Chromosome identification is critical for cytogenetic research and will accelerate studies on genetic variation and breeding, especially for those species with relatively little sequence information. So far, no reliable cytological landmarks have been developed to distinguish individual chromosomes in melon. In this study, using FISH (fluorescence in situ hybridization) combined with comparative genome information, we selected 21 cucumber fosmids anchored by SSR markers as chromosome-specific cytological markers for melon chromosomes. Moreover, with the help of melon centromeric satellite DNA repeats CentM, 45S rDNA and 5S rDNA, sequential FISH with 3 sets of multi-fosmid cocktails were conducted on the same metaphase cell, which allowed us to simultaneously identify each of the 12 metaphase chromosomes of melon and a standardized melon karyotype of somatic metaphase chromosomes was constructed. Finally, we compared the distribution of 21 FISH-mapped fosmids between melon and cucumber chromosomes, which allows a better understanding of the evolutionary process shaping these 2 species. Our study provides a basis for cytological characterization of the melon genome and comparative genomics of Cucurbitaceae.

Keywords:
Cross-species, Cucumber, FISH, Fosmid, Karyotyping, Melon
1.
Arumuganathan K, Earle ED: Nuclear DNA content of some important plant species. Plant Mol Biol Rep 9:208–218 (1991).
2.
Baudracco-Arnas S, Pitrat M: A genetic map of melon (Cucumis melo L.) with RFLP, RAPD, isozyme, disease resistance and morphological markers. Theor Appl Genet 93:57–64 (1996).
3.
Bhaduri PN, Bose PC: Cyto-genetical investigations in some common cucurbits, with special reference to fragmentation of chromosomes as physical basis of speciation. J Genet 48:237–256 (1947).
4.
Chen CC, Chen CM, Hsu FC, Wang CJ, Yang JT, et al: The pachytene chromosomes of maize as revealed by fluorescence in situ hybridization with repetitive DNA sequences. Theor Appl Genet 101:30–36 (2000).
5.
Chen JF, Staub JE, Adelberg JW, Jiang J: Physical mapping of 45S rRNA genes in Cucumis species by fluorescence in situ hybridization. Can J Bot 77:389–393 (1999).
6.
Cheng ZC, Buell CR, Wing RA, Gu M, Jiang J: Toward a cytological characterization of the rice genome. Genome Res 11:2133–2141 (2001).
7.
Dane F, Tsuchiya T: Chromosome studies in the genus Cucumis. Euphytica 25:367–374 (1976).
8.
Danin-Poleg Y, Reis N, Baudracco-Arnas S, Pitrat M, Staub J: Simple sequence repeats in Cucumis mapping and map merging. Genome 43:963–974 (2000).
9.
Dong F, Song J, Naess SK, Helgeson JP, Gebhardt C: Development and applications of a set of chromosome-specific cytogenetic DNA markers in potato. Theor Appl Genet 101:1001–1007 (2000).
10.
Fernandez-Silva I, Eduardo I, Blanca J, Esteras C, Picó B, et al: Bin mapping of genomic and EST-derived SSRs in melon (Cucumis melo L.). Theor Appl Genet 118:139–150 (2008).
11.
Fransz PF, Armstrong S, Jong JH, Parenell LD, Drunen C, et al: Integrated cytogenetic map of chromosome arms 4S of A. thaliana: structural organization of heterochromatic knob and centromere region. Cell 100:367–376 (2000).
12.
Han YH, Zhang ZH, Liu CX, Liu JH, Huang SW, et al: Centromere repositioning in cucurbit species: implication of the genomic impact from centromere activation and inactivation. Proc Natl Acad Sci USA 106:14937–14941 (2009).
13.
Han YH, Zhang ZH, Liu JH, Lu JY, Huang SW, et al: Distribution of the tandem repeat sequences and karyotyping in cucumber (Cucumis sativus L.) by fluorescence in situ hybridization. Cytogenet Genome Res 122:80–88 (2008).
14.
Huang SW, Li RQ, Zhang ZH, Li L, Gu XF, et al: The genome of the cucumber, Cucumis sativus L. Nat Genet 41:1275–1281(2009).
15.
Jackson SA, Cheng Z, Wang ML, Goodman HM, Jiang J: Comparative fluorescence in situ hybridization mapping of a 431-kb Arabidopsis thaliana bacterial artificial chromosome contig reveals the role of chromosomal duplication in the expansion of the Brassica rapa genome. Genetics 156:833–838 (2000).
16.
Jiang J, Gill BS: Nonisotopic in situ hybridization and plant genome mapping: the first 10 years. Genome 37:717–725 (1994).
17.
Jiang J, Gill BS, Wang GL, Ronald PC, Ward DC: Metaphase and interphase fluorescence in situ hybridization mapping of the rice genome with bacterial artificial chromosomes. Proc Natl Acad Sci USA 92:4487–4491 (1995).
18.
Kato A, Lamb JC, Birchler JA: Chromosome painting using repetitive DNA sequences as probes for somatic chromosome identification in maize. Proc Natl Acad Sci USA 101:13554–13559 (2004).
19.
Katzir N, Danin-Poleg Y, Tzuri G, Karchi Z, Lavi U, Cregan P: Length polymorphism and homologies of microsatellites in several Cucurbitaceae species. Theor Appl Genet 93:1282–1290 (1996).
20.
Kirkbride JH Jr: Biosystematic Monograph of the Genus Cucumis (Cucurbitaceae). (Parkway Publishers, Boone 1993).
21.
Koumbaris GL, Bass HW: A new single-locus cytogenetic mapping system for maize (Zea mays L.): overcoming FISH detection limits with marker-selected sorghum (S. propinquum L.) BAC clones. Plant J 35:647–659 (2003).
22.
Lim KB, Wennekes J, Jong JH, Jacobsen E, Tuyl JM: Karyotype analysis of Lilium longiflorum and Lilium rubellum by chromosome banding and fluorescence in situ hybridization. Genome 44:911–918 (2001).
23.
Lysak MA, Koch MA, Pecinka A, Schuert I: Chromosome triplication found across the tribe Brassiceae. Genome Res 15:516–525 (2005).
24.
Lysak MA, Cheung K, Kitschke M, Bures P: Ancestral chromosomal blocks are triplicated in Brassiceae species with varying chromosome number and genome size. Plant Physiol 145:402–410 (2007).
25.
Ma DW, Guo ZH, Zhang CH, Gao SZ, Wang M: A study on chromosome number and karyotype of melons (Cucumis melo L.). Acta Horticulture 402:61–65 (1995).
26.
Neuhausen S: Evaluation of restriction fragment length polymorphism in Cucumis melo. Theor Appl Genet 83:379–384 (1992).
27.
Park Y, Katzir N, Brotman Y, King J, Bertrand F: Comparative mapping of ZYMV resistances in cucumber (Cucumis sativus L.) and melon (Cucumis melo L.). Theor Appl Genet 109:707–712 (2004).
28.
Ramachandran C, Seshadri VS: Cytological analysis of the genome of cucumber (Cucumis sativus L.) and muskmelon (Cucumis melo L.). Z Pflanzenzüchtg 96:25–38 (1986).
29.
Ren Y, Zhang ZH, Liu JH, Staub JE, Han YH, et al: An integrated genetic and cytogenetic map of the cucumber genome. PLoS One 4:e5795 (2009).
30.
Ried T, Arnold N, Ward DC, Wienberg J: Comparative high resolution mapping of human and primate chromosomes by fluorescence in situ hybridization. Genomics 18:381–386 (1993).
31.
Ritschel PS, Lins TC, Tristan RL, Buso GS, Buso JA, et al: Development of microsatellite markers from an enriched genomic library for genetic analysis of melon (Cucumis melo L.) BMC Plant Biol 4:9 (2004).
32.
Sadder MT, Weber G: Karyotype of maize (Zea mays L.) mitotic metaphase chromosomes as revealed by fluorescence in situ hybridization (FISH) with cytogenetic DNA markers. Plant Mol Biol Rep 19:117–123 (2001).
33.
Schaefer H, Heibl C, Renner SS: Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events. Proc R Soc B 276:843–851 (2009).
34.
Shimotsuma M: Chromosome studies of some Cucumis species. Seiken Ziho 17:11–16 (1965).
35.
Tang X, Szinay D, Lang C, Ramanna MS, Vossen EAG: Cross-species bacterial artificial chromosome-fluorescence in situ hybridization painting of the tomato and potato chromosome 6 reveals undescribed chromosomal rearrangements. Genetics 180:1319–1328 (2008).
36.
Trivedi RN, Roy RP: Cytological studies in Cucumis and Citrullus. Cytologia 35:561–569 (1970).
37.
Wang YH, Thomas CE, Dean RA: A genetic map of melon (Cucumis melo L.) based on amplified fragment length polymorphism (AFLP) markers. Theor Appl Genet 95:791–798 (1997).
38.
Zhang YB, Chen JF, Yi HP, Feng JX, Wu MZ: Staining and slide-preparing technique of mitotic chromosomes and its use in karyotype determination of Cucumis melo L. Acta Bot Boreal-Occident Sin 25:1735–1739 (2005).
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