https://repository.kopri.re.kr/handle/201206/11544 Wed, 22 Apr 2026 09:28:34 GMT 2026-04-22T09:28:34Z https://repository.kopri.re.kr/handle/201206/12962 Title: The ultrastructure of resurrection: Post-diapause development in an Antarctic freshwater copepod Authors: Reed, Katherine A.; Lee, Sung Gu; Lee, Jun Hyuck; Park, Hyun; Covi, Joseph A. Abstract: The copepod, Boeckella poppei, is broadly distributed in Antarctic and subantarctic maritime lakes threatened by climate change and anthropogenic chemicals. Unfortunately, comparatively little is known about freshwater zooplankton in lakes influenced by the Southern Ocean. In order to predict the impact of climate change and chemicals on freshwater species like B. poppei, it is necessary to understand the nature of their most resilient life stages. Embryos of B. poppei survive up to two centuries in a resilient dormant state, but no published studies evaluate the encapsulating wall that protects theses embryos or their development after dormancy. This study fills that knowledge gap by using microscopy to examine development and the encapsulating wall in B. poppei embryos from Antarctica. The encapsulating wall of B. poppei is comprised of three layers that appear to be conserved among crustacean zooplankton, but emergence and hatching are uniquely delayed until the nauplius is fully formed in this species. Diapause embryos in Antarctic sediments appear to be in a partially syncytial mid-gastrula stage. The number of nuclei quadruples between the end of diapause and hatching. Approximately 75% of yolk platelets are completely consumed during the same time period. However, some yolk platelets are left completely intact at the time of hatching. Preservation of complete yolk platelets suggests an all-or-none biochemical process for activating yolk consumption that is inactivated during dormancy to preserve yolk for post-dormancy development. The implications of these and additional ultrastructural features are discussed in the context of anthropogenic influence and the natural environment. Mon, 01 Mar 2021 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/12962 2021-03-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/12181 Title: de novo Genome analysis of Polar organisms Authors: Park, Hyun Fri, 26 Feb 2021 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/12181 2021-02-26T00:00:00Z https://repository.kopri.re.kr/handle/201206/11791 Title: Transfection of Arctic Bryum sp. KMR5045 as a Model for Genetic Engineering of Cold-Tolerant Mosses Authors: Byun, Mi Young; Seo, Suyeon; Lee, Jungeun; Yoo, Yo-Han; Lee, Hyoungseok Abstract: Mosses number about 13,000 species and are an important resource for the study of the plant evolution that occurred during terrestrial colonization by plants. Recently, the physiological and metabolic characteristics that distinguish mosses from terrestrial plants have received attention. In the Arctic, in particular, mosses developed their own distinct physiological features to adapt to the harsh environment. However, little is known about the molecular mechanisms by which Arctic mosses survive in extreme environments due to the lack of basic knowledge and tools such as genome sequences and genetic transfection methods. In this study, we report the axenic cultivation and transfection of Arctic Bryum sp. KMR5045, as a model for bioengineering of Arctic mosses. We also found that the inherent low-temperature tolerance of KMR5045 permitted it to maintain slow growth even at 2°C, while the model moss species Physcomitrium patens failed to grow at all, implying that KMR5045 is suitable for studies of cold-tolerance mechanisms. To achieve genetic transfection of KMR5045, some steps of the existing protocol for P. patens were modified. First, protoplasts were isolated using 1% driselase solution. Second, the appropriate antibiotic was identified and its concentration was optimized for the selection of transfectants. Third, the cell regeneration period before transfer to selection medium was extended to 9 days. As a result, KMR5045 transfectants were successfully obtained and confirmed transfection by detection of intracellular Citrine fluorescence derived from expression of a pAct5:Citrine transgene construct. This is the first report regarding the establishment of a genetic transfection method for an Arctic moss species belonging to the Bryaceae. The results of this study will contribute to understanding the function of genes involved in environmental adaptation and to application for production of useful metabolites derived from stress-tolerant mosses. Fri, 01 Jan 2021 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/11791 2021-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/12183 Title: Study of environmental stress related Sanionia uncinata genes in response to drought stress Authors: Kim, Woo Taek Fri, 01 Jan 2021 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/12183 2021-01-01T00:00:00Z