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이주삼,가학현,이수철,김장생,조창현 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.1
본 연구는 우간다 농경지의 토양비옥도와 소규모 영농형태에서의 양분균형을 검토하여, 농촌빈곤의 원인을 파악하고 그 해결방안을 제시하고자 하였다. 우간다 농촌의 소규모 농가의 현장조사 자료 및 관련 문헌의 연구결과를 인용하였다. 1. 우간다의 농경지 토양은 강산성이었고, 비옥도는 낮았다. 특히 인산함량이 낮았다. 2. 농경지의 양분균형은 모든 영농형태와 일부 바나나 단작을 제외한 기타 재배작물의 단작에서 양분부족을 나타내었다. 3. 현재의 우간다 농촌 빈곤율을 토양비옥도 측면에서 다음과 같이 설명할 수 있다. 즉, 토양침식 및 부적절한 토양 양분관리 → 양분유실 → 토양비옥도 저하 → 양분부족 → 작물생산성 저하 → 빈곤 율 증가로 나타낼 수 있다. 4. 농경지의 비옥도 개선은 토양생산성 유지와 향상에 중요한 요인이며, 농촌 빈곤을 감소시키는데 기여한다. This study was conducted to investigate the soil fertility and nutrient balances of smallscale farming systems, and its relation to alleviation of rural poverty of Uganda. Data from the observations of the small-scale farming systems and from the literatures concerning the soil fertility and rural poverty of Uganda were analyzed. Tested soils of arable land showed a low values of soil pH and soil fertility. Especially, contents of phosphorus in soil were very low. When the nutrient balances were estimated for small-scale farming systems and several crop monocultures, they showed a negative values for macro elements (nitrogen, phosphorus, and potassium) in all small-scale farming systems except some banana-based arable lands. Especially, higher negative values of the nutrient balances were obtained at maize and soybean monocultures than other crops, which may be due to the fact that those were grown under deficient contents of nitrogen and phosphorus. Based on the results from analysis of soil fertility, the cause of existing rural poverty of Uganda can be explained as following flows in the viewpoint of soil characteristics; soil erosion and insufficient soil nutrient management cause nutrient losses in soil (low soil fertility). Low soil fertility, or nutrient deficiency in soil, results in low crop productivity per area, which, in turn, increases rural poverty. Improved soil pH and soil fertility of arable land is the most important factor for maintenance and increase of the soil productivity, and it may contribute to alleviation of the existing rural poverty in Uganda.
Klotho : Expression and Regulation at the Maternal-Conceptus Interface in Pigs
최요한,심장수,현상환,이은송,가학현 사단법인 한국동물생명공학회 2014 한국동물생명공학회지 Vol.29 No.4
Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing β-glucuronidaseactivity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium isimportant for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptorpotential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometriumduring pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determinedin pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during theestrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased betweenDays 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA wasexpressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expressionlevels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)-derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy statusandstage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play animportant role in the establishment and maintenance of pregnancy in pigs.
서희원,김민구,가학현 사단법인 한국동물생명공학회 2009 한국동물생명공학회지 Vol.24 No.4
Salivary lipocalin (SAL1) is a member of the lipocalin protein family that has a property to associate with many lipophilic molecules and was identified as pheromone-binding protein in pigs. Our previous study has shown that SAL1 is expressed in the uterine endometrium in a cell type- and implantation stage-specific manner and secreted into the uterine lumen in pigs. However, function of SAL1 in the uterus during pregnancy in pigs is still not known. To understand physiological function of SAL1 in the uterine endometrium during pregnancy in pigs, it needs to elucidate the ligand(s) for SAL1. Thus, to identify the ligand for SAL1 in the porcine uterus, we collected uterine luminal fluid from pigs on day 12 of pregnancy by flushing with PBS. Proteins from the uterine luminal fluid were separated by ion exchange chromatography and gel filtration. Fractions containing SAL1 protein were pooled and concentrated. Immunoblot analysis confirmed successful purification of SAL1. Then, we extracted lipids from the purified SAL1 protein and analyzed the lipids by liquid chromatography-mass spectrometry, and predicted to be steroid hormones and prostaglandins as SAL1 ligands. Results in this study showed that SAL1 protein in the uterine secretions has a small lipophilic molecule as a natural ligand. Further characterization of ligand extracted from purified SAL1 will be useful for understanding physiological function of SAL1 during pregnancy and its application to increase the pregnancy rate in pigs.
Comparative Analysis of Gene Expression in the Female Reproductive Organs
김민구,서희원,최요한,이창규,가학현 사단법인 한국동물생명공학회 2009 한국동물생명공학회지 Vol.24 No.2
To understand molecular and cellular mechanisms of many gene products in the female reproductive organs including the ovary and uterine endometrium as well as during embryo development, researchers have developed and utilized many effective methodologies to analyze gene expression in cells, tissues and animals over the last several decades. For example, blotting techniques have helped to understand molecular functions at DNA, RNA and protein levels, and the reverse transcription-polymerase chain reaction (RT-PCR) method has been widely used in gene expression analysis. However, some conventional methods are not sufficient to understand regulation and function of genes expressed in very complex patterns in many organs. Thus, it is required to adopt more high-throughput and reliable techniques. Here, we describe several techniques used widely recently to analyze gene expression, including annealing control based-PCR, differential display-PCR, expressed sequence tag, suppression subtractive hybridization and microarray techniques. Use of these techniques will help to analyze expression pattern of many genes from small scale to large scale and to compare expression patterns of genes in one sample to another. In this review, we described principles of these methodologies and summarized examples of comparative analysis of gene expression in female reproductive organs with help of those methodologies.