강우를 대서양과 태평양으로 배수하는 Continental Divide는 북미의 4대 주요 분수령 중 가장 중요한 수문학적 분수령으로 몬태나, 아이다호, 와이오밍, 콜로라도, 뉴멕시 코 등 5개 주에 걸쳐있으며, 북쪽으로 미국-캐나다의 국경 에서 남쪽의 미국-멕시코 국경까지 약 5,000km에 걸쳐 있 다. 미 국립공원관리청은 1980년대 초기부터 '생명징후 (vital sign) 모니터링' 이라는 용어를 사용였으며, 이는 보호 지역 자연자원의 전반적인 현황 또는 건강상태를 확인하고 보다 효율적인 관리를 위해 간섭이 필요한 상황들에 대한 조기경보 제공 등을 위한 적합한 표본을 추출 및 관리 하는 것을 목표로 하고 있다. 효율적인 보호지역 자연자원 관리를 위하여 국립공원관 리청은 미국내 주요 자연자원을 270개 이상의 공원을 포함 하는 32개의 생태지역 네트워크로 설정하여 장기적인 생태 모니터링 프로그램을 개발하였으며, 모니터링 프로그램은 보호지역 생태계의 장기적인 보호를 위하여 관련기관 또는 전문가 및 일반대중과 협력하며, 의사 결정의 기초를 위한 자연자원의 변화와 현황에 대한 광범위한 이해를 바탕으로 공원관리자들의 활동을 지원하는 것을 목표로 하고 있다. 또한, 체계적인 생명징후 모니터링 프로그램을 통해 얻은 폭넓고 과학적이며 신뢰할 수 있는 정보는 보호 자원에 대 한 의사 결정, 연구, 교육, 대중의 이해 증진 등 다양한 목적 을 위해 활용이 가능하다.
This study was conducted to investigate the efficacy of vitrification procedure for the cryopreservation of porcine oocytes and the utilization of vitrified oocytes as recipient cytoplasts for somatic cell nuclear transfer (NT), and observed that porcine oocytes are evaluated by pronuclear formation, and parthenogenetic development. Single fetal donor cells were deposited into the perivitelline space of vitrified enucleation oocytes, followed by electrical fusion and activation. NT embryos were cultured in NCSU-23 medium supplemented with 5% FBS, at in 5% and air. 1. When the developmental rates of the oocytes after being culture for hours vitrified with EDS and ETS were 42.0%, 38.0%, respectively. This results were lower than the control group(62.2%). 2. When the developmental rates of the oocytes after being culture for hours vitrified-thawed with sucrose and glucose, 5% PVP, NCSU-23 supplemented with 10% FBS were 33.3%, 25.9%, respectively. This results were lower than the control group(55.6%). 3. The fusion and development to the blastocyst stage between the NT embryos constructed with the vitrified and non-vitrified oocytes were significant differences. Developmental rate of oocytes and NT embryos constructed with the vitrified or non-vitrified oocytes were , respectively.
Although nuclear transfer (NT) techniques are used to clone animals, its efficiency is very low. Moreover, nuclear transfer has resulted in offspring with severe developmental problems, probably due to incomplete nuclear reprogramming. Nuclear reprogramming is characterized by functional modification of the transferred nucleus to allow it to direct normal embryo development with the potential to grow to term. Although the nature of the reprogramming factor(s) in mammals is not clear, various nuclear as well as cytoplasmic components are involved in the processes. In this article we review recent data on factors involved in the nuclear reprogramming of cloned embryos.
Transgenic mice containing GH Receptor (GHR) gene fused to metallothionein promoter were analyzed to evaluate effect of GHR expression on growth in vivo. Three founder mice lines contained copies of GHR transgene and transmitted these genes into F₁ and F₂ progenies. The mRNA expression of transgene was identified using RT-PCR with GHR genes in tissues. To analyze the effects of transgenes on growth performance, body weights of pups were measured at 4, 10 and 14 weeks after birth. The body weight of transgenic mice was higher compared with that of non-transgenic control mice regardless of sex (P<0.05). Body weights between transgenic and non-transgenic mice were increased with aging. Overall, GHR transgenic mice tended to grow about 10 to 15 % faster than non-transgenic mice without any pathological defects.