• 식물분류학회지
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• 제44권4호
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• pp.288-297
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• 2014

이 연구의 목적은 우리나라에서 식물학이 시작된 이후 57년이 넘도록 나자식물 분류군에 대하여 다음과 같이 잘못 인식되어 온 관행의 원인을 분석하는 데 있다. 즉, 수많은 식물(분류)학 관련 매체들에서, 나자식물(꽃이 피지 않는 종자식물)의 생식구조(cone 및 pollen)에 관한 용어 및 기재에 피자식물(꽃이 피는 종자식물)에서 사용되는 생식기관(꽃)의 용어들을 그대로 적용하여 쓰고 있다. 이로 인하여, 마치 나자식물이 꽃이 피는 식물(피자식물)인 것처럼 오도되고 있다. 특히, 이러한 오류의 관행은 각급 학교에서 교사와 학생들이 꽃에 대한 개념 및 정의를 이해하는 데 있어서 커다란 혼란을 불러 일으키고 있으며, 이는 식물(분류)학 교육에 심각한 문제가 아닐 수 없다. 따라서 많은 식물학 관련 매체들로부터 나자식물에 대하여 잘못 표현된 용어 및 기재를 조사하여, 이를 분계도, 생식구조의 해부학, 분류체계의 역사적 배경 등의 관점에서 분석하고 논의하였다.

• Clinical and Experimental Reproductive Medicine
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• 제47권1호
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• pp.68-76
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• 2020

Objective: Since sperm abnormalities are known to be a major reason for recurrent pregnancy loss (RPL), any defects in DNA structure and chromatin condensation can place embryos at risk in the early stage of development and implantation. As antioxidants such as vitamin C may play a protective role against the destruction of protamine genes in sperm chromatin, this study was conducted to evaluate the effects of vitamin C on chromatin and the expression of protamine genes in the male partners of couples with RPL. Methods: Twenty male partners of couples with RPL were selected as the intervention group and received vitamin C supplementation (250 mg daily for 3 months). Healthy fertile men (n = 20) were included as controls. Sperm chromatin, DNA integrity, and the expression levels of protamine genes were evaluated before and after treatment. Results: Significant differences were found in sperm morphology, protamine deficiency, and apoptosis between the two groups and before and after vitamin C administration. A significant change was found in mRNA levels of PRM1, PRM2, and the PRM1/PRM2 ratio after treatment. Conclusion: Daily oral administration of vitamin C may improve human sperm parameters and DNA integrity by increasing protamine gene expression levels in the male partners of couples with RPL. The beneficial effects of vitamin C supplementation as an antioxidant for the male partners of couples with RPL could lead to improved pregnancy outcomes in these cases.

• Animal Bioscience
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• 제35권9호
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• pp.1303-1313
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• 2022

Objective: The current study aimed to perform whole-genome resequencing of Chinese indigenous Mongolian sheep breeds including Ujimqin, Sunit, and Wu Ranke sheep breeds (UJMQ, SNT, WRK) and deeply analyze genetic variation, population structure, domestication, and selection for domestication traits among these Mongolian sheep breeds. Methods: Blood samples were collected from a total of 60 individuals comprising 20 WRK, 20 UJMQ, and 20 SNT. For genome sequencing, about 1.5 ㎍ of genomic DNA was used for library construction with an insert size of about 350 bp. Pair-end sequencing were performed on Illumina NovaSeq platform, with the read length of 150 bp at each end. We then investigated the domestication and signatures of selection in these sheep breeds. Results: According to the population and demographic analyses, WRK and SNT populations were very similar, which were different from UJMQ populations. Genome wide association study identified 468 and 779 significant loci from SNT vs UJMQ, and UJMQ vs WRK, respectively. However, only 3 loci were identified from SNT vs WRK. Genomic comparison and selective sweep analysis among these sheep breeds suggested that genes associated with regulation of secretion, metabolic pathways including estrogen metabolism and amino acid metabolism, and neuron development have undergone strong selection during domestication. Conclusion: Our findings will facilitate the understanding of Chinese indigenous Mongolian sheep breeds domestication and selection for complex traits and provide a valuable genomic resource for future studies of sheep and other domestic animal breeding.

• 한국수산과학회지
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• 제30권4호
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• pp.627-633
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• 1997

1995년 11월부터 1996년 10월까지 부산 수영만 인근해역에서 채집된 쭈굴감펭, Scorpaena miestoma의 생식소 구조, 생식세포의 발달 및 생식주기 등이 광학현미경 조직표본을 기초로 연구되었다. 정소의 내부조직상은 다수의 곡정세관으로 구성된다. 각각의 곡정세관은 여러개의 소낭 구조를 가지는데 각 소낭내의 생식세포들은 같은 단계의 발달상태를 보인다. 난소내부는 난소외막으로 부터 시작된 여러장의 난소박판으로 구성되어 있다. 난원세포는 난소박판의 내부상피에서 유래하며, 난모세포로 성장하면서 난소강쪽으로 돌출되어 난병에 의해 난소박판에 연결된다. 생물학적최소형은 암${\cdot}$수 모두 전장 12.5cm로 조사 되었다. 생식소숙도지수는 암 (3.81)${\cdot}$수(0.23) 모두 10월에 연중 최고치를 나타냈다. 암컷의 생식주기는 성장기 ($5\~8$월), 성숙기 ($9\~10$월), 완숙 및 산란기 ($11\~12$월) 그리고 회복 및 휴지기 ($1\~4$월)로 나눌 수 있다. 수컷의 생식주기는 성장기 ($6\~8$월), 성숙기 ($9\~10$월), 완숙 및 방정기 ($11\~l$월) 그리고 회복 및 휴지기 ($2\~5$월)로 나눌 수 있다.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제49차 추계학술대회
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• pp.121-122
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• 2005

• Journal of Plant Biology
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• 제30권1호
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• pp.43-57
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• 1987

The epidermal structure and stomatal types in vegetative and reproductive organs of three species of Bryophyllum(B. crenatum, B. diagremontion, B. tubiflorum) were described. The epidermal cells were polygonal, isodiametric, and rectangular in the leaves and stems, and elongated cells in the stamens, styles, and ovaries. These cells were commonly thick, and arched or sinuous in the leaves, epiphylous bunds, petals and ovaries. They were straight in the stems, petioles, pedicels, and peduncles. In both vegetative and reproductive organs, the subsidiary cell walls were commonly thin and mostly arched in all the organs. The great majority of the mature stomata in all the organs were helicocytic type with a helix of four to six subsidiary cells. The mature stomata varied from organ to organ with regard to the number and arangement of subsidiary cells. The ontogenetic type of stomata in all the organs was mostly helico-eumesogenous type. This type was subdivided into three subtypes such as parahelico-eumesogenous, anomohelico-eumesogenous, and diahelico-eumesogenous stomata on the basis of the division angle fo the guard mother cell. Sometimes, the anisoeumesogenous type was found in various organs. This type was subdivided into three subtypes such as paraniso-eumesogenous, anomoaniso-eumesogenous, and dianisoeummesogenous stomata. The tetra-eumesogenous and duplotetra-eumesogenous types were rarely found; the former in the leaf of B. crenatum and the latter in the leaf of B. diagremontiana. Anomometric patterns in the mesogenous categorry of stomatal types was observed in a few organs of all the materials. A new stomatal type with tetra-eumesogenous stoma within a girdle of three subsidiary cells fo aniso-eumesogenous in the leaf of B. diagremontiana was firstly observed in the vascular plants. This stoma was termed the cotetra-aniso-eumesogenous type. Anormal stomata such as aborted stomata, single guard cells, stoma with a constricted part in the middle of large guard cells, and arrested stomata were found in the various organs of all the materials.

• Clinical and Experimental Reproductive Medicine
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• 제45권3호
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• pp.101-109
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• 2018

In an age when a small quantity of sperm can lead to pregnancy through in vitro fertilization or intracytoplasmic sperm injection, selecting healthy sperm is important. Sperm DNA fragmentation (SDF) is known to be higher in infertile men. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and the alkaline comet test are SDF tests that directly measure DNA damage and have shown closer correlations with assisted reproduction results than indirect tools such as the sperm chromatin structure assay or the sperm chromatic dispersion test. It is difficult; however, to endorse a single test as the best test overall; instead, it is best to select a testing method based on each patient's clinical condition and goals. In a couple struggling with infertility, if the male partner has a high level of SDF, he should aim to decrease SDF through lifestyle modifications, antioxidant treatment, and ensuring an appropriate duration of abstinence, and physicians need to treat the underlying diseases of such patients. If sperm DNA damage continues despite the patient's and physician's efforts, other methods, such as micromanipulation-based sperm selection or testicular sperm extraction, should be used to select healthy sperm with nuclear DNA integrity.

• Animal cells and systems
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• 제1권1호
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• pp.53-61
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• 1997

Seasonal variation of the population structure and the reproductive pattern of the Korean striped field mouse, Apodemus agrarius, were investigated. High capture ratios in juveniles, young adult, and old adult mice were found during the period from October to November, from November to March, and from May to September, respectively, and extremely low capture ratios of old adults during the period from November to February were characteristic. It seemed that the young adults that survived during the winter might become older by summer and have been counted as the old adults. The breeding in the mice began earlier in males (from mid February or early March to late October) than in females (from mid March to late October), having a peak in August and September, and both the male and female mice weighing more than 20 g generally reached sexual maturation in general. In the breeding season, both young and old adult males had large testes with enlarged seminiferous tubules filled with numerous germ and Sertoli cells, and expanded caudal epididymides with a vast number of spermatozoa; the females had many Graafian follicles and corpora lutea in large ovaries, and developed uterine glands in the thick endometria. The lower ratios of the testis weight to the body weight in July and August in 1994 compared to 1995 seemed due to the extreme drought and considerably higher temperature in 1994, but the decrease in the ratio in mid-summer, only in the old mice, in both years might be explained partially by aging.

• Clinical and Experimental Reproductive Medicine
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• 제44권4호
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• pp.201-206
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• 2017

Objective: The aim of this study was to compare the efficacy of swim-up and density gradient centrifugation (DGC) for reducing the amount of sperm with fragmented DNA, sex chromosome aneuploidy, and abnormal chromatin structure. Methods: Semen samples were obtained from 18 healthy male partners who attended infertility clinics for infertility investigations and were processed with swim-up and DGC. The percentages of sperm cells with fragmented DNA measured by the sperm chromatin dispersion test, normal sex chromosomes assessed by fluorescence in situ hybridization, and abnormal chromatin structure identified by toluidine blue staining were examined. Results: The percentage of sperm cells with fragmented DNA was significantly lower in the swim-up fraction (9.7%, p= 0.001) than in the unprocessed fraction (27.0%), but not in the DGC fraction (27.8%, p= 0.098). The percentage of sperm cells with normal X or Y chromosomes was comparable in the three fractions. The percentage of sperm cells with abnormal chromatin structure significantly decreased after DGC (from 15.7% to 10.3%, p= 0.002). The swim-up method also tended to reduce the percentage of sperm cells with abnormal chromatin structure, but the difference was not significant (from 15.7% to 11.6%, p= 0.316). Conclusion: The swim-up method is superior for enriching genetically competent sperm.

• Reproductive and Developmental Biology
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• 제32권2호
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• pp.127-133
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• 2008

The objective of this study was two folds: to investigate the relationship between paternal identification rate and sperm quality parameters such as motility and sperm chromatin structure assay after heterospermic insemination; to see if mutual complement between tests and development of useful technique to enhance the fertility in artificial insemination. In individual boar's fertilizing ability, 3 high fertility boars showed significantly high fertility (p<0.05) compared to 3 low fertility boars, but there was no difference in litter size between two groups. Sperm motility test in pooled and individual semen using computer assisted sperm analysis (CASA) revealed that no significant difference among boars. The high fertile boar showed tendency of low %Red (High red fluorescence/green+red fluorescence) in sperm chromatin structure assay (SCSA) but paternal identification rate from piglets did not differ after heterospermic insemination. The correlation coefficient between individual or pooled semen function test and farrowing rates were well correlated as follows: %Red with litter size (r= - 0.53, p=0.03); %Red with paternal identification rates (r=-0.51, p=0.03); paternal identification rates with litter size (r=0.57, p=0.02). These results indicate that sperm chromatin structure assay and sperm quality parameter test in pooled semen are useful method to predict and evaluate the fertilizing capacity after heterospermic insemination in boars.