• Parasites, Hosts and Diseases
• /
• v.28 no.1
• /
• pp.53-62
• /
• 1990

The growth and developmental pattern of H. continua was observed after experimental infection of their metacercariae to chicks. The recovery rate of worms from the chicks at 1 to 28 days post-infection(PI) was 12.8% in average. The rate remained fairly high for early 4 days of infection but decreased thereafter rapidly till 28 days PI. Most of the nukes, 91.9%, were recovered from the ileum of the chicks. In metacercariae, genital organs such as the ovary, testes, seminal vesicle, seminal receptacle and genital sucker were recognizable. At one day PI Mehlis'gland appeared, and at 2 days follicular vitellaria were observed. At 3 days PI, eggs were formed in the uterine tubule and increased in number as the worm grew old. The worms reached $2,990{\;}{\mu\textrm{m}}$ in length and $525{\;}{\mu\textrm{m}}$ in width at 28 days PI. Genital organs developed rapidly in early stages of infection but slowly thereafter to 28 days Pl, whereas non-genital organs developed steadily through the infection period. It was proved by this experiment that chicks should be a moderately suitable final host of H. continua.

• Korean Journal of Ichthyology
• /
• v.26 no.3
• /
• pp.179-184
• /
• 2014

A histological study on the egg envelope and oogenesis of Gobiobotia brevibarba (Pisces, Cyprinidae) was carried out by a light microscope and a scanning electron microscope. Various developmental cells appeared in the ovary caught during May 2014, spawning season. For the relative area of oocyte, the ovary consisted of mature stage (74.5%), a vitellogenic stage (yolk granule stage, 16.6% and yolk vesicle stage, 6.6%) and previtellogenic stage (perinucleolus stage 2.2%), which means its spawning season. The cytoplasm of the perinucleolus oocyte is acidic and many nucleoli are located at the inner side of the nuclear membrane. The yolk vesicles, an early vitellogenic stage, has a follicular layer and a zona radiata clearly. Numerous villi, called an egg envelope, begin to form on the zona radiata. The yolk granules, an another vitellogenic stage, proceeds and they show a strong eosinophilic nature. Such yolk granules appeared between the yolk vesicles occupying most cytoplasm, and as the stage proceeds, there are some yolk masses fused with each other. Egg envelope is covered with plenty of villi ($2{\sim}3{\mu}m$ in the length) over the entire egg surface.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.2
• /
• pp.266-277
• /
• 2014

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with $4{\mu}g/mL$ of digitonin for 2 min at $4^{\circ}C$ in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at $18^{\circ}C$ was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos.

• Horticultural Science & Technology
• /
• v.32 no.1
• /
• pp.18-25
• /
• 2014

This study was conducted to investigated effects of water relation of mulching and trickle irrigation on the external and internal fruit quality in Satsuma mandarin grafted on trifoliate orange rootstock in a orchard assigned to randomly three groups; whole period of Tyvex mulching (TM), Tyvex mulching with trickle irrigation once a week from October 22 to harvesting season (WM) and non-mulching treatment (NM). The average soil moisture content in the TM was lower than the WM during the time of trickle irrigation from Oct. 21 to Nov. 28. The leaf water potential was at the level of ${\Psi}max$ of -1.5 to -2.5 MPa during whole period of Tyvex mulching treatment but gradually increased at the point of supplement of water. The water and osmotic potential in juice vesicle was decreased by drought but increased again in response to the supply of water in WM. The total soluble solids (TSS) in fruit juice was increased by drought stress, but diminished in response to supply of water after drought. The content of titratible acidity was increased by drought stress but gradually decreased due to supplement of water after drought, reached it at the level of 1%. It was suggested that the accumulation of the total soluble solids compensates the degree of active osmoregulation and the decrease in content of acidity accounts for the fast respiration and water uptake resulted of the water after drought.

• Development and Reproduction
• /
• v.16 no.3
• /
• pp.227-233
• /
• 2012

Circadian timing system plays a major role in a wide range of reproductive function. However it is plausible idea that other environmental and/or internal cue might be simultaneously participated in the optimal regulation of reproductive system. In the present study we extended the reverse feeding (RF) time regimen up to 8 weeks, then measured the general and reproductive indices of the animals. The animals of ad libitum feeding group (Control, CON) have free access to food for 4, 6 and 8 weeks, respectively. The day feeding animals (reverse feeding, RF group) have restricted access to food during daytime (09:00-18:00) for 4, 6 and 8 weeks, respectively. When the feeding schedules were over, key indices were measured. After 4 weeks and 8 weeks of feeding, body weights of animals were not significantly different. However, body weights of 6 weeks RF animals were significantly smaller than those of control animals (CON : RF = $333.46{\pm}12.71$ g : $289.91{\pm}8.31$ g, p<0.01). The blood glucose levels of 4 weeks RF animals were significantly decreased compared to the levels of control animals (CON : RF = $161.4{\pm}2.7$ mg/dL : $176.7{\pm}5$ mg/dL, p<0.01) while the levels of 6 weeks RF and 8 weeks RF animals were not different form those of control animals. Reproductive and non-reproductive tissue weights from 6 weeks RF group were significantly lowered than those from CON group (testis, CON : RF = $1.4714{\pm}0.0174$ g : $1.3724{\pm}0.0168$ g, p<0.001; epididymis, CON : RF = $0.3574{\pm}0.0059$ g : $0.3243{\pm}0.0068$ g, p<0.001; seminal vesicle, CON : RF = $0.1655{\pm}0.0068$ g : $0.1328{\pm}0.0054$ g, p<0.001; prostate, CON : RF = $0.3350{\pm}0.0231$ g : $0.2528{\pm}0.0143$ g, p<0.01). After 4 weeks and 8 weeks of reverse feeding, sperm counts in RF animals were markedly reduced than those in control animals[CON 4W : RF 4W = $121.17{\pm}9.96\;({\times}10^6)$ : $50.86{\pm}9\;({\times}10^6)$, p<0.001; CON 8W : RF 8W= $138.69{\pm}9.8\;({\times}10^6)$ : $108.94{\pm}4.22\;({\times}10^6)$, p<0.001]. Present study indicates that RF may induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. On-going longitudinal studies will allow a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.6
• /
• pp.781-787
• /
• 2017

Objective: The early growth response (Egr) family consists of four members (Egr1, Egr2, Egr3, and Egr4) that are zinc finger transcription factors. Among them, Egr3 is involved in transcriptional regulation of target genes during muscle spindle formation and neurite outgrowth. We previously showed that the immunoreactive Egr3 is localized on oocyte spindle and accumulate near the microtubule organizing center during meiosis I in mice. Egr3 was also shown to be localized on spermatocytes. We herein investigated if Egr3 is expressed in mouse gonads and if Egr3 blockade results in any defect in oocyte maturation. Methods: Expression of Egr3 in mouse gonads was examined by reverse transcription-polymerase chain reaction. Full-length Egr3 and truncated Egr3 (${\Delta}Egr3$) complementary RNAs (cRNAs) with Xpress tag at N-terminus and DsRed2 at C-terminus, and small interfering RNA (siRNA) targeting Egr3 were microinjected into mouse oocytes at germinal vesicle stage. Localization of microinjected Egr3 was examined by confocal live imaging and immunofluorescence staining. Results: Egr3 mRNA was detected in mouse ovaries and testes from 1 to 4 week-old mice. An uncharacterized longer transcript containing 5'untranslated region was also detected in 3 and 4 week-old gonads. Microinjected Xpress-Egr3-DsRed2 or Xpress-${\Delta}Egr3$-DsRed2 localized to nuclei and chromosomes during meiotic progression. Microinjection of these cRNAs or Egr3 siRNA in oocytes did not affect meiotic maturation. Immunofluorescence staining of Egr3 in Xpress-${\Delta}Egr3$-DsRed2-injected oocytes showed a positive signal only on meiotic spindle, suggesting that this antibody does not detect endogenous or exogenous Egr3 in mouse oocytes. Conclusion: The results show that Egr3 localizes to chromosomes during meiotic progression and that certain antibodies may not faithfully represent localization of target proteins in oocytes. Egr3 seems to be dispensable during oocyte maturation in mice.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.1
• /
• pp.87-94
• /
• 1996

For evaluating the suitability of human follicular fluid(HFF) as protein supplement in ART, this preliminary study was performed to examine the maturation promoting activity of HFF on mouse follicular oocytes in vitro. Mouse follicular oocytes were collected from ovaries of 21-28 day old ICR mice by puncturing the antral follicles with fine needle at 48 hours after PMSG injection. The oocytes were rinsed and cultured in modified Whittingham's $T_6$ medium containing purines or dbcAMP to maintain meiotic arrest, and different concentrations of HFF were added into the culture medium to examine the effect of HFF on releasing the oocytes from the suppressive influence of the meiotic inhibitors. As a control for HFF, the maturation promoting activity of human fetal cord serum(HFCS) was investigated and compared with the activity of HFF. While HFF was separated, by molecular weight(M.W), into high M.W. fraction(M.W>30,000) and low M.W. fraction(M.W<30,000) and the effects of the fractions on meiotic resumption were investigated in the presence of the meiotic inhibitors. Also hormone analysis was performed to compare the content of hormones in HFF with that in HFCS. Same concentrations of HFF and HFCS induced similar germinal vesicle break down(GVBD) rates of the oocytes meiotic arrested by purines(4mM hypoxanthine+0.75mM adenosine), but the extrusion rate of 1st polar body(PB) of the oocytes cultured in HFF(65.0%, P<0.05) was significantly higher than that(51.6%) in HFCS. While, in the presence of 200 M dbcAMP, the maturation promoting activity of HFF (GVBD: 70.5%, $p<10^{-6}$; 1st PB extrusion: 67.1%, $p<10^{-3}$) was significantly greater than that of HFCS(GVBD: 35.2%; 1st PB extrusion: 41.1%). The oocytes cultured in the fraction of HFF containing high M.W. components showed higher meiotic maturation rates than the oocytes cultured in the low M.W. fraction of HFF. Gonadotropins and $E_2$ were known to improve the completion of maturation changes, and the levels of these hormones were higher in HFF than in HFCS. Therefore, HFF was more effective than HFCS to use for promoting meiotic resumption of mouse oocytes in vitro.

• Applied Microscopy
• /
• v.6 no.1
• /
• pp.21-32
• /
• 1976

The origins and the functions of the multi vesicular bodies and the various structures of the membranes related to the cytolysomes were studied in the mycelium cells of Rhizopus nigricans, Aspergillus niger and A. ochraceus, in the hymenium and basidium cells of Agricus bisporus sand Rhizopogon rubesecens, in the cells of assimilation tissue of Marchtantia polymorpha and Pogonalum inflexum and in the mesophyll cells of Pteridium aqiulinum, Pinus densiflora, Ginkgo biloba and Panax ginseng fixed with glutaraldehyde-paraformaldehyde-$ OsO_4$. In Rhizopus nigricans, Aspergillus niger, A. ochraceus, Agricus bisporus sand Rhizopogon rubescens, the concentric multilamellar, multivesicular, myelin-vesicle-tubular and concentric parallel-lamellar complexes were originated from the plasmalemma, while in Marehantia polymorpha, Pogonatum inflexum, Pteridium aquilinum, Pinus densiflora, Ginkgo biloba and Panax ginseng, they were originated from plasmalemma and the cytoplasm. The structures originated from the plasmalemma may be grouped into multi vesicular body and myelin-like structure, both forming the secondary vacuoles or protruding into the central vacuoles and finally degrading, In some cases, endoplasmic reticulum within the cytoplasm encloses some part of the cytoplasm to form a circle where the membranous lamellae increase in number, while the enclosed cytoplasm decrease to be eventually replaced by the multilamellar structure which is released into the vacuoles and subsquently degraded. The structures originated from the cytoplasm are believed to be the cytosegresomes or cytolysomes closely related to the differentiation of the vacuoles. The possible fate of these structures are also discussed.

• Applied Microscopy
• /
• v.32 no.4
• /
• pp.377-383
• /
• 2002

We have detected the murine zinc transporter, ZnT3, and zinc ions in the mouse choroid plexus by immunocytochemistry (ICC) and zinc selenium autometallography ($ZnSe^{AMG}$), respectively. BALB/c mice served as experimental animals. Routine floating ABC immunocytochemical procedures were used for the ZnT3 immunocytochemistry, and the mice were injected intraperitoneally (i.p.) with sodium selenide (10 mg/kg) for the zinc selenium autometallography. The choroid plexus showed weak immunoreactivity (Ir) for ZnT3. At high magnification, ZnT3-Ir was seen to be located in the choroid epithelium and the connective tissue of the capillaries. At the EM level, a high electron density of ZnT3-immunoreactivity was restricted to vesicle membranes as well as microvilli in the apical membrane. In contrast, immunostaining of ZnT3 was completely absent in the basolateral plasma membrane and other cell organelles. After silver enhancement, fine $ZnSe^{AMG}$ grains were observed in both the epithelial and endothelial cells of the choroid plexus. Few $ZnSe^{AMG}$ grains present in the cell bodies of the choroid epithelial cells were located in multivesicular bodies. It is striking that very many $ZnSe^{AMG}$ grains were observed in the endothelial cells of the capillaries. These findings establish the choroid plexus as a non-neuronal pool of zinc ions in the brain, although the functional significance of this pool is not clear. The choroid epithelium, however, may play an important role in the transportation of zinc between the CSF and brain tissue.

• Applied Microscopy
• /
• v.30 no.2
• /
• pp.121-139
• /
• 2000

The morphogenesis of neuroblasts and plexiform layers, and establishment of its synapses were studied by electron microscopy in human embryos and fetuses ranging from 10 mm to 260 mm crown-rump length ($5\sim30$ weeks of gestational age). At 30 mm fetus the developing retina was composed of outer and inner neuroblastic layers . Cell division of outer neuroblast was occurred until 90 mm fetus. The transient layer of Chievitz was formed by 30 mm fetus, inner plexiform layer by 50 mm fetus, and outer plexiform layer by 150 mm fetus. The cytoplasm of differentiating ganglion cells contained ribosomes, rough endoplasmic reticula, Golgi complexes, microtubules and dense bodies. The processes of $M\ddot{u}ller$ cell penetrated between groups of ganglion cell axons, and formed the cellular component of the inner limiting membrane at 30 mm fetus. At 90 mm fetus radial fibers of M ller cells contained extensive smooth endoplasmic reticula and microtubules. In each specimen , apposing paired membrane specializations were classified as junctions without synaptic vesicles, conventional synapses and ribbon synapses. At 50 mm fetus the processes of neuroblasts in inner plexiform layer were interconnected by junctions without synaptic vesicles. Conventional synapses developed by addition of synaptic vesicles to initially vesicle-free junctions at 90 mm fetus. At 150 mm fetus ribbon synapses were first recognized by the inclusion of a prominent electron-dense material associated with synaptic vesicles. By 260 mm fetus conventional and ribbon synapses and junctions without synaptic vesicles formed similar to those found in the adult.