About Us

We are a research group in the Institute of Plant and Microbial Biology, Academia Sinica, Taiwan. The principal investigator of our group is Chih-Horng Kuo. Our research interests include: Evolution, Genomics, Metagenomics, Transcriptomics, Microbiology, and Bioinformatics.

研究室簡介

本研究室隸屬於中央研究院植物暨微生物學研究所, 研究室主持人為郭志鴻。 我們的研究興趣包含了演化生物學, 基因體學, 多源基因體學, 轉錄體學, 微生物學, 以及生物資訊學

Research: Genome Evolution in Symbiotic Bacteria

In microbial evolution, the development of a host-dependent lifestyle often has profound effects on the genome architecture. To better understand the evolutionary processes involved, as well as the functional consequences of changes in the gene content, we utilize genomics and transcriptomics tools to conduct comparative analyses among bacteria with different ecological niches. The recent research projects in our lab are based on two main study systems:

(1) Mollicutes

The class Mollicutes contains diverse groups of host-associated bacteria with no cell wall, including Mycoplasma (vertebrate pathogens), 'Candidatus Phytoplasma' (plant pathogens), and Spiroplasma (mostly insect symbionts, with few plant pathogens). The last group is of particular interest because unlike mycoplasmas and phytoplasmas, where all characterized species are obligate pathogens, the genus Spiroplasma contains species that are harmless commensals, beneficial symbionts, or pathogens with varying levels of host-dependence. Thus, comparative studies within this genus can improve our understanding of the evolutionary transitions between different lifestyles and shed light on the evolution of pathogenicity in bacteria. Our short-term goal in this system is to investigate the genetic mechanisms that may explain the phenotypic differences among species with distinct ecological niches. In the long-term, we plan to generate sufficient genomic data in this previously understudied genus such that comprehensive comparisons among different groups within Mollicutes will become possible.

(2) Agrobacterium

The plant-associated bacteria in the genus Agrobacterium are important because of their biotechnological use in plant transformation and their phytopathogenicity that impacts agriculture. Through collaboration with Dr. Erh-Min Lai in our institute, we are interested in the genetic diversity, genome evolution, and functional characterization across different subgroups within this diverse genus.

研究主題:共生菌之基因體演化

在微生物的演化上,一旦一個物種發展出對真核宿主的依存性,其基因體的結構經常會有大規模的變化。為了解與這些變化相關的演化過程和其基因內容之改變,本研究室利用基因體學及轉錄體學等工具進行不同細菌物種間的比較分析。近年之研究計畫包含兩個主要的生物系統:

(1) 柔膜細菌綱 (Mollicutes)

柔膜細菌綱為一群不具有細胞壁之宿主依存性細菌,包括黴漿菌(Mycoplasma; 脊椎動物病原)、植物菌質體 ('Candidatus Phytoplasma'; 為一群農業上重要之植物病原)、及螺旋菌質體 (Spiroplasma; 大多為昆蟲共生菌,少數物種為植物病原) 等代表性物種。其中黴漿菌和植物菌質體屬內皆為完全依賴宿主生存之絕對寄生菌,而螺旋菌質體屬內物種則可能與宿主進行片利共生、互利共生、或依賴程度不等的寄生。因此,在螺旋菌質體屬內跨物種的比較將有助了解細菌在生態棲位間的轉換及致病性的演化。針對此生物系統,本研究室的短期目標為調查可解釋物種間表現型差異之遺傳機制,而長期目標則是累積足夠的基因體資料以進行完整的跨屬分析。

(2) 農桿菌屬 (Agrobacterium)

農桿菌屬為一群與植物相關的細菌,由於這群細菌在植物基因轉殖上的應用和其在田間對農作物所產生的危害,在生物科技和農業的發展上都具有相當的重要性。本研究室與所內賴爾珉老師合作,共同進行農桿菌屬內物種的研究,藉以探討此屬內不同小群菌株間的遺傳歧異度、基因體演化、及功能性分析。