The honey bee soluble acetylcholinesterase 1 (AmAChE1) is overexpressed under the overwintering and brood rearing-suppressed conditions. To investigate the role of AmAChE1 in regulating acetylcholine (ACh) titer, ACh concentrations both in the head (neuronal) and abdomen (non-neuronal) were analyzed. ACh titer was significantly lower in both tissues of worker bees under the overwintering and brood rearing-suppressed conditions compared to control bees. The expression levels of another two factors that regulate ACh titer, choline acetyltransferase (AmAChT) and acetylcholinesterase 2 (AmAChE2), were not altered as judged by qPCR and native PAGE, suggesting that the lower ACh titer was mainly regulated by AmAChE1. For precise verification of AmAChE1 as an ACh titer regulator, honey bees were put under brood rearing-suppressed condition to induce AmAChE1 and injected AmAChE1 dsRNA to knock down the gene. The ACh titer of AmAChE1-knocked down honey bees was 1.9 and 2.6 folds higher than that of control bees in head and abdomen, respectively. Taken together, in spite of its extremely low catalytic activity, the overexpression of AmAChE1 is likely to be related with the low level of ACh homeostasis, perhaps via ACh sequestration, under brood rearingsuppressed condition, and likely induce metabolic changes through ACh receptors-related pathways.

The honey bee soluble acetylcholinesterase 1 (AmAChE1) is overexpressed under the overwintering and brood rearing-suppressed conditions. To investigate the role of AmAChE1 in regulating acetylcholine (ACh) titer, ACh concentrations in both the head (central nervous system) and abdomen (peripheral nervous system) were analyzed. ACh titer was significantly lower in both tissues of worker bees under the overwintering and brood rearing-suppressed conditions compared to control bees. Interestingly, the expression levels of choline acetyltransferase (AmChAT) and molecular marker genes of immune systems were significantly reduced in honey bee head under the same conditions. Taken together, ACh titer appears to be reduced via a cooperative interaction of the AmAChE1 overexpression and AmChAT underexpression and to be linked to reduced inmmune responses under the overwintering and brood rearing-suppressed conditions. The roles of AmAChE1 (with little catalytic activity) and AmChAT in the ACh homeostasis and signaling was discussed in the contexts of immune response and longevity regulation in honey bees.

The object of this study was to evaluate Japanese encephalitis virus (JEV) antibody titer changes in broodmares and foals. Antibodies of 112 sera were detected by applying hemagglutination inhibition test. To the best of our knowledge, this is the first report that compares antibody titers of foals to that of their dams in order for evaluate optimal time of JEV vaccination. Most mares` antibody titers were variable. However, the highest titers in foals presented in their first month, and antibodies titers in all foals decreased gradually over time. This study provides important benchmarks that can be used to select optimum time JEV of vaccination.

Canine distemper virus (CDV) causes serious and often fatal disease in dogs. Currently, various cells or cell lines have been used to detect or produce CDV. In order to set up the conditions, we separated two different cell lines from Madin-Darby canine kidney (MDCK) and named as MDCK-F (fibroblast-like) and MDCK-E (epithelial-like) by Na2EDDA treatment. CDV seed virus was prepared using MDCK cells and inoculated into MDCK-F and MDCK-E including MDCK with various ranges of multiplicity of infection (MOI) to confirm the optimal amount of virus inoculation. The virus titer of TCID50/ml was calculated by inoculation of serially diluted virus into 96-well plate of MDCK cells. The titer and cytopathic effect (CPE) in MDCK-E were compared to those in MDCK-F. The titer of seed CDV was 1.24×106 TCID50/ml. Optimal MOI was about 0.1 for both MDCK-F and MDCK-E to obtain highest titers of 108 TCID50/ml and 5 × 108 TCID50/ml respectively. CPE in MDCK-E was shown 4 days after inoculation whether in MNCK-F 5 6 days after inoculation. We can obtain highest titer of 5 × 108 TCID50/ml with 0.1 MOI using MDCK-E. MDCK-E was more susceptible for CDV production than MDCK-F.

SUMMARY I. 서 론 II. 재료 및 방법 III. 결 과 IV. 고 찰 V. 적 요 VI. 인용문헌

검정금파리의 변태에 따른 엑디스테로이드를 Radioimmunoassay법으로 측정하고, 난세포성숙에 미치는 엑디스테로이드의 효과를 조사하여 얻을 결과는 다음과 같다. 산락직후 존재하였던 난내 엑디스테로이드는 발생과정 중 감소하다가 부화 직전 다시 증가하였으며, 유충기와 용기의 성장 변태시 엑디스테로이드함량의 변화를 보면 유충-유충과 유충-용으로의 탈피시에 일시적인 증가현상을 나타냈다. 특히 용화 후 48시간에 높은 엑디스테로이드의 농도를 보였는데 이는 큐티클분비와 경화작용과 밀접한 관계가 있는 것으로 생각된다. 성충기에서는 수컷의 경우 엑디스테로이드가 거의 검출 되지 않은 반면, 암컷에서는 단백질원 섭식 후 96시간에 최고의 함량을 나타내어 난성숙도와 일치하는 변화를 보였다. 엑디스테로이드 처리와 난성숙도와의 관계를 보면, 1g 처리군은 대조군에서와 같은 성숙도를 나타내 차이를 보이지 않았으나, 5g처리군에서는 대조군에서 보다 12시간 빠르게 난세포성숙이 완료되어, 엑디스테로이드 처리시 임계농도 이상에서는 난세포조기성숙에 직접적인 영향을 미치는 것으로 나타났다.