• Development and Reproduction
• /
• v.10 no.1
• /
• pp.9-17
• /
• 2006

The cycle of the seminiferous epithelium and morphological features of spermatids in Crocidura dsinezumi were studied by light microscopy. The cycle of the seminiferous epithelium was divided into 12 stages. The dark type of spermatogonium(Ad) is appeared in all stages, and intermediate(In) in stage IV and B spermatogonium in stage V and VI were observed. The development of the acrosomal system, and changes in nuclear morphology of spermatids were divided into 14 steps. The Golgi, cap, acrosomal, maturation and spermiation phases were observed during steps $1{\sim}2$, steps $3{\sim}6$, steps $7{\sim}10$, steps $11{\sim}13$, and step 14, respectively. Our results provide the foundation for future studies of the spermiogenesis of Crocidura dsinezumis.

• Journal of Embryo Transfer
• /
• v.17 no.3
• /
• pp.195-201
• /
• 2002

This study was to assess the developmental capacity of oocytes matured in vitro after 20, 15, 10, 5 and 0 days of organ culture when ovaries were isolated from juvenile mice at 0-, 5-, 10-,15- and 20-day old, respectively, and to develop in vitro culture system that observed a view to morphology of ovaries and nucleus maturation of oocytes. The size of ovaries decreased 35.9%, 8.7%, 1.2% and 14.4% after 20, 15, 10, 5 days of organ culture when the ovaries were isolated from 0-, 5-, 10 and 15-day old mice, respectively. After organ culture, the recovery rates, diameters of oocytes and the number of oocytes progressed from GV to MII were increased as increasing age of mice.

• Reproductive and Developmental Biology
• /
• v.34 no.3
• /
• pp.257-262
• /
• 2010

The purpose of this study is to establish a basic culture system enabling in vitro culture of chicken blastodermal cells and to test the feasibility of retrovirus-mediated gene transfer to the cultured cells. The blastodermal cells were isolated from freshly laid eggs of stage X and cultured with or without STO feeder layer cells. Stem cell-like morphology was maintained after multiple passages and RT-PCR analysis proved expression of several stem cell specific genes. Immunocytochemical analysis using antibodies of anti-EMA-1 and anti-SSEA-1 also showed the feature of stem cells. Infection of the cultured blastodermal cells with LNCGW retrovirus vector resulted in successful transfer of foreign genes. The results of this study may be useful in establishing stem cell-mediated transgenic chicken production.

• Reproductive and Developmental Biology
• /
• v.34 no.3
• /
• pp.169-173
• /
• 2010

Correlations between cumulus cells and germinal vesicle (GV) chromatin configuration were examined in porcine oocytes. Cumulus-oocyte complexes (COCs) were collected from 2~6 mm follicles and divided into three categories according to cumulus cell morphology. "A" group was compacted COCs with more than three cumulus cell layers. "B" group was COCs with less cumulus cell layers than "A" group. "C" group was COCs with one or less layer of cumulus cells. Cumulus cells were removed 0.1% hyaluronidase, and denuded oocytes were stained with Hoechst 33342. GV chromatin configuration was classified into GV-Con and GV-Dis. GV-Con meant that a nucleus was surrounded by condensed chromatin in a ring. GV-Dis meant that filamentous chromatin clumps were distributed in nucleus. The proportion (80.2%) of GV-Con in "A" group was significantly higher than "B" (62.0%) or "C" (44.9%). The proportion (55.1%) of GV-Dis in "C" group was significantly higher than "A" (19.8%) or "B" (38.0%). The meiotic competence of COCs was examined after 44 h culture. The proportion (90.0%) of oocytes reaching to metaphase II (M-II) in "A" group was significantly higher than "B" (76.5%) or "C" (45.5%). In conclusion, oocytes with good quality cumulus cell layers are synchronized early GV stage, and early GV stage is important for meiotic competence in pigs.

• Applied Microscopy
• /
• v.26 no.3
• /
• pp.267-275
• /
• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• Korean Journal of Animal Reproduction
• /
• v.20 no.1
• /
• pp.9-17
• /
• 1996

This study was conducted to investigate freezability of in vitro and in vitro matured rabbit oocytes, possibility of NT using frozen-thawed unfertilized oocytes, and NT efficiency by zona-slit micromanipulation. After freezing of in vitro matured oocytes, 33 to 49% of oocytes appeared normal morphology and 1.0M DMSO and 1.5M glycerol showed slightly high survival rate, but there was no difference in survival between two cryoprotectants. Freezability of in vitro matured oocytes was low in 1.5M glycerol and more sensitive to freezing. Efficiency of enucleation and fusion rate in method B was higher than that in method A and no difference in this efficiency was between 3 groups of oocytes in method B. Cleavage rate and developmental capacity to M＋B stage of fused embryos derived from frozen oocytes was greatly lower than that from fresh oocytes, respectively(39.1% : 79.5% ; 3.1% : 19.3%) and there was no difference in cleavage rate between DC voltages in two group oocytes. Additional incubation in cytochalasin B after electrical stimulation did not affect embryo development. In conclusion, it is suggested that enucleation and nucelar transfer by slitting of zona is more effective method in rabbit and that further study on optimum freezing conditions for in vitro matured oocytes is necessary to use as recipient oocytes.

• Fisheries and Aquatic Sciences
• /
• v.8 no.1
• /
• pp.17-26
• /
• 2005

The ultrastructure of germ cells during spermatogenesis and the structural changes in the epithelial cells of the seminal vesicle with testicular development in male Neptunea (Barbitonia) arthritica cumingii were investigated monthly based on electron microscopic and histologic observations. N. arthritica cumingii (Gastropod: Buccinidae) undergoes internal fertilization and possesses a modified type of spermatozoon, which is approximately 20$\mu$m long. The axoneme of the tail flagellum consists of nine peripheral pairs of microtubules and one central pair. Many spermatozoa occur in the acini of the testis in the ripe stage and are transported to the seminal vesicles in the accumulating phase. In males, the monthly gonadosomatic index began to increase in September and reached a maximum in February. Subsequently, it decreased rapidly after April. The testis of this species can be classified into four developmental stages: the active (August to September), ripe (October to July), copulation (April to July), and recovery (July to August) stages. Structural changes in the epithelial cells of the seminal vesicles of this species could be classified into three phases: (1) S-I (resting), (2) S-II (accumulating), and (3) S-III (spent) phases. The morphology and structure of the epithelial cells of the seminal vesicle differed in each phase; the cells were cuboidal, squamous, or columnar in the resting, accumulating, or spent phases, respectively.

• The korean journal of orthodontics
• /
• v.17 no.1
• /
• pp.23-32
• /
• 1987

There are variations in regional cranial and facial balance as a normal developmental process and regional imbalances often tend to compensate each other to provide functional equilibrium. This study was designed to analyse the patterns of morphologic harmony and inharmony inherent in normal occlusion and malocclusion. The subjects consisted of 92 individuals with normal occlusion and 60 Class III malocclusion patients. Their lateral cephalograms were traced and analysed using the counterpart analysis described by Enlow. The normal occlusion group was divided into Normal Types A and B according to the relative positions of Points A and B. The following conclusions were reached: 1 The normal occlusion consisted of $28.3\%$ of Normal Type A and $69.6\%$ of Normal Type B. 2. The Normal Type A and B differed from each other in the morphology of the cranial base, the mandibular ramus and corpus, and the functional occlusal plane. The Normal Type B showed considerable mandibular protrusion effect in the effective dimension and alignment of the above factors. 3. Most normal individuals showed some degree of disharmony among morphologic factors but the deviations were relatively small. 4. The Normal Type B was less balanced than the Normal Type A. 5. More regional imbalances were involved in Class III malocclusion and the imbalances were more severe.

• Biomedical Science Letters
• /
• v.13 no.1
• /
• pp.61-69
• /
• 2007

The cycle of the seminiferous epithelium and the development of spermatids of Apodemus agrarius coreae were observed using a light microscope. The cycle of the seminiferous epithelium was divided into 10 stages, and developing spermatids were subdivided into 10 steps. The Golgi phases occurs the first two steps ($St_1,\;St_2$), and the cap phases had the next two consecutive steps ($St_3$ and $St_4$). The acrosomal phases consisted of steps $5{\sim}8$ ($St_5-St_8$), and the remaining two steps consisted the maturation ($St_9$) and spermiation ($St_{10}$) phases, respectively. Type Ad spetmatogonia are appeared in all stages (I-X). Type Ap spermatogonia appeared from stage I and II, In spermatogonia from stage III, IV and V, and B spermatogonia from stages VI. The leptotene spermatocytes appeared from stage VII, zygotene from stages I, II, VIII, IX and X, pachytene from stage III to VIII, diplotene in stage IX, and meiotic figures and secondary spermatocytes in stage X. These data are considered in relation to interspecific differences in sperm morphology.

• Animal cells and systems
• /
• v.3 no.4
• /
• pp.369-374
• /
• 1999

The life history and development of Tetrastichus sp. parasitizing fallwebworm pupa in Korea were studied. The mean lifetime fecundity was 94.7 with a maximum of 125, and the portion of female progeny averaged 90.3%. A male and a female lived for an average of 19.8${\pm}$4.5 and 21.7${\pm}$4.2 days, respectively. The duration of development for each stage was as follows: egg, 2 d; the 1st instar larva, 2${\pm}$1 d; the 2nd instar larva, 2${\pm}$1 d: the 3rd instar larva, 3${\pm}$1 d; the 4th instar larva, 6${\pm}$2 d; and pupa, 8${\pm}$2 d. Total developmental duration from hatching of the larva to adult emergence required 21.1${\pm}$3.7 d, and females took 1-2 days more than males in the incubator (28$^{\circ}C$, 70% RH, and 16:8 LD).