title: Identification of exotic genetic components and DNA methylation pattern analysis of three cotton introgression lines from Gossypium bickii.
abstract: The impact of alien DNA fragments on plant genome has been studied in many species. However, little is known about the introgression lines of Gossypium. To study the consequences of introgression in Gossypium, we investigated  2000 genomic and  800 epigenetic sites in three typical cotton introgression lines, as well as their cultivar (Gossypium hirsutum) and wild parents (Gossypium bickii), by amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP). The results demonstrate that an average of 0.5% of exotic DNA segments from wild cotton is transmitted into the genome of each introgression line, with the addition of other forms of genetic variation. In total, an average of 0.7% of genetic variation sites is identified in introgression lines. Simultaneously, the overall cytosine methylation level in each introgression line is very close to that of the upland cotton parent (an average of 22.6%). Further dividing patterns reveal that both hypomethylation and hypermethylation occurred in introgression lines in comparison with the upland cotton parent. Sequencing of nine methylation polymorphism fragments showed that most (7 of 9) of the methylation alternations occurred in the noncoding sequences. The molecular evidence of introgression from wild cotton into introgression lines in our study is identified by AFLP. Moreover, the causes of petal variation in introgression lines are discussed.
authors.affiliation: Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture, Cotton Research Institute, Chinese Academy of Agricultural Sciences, Anyang, Henan 455004, China.
authors.forename: Shou-Pu
authors.initials: SP
authors.lastname: He
authors.forename: Jun-Ling
authors.initials: JL
authors.lastname: Sun
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Xiong-Ming
authors.initials: XM
authors.lastname: Du
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics*; D057890:Epigenomics; D014644:Genetic Variation; D018745:Genome, Plant / Q000235:genetics; D003368:Gossypium / Q000235:genetics*; D006824:Hybridization, Genetic; D011110:Polymorphism, Genetic
chemical_list: D003596:Cytosine