基于全基因组数据的甜橙分子细胞遗传学图谱构建

Sweet orange is one main fruit crop of citrus species in the world. It is meaning and important for learning sweet orange genome constitution and genetic rule by chromosome analysis to do molecular cytogenetic research in sweet orange. With sweet orange genome sequencing project performed, its genetical map and cytological map needs to be integrated urgently in order to put DNA sequence into chromosome position. But sweet orange small chromosomes of similar morphology and lack of efficient marker hampered cytological research and its use. Now whole genome sequencing approaches in our lab makes good chance to explore new molecular markers for identifying every chromosome and do deeply genome genetic research combining cytological research in sweet orange. This proposal plans to establish sweet orange mitotic and pachytene chromosomes cytological map including repetitive sequence distribution, based on chromosomal fluorescence banding pattern. Furthermore fluorescence in situ hybridization (FISH) will be employed for screening out enough molecular probes to identify every chromosome in sweet orange, after analysis candidate tandem repeat sequences and specific BAC (bacterial artificial chromosome, BAC) anchored linkage groups from sweet orange genome sequencing data. Then a high-solution molecular cytogenetical map of sweet orange combining chromosome morphology and chromosome types will be built, which will integrate the genetic location of these molecular probes with their cytological position. At last the molecular cytogenetical map will be applied to enhance genome sequencing data assembly result, aiming at the future improving and perfecting of sweet orange genome sequencing. Also this map will lay the groundwork and play an important role in analysis of sweet orange genome heterozygosity, Citrus species and their relatives’ chromosome evolution and comparative genomics research.

甜橙是世界和我国最重要的柑橘栽培类型。我国已自主完成甜橙全基因组测序。构建甜橙分子细胞遗传学图谱是对柑橘基因组测序项目的后续研究，对结合染色体分析认识甜橙基因组结构，深入了解其遗传规律具有重要意义。甜橙染色体较小且形态相近，缺乏有效标记，以致细胞学研究相对滞后。甜橙基因组信息为开发识别染色体的分子标记、从而加强其基因组遗传研究提供了基础数据平台。本申请项目拟对基因组数据进行生物信息学分析和FISH实验，筛选区分甜橙染色体的重复序列或BAC分子探针，整合细胞学图与遗传连锁图或基因组测序Scaffold，将甜橙测序数据与真实染色体对应；并在减数分裂粗线期染色体上构建甜橙高分辨率的分子细胞遗传学图谱，补充和完善甜橙基因组遗传信息。本申请项目的前期基础扎实，其实施有望为甜橙基因组的杂合性分析、柑橘类植物染色体进化及比较基因组学等研究奠定基础。

甜橙是世界和我国最重要的柑橘栽培类型。我国已自主完成甜橙全基因组测序。构建甜橙分子细胞遗传学图谱是对柑橘基因组测序项目的后续研究，对结合染色体分析认识甜橙基因组结构，深入了解其遗传规律具有重要意义。甜橙染色体较小且形态相近，缺乏有效标记，以致细胞学研究相对滞后。甜橙基因组信息为开发识别染色体的分子标记、从而加强其基因组遗传研究提供了基础数据平台。本项目对基因组数据进行生物信息学分析和FISH实验，筛选区分甜橙染色体的BAC克隆、重复序列和寡核苷酸序列等分子探针，整合细胞学图与遗传连锁图、基因组测序拼接框架，将甜橙测序数据与真实染色体对应；并尝试在减数分裂粗线期染色体上构建甜橙高分辨率的分子细胞遗传学图谱，补充和完善甜橙基因组遗传信息。本项目的研究结果为深入开展甜橙基因组的杂合性分析、染色体结构变异鉴定、柑橘类植物染色体进化及比较基因组学等研究奠定了扎实的基础。