• Development and Reproduction
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• v.12 no.2
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• pp.117-124
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• 2008

The efficient strategies to cope with unpredictable and/or harmful environmental changes have been developed by every organism in order to ensure its survival and continuity of it's own species. As a results, all living things on earth maintain dynamically internal stability via a process termed 'homeostasis' among physiological parameters despite of external environment changes. Stress is an emotional and physical response to threat homeostasis. Stress may have not only transient but rather permanent effect on the organism; recent evidence clearly show that prenatal stress could organize or imprint permanently physiological systems without any change in genetic codes, a process known as 'epigenetic programming'. In this review, a series of reproduction-associated events occurred in prenatally stressed male rats such as alteration in the structure of sexually dimorphic brain regions, modification of neurotransmitter metabolism, changes in reproductive endocrine status, and finally, disorders of sexual behavior will be introduced. The fetal brain is highly sensitive to prenatal programming and glucocorticoids in particular have powerful brain-programming properties. The chronic hyperactivation of fetal brain by maternal stress-induced glucocorticoid input will provide new program via increasing the neuroplasticities. This 'increased neuroplasticities' will be the basis for the 'increased phenotypic plasticities' rendering the organism's better adaptation to environmental challenges. In conclusion, organism who experienced 'harsh' environment in his fetal life seems to give up a certain portion of reproductive competence to make good chance of survival in his future life by epigenetic (re)programming.

• Korean Journal of Animal Reproduction
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• v.18 no.4
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• pp.285-297
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• 1995

The mammalian oviduct is a place where ontogeny of an animal begins. Nowadays, however, it is possilbe to manipulate a part of physiological events occurring in the oviduct so that fertilization of gametes and early embryonic development of zygotes could proceed outside oviductal environment. Rabbit zygotes readily develop to blastocysts in a conventional culture condition. Most of the mouse fertilized eggs do so when cultured under a specific environment, e.g., in a medium containing ethylenediamine tetraacetic acid. Similarly, a significant number of zygotes from rat, sheep, pig or cattle can develop to blastocysts if they are cultured in the presence of particular component which appear to be somewhat species-specific. Instead of changing the components of medium, somatic cells including oviductal epithelial cells, have widely been used to improve mammalian embryonic development in vitro. Many investigators have reported that mammalian zygotes, whether fertilized in vivo or in vitro, could develop to blastocysts when they were cultured on a monolayer of various kinds of somatic cells or even in a somatic cell-conditioned medium. While little is known about the nature of embryotrophic factor(s) produced in vitro by somatic cells, the existence fo oviduct-specific protein(s) has consistently been demonstrated in many laboratories. Some of these proteins are reported to be associated with oviductal eggs. However, the physiological role of these proteins has still to be determined. Recently we observed that the perivitelline space of mouse oocytes was fluorescently stained with various fluorochrome-protein conjugates following ovulation into the oviducts or upon their expossure to oviductal extracts. Furthermore, it was also found that cattle or pig oviductal fluid gave similar results when examined using mouse ghost ZP. These observations lead to suggest that mammalian oviduct induces changes of biochemical properties of oocytes. Further studies are needed to clarify the nature of oviductal factor(s) and the physiological meaning of the reaction.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.845-855
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• 2000

As high as 50% of pregnancies are known to fail and the majority of such losses occur during the peri-implantation period. For the establishment of pregnancy in mammalian species, therefore, implantation of the conceptus to the maternal endometrium must be completed successfully. Physiological events associated with implantation differ among mammals. In ruminant ungulates, an elongation of the trophohlast in early conceptus development is required before the attachment of the conceptus to the uterine endometrium. Moreover, implantation sites are restricted to each uterine caruncula where tissue remodeling, feto-maternal cell fusion and placentation take place in a coordinated manner. These unique events occur under strict conditions and are regulated by numerous factors from the uterine endometrium and trophoblast in a spatial manner. Interferon-tau (IFN-${\tau}$), a conceptus-derived anti-Iuteolytic factor, which rescues corpus luteum from its regression in ruminants, is particularly apt to play an important role as a local regulator in coordination with other factors, such as TGF-${\beta}$, Cox-2 and MMPs at the attachment and placentation sites.

• Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.145-158
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• 2024

Life history characteristics, habitat landscape, and historical events are believed to have shaped the patterns of genetic variation in many taxa. The bony lip barb, Osteohilus vittatus, represent a potamodromous fish that complete all life cycle in freshwater and is widely distributed in Southeast Asia. It usually lives in small rivers and other freshwater habitats, and movement between habitats for either food or reproduction has been typical. These life history characteristics may promote gene flow, leading to less structured populations. However, many freshwater habitats are fragmented, which restricts gene flow. We investigate how this interplay has shaped patterns of genetic variation and phylogeographic structure within this species in the Sundaland, a biodiversity hotspot with a complex geological history, using mitochondrial cytochrome oxidase I (mtCOI) as a genetic marker. Forty-six mtCOI sequences of 506 bp long were collected from ten localities, eight geographically isolated and two connected. The sequences were used for population genetic and phylogeographic analyses. Our results showed a low genetic diversity within populations but high between populations. There was a deep phylogeographic structure among geographically isolated populations but a lack of such structure in the connected habitats. Among geographically isolated populations, sequence divergence was revealed, ranging from 1.8% between Java and Sumatra populations to 12.2% between Malaysia and Vietnam. An indication of structuring was also observed among localities that are geographically closer but without connectivity. We conclude that despite high dispersal capacity, the joint effects of historical events, long-term geographic isolation associated with sea level oscillation during the Pleistocene, and restricted gene flow related to lack of habitat connectivity have shaped the phylogeographic structure within the O. vittatus over the Sundaland.

• Journal of Popular Narrative
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• v.25 no.1
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• pp.393-425
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• 2019

This paper focuses on Alain Resnais's representative works (1955), (1959), and (1963), and analyzes how he implements a representation of memory though cinematic apparatus. These three films deal with horrific memories that seem impossible to reproduce aesthetically such as the Holocaust, the Hiroshima Atomic Bomb, World War II, and the war in Algeria. The reappearance of events that stripped humans of even their minimum dignity can naturally be associated with ethical issues. These events can never be reproduced because they cannot be explained in the human language. It is also impossible to reproduce in a way that doesn't invade other peoples' sufferings, nor displays the pain of others as spectacles. Alain Resnais was a director who realized that if factual representation was not possible from the beginning, truthfulness would have to be approached through cinematic form. Therefore, he tries to overcome these problems through cinematic forms. First, he shifts to action films to avoid the obscenity of documentary. shows the records of camps captured by German forces in the past, while shows the pain of others in a fictional form of representation. Next, he describes how the trauma affects the identity of the main character through a flashback in , but also shows a main character who is experiencing trauma without a flashback in Flashbacks have the effect of showing the effects of trauma on the main character, but at the same time they involve the obscenity of enjoying the suffering of others. Nonetheless, the absence of flashbacks highlights the impossibility of representation. This is because it is not silent in the impossibility of representation but is constantly approaching. The attitude that repeatedly circles around impossibility is an ethical form that maximizes the impossibility of representation. In conclusion, this is the ethics of representation that Alain Resnais showed in his films.