• Applied Microscopy
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• v.40 no.3
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• pp.169-176
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• 2010

Black molly (Poecilia sphenops) and sailfin molly (Poecilia latipinna) are a teleost belonging to Poeciliidae. The spermatogenesis between two species were investigated by light and electron microscope. The whitish testes of both black molly and sailfin molly were located between intestine and air bladder. The size of testis was major axis 7 mm, minor axis 2 mm. The testis contained numerous testicular cysts. In both black molly and sailfin, primary spermatocytes were comparatively large ellipsoidal, and mitochondria showed a marked development. The secondary spermatocyte was smaller than that of primary spermatocyte, highly condensed according to their development. The nucleus with electron-dense was round shape and flagella started to be formed. In spermiogenesis, chromatin was more condensed. The mitochondria were rearranged along the tail. The number of mitochondria was 2 to 4 in cross section and 8 to 10 in longitudinal section. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins. In conclusion, spermatogenesis and sperm morphologies of these two species were same. These morphological similarity seems to be an indication of the Poeciliidae.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.331-337
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• 1994

Response of the oocytes to parthenogenetic activation is one of the indice for cytoplasmic maturation. Maturational age-dependent parthenogenetic activation was examined in bovine oocytes. Follicular oocytes recovered from the slaughter house ovaries were matured in vitro in TCM 199+15% FCS+1Oiu/ml PMSG +10 iu/ml hCG from 24 to 48 h at 6 h intervals. The in vitro matured oocytes were activated by 7% ethanol for 7 min. The nuclear maturation and the cytoplasmic maturation were analysed by the nuclear configuration and pronuclei formation stained by rapid staining method. Cumulus oophori expansion increased as the maturation time increased. Proportions of the nuclear maturation were 81, 89, 72, 60 and 60% in IVM 24, 30, 36, 42 and 48 h groups, respectively. Abnor¬mality in metaphase II chromosome increased sharply from 36 h IVM. The rates of the pronuclei formation and diploid upon ethanol activation were 67, 68, 73, 84 and 87%, and 4, 5, 10, 16 and 20% in IVM 24, 30, 36, 42 and 48 h groups, respectively. It was suggested that maturational age increased the formation of the pronuclei and diploid, and that cytoplasmic maturation require longer maturation period than normal nuclear maturation. These results should be useful for determination of an appropriate time for fertilization in mammalian eggs matured or preincubated in vitro.

• Applied Microscopy
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• v.2 no.1
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• pp.7-15
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• 1972

The morphological and fine structural changes during the oogensis of Clonorchis sinensis were studied on the developing ovums in the ovary and ootype with electron microscope. Adult worms were removed from the hepar of the which and previously infected with metacercariae of Clonorchis sinensis. The ovary including the Mehlis' glands and an ootype from adult worm was prefixed for 1-2 hours in 1.25% glutaraldehyde buffered with 0.2M cacodylate at PH 7.2, secondarily fixed for 30 minutes in potassium bicromate and postfixed for an hour in 1% osmic acid buffered with 0.4M cacodylate at PH 7.2. After fixation tissues were dehydrated in an alcohol series, embedded in Epon 812 from propylene oxide and stained with saturated uranyl acetate and $Pn(NO_3)_2$ solution. Material was examined with a Hitachi HS-7S electron microscope. The periphery of the ovary, except for the posterior region, is made up of oogonia. As the oogonia divide they proliferate primary oocytes toward the central part of the ovary. After a period of growth the primary oocyte leaves the ovary and is penetrated by a sperm in the ootype. Sperm penetration immediately activates the primary oocyte to resume its meiotic activity. After the oocytes meiotic activity is completed, the pronuclei fuse to form a single cleavage nucleus which possesses two nucleoli. As the oocytes develop their cytoplamic materials are abundant; small mitochondria are abundant and often their profiles are more unmerous in one part of the cytoplasm than elsewhere; the granular endoplasmic reticulum becomes alveolar-sac form after it leaves the ovary it becomes stratified form. The reticulate Golgi apparatus is apparent in the developed oocyte. A little of cortical granules are distributed inside of the plasma membrane I oogonia and large quantity of cortical granules are arranged just inside of the plasma membrane of the primary oocyte and after fertilization they are disappeared with broken out.

• Development and Reproduction
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• v.13 no.1
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• pp.25-33
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• 2009

The cycle of the seminiferous epithelium and development of spermatids of Apodemus speciosus peninsulae were observed using a light microscope. On the basis of developing spermatocyte and spermatid, the cycle of the seminiferous epithelium was divided into 9 stages. Type Ad spermatogonia were appeared in all stages ($I{\sim}IX$). The Ap, In, and B types of spermatogonia were appeared from stage I, II and III, and IV, respectively. In prophase of first meiosis, the leptotene spermatocytes appeared from stage V and VI, zygotene spermatocytes from stages I, II, VII, VIII, and IX, pachytene spermatocytes from stage III to VII, diplotene spermatocytes in the stage VIII, and secondary spermatocytes in stage IX. On the basis of morphology of spermatid head, developing of nuclear and acrosome and the morphological change of cytoplasm, the developing of spermatids was divided into 12 steps. Considering all the results, A. s. peninsulae displayed very similar result with A. agrarius coreae that is allied species when compare correct characters developing of spermatids with spermatogonia and appearance time of the spermatocyte. Appearance time of the same cell and number of spermatogonial generation was thought that characters of the species, and information may be useful in identifying the species.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.160-166
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• 2010

A homothallic filamentous fungus Aspergillus nidulans has been used as the a model organism for studying growth and development for eukaryotic system. Various studies about specific transcription factors have been performed for elucidating the molecular mechanisms of growth, asexual and sexual developmental processes. Among them, the fkhE gene (AN2025.3) is located in chromosome VII and contains an ORF encoding 718 amino acid polypeptide intervening with two short introns. The cDNA sequencing revealed that at least four types of alternative splicing events were occurred when the fkhE gene was transcribed. The putative FkhE polypeptide contains a conserved forkhead domain and a bipartite nuclear localization signal at it's N-terminus and C-terminus, respectively. Deletion of fkhE resulted in impaired conidiophore formation in a solid medium. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhE deletion mutant produced conidiophores and conidia under the submerged culture, indicating that the fkhE gene is involved in asexual developmental process similar to the fkhF gene.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.468-473
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• 2009

Fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) were used for chromosome analysis of hybrids (2n=16) between onion (Allium cepa L., 2n=2X=16) and welsh onion (A. fistulosum L., 2n=2X=16). 5S rDNA, 45S rDNA, and tandemly repeated DNA (TSD) sequence were used as probes for FISH analysis. A. fistulosum specific DNA probe of telomeric repeats and A. fistulosum DNA were used for GISH analysis. In the analysis of meiotic chromosome GISH revealed that hybrids have 7 bivalants and 2 univalents chromosome and 2 univalents were derived from A. fistulosum chromosomes. In somatic chromosomes of hybrid each 8 chromosomes were derived from A. cepa and A. fistulosum, respectively. FISH signal of 45S rDNA probe in A. fistulosum was detected at secondary constriction of chromosomes, while FISH signal in A. cepa was observed in both secondary constriction and telomere of chromosomes. TDS signals in A. fistulosum chromosomes were detected at all subtelomeric of 8 chromosomes and also in 2 pericentromeric of the chromosomes, whereas TDS signals in A. cepa were observed only in subtelomeric in all chromosomes. The pattern of TDS signal in hybrid chromosomes was similar to those of A. fistulosum chromosomes.

• Journal of Life Science
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• v.29 no.1
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• pp.105-111
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• 2019

In recent years, progress has been made in the search for the development of new anti-cancer agents by employing specific inhibitors of histone deacetylase (HDAC)-6 to block signal transduction pathways in cancer cells. This study examined the effects of tubastatin A (TubA), an HDAC-6 inhibitor, on the growth and development of immature oocytes in murine ovaries using RNA sequencing analysis. The results from a gene set enrichment analysis (GSEA) indicated that the expression of most of the gene sets involved in the cell cycle and control and progression of meiosis decreased in the TubA-treated group as compared with that in germinal vesicle (GV) stage oocytes. In addition, an ingenuity pathway analysis (IPA) suggested that TubA not only caused increased expression of p53 and pRB and decreased expression of CDK4/6 and cyclin D but also caused elevated expression of genes involved in the control of the DNA check point in G2/M stage oocytes. These results suggest that TubA may induce cell cycle arrest and apoptosis through the induction of changes in the expression of genes involved in signal transduction pathways associated with DNA damage and the cell cycle of immature oocytes in the ovary.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.375-383
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• 2000

The nuclear maturation and developmental competence of immature, oocytes collected from donors at various morphology of corpus luteum (CL) and fertilized in vitro was investigated by comparing the meiotic activity and the yields of embryos. Ovaries were divided and classified into 4 groups as the following criteria : Group 1 ; ovaries showed evidence of recent ovulation (corpus hemorragicum). Group 2 ; apex of CL was red or brown. Vasculization was limited to periphery of CL. Group 3 ; apex of CL was orange or tan. Vasculization was covered over apex of CL. Group 4 ; CL was light yellow to white and firm in texture and the vascular network on the surface of CL had disappeared. Modified TCM 199 was used for maturation in vitro of immature oocytes and development was induced by using TLP-PVA as a basic medium. When oocytes collected from each group of donors had been matured for 4, 14, and 24 hours in vitro, the proportion of oocytes reaching metaphase I and metaphase II were not different among oocytes from 4 group of ovaries. Mature metaphase II stage of oocytes in each group was first observed at 14 hours, whereas completion of maturation of. oocytes in each group was at 24 hours. Luteal morphology of ovaries had little effect on the proportion of embryos reached 2 cells and 8 cell stage. However, the proportion of embryos cleaved to morula and blastocyst stage was significantly higher in the oocytes obtained from group 1 and 3 than in the oocytes from group 2 and 4 (p＜0.05). This data suggest that reproductive status of the donor significantly influence the yield of in vitro embryos.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.305-315
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• 2001

In this study, the production of transgenic embryo was attempted by microinjection or round spermatid cultured with foreign DNA. At first, the expression of haploid spermatids specific gene, mTP1 in mouse and hPrm2 in hamster spermatids were investigated by RT-PCR method in testes of young mice and hamster testis. The specific gene expression first appeared at 18 days post partum (dpp) in mice spermatid and 20 dpp in hamster spermatid. Therefore, the round spermatids isolated from 17 dpp mice and 19 dpp hamster were used for the introduction of foreign EGFP gene into haploid round spermatids. For the introduction of EGFP gene haploid round spermatids suspended in medium including EGFP gene were treated with a different electric field strength at 0.11, 0.18 and 0.44 ㎸/cm. After electrical stimulation, viability of testicular sperm cells and 67.6%, 66.4% and 49.9%, in mice and 62.6%, 57.9% and 27% in hamster, respectively. These values were significantly lower than those of non-treated control groups 80.5% in mouse and 69.1% in hamster After 72 hrs culture, the highest expression rate of EGFP gene, 28.5% in mice and 32.1% in hamster were obtained from tile spermatogenic cells electroporated by the field strength or 0.18 ㎸/cm. Then, the ability of fertilization and embryonic development of haploid spermatids transfected with foreign EGFP gene were estimated by the microinjection of spermatids into hamster oocytes. The Irate pronuclear formation rate (77.5%) was lower than non-treated control (80%), and the cleavage rate of the treated group (58.8%) was lower than control (65%). To prove the foreign EGFP integration in hamster embryos, 2-cell stage hamster embryos were subjected to the observation under the fluorescence microscope, and the PCR analysis. As a result, about 44% of 2-cell embryos were showed the integration of EFGP gene into their genome. Therefore, These results suggest the possibility to produce transgenic hamsters by microinjection of haploid spermatid transfected with foreign DNA.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.547-554
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• 2004

Telomeres are nucleoprotein structures at the ends of chromosomes consisting of tandem repeat sequences of . (TTAGGG)n. Telomeres serve as guardians of the genome, protect individual chromosomes within the nucleus, and help in meiotic pairing of homologous chromosomes. To investigate the telomere distributions of cattle and pig chromosomes, fluorescence in situ hybridization(FISH) was carried out on metaphase spreads of in vitro fibroblast cultures from Holstein and Landrace using a human telomeric DNA repeat probe. Results indicate that the distinct double spots on both ends of chromosomes of cattle and pigs were observed. In cattle, there was a random variation in the intensity of telomere signals among chromosomes. In pigs, an interstitial telomeric signal was observed on the chromosome 6q1 of all the cells examined. According to quantitative fluorescence in situ hybridization(Q-FISH) analysis, some chromosomes had consistently much more telorneres at one end of chromosomes. In general, both species had consistently much more telomeres at q-end than p-end on most of chromosomes. The relative amount of telomeres on bovine chromosomes was higher than that on pig chromosomes. In additions, Y chromosome had the highest relative amount of telorneres in cattle and pigs.