Comparison of Spinach Sex Chromosomes with Sugar Beet Autosomes Reveals Extensive Synteny and Low Recombination at the Male-Determining Locus. (25th August 2016)

• Record Type: Journal Article
• Authors: Takahata, Satoshi; Yago, Takumi; Iwabuchi, Keisuke; Hirakawa, Hideki; Suzuki, Yutaka; Onodera, Yasuyuki
• Is Part Of: Journal of heredity. Volume 107:Number 7(2016)
• Page Start: 679
• Page End: 685
• Publication Date: 2016-08-25
• Subjects: autosome -- Beta vulgaris -- centromere -- sex chromosome -- Spinacia oleracea -- synteny; Breeding -- Periodicals; Plant breeding -- Periodicals; Heredity -- Periodicals; 576.5
• DOI: 10.1093/jhered/esw055
• Languages: English
• ISSNs: 0022-1503

Abstract

Abstract: Spinach ( Spinacia oleracea, 2 n = 12) and sugar beet ( Beta vulgaris, 2 n = 18) are important crop members of the family Chenopodiaceae s . s . Sugar beet has a basic chromosome number of 9 and a cosexual breeding system, as do most members of the Chenopodiaceae s . s. family. By contrast, spinach has a basic chromosome number of 6 and, although certain cultivars and genotypes produce monoecious plants, is considered to be a dioecious species. The loci determining male and monoecious sexual expression were mapped to different loci on the spinach sex chromosomes. In this study, a linkage map with 46 mapped protein-coding sequences was constructed for the spinach sex chromosomes. Comparison of the linkage map with a reference genome sequence of sugar beet revealed that the spinach sex chromosomes exhibited extensive synteny with sugar beet chromosomes 4 and 9. Tightly linked protein-coding genes linked to the male-determining locus in spinach corresponded to genes located in or around the putative pericentromeric and centromeric regions of sugar beet chromosomes 4 and 9, supporting the observation that recombination rates were low in the vicinity of the male-determining locus. The locus for monoecism was confined to a chromosomal segment corresponding to a region of approximately 1.7Mb on sugar beet chromosome 9, which may facilitate future positional cloning of the locus.