DGI: Easy and Efficient Inference for GNNs

While many systems have been developed to train Graph Neural Networks (GNNs), efficient model inference and evaluation remain to be addressed. For instance, using the widely adopted node-wise approach, model evaluation can account for up to 94% of the time in the end-to-end training process due to neighbor explosion, which means that a node accesses its multi-hop neighbors. On the other hand, layer-wise inference avoids the neighbor explosion problem by conducting inference layer by layer such that the nodes only need their one-hop neighbors in each layer. However, implementing layer-wise inference requires substantial engineering efforts because users need to manually decompose a GNN model into layers for computation and split workload into batches to fit into device memory. In this paper, we develop Deep Graph Inference (DGI) -- a system for easy and efficient GNN model inference, which automatically translates the training code of a GNN model for layer-wise execution. DGI is general for various GNN models and different kinds of inference requests, and supports out-of-core execution on large graphs that cannot fit in CPU memory. Experimental results show that DGI consistently outperforms layer-wise inference across different datasets and hardware settings, and the speedup can be over 1,000x.Comment: 10 pages, 10 figure

Mixture of tree species enhances stability of soil bacterial community through phylogenetic diversity

The composition of tree species might influence microbial diversity considerably, yet investigation of the consequences of changes in diversity on stability of the microbial community is still in its early stages. Understanding how diversity governs community stability is vital for predicting the response of an ecosystem to environmental changes. Phylogenetic diversity (PD) describes the distinct evolution of species in a community, and might be useful for estimating the effects of biodiversity on ecosystem function and stability. High‐throughput 16S rRNA gene sequencing was used to examine soil bacterial phylogenetic distances, phylogenetic diversity and interactions between individuals in five single‐species plantations and three mixed‐species plantations. The plantations were established on the same initial substrate, and sampling was at 68 relatively spatially independent sites. Our results showed that mixed tree species enhanced soil bacterial phylogenetic diversity and community stability, and that phylogenetic diversity had a positive effect on stability of the soil microbial community. We also found evidence that microbial communities characterized by distantly related species with weak interactions were more stable in mixed plantations than communities with strong interactions in single‐species plantations. These results may be explained by the ‘insurance hypothesis’, that large phylogenetic diversity of microbial communities which share different ecological niches insures them against decline in their stability. This is because, even if some microbial species fail to deal with environmental change, others might not necessarily be affected similarly. Our findings demonstrate that phylogenetic diversity is the main controlling factor of the variation in stability across sites and requires more attention in sustainable forest management

DDX60 Is Associated With Glioma Malignancy and Serves as a Potential Immunotherapy Biomarker

DDX60, an interferon (IFN)-inducible gene, plays a promotional role in many tumors. However, its function in glioma remains unknown. In this study, bioinformatic analysis (TCGA, CGGA, Rembrandt) illustrated the upregulation and prognostic value of DDX60 in gliomas. Immunohistochemical staining of clinical samples (n = 49) validated the DDX60 expression is higher in gliomas than in normal tissue (n = 20, P < 0.0001). It also could be included in nomogram as a parameter to predict the 3- and 5-year survival risk (C-index = 0.86). The biological process of DDX60 in glioma was mainly enriched in the inflammatory and immune response by GSEA and GO analysis. DDX60 expression had a positive association with most inflammatory-related functions, such as hematopoietic cell kinase (HCK) (R = 0.31), interferon (R = 0.72), STAT1 (R = 54), and a negative correlation with IgG (R = −0.24). Furthermore, DDX60 expression tends to be positively related to multiple infiltrating immune cells, while negatively related to CD56 dim nature killer cell in glioma. Some important immune checkpoints, like CTLA-4, PD-L1, EGF, CD96, and CD226, were all positively related with DDX60 (all Pearson correlation R > 0.26). The expression and correlation between DDX60, EGF, and PD-L1 were confirmed by western blot in clinical samples (n = 14, P < 0.0001) and GBM cells. These results indicated that DDX60 might have important clinical significance in glioma and could serve as a potential immune therapeutic target

Consensus interpretation of the p.Met34Thr and p.Val37Ile variants in GJB2 by the ClinGen Hearing Loss Expert Panel

Purpose: Pathogenic variants in GJB2 are the most common cause of autosomal recessive sensorineural hearing loss. The classification of c.101T>C/p.Met34Thr and c.109G>A/p.Val37Ile in GJB2 are controversial. Therefore, an expert consensus is required for the interpretation of these two variants. Methods: The ClinGen Hearing Loss Expert Panel collected published data and shared unpublished information from contributing laboratories and clinics regarding the two variants. Functional, computational, allelic, and segregation data were also obtained. Case-control statistical analyses were performed. Results: The panel reviewed the synthesized information, and classified the p.Met34Thr and p.Val37Ile variants utilizing professional variant interpretation guidelines and professional judgment. We found that p.Met34Thr and p.Val37Ile are significantly overrepresented in hearing loss patients, compared with population controls. Individuals homozygous or compound heterozygous for p.Met34Thr or p.Val37Ile typically manifest mild to moderate hearing loss. Several other types of evidence also support pathogenic roles for these two variants. Conclusion: Resolving controversies in variant classification requires coordinated effort among a panel of international multi-institutional experts to share data, standardize classification guidelines, review evidence, and reach a consensus. We concluded that p.Met34Thr and p.Val37Ile variants in GJB2 are pathogenic for autosomal recessive nonsyndromic hearing loss with variable expressivity and incomplete penetrance

Clinicopathological Significance and Prognostic Value of DNA Methyltransferase 1, 3a, and 3b Expressions in Sporadic Epithelial Ovarian Cancer

Altered DNA methylation of tumor suppressor gene promoters plays a role in human carcinogenesis and DNA methyltransferases (DNMTs) are responsible for it. This study aimed to determine aberrant expression of DNMT1, DNMT3a, and DNMT3b in benign and malignant ovarian tumor tissues for their association with clinicopathological significance and prognostic value. A total of 142 ovarian cancers and 44 benign ovarian tumors were recruited for immunohistochemical analysis of their expression. The data showed that expression of DNMT1, DNMT3a, and DNMT3b was observed in 76 (53.5%), 92 (64.8%) and 79 (55.6%) of 142 cases of ovarian cancer tissues, respectively. Of the serious tumors, DNMT3a protein expression was significantly higher than that in benign tumor samples (P = 0.001); DNMT3b was marginally significant down regulated in ovarian cancers compared to that of the benign tumors (P = 0.054); DNMT1 expression has no statistical difference between ovarian cancers and benign tumor tissues (P = 0.837). Of the mucious tumors, the expression of DNMT3a, DNMT3b, and DNMT1 was not different between malignant and benign tumors. Moreover, DNMT1 expression was associated with DNMT3b expression (P = 0.020, r = 0.195). DNMT1 expression was associated with age of the patients, menopause status, and tumor localization, while DNMT3a expression was associated with histological types and serum CA125 levels and DNMT3b expression was associated with lymph node metastasis. In addition, patients with DNMT1 or DNMT3b expression had a trend of better survival than those with negative expression. Co-expression of DNMT1 and DNMT3b was significantly associated with better overall survival (P = 0.014). The data from this study provided the first evidence for differential expression of DNMTs proteins in ovarian cancer tissues and their associations with clinicopathological and survival data in sporadic ovarian cancer patients

Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial

Background: Previous cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes. Methods: We conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment. Results: Forty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference − 0.40 [95% CI − 0.71 to − 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference − 1.6% [95% CI − 4.3% to 1.2%]; P = 0.42) between groups. Conclusions: In this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness. Trial registration: ISRCTN, ISRCTN12233792. Registered November 20th, 2017

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial.

BackgroundPrevious cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes.MethodsWe conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment.ResultsForty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference - 0.40 [95% CI - 0.71 to - 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference - 1.6% [95% CI - 4.3% to 1.2%]; P = 0.42) between groups.ConclusionsIn this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness.Trial registrationISRCTN, ISRCTN12233792 . Registered November 20th, 2017

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial (vol 26, 46, 2022)

BackgroundPrevious cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes.MethodsWe conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment.ResultsForty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference - 0.40 [95% CI - 0.71 to - 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference - 1.6% [95% CI - 4.3% to 1.2%]; P = 0.42) between groups.ConclusionsIn this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness.Trial registrationISRCTN, ISRCTN12233792 . Registered November 20th, 2017

아시아 양서류와 전세계적으로 새롭게 문제시되는 Chytrid 곰팡이의 공진화

학위논문 (박사)-- 서울대학교 대학원 : 자연과학대학 생명과학부, 2019. 2. Waldman, Bruce .전염병은 생물 다양성, 세계 보건 및 경제에 대한 거대한 위협으로 알려져 있다. 인류의 새로운 전염병의 약 60% 는 인체 감염 동물 병원체에서 유래되었으며 약 70% 는 야생 동물 병원소를 보유하고 있다. 그러므로 야생 생물 질병 역학을 연구하는 것은 전파 패턴과 병원체와 숙주의 상호 작용 역학을 이해하여 전 세계적으로 제어하는 데 중요합니다. Chytridiomycosis는 곰팡이 병원균 인 Batrachochytrium dendrobatidis (Bd)에 기인하여 전 세계적으로 양서류의 개체수 감소와 종의 멸종과 관련이 있지만 아시아에서는 그렇지 않다. 아시아에서는 Bd 병원체와 양서류 숙주가 100 년 이상 공동 진화했다. 따라서 아시아 양서류 개체군의 감염에 대한 회복력은 풍토병 Bd 계통의 감소한 병독성이나 병원균에 대한 향상된 내성 또는 둘 모두로 인해 생길 수 있다. 한국 양서류 (Bombina orientalis)에서 분리 된 BdAsia-1은 전 세계적으로 양서류 개체수 감소와 관련된 재조합 글로벌 유행병 계통 (BdGPL)의 진화적 기초가 될 것으로 제안되었다. 그러나 BdAsia-1의 병독성은 여전히 명확하지 않았다. 이전 논문들은 아시아 양서류가 더 저항력이 있다고 주장했지만, 그것을 증명하기 위해 수행 된 감염 실험은 없었다. 이 프로젝트에서 필자는 오스트레일리아의 한 감수성 종인 Litoria caerulea를 사용하여 BdAsia-1과 BdGPL 간의 병독성을 비교 한 다음 두 Bd lineages을 사용하여 한국 양서류 (Bufo gargarizans, B. orientalis 및 Hyla japonica)의 감수성을 테스트했다. 피험자는 모두 감염되었지만 한국 양서류는 Bd lineages과는 상관없이 신속하게 감염을 치유하였다. 한국의 양서류들은 명백한 증상 없이 생존했다. 대조적으로, L. caerulea는 BdAsia-1 또는 BdGPL에 의한 감염 후 신체 상태의 악화를 겪었으며 시간이 지남에 따라 점진적으로 더 높은 Bd 부하를 나타냈다. 그 후, 대부분의 피험체는 사망했다. L. caerulea에 대한 효과를 비교하면, BdAsia-1은 BdGPL보다 더 빠른 질병 진행을 유도했다. 결과는 BdAsia-1 혈통에 속하는 두 개의 한국 Bd 균주 (KBO327 및 KBO347)가 모두 L. caerulea에 과민성이었으며 BdGPL에 비해 약한 증상이 없음을 분명하게 나타냈다. 테스트 한 모든 한국 양서류는 Bd 계통에 저항성 또는 내성을 지녔다. 병원체의 병독성은 풍토성 아시아 양서류 숙주 종에서 적응 면역 반응에 대한 강력한 선택을 유도했을지도 모른다. 질병에 대한 감수성은 종내 및 종간 다양하며, 상속 가능한 면역 유전 학적 변이에 기인 한 것으로 보인다. 주요 조직 적합성 복합체 (major histocompatibility complex, MHC)는 선택적 질병 저항성 메커니즘을 연구하기위한 우선 순위 중 하나이다. 이전의 연구에서, 일부 감수성 종의 MHC I 및 MHC II 유전자는 Bd에 의한 숙주 감염에 의해 상향 조절되는 것으로 나타났으나 저항성 종은 전사 발현에 있어 비교할 만한 변화를 나타내지 않았다. Bd 내성 종은 MHC-II 항원 결합 홈 내에서 비슷한 포켓 구조를 공유한다. 감수성이 있는 종들 중에, 전염병의 생존자들은 이러한 형태를 암호화하는 대립 유전자를 가지고있다. 동형 접합 저항성 유전자를 가진 개체는 강화된 저항성으로 인해 병원체의 병독성을 촉진시키는 환경 조건에서 이익을 얻는 것으로 보인다. 반복적으로 감염되고 이어서 Bd를 제거한 실험체는 병원체에 대해 후천 면역 반응을 일으킬 수 있다. Bd에 대한 내성을 나타내는 MHC 대립 형질에 대한 강한 방향성도태는 다른 병원체에 반응하는데 필요한 유전적 다양성을 고갈시킬 수 있다. Chytridiomycosis에 대한 내성은 생활사 비용을 초래하며, 이에 대한 추가 연구가 필요하다.. 그러나 이전의 양서류 연구는 거의 모든 MHC genotyping은 모든 대립 유전자를 효율적으로 식별하고 신뢰할 만한 결과를 제공하는 데 한계가 있는 전통적인 단일 PCR 기반 시퀀싱을 사용하였다. 이것은 MHC II와 Bd 저항성의 연관성에 대한 이전 연구 결과의 신뢰성을 크게 떨어트렸다. 따라서, 나는 각 샘플에 대해 독립적으로 3 개의 amplicon을 증폭시킨 후, L. caerulea 및 B. gargarizans의 MHC II 유전자형에 대해 next generation sequencing을 적용하였다. 두 종 모두에서 많은 MHC II 대립 유전자가 동정 되었다. 각 대립 유전자는 개인 및 기관 수준에서 차등적이고 상대적인 유전자 발현을 보였다. MHC II는 L. caerulea와 B. gargarizans에서 균형 잡힌 선택을 하고 있었지만 MHC II 대립 유전자의 펩타이드 결합 부위와 WuKa 부위의 일부 코돈은 L. caerulea에서 강한 양성 선택을 하고 있었다. 또한 Wu-Kabat의 다양성은 L. caerulea에서 B. gargarizans의 다양성보다 유의하게 높았으며, L. caeurlea에서 더 높은 단백질 다양성을 나타냈다. 더욱이 L. caerulea에서 양성으로 선별 된 PBR과 WuKa 부위의 대부분은 B. gargarizans에서 완전히 보존되어 Bd 저항성과 관련이 있음을 시사한다. 그러나, Bd 처리 및 감수성과 관련하여 상이한 MHC II 대립 유전자의 명확한 유전자 발현 패턴은 관찰되지 않았다. 두 개의 저항성 L. caerulea 개체에서 5 개의 고유 한 MHC II 대립 유전자가 발견되었지만 L. caerulea의 저항성 표본 크기가 작아 저항성과 관련하여 이 대립 유전자의 명확한 패턴을 확인할 수는 없었다. 후속연구가 L. caerulea에서 양성적으로 선택된 부위의 역할을 입증하기 위해 수행되어야 한다.Infectious diseases have been known as huge threats to biodiversity, global health and economy. About 60% of human emerging infectious diseases derived from zoonotic pathogens, and among which, about 70% had wild animal reservoirs. Therefore, studying wild life diseases dynamics is vital for understanding propagation patterns and interaction dynamics of pathogens and hosts in order to control them globally. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has been implicated in population declines and species extinctions of many amphibians around the world, but not in Asia. In Asia, the Bd pathogen and its amphibian hosts have co-evolved over 100 years or more. Thus, resilience of Asian amphibian populations to infection might result from attenuated virulence of endemic Bd lineages, evolved immunity to the pathogen, or both. BdAsia-1, isolated from South Korea amphibians (Bombina orientalis), was suggested to be evolutionarily basal to recombinant global pandemic lineages (BdGPL), which associated with worldwide amphibian population declines. However, the virulence of BdAsia-1 was still not clear. Although previous papers have suggested Asian amphibians were more resistant, there was no infection experiments performed to prove it. In this project, I firstly compared the virulence between BdAsia-1 and BdGPL using a known Australasian susceptible species, Litoria caerulea, then tested susceptibility of three Korean amphibians (Bufo gargarizans, B. orientalis, and Hyla japonica) using both lineages. Subjects became infected in all experimental treatments, but Korean species rapidly cleared themselves of infection, regardless of Bd lineage. Individuals of Asian species survived with no apparent secondary effects. By contrast, L. caerulea, after infection by either BdAsia-1 or BdGPL, suffered deteriorating body condition and carried progressively higher Bd loads over time. Subsequently, most subjects died. Comparing their effects on L. caerulea, BdAsia-1 induced more rapid disease progression on L. caerulea than BdGPL. My results clearly indicated that two Korean Bd isolates (KBO327 and KBO347) belonging to BdAsia-1 lineage were both hypervirulent to L. caerulea, with no sign of attenuation than BdGPL. All Korean amphibians I tested were resistant to or tolerant of both Bd lineages. The pathogens virulence may have driven strong selection for adaptive immune responses in endemic Asian amphibian host species. Susceptibility to the disease varies both within and among species, most likely attributable to inheritable immunogenetic variation. Major histocompatibility complex (MHC) is one of the priorities for investigating the mechanisms of disease resistance selection. In previous research, MHC I and MHC II genes of some susceptible species were shown to be up-regulated following host infection by Bd, but resistant species exhibited no comparable changes in transcriptional expression. Bd-resistant species shared similar pocket conformations within the MHC-II antigen-binding groove. Among susceptible species, survivors of epizootics bear alleles encoding these conformations. Individuals with homozygous resistance alleles appear to benefit by enhanced resistance, especially in environmental conditions that promote pathogen virulence. Subjects that are repeatedly infected and subsequently clear Bd can develop an acquired immune response to the pathogen. Strong directional selection for MHC alleles that encode resistance to Bd may deplete genetic variation necessary to respond to other pathogens. Resistance to chytridiomycosis incurs life-history costs that require further study. However, almost all MHC genotyping in previous amphibian research was based on single PCR derived traditional cloning based sequencing, which has limitations to identify all alleles efficiently and provide reliable results. This greatly reduced the reliability of the former findings- the association of MHC II with Bd resistance. Therefore, I amplified three amplicons independently for each sample, then applied next generation sequencing to genotype MHC II in L. caerulea and B. gargarizans. A number of MHC II alleles were identified in both species. Each allele had differential abundance and relative gene expression in both individual and organ level. MHC II was under balancing selection in both L. caerulea and B. gargarizans, but some codons in peptide binding region and WuKa sites of MHC II alleles were under strong positive selection in L. caerulea. Moreover, Wu-Kabat variability was significantly higher in L. caerulea than that in B. gargarizans, indicating a higher protein variability in L. caeurlea as well. Moreover, most of the positive selected PBR and WuKa sites in L. caerulea were completely conserved in B. gargarizans, suggesting these sites might associate with Bd resistance. However, no clear gene expression pattern of different MHC II alleles was observed regarding to Bd treatment and susceptibilities. Although there were five unique MHC II alleles found in two resistant L. caerulea individuals, I did not observe clear patterns of these alleles relating to resistance owing to limited resistant sample size in L. caerulea. Further studies should be performed to demonstrate the roles of the positively selected sites in L. caerulea.Chapter 1. Introduction 1 Chapter 2. Ancestral Chytrid Pathogen Remains Hypervirulent Following Co-evolution with Amphibian Hosts 15 Abstract. 16 2.1 Introduction 18 2.2 Methods 22 2.2.1 Animal collection and husbandry. 22 2.2.2 Infection expeirment. 25 2.2.3 Bd screening and pathogen loads. 26 2.2.4 Body condition measurements 27 2.2.5 Histology 28 2.2.6 Statistics. 28 2.3 Results 30 2.3.1 BdAsia lineage is lethal to L.caerulea. 30 2.3.2 Pathogen load and histological confirmation in L. caerulea 34 2.3.3 Virulence verification of BdAsia-1 using another BdAsia-1 strain (KBO327) 37 2.3.4 Korean amphibians showed resistance both to BdAsia-1 and BdGPL 39 2.4 Discussion 42 Chapter 3 Major Histocompatibility Complex (MHC) Variation and the Evolution of Resistance to Amphibian Chytridiomycosis. 52 Abstract 53 3.1 Introduction 55 3.2 How does Bd damage hosts 56 3.3 How does Bd infection alter MHC expression 59 3.4 MHC genetic diversity and susceptibility to Bd infection. 63 3.5 Bd-induced immunological memory 67 3.6 MHC resistance alleles incur tradeoffs 69 3.7 Toll-like receptors (TLRs). 71 3.8 Concluding Remarks 72 Chapter 4 Characterization of MHC IIß1 in Bd Susceptible and Resistant Amphibian. 74 Abstract 75 4.1 Introduction 77 4.2 Methods. 80 4.2.1 Samples collection 80 4.2.2 RNA isolation 80 4.2.3 MHC II genotyping by cloning based sequencing 81 4.2.4 MHC II genotyping based on next generation sequencing. 82 4.2.5 Amino acid structure comparison and PBR annotation. 86 4.2.6 Selection tests 86 4.2.7 Phylogenetic trees construction 87 4.2.8 Statistics 88 4.3 Results 89 4.3.1 NGS has distinct advantages in amphibian MHC genotyping 89 4.3.2 L. caerulea smd B. gargarizans have a similar number of alleles per individual as well as copy number variation(CNV) at MHC II ß1 89 4.3.3 Differential gene expression patterns of MHC IIß1 between L. caeruela and B. gargarizans 100 4.3.4 MHC IIB is under strong balancing selection in both species, but some sites were under strong positive selection in L. caerulea 106 4.3.5 Phylogenetic analysis 113 4.4 Discussion. 118 Chapter 5. General Conclusion. 126 Bibliography. 131 Abstract in Korean 159 Acknowledgement 163Docto