본 연구는 Tetraselmis suecica와 T. tetrathele의 영양물질 증진효과를 가져올 수 있는 배양시스템 구축을 위하여, 발광다이오드 (LED)의 파장별(청색; 450 nm, 황색; 590 nm, 적색; 630 nm) 탄수화물, 단백질, 지질 함량을 측정하였다. 두 종 모두 단백질 비율(42~69%)이 가장 높았으며, 생장속도가 낮았던 황색파장에서 탄수화물, 단백질, 지질의 높은 함량을 보였고, 생장속도가 가장 높았던 적색파장에서는 낮은 함량을 보였다. 이러한 결과는 세포 분열 속도의 감소로 인해 단백질 합성과 함께 세포의 화학적 조성과 효소 활동에 변화를 주어 지질과 탄수화물 함량이 증가한 것으로 생각된다. 따라서, T. suecica와 T. tetrathele의 유용한 생화학적 물질의 증대를 위해 대수생장기 초 기와 중기는 적색 LED 그리고 대수생장기 후기에는 황색 LED를 주사하는 2단계 LED 배양을 제안하였다.

배양실험을 바탕으로 다양한 수온과 염분 조건에서 유독 와편모조류 Alexandrium pacificum (LIMS-PS-2611)의 생장속도와 마비성 패독(PST)의 변화를 조사하였다. A. pacificum는 수온 25℃, 염분 30 psu 조건에서 최대생장속도를 보였으며, 최대생장속도의 70% 이상은 수 온 20~25℃, 염분 25~35 psu 구간에서 나타났다. A. pacificum 체내의 PST 주요성분은 N-sulfocarbamoyl계의 C1+2와 GTX5이었으며, 미량성분 은 carbamate계의 neoSTX이었다. 수온과 염분에 따른 독함량의 변화를 보면, A. pacificum는 수온 20℃, 염분 30 psu의 조건에서는 비교적 낮 은 독 함량을 보였다. 염분의 증가에 따라 독 함량이 증가하는 경향을 나타냈다. 그러나 최대생장속도를 보였던 수온과 염분 조건에서는 낮은 독 함량을 보였다. 따라서 6월 수온이 20-25℃ 범위일 때 발생하는 이매패류 독화현상은 A. pacificum에 의한 영향일 가능성이 있다.

본 연구에서는 와편모조류 Alexandrium affine(LIMS-PS-2345)의 생장에 미치는 용존태 무기 및 유기 영양염의 영향을 조사하였 다. 영양염 흡수 동력학 실험에서 A. affine의 최대흡수속도(ρmax)와 반포화상수(Ks)는 질산염에서 77.0 pmol/cell/hr과 17.6 μM, 인산염에서 15.5 pmol/cell/hr과 3.88 μM로 산출되어, 무기영양염에 대하여 높은 요구량 및 낮은 친화성을 가지고 있는 것으로 나타났다. 유기 영양염에 따른 A. affine의 생장속도를 확인한 결과, 유기 질소 urea, glycine와 유기 인 adenosine triphosphate(ATP), glycerol phosphate(Glycerol-P) 첨가구에서 무기 영양염 첨가구의 70 % 이상 생장속도를 보였다. 따라서 낮은 무기 영양염 환경에서 A. affine의 우점화와 종간경쟁에서 우위를 위해서는 용존태 유기 영양염의 이용이 필요할 것으로 생각된다.

Feral cats are widely considered to be leading the potential impacts on public health. This study aimed to provide estimates of vital data for feral cats relating Trap-Neuter-Return (TNR) to establish strategies effectively to manage feral cats in Pyeongtaek. Thus, this study focused on estimating feral cat population in Pyeongtaek and conducted a comparative analysis of the data for feral cats in Seoul (2013). The number of feral cats was estimated from 23,069 to 26,655 in Pyeongtaek, 2019. In relation to human population, when comparing the number of feral cats of Pyeongtaek and Seoul, it ranged from 4.57% to 5.28%, and from 1.97% to 2.55% respectively. This showed that Pyeongtaek was higher than Seoul. Fewer kittens were found in high-density areas, which the TNR project is believed to be generally effective in controlling the number of feral cats. In conclusion, in urban and rural complexes such as Pyeongtaek City, the number of feral cats compared to the population was higher than that of Seoul City, and the TNR program is believed to be somewhat effective in controlling the number of feral cats. When implementing TNR, it is necessary periodically to investigate the population and reflect them in policymaking.

본 연구에서는 실내에서 다양한 수온과 염분 조건에서 유독와편모조류 Alexandrium catenella(Group I)의 생장과 함께 마비성패 독의 함량을 조사하였다. A. catenella의 수온과 염분 최적생장은 각각 20~30℃과 20~30 psu였으며, 광온성과 광염성종으로 나타났다. A. catenella는 낮은 수온 구간(10℃와 15℃)에서 독함량과 독성이 높게 나타났으며, 염분에 따라서는 차이가 크지 않았다. 따라서 15℃이하의 수온에서 본 종주와 같은 생리적인 특성을 가진 유독와편모조류가 우점한다면, 이매패류는 빠르게 독화될 가능성이 있다. 향후 A. catenella의 출현에 따른 마비성패독 예찰·예보를 위해 다양한 환경변화에 따른 A. catenella의 다른 종주와 상업적인 이매패류 독화에 대한 연구가 더 필요한 것으로 판단된다.

Skeletonema pseudocostatum의 세포는 규산질 성분의 돌기에 의한 사슬 형태로, 길이는 6~17.3 μm였고, 엽록체는 세포 당 1~2개를 포함하고 있었다. 주사전자현미경 관찰결과 Skeletonema 종을 구분할 수 있는 가장자리 받침돌기끝 (terminal fultoportula process)은 끝이 갈라지거나, 갈고리 모양이었고, 길이가 1.67±0.5 μm이고, 개각의 가장자리에 위치해 있으며, 개수는 8.10±1.1개로 개각의 크기에 따라 다양하게 나타났다. 말단세포 입술돌기 (terminal rimoportula process)는 두꺼운 원통형의 나팔관 모양으로, 개각의 중앙 근처에 위치하였고, 길이는 1.1±0.6 μm 였으며, 개수는 1개였다. 연결세포 받침돌기 (intercalary fultoportula process)는 대부분 1 : 1 결합으로 서로 맞물려있는 형태였고, 1 : 2 결합도 종종 발견되었다. 계통분석 결과는 형태적 특징이 유사한 종 간의 유전학적 거리가 가깝다는 것을 나타냈고, 지리적 기원이 다른 동일 종의 경우, 유전적 차이를 보이지 않았다. 이는 S. pseudocostatum은 지리적 위치와 상관없이 유전적 차이가 나타나지 않는 단일계통 (monophyly)이라는 것을 의미한다.

본 연구는 마비성 독소 표준물질의 안정적인 공급을 위해 친환경적이고 경제성이 우수한 발광다이오드 광원의 파장을 이용하 여, PST의 원인종 Alexandrium catenella와 A. pacificum의 독 함량을 증대시킬 수 있는 가능성을 살펴보았다. 파장별 광량과 생장속도의 관계 를 보면, 반포화상수(Ks)는 두 종 모두 적색파장에서 가장 높게 나타났고, 청색파장에서 가장 낮았다. 빛 파장에 따른 독함량의 경우, 적색 파장이 A. catenalla은 최고 약 8배 그리고 A. pacificum은 약 3.4배 다른 파장보다 높았다. 그리고 광량에 대한 친화성을 나타내는 Ks와 독농 도와 밀접한 관련이 있는 것으로 나타났다. 따라서 세포당 독농도 증가를 위한 배양법은 초기에 세포수량의 확보 및 빠른 생장속도를 유 도하기 위해서 청색파장을, 대수생장기 후기에는 적색파장을 주사하여, 세포내 독함유량을 증가시킬 수 있는 2단계 배양법을 제시할 수 있을 것으로 생각된다.

와편모조류 Alexandrium affine의 생장에 대한 수온, 염분 및 광 조건 실내실험을 통해서 살펴보았다. A. affine의 최대성장속도(0.69 day-1)는 수온 25℃, 염분 25psu로 나타났으며, 최적생장(최대성장속도의 80%)은 수온 20~25℃의 염분은 20~35psu로 나타났다. 따라서 A. affine는 비교적 협온성이며, 광염성의 생리학적 특성을 가지고 있는 것으로 생각된다. 광량에 따른 생장 실험결과에서 유도된 생장식은 μ=0.75(I-4.25)/(I+65.47)로, 보상광량(Ic)은 4.25μmol m-2 s-1, 반포화광량(KI)은 57.0μmol m-2 s-1로 나타났다. 결론적으로 A. affine는 하계에 낮은 광, 염분의 변동 폭이 큰 연안해역에서도 우점화 할 수 있는 유리한 생리적 특성을 보이는 것으로 판단된다.

본 연구는 담녹조강 Tetraselmis suecica와 T. tetrathele의 인산염 흡수에 미치는 발광다이오드의 파장의 영향을 조사하였다. 파장은 청색 발광다이오드(LED; 450 nm), 황색 LED(590 nm), 적색 LED(630 nm) 그리고 형광램프(control)이며, 조도는 100 μmol m-2 s-1로 주사하였 다. T. suecica와 T. tetrathele의 최대흡수속도(ρmax)는 적색 LED에서 6.35 pmol cell-1 hr-1와 9.85 pmol cell-1 hr-1로 나타났으며, 반포화농도(Ks)는 9.43 μM와 21.2 μM로 나타났다. 이는 적색 LED 아래에서 T. suecica와 T. tetrathele가 다른 파장보다 영양염에 대한 친화성이 높다는 것으로 의미한다. 따라서 경제성 및 생산성 향상을 위한 Tetraselmis 배양시스템(광배양기)의 최적 광원은 낮은 영양염 상태에서도 높은 생장속도를 보이는 적색 LED가 적합할 것으로 판단된다.

Toll and IMD pathways play an important role in producing antimicrobial peptides (AMPs) through NF-κB in insects. The functions of IκB kinase (IKK) complex regulating the NF-κB signaling cascade have not yet been investigated in Tenebrio model. Here, we identified TmIKK-β (or TmIrd5) which contains 2,112 bp encoding 703 amino acid residues. Domain analysis shows that TmIKK-β contains one Serine/Threonine protein kinases catalytic domain. Developmental expression patterns indicate that TmIKK- β gene was highly expressed in early pupal (P1) and adult (A5) stages. Tissue specific profiles show that TmIKK-β was highly expressed in the integuments in last instar larvae, and fat body and hemocytes in 5 day-old adults. TmIKK-β1 transcripts were strongly induced at 3 and 12 h-post injection of E. coli, and 3 h-post injection of S. aureus or C. albicans in hemocytes. In gut, TmIKK-β transcripts were slightly induced by E. coli (at 6, 9 and 24 h) and C. albicans (at 24 h), while it was not induced by S. aureus challenge. Moreover, it was highly induced at 6 h-post injection of E. coli and then it was gradually decreased in the fat body. To understand the immunological role of TmIKK-β, gene specific RNAi and mortality assay was performed. Depletion of TmIKK-β mRNA leads to increase microbial susceptibility of larvae against E. coli, S. aureus and C. albicans. In addition, induction patterns of fourteen AMP genes in response to microbial challenge was tissue specifically investigated in TmIKK-β–silenced T. molitor larvae. The results suggest that expression of ten AMP genes out of fourteen genes were drastically decreased by TmIKK-β RNAi in fat body, suggesting that TmIKK-β plays an important role in antimicrobial innate immune responses.

It has been well known that IKK-β, -ε and –γ play a pivotal role in IMD pathway. In this study, TmIKK-ε was identified and their functions in countering pathogenic infections were investigated. We identified TmIKK-ε gene which including 2,196 bp nucleotides (encoding 731 amino acid residues). Domain analysis of TmIKK-ε indicates that there is one Serine/Threonine protein kinases catalytic domain. TmIKK-ε gene was highly expressed in 2 day-old pupal stage and the expression was gradually decreased until 1 day-old adults. Then the expression was slightly increased until 4 day-old adult stage. Tissue specific expression of TmIKK-ε mRNA was high in the gut, integuments and hemocytes in last instar larvae, and fat body, Malpighian tubules and testis in 5-daysold adult. In hemocytes, TmIKK-ε was drastically induced by E. coli injection after 3 h and by S. aureus at 3 and 12 h-post injection. In gut, expression level of TmIKK-ε was high at 6 h-post injection of microbial injection. Expression of TmIKK-ε in fat body was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-ε, gene specific RNAi and mortality assay were performed. TmIKK-ε RNAi caused increased larval mortality against E. coli, not S. aureus and C. albicans. Finally, to investigate the induction patterns of Tenebrio fourteen AMP genes in response TmIKK-ε RNAi, three microorganisms were treated into TmIKK-ε-silenced T. molitor larvae. Nine out of fourteen AMP genes were not induced by microbial challenge in TmIKK-β dsRNA-injected group. Taken together, our results indicate that TmIKK-ε may regulates nine antimicrobial peptide genes in response to microbial challenge in T. molitor fat body.

Autophagy is an important self-eating process to eliminate damaged or unused organelles. We identified nine autophagy-related genes (Atg) including AaAtg-1, -3, -4b, -4d, -5, -6, -8, -12 and -13 from the Asian tiger mosquito, Aedes albopictus. Developmental expression patterns indicate that mRNA levels of AaAtg-1, -3, -4b, -4d, -5, -6, -12 and -13 were highly expressed in egg, whereas expression of AaAtg8 was high in 1stand3rdinstarlarvalstages. TissuespecificexpressionofthesegenesindicatesthatAaAtg1 was highly expressed in thorax and midgut in blood-fed adult female mosquitoes (BF), and head and thorax in sugar fed adult female mosquitoes (SF). Transcript level of AaAtg3 was high in thorax in BF, but head, thorax and Malpighian tubules in SF. AaAtg4b, -4d mRNA levels were significantly high in Malpighian tubules in BF, and head in SF, respectively. AaAtg-5 and -6 transcripts were highly expressed in head in BF, and expression of AaAtg-8 was high in Malpighian tubules in BF. Levels of AaAtg-12 and -13 mRNAs were significantly high in head and midgut in BF. Induction patterns of AaAtg genes against pathogens showed that AaAtg-1, -3, -4b, -8, -12 and -13 were strongly induced at 6 h-post injection of S. aureus, and mRNA levels of AaAtg-1, -3 and -13 were significantly induced by E. coli challenge after 3 h-post injection in SF abdominal carcass. In SF midgut, AaAtg-1, -3, -4b, -4d, -5, -6, -12 and -13 transcripts were drastically induced at 9 h-injection of E. coli and S. aureus, while expression of AaAtg-8 was highly induced by S. aureus and C. albicans at 9 h-post injection. Each AaAtg gene was slightly induced by E. coli, S. aureus or C. albicans at different time points in abdominal carcass in BF. Interestingly, AaAtg-8 was not induced by microbial challenge. While eight other Atg genes except AaAtg-8 were highly influenced by S. aureus at 6 and 9 h-post injection, E. coli at 3 h-post-treatment, and 3, 6, and 9 h-post inoculation. In the future, we will characterize the functional roles of autophagy during mosquito-microbes interaction.

Host defense against pathogen invasion highly relies on immune defense machinery that is controlled by the nuclear factor-κB (NF-κB) of transcription factors. The Toll pathway are well known as an insect innate immune mechanism to protect host itself from invaded pathogens. Basically, in the edible insect, Tenebrio molitor, the Toll pathway is primarily activated by polymeric Lys-type peptidoglycans (PGNs), and components of fungal cell walls, β-1,3-glucan. Based on the current studies, the tremendous study has been focused on recognition and subsequent activation of spätzle in haemolymph, hence, there is a grave gap for intracellular event. Herein, in order to understand intracellular event of Toll signaling pathway, the Dorsal gene were identified. Moreover, domain analyses of TmDorsal2 gene indicate that there are two major domains such as Rel homology domain (RHD), ig-like, plexins, and transcription factors (IPT) domains. Based on the achieved results, TmDorsal2 mRNA was highly expressed in 1-day old pupa. Furthermore, TmDorsal2 was highly expressed in Malpighian tubules and fat body in last instar larvae (LL), and likewise mainly expressed in Malpighian tubules during adult 5-day old period, also the lowest expression of TmDorsal2 was observed in gonads. Moreover, TmDorsal2 mRNA levels after infection with E. coli appreciably went up at 6 and 9h time points. To investigate the effects of TmDorsal2 RNAi on larval susceptibility against various pathogens namely E. coli, S. aureus or C.albicans, dsRNA of TmDorsal2 has been synthesized the larvae dissected after 24h. As a result, TmAttacin1a, 1b and 2, TmDefencine1 and 2, TmTenecin1, 2, 3 and 4, TmCecropin2, TmColeoptericin1 and 2, Thaumatin-like protein 1 and 2 markedly reduced in the gut after injecting all mentioned microbes. In contrast, TmTenecin 2, Thaumatin-like protein 1 and 2 strikingly increased after microbe injection in the fat body. Interestingly, the most AMPs gene expression in whole body experimental case were upregulated. On the horizon, we will investigate effects of TmDorsal1 RNAi on larval susceptibility against various pathogens. Taken together, our studies may aid to understand insect innate immunity.

IKK-γ is an essential protein to form IKK complex which regulate NF-κB. We identified TmIKK-γ (or TmKenny) gene which has 1,521 bp of nucleotides encoding 506 amino acid residues. Domain analysis of TmIKK-γ shows that there are one NF-κB essential modulator (NEMO) domain and a leucine zipper domain. Expression of TmIKK-γ gene was gradually increased from egg to 2-day-old pupal stage, dramatically decreased until 7 day-old pupal stage, and then it was gradually increased. TmIKK-γ transcripts were highly expressed in fat body and hemocytes in late instar larvae and integuments, fat body and Malpighian tubules in 5 day-old adult. TmIKK-γ was drastically induced by E. coli after 3 h challenges and by S. aureus at 3 and 12 h-post injection in hemocytes. TmIKK-γ was not induced by C. albicans although it was significantly induced by E. coli (at 3, 6 and 24 h) and S. aureus (at 9 h) in gut. In fat body, expression of TmIKK-γ was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-γ, gene specific RNAi and mortality assay was performed. larval mortality against microbial challenge was dramatically increased by TmIKK-γ RNAi. Furthermore, we investigate the tissue specific induction patterns of fourteen AMP genes in response TmIKK-γ dsRNA-treatment. In fat body, ten AMP genes out of fourteen was not significantly induced by microbial challenge in TmIKK-γ dsRNA-treated group. Based on these results, TmIKK-γ might play an important role in antimicrobial innate immune responses in Tenebrio molitor.