• Clinical and Experimental Reproductive Medicine
• /
• v.33 no.3
• /
• pp.171-178
• /
• 2006

Objective: Human embryonic stem (ES) cells have a great potential in regenerative medicine and tissue engineering. The human ES cells could be differentiated into specific cell types by treatments of growth factors and alterations of gene expressions. However, the efficacy of guided differentiation and isolation of specific cells are still low. In this study, we characterized isolated cells from differentiated human ES cells by magnetic activated cell sorting (MACS) system using specific antibodies to cell surface markers. Methods: The undifferentiated hES cells (Miz-hESC4) were sub-cultured by mechanical isolation of colonies and embryoid bodies were spontaneously differentiated with DMEM containing 10% FBS for 2 weeks. The differentiated cells were isolated to positive and negative cells with MACS system using CD34, human epithelial antigen (HEA) and human fibroblast (HFB) antibodies, respectively. Observation of morphological changes and analysis of marker genes expression were performed during further culture of MACS isolated cells for 4 weeks. Results: Morphology of the CD34 positive cells was firstly round, and then it was changed to small polygonal shape after further culture. The HEA positive cells showed large polygonal, and the HFB positive spindle shape. In RT-PCR analysis of marker genes, the CD34 and HFB positive cells expressed endodermal and mesodermal genes, and HEA positive cells expressed ectodermal genes such as NESTIN and NF68KD. The marker genes expression pattern of CD34 positive cells changed during the extension of culture time. Conclusion: Our results showed the possibility of successful isolation of specific cells by MACS system from undirected differentiated human ES cells. Thus, MACS system and marker antibodies for specific cell types might be useful for guided differentiation and isolation of specific cells from human ES cells.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.3
• /
• pp.311-318
• /
• 1996

Mycoplasmas have long been suspected of contributing to involuntary infertility in couples. However considerable disagreement exits concerning the role of genital mycoplasma infection in human infertility. Several investigators have noted abnormalities in the semen analysis of men with positive mycoplasma cultures, and early epidemiologic studies indicated that Ureaplasma urealyticum was linked to human reproductive failure on the basis of higher frequencies of isolation from infertile versus fertile couples and successful pregnancies in infertile couples after doxycycline therapy. However, subsequent investigators have questioned these findings because there are many studies in which treatment for mycoplasma in the male or female did not demonstrate an improved pregnancy rate, and semen samples from unexplained infertile men containing ureaplasmas have not revealed poorer motility, fewer spermatozoa and more aberrant forms. The objective of this study were to investigate the incidence rate of mycoplasma in semen and to investigate whether the presence of mycoplasma in semen makes significant difference to the semen volume, sperm motility and sperm counts. The results were that the rate of isolation of mycoplasma species was 70.3%. Semen volume is $2.84{\pm}1.01ml$ for culture negative and $3.15{\pm}1.42ml$ for culture positive group. Sperm motility is $46.23{\pm}15.80%$ for culture negative and $50.09{\pm}15.69%$ for culture positive group, and sperm count is $95.47{\pm}47.14({\times}(P)10^6/ml)$ for culture negative and $86.73{\pm}47.59({\times}10^6/ml)$ for culture positive group. In conclusion, we suggest that the presence of mycoplasma in semen makes no significant differences to the sperm parameters.

• Animal Systematics, Evolution and Diversity
• /
• v.12 no.4
• /
• pp.331-347
• /
• 1996

The geographic distribution and variation for Rhinogobius brunneus were surveyed by means of allozymic and morphological analyses and it was revealed that the Korean populations of R. brunneus comprise three distinct types, Type-A, Type-B, and Type-C, which show considerable differentiation to a degree of interspecific level(Rogers' S(1972): $S_{A-B}$=0.631, $S_{A-C}$=0.628, $S_{B-C}$=0.661). In addition, no evidence of gene flow among the types was found at sympatric area and it is assumed that reproductive isolation is completed. Moreover there is microhabitat segregation according to the distance from river mouth among each types and which segregation was regarded as a factor to facilitate reproductive isolating mechanism. Therefore, based on the evidence presented above, these three types of R. brunneus are considered as typical discrete species.

• Clinical and Experimental Reproductive Medicine
• /
• v.11 no.2
• /
• pp.69-76
• /
• 1984

In order to obtain high proportion of Y sperm the semen was laid over 6%,10% and 20% bovine serum albumin. Separated sperm were stained with quinacrine mustard in order to see F - body which could be seen in human Y sperm. But we could'nt find F-body in the bull sperm. So sperm were compared with size of sperm head. As a result of observation separated sperm was small in size of length and width of sperm head as compared with control sperm. So it was found that the proportion of Y sperm showed a marked increase in separated layer. Then the higher albumin density was, the higher the proportion of Y sperm which had smaller head and faster motility was. But the higher albumin density was, the lower the recovery rate of sperm was. So it was hard to separate Y sperm in oligospermia.

• Animal cells and systems
• /
• v.16 no.2
• /
• pp.135-144
• /
• 2012

$Dendronephthya$ $castanea$ Utinomi, 1952 is a member of the family Nephtheidae, and dominates shallow waters adjacent to the southern part of Jejudo Island, Korea. This species is a gonochoric internal brooder with a sex ratio of 1:1, and releases planulae around the time of the full and new moon from July to September, when the seawater temperature peaks. The gametogenic cycle is annual, and oogenesis (12 months) is longer than spermatogenesis (4-5 months). No difference in reproductive features including sexuality, sex ratio, gametogenesis and gametogenic cycles was found between the sympatric species $D.$ $castanea$ and $D.$ $gigantea$, and there was no temporal reproductive isolation. Investigation of the morphological taxonomy and molecular biology of these species indicates that they have very similar or identical traits, suggesting an absence of speciation and a need for taxonomic reclassification.

• Korean journal of applied entomology
• /
• v.58 no.4
• /
• pp.305-311
• /
• 2019

Artificial interspecific matings between Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) were conducted to know the possibility of hybridization of the two sympatric species. Reciprocal crossings successfully produced F1 hybrids. Most of F2 crosses yielded progenies except all mating trials with females of F1 hybrid obtained from M. phaseoli female. Inbreedings of the F2 hybrids produced F3 progenies. In backcrossings between F1 hybrids and parent lines, all the two mating trials with females of F1 hybrid obtained from M. phaseoli females did not produce any progeny, while other 6 backcrosses produced the next generations. Inbreedings of the backcross lines also produced subsequent progenies. These results indicated that F1 females produced from hybridization between M. phaseoli females and M. falcana males were sterile. Conclusively, it suggested that a partial reproductive isolation at a postzygotic stage can occur between the two sympatric species.

• Proceedings of the Zoological Society Korea Conference
• /
• 1996.10a
• /
• pp.59.2-59
• /
• 1996

No Abstract, See Full Text

• 대한생식의학회:학술대회논문집
• /
• 2003.12a
• /
• pp.147-148
• /
• 2003

• Korean Journal of Veterinary Research
• /
• v.39 no.2
• /
• pp.318-326
• /
• 1999

Respiratory pathogenic effects of several porcine reproductive and respiratory syndrome virus(PRRSV) isolates were examined in swine tracheal ring(STR) cultures by examining their effect on ciliary activity. One high and one low pathogenic PRRSV isolates were then selected and their pathogenicity investigated in 3-week-old conventional PRRSV-seronegative pigs. Ten pigs each were inoculated intranasally with the high or low pathogenic PRRSV isolate and 6 pigs were sham inoculated as negative controls. Two pigs each from the inoculated group and one pig each from negative control group were killed on 4, 7, 14, 21 and 28 days postinoculation(pI). At necropsy, degrees of gross lung lesion was determined. Turbinate, tonsil, trachea and lung samples were collected for virus isolation or histopathology. Gross lung lesions were observed mainly on 14 days PI with high and low pathogenic isolates inducing moderate diffuse and mild gross lung lesions, respectively. Inoculation of either the high or low pathogenic virus resulted in loss of cilia in ciliated epithelium of turbinates and trachea between 7 and 28 days PI. High pathogenic virus caused increased number of Goblet cells in the tracheal epithelial layer between 4 and 21 days PI whereas the low pathogenic virus did it between 14 and 28 days PI and with a lesser degree. Although both viruses produced interstitial pneumonia, the lesion was less severe with the low pathogenic virus. The isolation of high pathogenic virus from tissues and sera was earlier and more consistent than that of the low pathogenic virus. The agreement between in vitro and in vivo tests indicates that STR cultures may be used as a routine method to determine the respiratory pathogenicity of PRRSV isolates.

• Clinical and Experimental Reproductive Medicine
• /
• v.30 no.4
• /
• pp.293-298
• /
• 2003

목 적: 인간의 배아줄기세포는 전분화능과 영속성을 가지고 있어 발생 및 분화에 관련된 기초 연구 뿐 만 아니라 재생의학, 약물검색 등에서도 매우 유용한 재료로 이용될 수 있다.본 연구에서는 유전체의 변형이 배아줄기세포주의 확립 효율에 미치는 영향을 살펴보고자 비정상적인 포배기 배아에서 내세포괴를 분리하여 배양하였다. 연구 방법: 인간의 체외수정 및 배아이식술에서 공여 받은1개 또는3개의 전핵이 관찰되는 비정상 수정란 (n=20)과 착상전 유전진단에서 이수성이 확인된 배아 (n=27)를 대상으로 하였다. 일반적인 immunosurgery 방법으로 영양배엽세포들을 제거하고 내세포괴를 분리한 후 PMEF 혹은 STO feeder 세포위에서 배양하였다. 배아줄기세포의 배양시스템을 검증하기 위해서 이미 확립된 Miz-hES1 cell line을 동시에 같은 조건 하에서 계대배양하였다. 결 과: 비정상 수정란에서 발생된 포배기 배아에서 분리한 1개의 내세포괴가 배아줄기세포와 유사한 colony를 형성하였으나, 계대배양에는 실패하였다. 이수성 배아에서 발생된 포배기 배아의 내세포괴 배양에서는 두개의 colony가 계대배양 중에 영양배엽세포의 형태로 분화되어 미분화 상태를 유지하지 못하였다. 동일한 시기와 조건 하에서 계대배양된 Miz-hES1 cell line이 미분화상태로 유지됨을 karyotyping (46, XY)과 immunophenotyping (positive in SSEA-3 and -4)으로 확인하였다. 결 론: 본 연구의 결과에서 비정상 수정란과 이수성 배아에서 발생된 포배기 배아에서 유래한 내세포괴는 배아줄기세포주 확립 및 미분화 상태 유지 능력이 매우 저조한 것으로 여겨진다. 따라서, 인간의 배아줄기세포주를 확립하는데 있어 배아의 정상여부가 중요한 요소로 작용할 것으로 생각된다.