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Tissue & Cell Oct 2023Macrobrachium amazonicum is a species of economic interest with a wide distribution in the Americas and high morphological and reproductive variability. Three phenotypes...
Macrobrachium amazonicum is a species of economic interest with a wide distribution in the Americas and high morphological and reproductive variability. Three phenotypes can be observed in this species: i) large-size amphidromous, ii) large-size and iii) small-size hololimnetic prawns. In the present work, the morphological, histochemical and ultrastructural aspects of ovarian development in the three phenotypes were comparatively analyzed. In addition, the interaction between the ovary and the hepatopancreas was investigated in these phenotypes through the use of gonadosomatic (GSI) and hepatosomatic (HSI) indices. Despite the morphological differences and different reproductive strategies adopted by the females, the macroscopic, histochemical and ultrastructural patterns of ovarian development showed no differences between the phenotypes. The ovaries were macroscopically classified into five stages of development (I to V). In early stages (I and II), the ovaries are full of oogonia, previtellogenic oocytes and oocytes in primary or endogenous vitellogenesis. At these stages, the rough endoplasmic reticulum (RER) produces a granular electron-dense material and sends it to the Golgi apparatus, where it will be modified, compacted and transformed into immature yolk granules. From stage III, secondary or exogenous vitellogenesis begins (with no interruption of endogenous vitellogenesis), where follicular cells nourish the oocytes and extracellular material is absorbed by endocytic vesicles, which fuse with immature yolk granules (forming mature granules) or with existing mature yolk granules. In stages IV and V, secondary vitellogenesis continues and mature yolk granules progressively occupy the cytoplasm. In M. amazonicum, the patterns of increase in oocyte diameter are quite similar between phenotypes, being greater in the small-size phenotype. This is related to the formation of larger oocytes/eggs and the production of large lipid reserves for their larvae. Changes in GSI and HSI during ovarian development show strong similarity between phenotypes, supporting the results obtained by histology and ultrastructure. Females in stages III and IV mobilize hepatopancreas reserves for ovarian maturation, which justifies the higher HSI values recorded in these stages. On the other hand, females in stage V show higher GSI and lower HSI values, indicating a mobilization of resources for the end of ovarian development as the females are ready to spawn.
Topics: Animals; Female; Palaemonidae; Oocytes; Ovary; Oogonia; Phenotype
PubMed: 37499319
DOI: 10.1016/j.tice.2023.102166 -
Integrative Organismal Biology (Oxford,... 2023In high-latitude environments where seasonal changes include periods of harsh conditions, many arthropods enter diapause, a period of dormancy that is hormonally...
In high-latitude environments where seasonal changes include periods of harsh conditions, many arthropods enter diapause, a period of dormancy that is hormonally regulated. Diapause is characterized by very low metabolism, resistance to environmental stress, and developmental arrest. It allows an organism to optimize the timing of reproduction by synchronizing offspring growth and development with periods of high food availability. In species that enter dormancy as pre-adults or adults, termination of diapause is marked by the resumption of physiological processes, an increase in metabolic rates and once transitioned into adulthood for females, the initiation of oogenesis. In many cases, individuals start feeding again and newly acquired resources become available to fuel egg production. However, in the subarctic capital-breeding copepod , feeding is decoupled from oogenesis. Thus, optimizing reproduction limited by fixed resources such that all eggs are of high quality and fully-provisioned, requires regulation of the number of oocytes. However, it is unknown if and how this copepod limits oocyte formation. In this study, the phase in oocyte production by post-diapause females that involved DNA replication in the ovary and oviducts was examined using incubation in 5-Ethynyl-2'-deoxyuridine (EdU). Both oogonia and oocytes incorporated EdU, with the number of EdU-labeled cells peaking at 72 hours following diapause termination. Cell labeling with EdU remained high for two weeks, decreasing thereafter with no labeling detected by four weeks post diapause, and three to four weeks before spawning of the first clutch of eggs. The results suggest that oogenesis is sequential in with formation of new oocytes starting within 24 hours of diapause termination and limited to the first few weeks. Lipid consumption during diapause was minimal and relatively modest initially. This early phase in the reproductive program precedes mid-oogenesis and vitellogenesis 2, when oocytes increase in size and accumulate yolk and lipid reserves. By limiting DNA replication to the initial phase, the females effectively separate oocyte production from oocyte provisioning. A sequential oogenesis is unlike the income-breeder strategy of most copepods in which oocytes at all stages of maturation are found concurrently in the reproductive structures.
PubMed: 37361914
DOI: 10.1093/iob/obad020 -
Journal of Phycology Apr 2019Temperate kelp forests (Laminarians) are threatened by temperature stress due to ocean warming and photoinhibition due to increased light associated with canopy loss....
Temperate kelp forests (Laminarians) are threatened by temperature stress due to ocean warming and photoinhibition due to increased light associated with canopy loss. However, the potential for evolutionary adaptation in kelp to rapid climate change is not well known. This study examined family-level variation in physiological and photosynthetic traits in the early life-cycle stages of the ecologically important Australasian kelp Ecklonia radiata and the response of E. radiata families to different temperature and light environments using a family × environment design. There was strong family-level variation in traits relating to morphology (surface area measures, branch length, branch count) and photosynthetic performance (F /F ) in both haploid (gametophyte) and diploid (sporophyte) stages of the life-cycle. Additionally, the presence of family × environment interactions showed that offspring from different families respond differently to temperature and light in the branch length of male gametophytes and oogonia surface area of female gametophytes. Negative responses to high temperatures were stronger for females vs. males. Our findings suggest E. radiata may be able to respond adaptively to climate change but studies partitioning the narrow vs. broad sense components of heritable variation are needed to establish the evolutionary potential of E. radiata to adapt under climate change.
Topics: Acclimatization; Animals; Climate Change; Ecosystem; Female; Kelp; Life Cycle Stages; Male
PubMed: 30506918
DOI: 10.1111/jpy.12820 -
Plant Disease Apr 2023Panax notoginseng (Burkill) F.H. Chen, known as ''sanqi'', is widely used for its medicinal and tonic effects in China, such as treatment of cardiovascular diseases and...
Panax notoginseng (Burkill) F.H. Chen, known as ''sanqi'', is widely used for its medicinal and tonic effects in China, such as treatment of cardiovascular diseases and antioxidant effects. However, root rot disease is the most destructive disease that hampers industrial development (Mi et al. 2017). In August 2018 and 2019, samples displaying symptoms of root rot, such as unnormal, stunted growth and chlorotic leaves, were dug out with a shovel and put in clean sample-bags from four production bases in Wenshan (around 23.5° N; 104° E), Yunnan province, the biggest "sanqi" production area in China, with over 20 thousand ha. Among production bases, root rot incidence typically ranged from 10% to 20%, but in a few number of severe cases, exceeded 70%. Typical symptomatic root tubers were washed with tap water, surface-sterilized in 5% NaClO for 1 min followed by 70% alcohol for 30 s, and rinsed three times with sterile water. The diseased tissues were excised and placed on rye sucrose agar medium (RSA) supplemented with 25 mg/L rifampin and 50 mg/L kanamycin, then incubated at 25°C in the dark for five days. Colonies with different features grew from the diseased pieces and twenty oomycete-like colonies, (white, dense, aerial mycelia with rapid radiate growth) were chosen for further investigation. Microscopic observations showed terminal and intercalary hyphal swellings, which were either globose or limoniform, thin-walled, mostly smooth, and 13-28 µm wide (average 20.3 µm). Oogonia were globose or rarely fusiform, mostly intercalary, 11-19 µm wide (average 13 µm), provided with a varying number of blunt, digitate projections. Oospores were plerotic, rarely aplerotic, thin-walled, and 16-19 μm wide (average 18.6 μm). Antheridia usually originated at various distances from the oogonium and appeared- clavate and crook-necked, making apical contact with the oogonium. Based on typical morphological features described, the isolates were putatively identified as Pythium spinosum (van der Plaats-Niterink 1981). The internal transcribed spacer region (ITS) and cytochrome c oxidase subunit II (CoxII) of isolates SQ00803 and SQ00903-1 were sequenced using universal primers ITS1/ITS4 and FM58/FM66 (Villa et al. 2006). The nucleotide sequences were deposited to GenBank with the accession numbers MN369530, MN370548, MN561687 and MN561688, respectively. Blastn analysis of ITS sequences showed 99.58% similarity to those of Globisporangium spinosum isolates CBS275.67 and CBS276.67 (accession number AY598701 and HQ643792). CoxII sequences showed 99.82% to 100% similarity to G. spinosum isolates (accession number GU071755 and AF196616). For pathogenicity tests, nine two-year-old healthy sanqi plants grown in sterilized substrate in plastic pots under greenhouse conditions were inoculated with 5×104 CFU/ml zoospore suspension of G. spinosum by root-drenching method (Dixon et al. 1984). Three non-inoculated plants drenched with sterile water were used as controls. All plants were incubated in a growth chamber at 25°C with a 16/8-h photoperiod. After two weeks, inoculated sanqi plants showed discoloration and chlorosis of leaves with water-soaked root rot. Control plants were symptomless and healthy. Colonies resembling G. spinosum were re-isolated from infected root tissues and showed the same morphological features as G. spinosum, thus fulfilling Koch's postulates. G. spinosum originally isolated from seedlings of Anthirrhinum majus has been reported to cause root rot disease on many plant species worldwide (Lévesque and De Cock 2004). Recently, based on whole genome sequencing and phylogenomic analysis, P. spinosum was transferred to Globisporangium genus. Therefore, P. spinosum is now classified as G. spinosum (Hai et al. 2022). To our knowledge, this is the first report of G. spinosum causing root rot of P. notoginseng in China. This research will contribute to the development of integrated management strategies for P. notoginseng root rot.
PubMed: 37081634
DOI: 10.1094/PDIS-05-22-1216-PDN -
Biology of Reproduction Jul 2018This review focuses on those mouse mutations that cause an effect on the morphology, viability, and/or behavior of primordial germ cells (PGCs) and gonocytes at specific... (Review)
Review
This review focuses on those mouse mutations that cause an effect on the morphology, viability, and/or behavior of primordial germ cells (PGCs) and gonocytes at specific steps of their fetal development up to the start of spermatogenesis, a few days after birth. To restrict the area covered, mice with mutations that cause abnormal hormone levels or mutations of genes not expressed in germ cells that secondarily cause spermatogenic problems are not discussed. To make our literature search as comprehensive as possible, Pubmed was searched for "(primordial germ cells OR prospermatogonia OR prespermatogonia OR gonocytes OR spermatogonia or meiosis or spermiogenesis or spermatogenesis) AND mouse AND (knockout or mutant or transgenic)." This search started at 2003 as mutants created earlier were already retrieved for a previous review. The resulting citations were then further selected for complete or partial arrests at the level of PGCs and/or gonocytes. Fifty-nine protein coding genes and two miRNA coding genes were found that arrest the development of PGCs and gonocytes at specific steps providing a better insight into the regulation of the development of these cells. As to be expected, often problems in fetal germ cell development have an effect on the fertility of the mice at adulthood.
Topics: Animals; Cell Cycle Checkpoints; Male; Mice; Mutation; Oogenesis; Oogonia; Spermatogenesis; Spermatogonia
PubMed: 29590307
DOI: 10.1093/biolre/ioy075 -
American Journal of Translational... 2022To detect mRNA and protein expression of meiosis-specific genes in human umbilical cord mesenchymal stem cells (hUMSCs) in an co-culture microenvironment with mouse...
OBJECTIVE
To detect mRNA and protein expression of meiosis-specific genes in human umbilical cord mesenchymal stem cells (hUMSCs) in an co-culture microenvironment with mouse primordial germ cells (PGCs), and to further explore the effective potential of hUMSCs to differentiate into PGCs.
METHODS
HUMSCs were obtained from human Wharton's jelly fragments by adherent culture. PGCs were derived from 12.5 days post-coitum (dpc) BalbC mice. Then hUMSCs were co-cultured with PGCs in Matrigel, inside or outside of a culture chamber, respectively. The changes in morphology and cytogenetic characteristics were observed. SCP3 and DDX4 expression in hUMSCs were detected and analyzed using immunofluorescence staining. Oct-4, Stra8, Zp3 and Dmc1 gene expressions in PGCs, hUMSCs, and hUMSCs after co-culture with PGCs were analyzed by real time reverse transcription-polymerase chain reaction.
RESULTS
Both hUMSCs and PGCs expressed Oct-4 at different degrees. After co-culture with PGCs, hUMSCs became rounded and showed AKP activity. HUMSCs suspension-cultured in Matrigel or adherent cultured with cell chamber significantly expressed Stra8, DMC1, SCP3 and DDX4 genes.
CONCLUSION
HUMSCs can be induced to express PGC-specific genes Stra8 and DMC1, spermatogonium/oogonium-specific genes SCP3 and DDX4 that predict directed differentiation potential into early germ cells at a molecular level.
PubMed: 36628204
DOI: No ID Found -
Reproduction (Cambridge, England) Mar 2021The germ cell lineage ensures the creation of new individuals and perpetuates the genetic information across generations. Primordial germ cells are pioneers of gametes...
The germ cell lineage ensures the creation of new individuals and perpetuates the genetic information across generations. Primordial germ cells are pioneers of gametes and exist transiently during development until they differentiate into oogonia in females, or spermatogonia in males. Little is known about the molecular characteristics of primordial germ cells in cattle. By performing single-cell RNA-sequencing, quantitative real-time PCR, and immunofluorescence analyses of fetal gonads between 40 and 90 days of fetal age, we evaluated the molecular signatures of bovine germ cells at the initial stages of gonadal development. Our results indicate that at 50 days of fetal age, bovine primordial germ cells were in the early stages of development, expressing genes of early primordial germ cells, including transcriptional regulators of human germline specification (e.g. SOX17, TFAP2C, and PRDM1). Bovine and human primordial germ cells also share expression of KIT, EPCAM, ITGA6, and PDPN genes coding for membrane-bound proteins, and an asynchronous pattern of differentiation. Additionally, the expression of members of Notch, Nodal/Activin, and BMP signaling cascades in the bovine fetal ovary, suggests that these pathways are involved in the interaction between germ cells and their niche. Results of this study provide insights into the mechanisms involved in the development of bovine primordial germ cells and put in evidence similarities between the bovine and human germline.
Topics: Animals; Cattle; Cell Differentiation; Cell Lineage; Female; Germ Cells; Gonads; Humans; Male; Sequence Analysis, RNA; Spermatogonia
PubMed: 33275120
DOI: 10.1530/REP-20-0313 -
Plants (Basel, Switzerland) Sep 2022Oedogoniales comprises the three genera , , and , which include more than 600 described species. The classification of Oedogoniaceae is currently based on morphology,...
Oedogoniales comprises the three genera , , and , which include more than 600 described species. The classification of Oedogoniaceae is currently based on morphology, and the complicated morphological characteristics make species identification difficult, with the limited molecular data also restricting the phylogenetic analysis. In the present study, we collected 47 specimens from China and sequenced 18S rDNA, ITS2, ITS (ITS1 + 5.8S + ITS2), and rbcL sequences to conduct phylogenetic analyses. We selected nine morphological characteristics, most of which were considered important in traditional systematics, for comparison with the molecular phylogeny results. All the topologies based on different datasets showed similar results; was a paraphyletic group, and and clustered with . The morphological characteristics matching the phylogenetic results showed that the types of sexual differentiation, characteristics of the oogonium (including shape, types of aperture, and ornamentation of oospore wall), division types of antheridial, and number of sperm of each antheridial, which are considered the most important morphological characteristics in traditional taxonomy of , did not form monophyletic lineages respectively, indicating that traditional systematics may not reflect the real phylogeny of the genus . In addition, a new taxonomical classification of the genus was presented according to the shapes of basal cells, which matched well with the phylogenetic topologies. In addition, we propose to divide the genus into two sections, section and section , representing the species with spherical or sub-hemispherical basal cells and elongated basal cells, respectively.
PubMed: 36145821
DOI: 10.3390/plants11182422 -
Zoology (Jena, Germany) Jun 2023There is a gap in our knowledge of microorganization and the functioning of ovaries in earthworms (Crassiclitellata) and allied taxa. Recent analyses of ovaries in...
There is a gap in our knowledge of microorganization and the functioning of ovaries in earthworms (Crassiclitellata) and allied taxa. Recent analyses of ovaries in microdriles and leech-like taxa revealed that they are composed of syncytial germline cysts accompanied by somatic cells. Although the pattern of cyst organization is conserved across Clitellata - each cell is connected via one intercellular bridge (ring canal) to the central and anuclear cytoplasmic mass termed the cytophore - this system shows high evolutionary plasticity. In Crassiclitellata, only the gross morphology of ovaries and their segmental localization is well known, whereas ultrastructural data are limited to lumbricids like Dendrobaena veneta. Here we present the first report about ovarian histology and ultrastructure in Hormogastridae, a small family of earthworms inhabiting the western parts of the Mediterranean sea basin. We analyzed three species from three different genera and showed that the pattern of ovary organization is the same within this taxon. Ovaries are cone-like, with a broad part connected to the septum and a narrow distal end forming an egg string. Ovaries are composed of numerous cysts uniting a small number of cells, eight in Carpetania matritensis. There is a gradient of cysts development along the long ovary axis, and three zones can be distinguished. In zone I, cysts develop in complete synchrony and unite oogonia and early meiotic cells (till diplotene). Then (zone II), the synchrony is lost, and one cell (prospective oocyte) grows faster than the rest (prospective nurse cells). In zone III, oocytes pass the growth phase and gather nutrients; at this time, their contact with the cytophore is lost. Nurse cells grow slightly, eventually die via apoptosis, and are removed by coelomocytes. The most characteristic feature of hormogastrid germ cysts is the inconspicuous cytophore in the form of thread-like thin cytoplasmic strands (reticular cytophore). We found that the ovary organization in studied hormogastrids is very similar to that described for D. veneta and propose the term "Dendrobaena" type of ovaries. We expect the same microorganization of ovaries will be found in other hormogastrids and lumbricids.
Topics: Female; Animals; Ovary; Oligochaeta; Oogenesis; Oocytes; Germ Cells
PubMed: 36871333
DOI: 10.1016/j.zool.2023.126081 -
Plant Disease May 2022Photinia × fraseri Dress is a hybrid species of Rosaceae and Photinia genus which is widely cultivated in China. During 2020 and 2021, approximately 80% of plants...
Photinia × fraseri Dress is a hybrid species of Rosaceae and Photinia genus which is widely cultivated in China. During 2020 and 2021, approximately 80% of plants growing in Xuanwu district of Nanjing, China, exhibited disease symptoms including blight, necrosis, and dieback of crowns and roots. Symptomatic root tissues collected from 2-year-old plants were rinsed with water, cut into 2-mm tissues which were surface-sterilized in 70% ethanol for 60 s, and plated onto 10% V8 PARP agar and incubated in the dark at 26°C for 3 days. Hyphae emerged from 70% of the samples. Two representative isolates (PF-he2, PF-he3) were obtained and deposited. Ten agar plugs (2×2 mm2) of each isolate were transferred into 10 mL of 10% V8 juice to produce mycelial mats. To stimulate sporangial production, 3-5 drops of soil extract solution (soil collected from healthy fields, immersed in sterile water, and filtered) were added to each plate. Sporangia were terminal, ovoid to globose or papillate. The zoospores were 7.1-9.3 µm in diameter. Each oogonium contained a single, smooth, spherical and aplerotic oospore with a diameter of 24.5-32.6 μm. These morphological properties resemble those of Phytopythium helicoides (CBS286.31 from S. F. Ashby). For molecular identification, the large subunit (LSU) rDNA, cytochrome c oxidase I (COXI) gene, and COXII gene were amplified using the primer pairs NL1/NL4 , FM55/FM52R , and FM66/FM58 . The LSU, COXI, and COXII sequences of isolate PF-he2 were 100% (763/763 nt), 98.07% (1066/1087 nt), 99.64% (561/563 nt) identical to isolate CBS 286.31 (AY598665.2), GDGJ6 (KT750956.1), and TC3 (MN952224.1), respectively. Based on the morphological and molecular analysis, the two isolates shared 100% homology were identified as Phytopythium helicoides. The pathogenicity of two isolates were tested on potted 2-yr-old (40-cm tall) P. × fraseri. Six plants were dug up to expose root balls which were wounded before inoculations with a sterile needle, and then inoculated with zoospore suspension (106 zoospore/mL). Controls were treated with ddH2O. Three seedlings/isolate were used for each treatment including controls. All plants were repotted using the original sterilized potting mix and pots. After inoculation, the plants were covered with plastic bags, and sterilized H2O was sprayed into the bags twice per day to maintain humidity and kept in a greenhouse at the day/night temperatures at 25/16 °C. All the inoculated plants showed lesions similar to those observed in the field after 23 days , whereas controls were asymptomatic. The isolates were reisolated from the lesions and sequenced as P. helicoides which has found causing root rot on Nelumbo nucifera, Rhododendron pulchrum, Zea mays in China, and also on Fragaria × ananassa in America, Peach Rootstock in California. Globally, this is the first report of P. helicoides causing crown blight and root rot of P. × fraseri. Management programs are under development to contain the spread of P. helicoides and treat diseased plants.
PubMed: 35581911
DOI: 10.1094/PDIS-03-22-0672-PDN