• ALGAE
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• 제17권3호
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• pp.145-151
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• 2002

Three species of marine algae, two browns and one red were newly reported from the eastern and the southern coast of Korea including Cheju Island. their vegetative and reproductive structures were described. Colpomenia phaeodactyla Wynne et J.N. Norris (Scytosiphonaceae, Phaeophyceae) commonly occured in middle to lower intertidal zone of southern coast. Plants consisted of clusters of elongated and hollow sacs arising from an adherent colpomenioid base. Plurilocular sporangia were multiseriate, forming dense, extensive sori over the erect sacs. Cutleria adspersa (Mertens ex Roth) De Notaris (Cutleriaceae, Phaeophyceae) was collected from subtidal region of Cheju Island. It was characterized by broadly fan-shaped habits with golden brown colour and hair-fringed margines, attached by rhizoids along undersurface. Halarachnion latissimum Okamura (Furcellariaceae, Rhodophyceae) was found adrift from several areas of southern coast. Plants were brownish red, filmy and dlicate, membranaceous roundish fronds. Cystocarps were globular and formed under the cortical layer. Tetrasporangia were oblong and zonately divided.

• Reproductive and Developmental Biology
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• 제41권2호
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• pp.41-50
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• 2017

Until today, success in germline cells and tissue cryopreservation is limited mainly due to the poor understanding of the complex physiological processes can lead to cell damage during cryopreservation. Germline cells, from both male and female, have unique ability to differentiate into one or more cell lines and thus it becomes a crucial point to store them in subzero temperature with the minimal damage of their functional properties and maximum recovery of unchanged and viable cells when thawed. In the past three decades, a vast research has been performed using various different animal models which in fact have led to development of new methodologies and optimization of older one. However, successful use of animal model has provided the opportunity in research with human germline cells and tissues preservation, but not in all the cases. Therefore, the use of new cryo-protective chemicals and modified protocols have been often found in different groups of researchers based on the types, physical structures, utility and animal species of the specimens to be cryopreserved. This review discusses about the basics of different types of cryopreservation methodologies and commonly used optimized protocols and cryoprotectants for germline cells and tissues preservation.

• Applied Microscopy
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• 제46권2호
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• pp.83-88
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• 2016

Structural differentiation of the connective stalk in giant duckweed, Spirodela polyrhiza, was examined to reveal the anatomical and ultrastructural characteristics within reduced shoot. The study focuses primarily on structural features of the connective stalk (CT), which connect offspring to their mother fronds. Photoautotrophic offspring fronds remained connected by stalks to mother fronds in the reproductive pockets until separation. The CT originated from the meristematic region of the abaxial frond and joined the fronds laterally with two abscission layers. The most notable features of the CT were polymorphic mitochondria, random occurrences of fibrillar structures in intercellular spaces, and great variability in cell wall thickness. Vascular tissues in CTs were highly reduced, demonstrating only a central vascular strand. Grana with 2 to 4 thylakoids and starch grains were found in the chloroplasts. A chlorophyll assay indicated high chlorophyll concentrations in daughter fronds and low concentrations in CTs. The frond and CT, while physically connected to each other, functioned independently. Despite great reduction in S. polyrhiza, the CT has proven to be very efficient for separating offspring from the mother frond, which lends to its capacity for rapid vegetative reproduction. The ultrastructural aspects of CTs in S. polyrhiza were characterized for the first time in this study.

• 대한세포병리학회지
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• 제19권1호
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• pp.47-51
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• 2008

Adenomatoid tumor is a benign neoplasm of a mesothelial origin, and it usually occurs in the reproductive organs, especially in the epididymis. The author experienced a case of adenomatoid tumor involving the tunica albuginea and testicular parenchyme without any evidence of epididymis involvement. The patient was a 36-year-old man with a painless scrotal mass that he had experienced for 2 months, and this mimicked testicular neoplasia, including metastatic carcinoma, or other benign lesions. The imprint cytology of the tumor showed a hypocellular smear with mainly arranged cells in cohesive monolayered clusters along with occasional singly dispersed cells and naked nuclei in a clean background. The cellular clusters formed vague glandular and cord-like structures. The tumor cells were large polygonal to columnar cells with a relatively monomorphic appearance. The nuclei were oval to round shape and they showed vesicular, fine chromatin and inconspicuous nucleoli. The cytoplasm was moderate to abundant, and it contained fine vacuoles in some tumor cells. Mitoses and cellular pleomorphism were not present. Awareness of the cytologic finding of this lesion is necessary to screen or differentiate a testicular or paratesticular mass before and/or during surgery because the cytology may be useful as a diagnostic tool. Pathologists should be aware of the cytologic features of common lesions in this anatomic region so as to avoid performing aggressive and unnecessary surgical procedures.

• 대한수의학회지
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• 제61권3호
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• pp.25.1-25.7
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• 2021

The axolotl has extraordinary regeneration capacity compared to other vertebrates. This remarkable potential has been attributed to its life-long neoteny, characterized by the exhibition of embryonic characteristics at the adult stage. A recent study provided a detailed morphological analysis of the sperm morphology of the Ambystoma mexicanum using routine and detailed histological techniques. The primary purpose of the present study is to describe a simple and inexpensive method for evaluating the morphology of axolotl sperm. In this study, spermatophore structures were collected and spread on slides and air-dried. The slides were stained with periodic acid Schiff, toluidine blue, Masson's trichrome, Giemsa, Spermac, and Diff-Quik dye for a morphological examination. The slides were coated with gold/palladium for a scanning electron microscopy examination. The sperm of the axolotl consisted of an elongated head, a neck, and a flagellum covered with an undulating membrane. The lengths of the midpiece, tail, and head were 8.575 ㎛, 356.544 ㎛, and 103.661 ㎛, respectively. In the flagellum part, the wavy membrane structure, whose function has not been explained, surrounds the tail. The data obtained from this study will constitute an important step in designing future research on the reproductive and regeneration capacity of the axolotl.

• ALGAE
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• 제34권3호
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• pp.187-198
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• 2019

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espirito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ${\geq}2.5$ and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.

• ALGAE
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• 제34권3호
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• pp.199-216
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• 2019

Platysiphon verticillatus and Punctaria glacialis are synonymized by mainly on the basis of shared genes, nine identical sequences. Our hypothesis is that synonymy is erroneous. We posit the many differences of biological features between the two species, their ecological preferences, and occurrences do not support synonymy. Arcticophycus (nov. gen.) is described and contains the new combination Arcticophycus glacialis. Asexual, vegetative, life histories are proposed. Novel reproductive structures are described including previously unknown features of thallus development in the life history of both species. Discovery of the novel Platysiphon cyst, and dual sporangia types in Arcticophycus, is critical in establishing a probable strategy for survival through the Arctic winter for each annual species. Pl. verticillatus is erect, tubular, ovoid to circular in X sections, flaccid, non-parenchymatous, light brown, 10-15 cm high with distinctive photosynthetic hairs in clusters or whorled on the upper one third of the thallus. A. glacialis is erect, planar, robust, parenchymatous, dark brown and hairs absent. The Halosiphon clade is named, consisting of four genera: Halosiphon, Platysiphon, Arcticophycus, and Stschapovia. Occurrence of these genera is identified. Emended are the genus Platysiphon, the family Platysiphonaceae and the order Stschapoviales.

• 한국수산과학회지
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• 제17권5호
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• pp.423-435
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• 1984

1982년 9월부터 1983년 8월까지 일본국 정강현 빈명군 빈명호입구 연안에서 채집된 그물코쥐치, Rudarius ercodes를 대상으로 생식생태를 파악하기 위하여 연간 생식소숙도지수(GSI)와 간숙도지수(HSI)의 변화를 조사하였고 이들 생식소발달과정을 광학 및 전자현미경적 방법에 의해 조사하였다. GSI는 일장이 길어지며 수온이 상승하는 3월부터 상승하기 시작하여 6월에서 8월까지 년중 최대값을 나타내고, 9월부터 하강하여 11월부터 이듬해 2월까지 변화없이 연중 최저값을 나타냈다. GSI의 연간변화는 수컷의 경우 뚜렷하지 못하고 암컷의 경우는 GSI와 역상관 관계를 가지고 변하고 있다. 즉 생식소가 발달하는 하계에는 HSI값이 떨어지고, 생식소가 퇴화되는 동계에는 HSI값이 최대로 높아진다. 난소는 많은 난소소낭으로 구성된 1쌍의 낭상형 구조를 이루고 있고, 이들 난소소낭 상피에서 난원세포가 분열증식되고 있다. 초기 난모세포는 세포질이 호염기성이고 핵막을 따라 여러 개의 분산인을 가진다. 완숙 난모세포는 $300{mu}$ 내외로 핵이 동물극으로 이동되면서 핵막이 소실되고, 원형질구성이 극히 한정되며, 대부분의 세포질은 난황과 유구에 의해 충만된다. 배란후 난소소낭에 잔존하는 여포성장중인 난모세포들은 퇴화흡수되나, 아직 여포가 형성되지 못한 초기 주변인기 난모세포들은 퇴화되지 않고 이듬해 난소활성과 함께 성장되어 간다. 난모세포가 성숙되고 난황 축적이 활발해지면서 mitochondria와 과립성소포체가 급격히 증가하는데 이들은 난모세포의 성숙과 난황 축적에 기능적으로 관계가 있는 것 같다. 성숙난모세포의 미세융모의 홈에 뻗은 여포돌기 선단에 난황전구물질로 생각되는 $5{\sim}6$ 층의 원반상고전자밀도 구조물이 나타나고 있다. 정소는 좌우 1 쌍의 엽상구조를 가지며 후방에서 합일되어 저정낭을 이룬다. 정소의 피질층은 정자형성이 일어나는 정소소낭으로 구성되어 있고 수질층은 이들 소낭과 연결된 여러 갈래의 수정관이 분포한다. 성장중인 정소의 간질에는 소관상 cristae가 발달된 대형 mitochondria와 다수의 소포체를 가진 steroid 계 hormone 생성분필세포가 존재한다. 정자의 두부는 핵중앙에 깊이 함입된 중심강이 있어 U 자형을 이루고 첨체는 극히 빈약하다. 중편의 mitochondria는 커다란 구형의 부핵을 형성하고 있으며, 미부의 axoneme을 이루는 미세소관은 9+9+2형을 나타낸다. 생식연주기는 3월부터 7월에 걸친 성장기 5월부터 9월까지의 성숙기, 5월중순부터 10월 초순까지의 산란기, 그리고 10월부터 이듬해 2월까지의 휴식기 등 연속적인 주기로 구분할 수 있었고 산란성기는 6월부터 8월까지였다.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.207-215
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• 2009

시상하부-뇌하수체-생식소(hypothalamus-pituitary-gonad, HPG) 호르몬 축의 활성에 영향을 미치는 수많은 인자들은 생식 기능을 조절하고, 사춘기 개시와 폐경기 진입과 같은 뚜렷한 생식 능력의 단계 전이를 초래한다. 지방세포로부터 분비되는 다기능적 호르몬인 leptin의 발견 이후, 곧 이어 생식과 신체의 에너지 균형 사이의 긴밀한 관계에 대한 증거들이 밝혀졌다. 위장관으로부터 분비되는 또 다른 다기능 호르몬인 ghrelin은 이미 알려져 있던 growth hormone secretagogue receptor(GHSR)의 내인성 리간드이며, 에너지 항상성의 조절에서 leptin에 상응하는 물질로 알려졌다. 예상대로, ghrelin 또한 HPG 축의 활성의 조절을 통해 생식 능력을 조절함이 증명되었다. 이 논문은 ghrelin의 발견과 유전자 구조, 조직 내의 분포, 그리고 역할과 HPG 축에서의 생식 호르몬 분비 조절에 대한 포유동물의 생식에서의 ghrelin-GHSR 신호에 관한 최신 정보를 요약한 것이다. 뇌하수체에서의 POMC 유전자 발현과 유사하게, preproghrelin 유전자는 alternative splicing과 번역 후 변형(posttranslational modification)을 거치는 복잡한 레퍼토리의 전사체들과 펩티드 산물을 만들어 낸다. 에너지 항상성을 제외한 신체 생리 기능의 조절에서의 preproghrelin 유전자 산물의 역할에 관한 정보는 제한적이지만, 신진 대사와 생식 사이에서의 ghrelin의 상호작용에 관해서는 충분한 증거들이 있다. 흰쥐와 인간에서, ghrelin 수용체인 GHSRs(GHSR1a와 GHSR1b)의 분포는 본래 ghrelin의 표적으로 여겨진 시상하부와 뇌하수체뿐만 아니라 정소와 난소에서도 확인되었다. 뇌와 생식소에서도 preproghrelin 유전자 발현이 확인되었는데, 이것은 HPG 축에서 ghrelin이 국부적인 역할을 담당할 가능성을 시사한다. 비록 뇌하수체에서의 기능은 아직 확실치 않지만, ghrelin은 시상하부의 GnRH, 뇌하수체의 생식소자극호르몬과 생식소의 성 스테로이드 호르몬 분비에 대한 음성적인 조절자로서의 역할을 수행하는 것으로 보인다. 최근의 연구들은 사춘기 개시, 그리고 아마도 폐경기 진입의 조절에서 ghrelin의 관여를 시사한다. 이제 ghrelin이 '뇌-위장관' 축의 필수적인 호르몬 요인이며, 신 진 대사와 생식 사이를 연결하는 조절 물질이라는 가능성은 매우 높다. '배부름'을 반영하는 leptin 신호와는 정반대인 ghrelin 신호는 신체 에너지 균형 상태로 볼 때 '배고픔'을 표현하는 것으로 생각되며, 항상성의 유지에서 최우선 사항으로 고려되지 않는 생식으로의 에너지 투자가 이루어지지 않도록 하는데 필수적일 것으로 사료된다. 생식능력 조절에 있어서 ghrelin의 보다 명확한 작용 메커니즘과 역할에 대한 깊은 통찰력을 얻고 성공적인 생의학적 적용을 위해서는 향후 더 많은 연구들이 필요하다.

• 한국임상수의학회지
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• 제15권2호
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• pp.307-318
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• 1998

Accuracy of rectal palpation and ultrasonography for differential diagnosis of subestrous dairy trows were investigatedl using the result of pIRsma progesterone assay. The ovaries were examined 2 times of 10 days interval in 520 posearom and postinsemination subestroHs dairy cows, using rectal palpation and B-mode transrectal ultrasonography. The results of rectal palpation, ultrasonographic examination and measurement of plasma progesterone profiles in 520 subestrous dairy cows were silent brat or error of estrus detection 303 (58.3%), persistent corpus luteum 59 (11.3%), follicular cyst 37 (7.1%), luteal cyst 16 (3.1%), inactive ovary 9 (1.7%), granulosa tumor 1 (0.2%), hydmsalphinx 1 (0.2%), endomehris 81 (15.6%), pyometra 12 (2.3%) and mummified fetus 1 (0.2%), respectively. Accuncy of rectal palpation and ultrasonography for diagiosing ovarian disordeir based on plasma progesterone profiles were silent heat or error of estrus detection 80.5% and 96.7%$\boxUl$ persistent corpus luteum 57.6% and 94.9%, follicular cyst 62.5% and 91.9%1 luteal cyst 62.5% and 87.5%, maclive ovary 55.6% and 88.9% and granulosa cell tumor 100% and 100%, respectively. Acnuucy of rectal palpation for diagnosing uterine disorders based on ultrasonography was pyometra 75.0%1 endometritis 51.9% and mummified fetus 100%, respectively. Cbaracteristic ultrasonographic appearances of ovaries in subestrous dairy cows were as follows; Silent heat or error of estrus detection: anechoic follicle or hypoechoic corpus luteum than ovarian stroma was alternately present on Day 0 (first examination) and Day 10. Follicular cyst: uniformly nonechogenic ovarian structure $\geq $ 25 mm in diameter with a wall < 3 mm was present in ipsilateral on Day 0 and Day 10. Luteal cyst: luteal cyst was similar to follicular cysts but thickness of cystic wall was $\geq $ 3 mm. Inactive ovary : structures within ovaries was not present on Day 0 Bnd Day 10. Characteristic uthssonograpsc appearances of uterus in subestrous dairy cows were as follows; Endometritis: characterized by uterine lumen containing fluid in which 'snowy'echogenic particles art suspended. Pyometra: ultrasonographic appearance of pyometra was diffuse echogenic particles distributed in fluid within the distended uterus, and a thickened uterine wall. These results indicated that ultrasonography was practical far diagnosing reproductive disorders. To diagnosing ovarian disorders, ultrasonography should be carried out 2 times of 10 days interval and rndometritis should be differentiated with uterus of luteal phase in normal cycling cows.