• 제목/요약/키워드: reproductive biology

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Molecular analyses and reproductive structure to verify the generic relationships of Hypnea and Calliblepharis (Cystocloniaceae, Gigartinales), with proposal of C. saidana comb. nov.

  • Yang, Mi Yeon;Kim, Myung Sook
    • ALGAE
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    • 제32권2호
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    • pp.87-100
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    • 2017

  • The genera Hypnea and Calliblepharis of the family Cystocloniaceae are discriminated by their female reproductive structure, especially in the formation of carposporangia and gonimoblasts. Hypnea saidana, once classified based on obsolete evidence, has not been studied phylogenetically using molecular analysis and detailed reproductive structure though it shares many morphologic features with the genus Calliblepharis. To provide better understanding of generic relationship of H. saidana with Hypnea and Calliblepharis, we carried out molecular analyses using the nuclear-encoded small subunit ribosomal DNA (SSU) and chloroplast-encoded large subunit of the RuBisCO (rbcL), and exact morphological observations focusing on the reproductive structures of wild specimens. Our molecular phylogeny showed that H. saidana is closely related to Calliblepharis, but distinct from the clade of Hypnea. Female reproductive structure of H. saidana characterized by upwardly developing chains of carposporangia, central reticulum of cell, and gonimoblast filaments not connected to the pericarp provides definite evidence to assign the taxonomic position of this species to Calliblepharis. Based on our combined molecular and morphological analyses, we have proposed Calliblepharis saidana comb. nov., expanding the distribution of Calliblepharis habitat from the eastern Atlantic South Africa, the northern Indian Ocean, Australasia, and Brazil to the western Pacific Ocean.

  • https://doi.org/10.4490/algae.2017.32.5.15 인용 PDF KSCI

나자식물이 꽃피는 식물로 인식되고 있는 잘못된 관행의 분석 (Analysis of the misguided practice of recognizing Gymnosperms as flowering plants)

  • 이규배
    • 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.

  • https://doi.org/10.11110/kjpt.2014.44.4.288 인용 PDF KSCI

한국 동해 해역에서 채집된 살오징어 (Todarodes pacificus)의 성성숙과 생식주기 (Sexual Maturity and Reproductive Cycle of the Common Squid Todarodes pacificus in the East Sea of Korea)

  • 백혜자;김재원;조윤정;김수암
    • 한국수산과학회지
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    • 제39권6호
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    • pp.472-479
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    • 2006

  • The sexual maturity and reproductive cycle of the common squid, Todarodes pacificus captured from the East Sea, Korea, between January 2004 and January 2006, were investigated by documenting changes in the gonadosomatic index (GSI), gonad development, and oocyte size frequency distribution. The GSI of females began to increase in July, reached a maximum in August, and then gradually decreased. The GSI of males increased from July to March. Using gonad histological observations, we identified four oocyte developmental stages. The changes in GSI and gonad tissue resulted in the classification of the annual reproductive cycle into the following four successive stages: immature (April to June), growing (June to July), mature (July to August), and ripe and spawning (August to March). According to the oocyte diameter size frequency distribution in the ovary, this species appeared to have asynchronous oocyte development and one spawning time.

  • https://doi.org/10.5657/kfas.2006.39.6.472 인용 PDF KSCI

Estrogen Receptor Alpha Agonist Propyl Pyrazole Triol Causes Alterations of the Morphology and Function of the Mouse Male Reproductive System

  • Lee, Eun-Jung;Cho, Hyun-Wook
    • Animal cells and systems
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    • 제13권2호
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    • pp.205-212
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    • 2009

  • Known as a female hormone, estrogen, performs important functions, and the activities of the hormone are mediated via the estrogen receptor. The principal objective of the present study was to assess the effects of a estrogen receptor agonist in male reproductive organs. In this study, the estrogen receptor alpha agonist, PPT, was injected subcutaneously into adult male mice. The effects of PPT on the murine reproductive system were histologically assessed at 3,5, and 8 weeks after treatment. In the treatment group, reductions were observed in the weight of the body, testis and epididymis. Microscopic examination revealed a reduction in seminiferous tubular diameter in the testis, and epithelial cell height in the epididymis during the experiment. 8 weeks after treatment, spermatogenesis was not detected, nor was the lumen of the seminiferous tubules. In the fertility test, 1 week after PPT injection, the fertilizing ability of males was decreased, and on the 2nd and 3rd weeks, complete infertility was observed. In conclusion, the injection of high concentrations of PPT into adult males induced physiological changes, including infertility, and also induced morphological changes, including a reduction in the height of epithelial cells within the reproductive system.

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