Since 2007, diamide insecticides have been widely used in Korea to control various types of lepidopteran pests including Spodoptera exigua. For nearly a decade, diamide resistance in field populations of S. exigua across 18 localities has been monitored using bioassays. Based on the LC50 values, some field populations showed a high level of resistance against chlorantraniliprole, although regional and temporal variations were observed. To investigate resistance at a molecular level, mutations (Y4701C, I4790M, and G4946E) were examined in the ryanodine receptor (RyR), which is the primary mechanism underlying diamide insecticide resistance. As a result, only I4790M mutation was found in most of field populations. As resistance levels varied significantly despite the uniform presence of the I4790M mutation, we considered the presence of another resistance factor. Further, the I4790M mutation was also found in S. exigua specimens collected prior to the commercialization of diamide insecticides in Korea as well as in other countries, such as the USA. This finding led us to hypothesize that the I4790M mutation were predisposed in field populations owing to selection factors other than diamide use. For further clarification, we conducted whole-genome sequencing of S. exigua (449.83 Mb) and re-sequencing of 18 individuals. However, no additional non-synonymous mutations were detected in the RyR-coding region. Therefore, the high level of diamide insecticide resistance in Korean S. exigua is not caused by mutations at the target site, RyR, but is attributed to other factors that need to be investigated in future studies.

평균연령의 증가에 따른 인구고령화는 현대사회의 공통적 당면과제이며, 이에 따른 퇴행성 근감소증의 발생 및 증가는 이에 대한 새로운 해결책을 요구한다. 근감소증은 단백질의 불균형 및 운동부족, 염증 증가 등 다양한 요소에 의해 발생하므로, 과학적 원인분석을 통한 다각도적 접근이 필요하다. 이는 식품산업의 새로운 블루오션을 창조 할 수 있으나, 현재 국내의 근감소증 개선 식품성분에 관한 연구는 태동 단계라고 할 수 있다. 제품 개발 현황의 경우 단백질을 이용한 제품이 대다수인 반면, 미국의 경우 단백질 유래 원료뿐만 아니라 현미, 갈조류, 사과껍질 등 식물 유래 원료를 이용하여 다양한 제품을 출시하고 있다. 또한, 근감소증 개선 효과가 있는 원료에 대한 특허 출원 은 증가하는 추세지만, 지표성분에 대한 연구는 아직 미비하다. 국내와 비교했을 때 미국을 비롯한 국외 학계 및 산업계는 비교적 많은 연구와 개발을 이루고 있다. 하지만 제품의 소재가 주로 대두단백 및 유청단백 등에만 국한되어 있으며, 운동보조제 위주의 접근으로 인해 제형의 한계가 존재하는 상황이다. 따라서, 근감소증을 개선할 수 있는 다양한 과학적 기작 연구와 함께 소재개발을 통하여 식품 산업의 새로운 시장을 열어갈 선구적 연구가 필요하다.

Whole grain cereal (WGC)-rich diets provide macronutrients that are important for the regulation of energy metabolism. The current study evaluated whether WGCs had a preventive effect on sarcopenic obesity in high-fat diet (HFD)-induced obese mice. C57BL/6N mice were fed a normal diet (ND), ND+WGC, HFD, and HFD+WGC for 12 weeks. WGCs significantly reduced body weight gain, food efficiency ratio, fat mass, and adipocyte size in HFD-induced obese mice. WGCs attenuated HFD-induced nonalcoholic fatty liver disease by decreasing liver weight and hepatic fat accumulation. In addition, WGCs increased muscle strength and muscle mass in HFD-induced obese mice as well as in ND mice. Taken together, WGCs can be employed as functional food materials for the prevention of sarcopenic obesity by inhibiting fat accumulation and increasing muscle mass.