title: Single-copy gene-based chromosome painting in cucumber and its application for chromosome rearrangement analysis in Cucumis.
abstract: Chromosome painting based on fluorescence in situ hybridization (FISH) has played an important role in chromosome identification and research into chromosome rearrangements, diagnosis of chromosome abnormalities and evolution in human and animal species. However, it has not been applied widely in plants due to the large amounts of dispersed repetitive sequences in chromosomes. In the present work, a chromosome painting method for single-copy gene pools in Cucumis sativus was successfully developed. Gene probes with sizes above 2 kb were detected consistently. A cucumber karyotype was constructed based on FISH using a cocktail containing chromosome-specific gene probes. This single-copy gene-based chromosome painting (ScgCP) technique was performed by PCR amplification, purification, pooling, labeling and hybridization onto chromosome spreads. Gene pools containing sequential genes with an interval less than 300 kb yielded painting patterns on pachytene chromosomes. Seven gene pools corresponding to individual chromosomes unambiguously painted each chromosome pair of C. sativus. Three mis-aligned regions on chromosome 4 were identified by the painting patterns. A probe pool comprising 133 genes covering the 8 Mb distal end of chromosome 4 was used to evaluate the potential utility of the ScgCP technique for chromosome rearrangement research through cross-species FISH in the Cucumis genus. Distinct painting patterns of this region were observed in C. sativus, C. melo and C. metuliferus species. A comparative chromosome map of this region was constructed between cucumber and melon. With increasing sequence resources, this ScgCP technique may be applied on any other sequenced species for chromosome painting research.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Qunfeng
authors.initials: Q
authors.lastname: Lou
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yuhua
authors.initials: Y
authors.lastname: He
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Jia
authors.forename: Chunyan
authors.initials: C
authors.lastname: Cheng
authors.forename: Wei
authors.initials: W
authors.lastname: Guan
authors.forename: Shuqiong
authors.initials: S
authors.lastname: Yang
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Chen
mesh_terms: D002874:Chromosome Mapping; D020223:Chromosome Painting / Q000379:methods*; D032461:Chromosomes, Plant / Q000235:genetics*; D028463:Cucumis melo / Q000235:genetics*; D018553:Cucumis sativus / Q000166:cytology / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D049471:Pachytene Stage; D016133:Polymerase Chain Reaction
keywords: Cucumis sativus; chromosome painting; chromosome rearrangement; fluorescence in situ hybridization; single-copy gene; technical advance