.g., spermatogonia and primary spermatocytes), cells were cultured for 7 days and immunochemically stained against germ cell marker protein Vasa. Areas occupied by Vasa-positive cells indicated that vitrification led to better survival of germ cells than the freezing method, and the best result was obtained with 5 M PG, about 50% recovery of germ cells following vitrification. In the case of ovarian cells containing oogonia and stage I, II, and IIIa oocytes, vitrification with 5 M DMSO resulted the best survival of oogonia, with equivalent cell numbers to those cultured without vitrification. The present data suggest that male and female gonial cells of the endangered species G. caerulescens can be efficiently cryopreserved using suitable cryoprotectants for spermatogonia and oogonia, respectively.
Topics: Animals; Cryopreservation; Cryoprotective Agents; Cyprinidae; Endangered Species; Female; Freezing; Male; Oocytes; Spermatogonia; Vitrification
PubMed: 29192358
DOI: 10.1007/s10695-017-0449-x -
Frontiers in Genetics 2023The correct pairing and separation of homologous chromosomes during meiosis is crucial to ensure both genetic stability and genetic diversity within species. In...
The correct pairing and separation of homologous chromosomes during meiosis is crucial to ensure both genetic stability and genetic diversity within species. In allodiploid organisms, synapsis often fails, leading to sterility. However, a gynogenetic allodiploid hybrid clone line (GDH), derived by crossing red crucian carp ( ♀) and common carp ( ♂), stably produces diploid eggs. Because the GDH line carries 100 chromosomes with 50 chromosomes from the red crucian carp (RCC; ♀, 2n = 2x = 100) and 50 chromosomes from the common carp (CC; L., ♂, 2n = 2x = 100), it is interesting to study the mechanisms of homologous chromosome pairing during meiosis in GDH individuals. By using fluorescence hybridization (FISH) with a probe specific to the red crucian carp to label homologous chromosomes, we identified the synaptonemal complex immunofluorescence assay of synaptonemal complex protein 3 (SCP3). FISH results indicated that, during early ovarian development, the GDH oogonium had two sets of chromosomes with only one set from leading to the failure formation of normal bivalents and the subsequently blocking of meiosis. This inhibition lasted at least 5 months. After this long period of inhibition, pairs of germ cells fused, doubling the chromosomes such that the oocyte contained two sets of chromosomes from each parent. After chromosome doubling at 10 months old, homologous chromosomes and the synaptonemal complex were identified. Causally, meiosis proceeded normally and eventually formed diploid germ cells. These results further clarify the mechanisms by which meiosis proceeds in hybrids.
PubMed: 36923790
DOI: 10.3389/fgene.2023.998775 -
Genes, Chromosomes & Cancer Jun 2021Teratomas are the most common tumors in the ovary during childhood. Previous studies suggested that they may be derived from germ cells at any developmental stage from...
Teratomas are the most common tumors in the ovary during childhood. Previous studies suggested that they may be derived from germ cells at any developmental stage from premeiotic oogonia through meiotic oocytes to post-meiotic ova. The majority of mature teratomas reveal normal karyotypes and immature teratomas show higher frequency of chromosomal abnormalities. We analyzed fresh tissue samples from 25 primary ovarian teratomas and three extraovarian deposits using whole genome single nucleotide polymorphism (SNP) array and karyotype. SNP array detected five patterns of copy neutral loss of heterozygosity (CN-LOH): failure of meiosis I (type I) in 12 tumors, failure of meiosis II (type II) in six tumors, endoreduplication of a haploid ovum (type III) in two tumors, premeiotic error (type IV) in four tumors, and both meiotic I and meiotic II errors in one tumor (type V). Three tumors with type I error had a single chromosome showing meiotic II error, and two tumors with type II error had a single chromosome showing premature sister-chromatid separation in meiosis I. Lack of recombination in multiple chromosomes in meiosis I were common, chromosomes 17, 7, 8, 21, and 22 were most commonly involved. Abnormal karyotypes were observed in four teratomas including +3, del(3q), +7, +8, +12, and i(18q). The extraovarian deposits revealed the same CN-LOH pattern as the primary teratoma. In summary, SNP array reveals the origin of ovarian teratoma and we propose a new mechanism that consecutive meiotic I and II errors occur frequently in ovarian teratomas.
Topics: Abnormal Karyotype; Adolescent; Child; Chromosomes; Female; Humans; Loss of Heterozygosity; Meiosis; Ovarian Neoplasms; Polymorphism, Single Nucleotide; Recombination, Genetic; Teratoma
PubMed: 33377559
DOI: 10.1002/gcc.22934 -
Life Science Alliance May 2021The in vitro reconstitution of human germ-cell development provides a robust framework for clarifying key underlying mechanisms. Here, we explored transcription factors...
The in vitro reconstitution of human germ-cell development provides a robust framework for clarifying key underlying mechanisms. Here, we explored transcription factors (TFs) that engender the germ-cell fate in their pluripotent precursors. Unexpectedly, , , and , which act under the BMP signaling and are indispensable for human primordial germ-cell-like cell (hPGCLC) specification, failed to induce hPGCLCs. In contrast, or , immediate BMP effectors, combined with and , generated hPGCLCs. / knockouts dose-dependently impaired BMP-induced hPGCLC specification, whereas / expression remained unaffected in , , or knockouts. In cynomolgus monkeys, a key model for human development, , , and were co-expressed exclusively in early PGCs. Crucially, the TF-induced hPGCLCs acquired a hallmark of bona fide hPGCs to undergo epigenetic reprogramming and mature into oogonia/gonocytes in xenogeneic reconstituted ovaries. By uncovering a TF circuitry driving the germ line program, our study provides a paradigm for TF-based human gametogenesis.
Topics: Animals; Cell Differentiation; Cell Lineage; Female; GATA Transcription Factors; Germ Cells; Humans; Induced Pluripotent Stem Cells; Macaca fascicularis; Mice; Mice, Inbred ICR; SOXF Transcription Factors; Signal Transduction; Transcription Factor AP-2; Transcription Factors
PubMed: 33608411
DOI: 10.26508/lsa.202000974 -
Theriogenology Apr 2015We report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate...
We report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate a germline chimera as a potential tool for surrogate reproduction and gene banking. Cells were dissociated from testis, characterized by mostly spermatogonia, and from ovary, exclusively comprising oogonia and previtellogenic oocytes, of Acipenser baerii, using 0.3% trypsin (2 hours, 23 °C) dissolved in PBS, isotonic with blood plasma. The dissociated germ cells were sorted by Percoll gradient centrifugation followed by immunolabeling with germ cell-specific vasa antibody DDX4, while 10% to 30% Percoll solution contained 79.4% and 70.8% labeled testicular and ovarian cells. Sorted germ cells were transplanted into a cavity close to a presumptive genital ridge of newly hatched heterospecific Acipenser ruthenus larvae with fluorescein isothiocyanate-labeled endogenous primordial germ cells. The transplanted germ cells were randomly distributed in the body cavity through 30-day posttransplantation (dpt). Subsequently, the cells were organized into genital ridges 50 dpt and proliferated 90 dpt. The number of both transplanted and endogenous germ cells significantly increased from 18.1, 22.2, and 29.1 (30 dpt) to 108.5, 90.8, and 118.5 (90 dpt) in ovarian, testicular, and endogenous germ cells, respectively (P < 0.05). The efficiency of transplantation was 60% (counted 90 dpt).
Topics: Animals; Female; Fishes; Germ Cells; Male; Ovary; Sexual Maturation; Testis
PubMed: 25559841
DOI: 10.1016/j.theriogenology.2014.12.010