title: Genes of both parental origins are differentially involved in early embryogenesis of a tobacco interspecies hybrid.
abstract: BACKGROUND
  In animals, early embryonic development is largely dependent on maternal transcripts synthesized during gametogenesis. However, in higher plants, the extent of maternal control over zygote development and early embryogenesis is not fully understood yet. Nothing is known about the activity of the parental genomes during seed formation of interspecies hybrids.
  
  
  RESULTS
  Here, we report that an interspecies hybridization system between SR1 (Nicotiana tabacum) and Hamayan (N. rustica) has been successfully established. Based on the system we selected 58 genes that have polymorphic sites between SR1 and Hamayan, and analyzed the allele-specific expression of 28 genes in their hybrid zygotes (Hamayan x SR1). Finally the allele-specific expressions of 8 genes in hybrid zygotes were repeatedly confirmed. Among them, 4 genes were of paternal origin, 1 gene was of maternal origin and 3 genes were of biparental origin. These results revealed obvious biparental involvement and differentially contribution of parental-origin genes to zygote development in the interspecies hybrid. We further detected the expression pattern of the genes at 8-celled embryo stage found that the involvement of the parental-origin genes may change at different stages of embryogenesis.
  
  
  CONCLUSIONS
  We reveal that genes of both parental origins are differentially involved in early embryogenesis of a tobacco interspecies hybrid and functions in a developmental stage-dependent manner. This finding may open a window to seek for the possible molecular mechanism of hybrid vigor.
authors.affiliation: Key Laboratory of Ministry of Education for Plant Development Biology, College of Life Science, Wuhan University, Wuhan, China.
authors.forename: Jun-E
authors.initials: JE
authors.lastname: Zhang
authors.forename: An
authors.initials: A
authors.lastname: Luo
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Xin
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Shi-Sheng
authors.initials: SS
authors.lastname: Li
authors.forename: Liang-Huan
authors.initials: LH
authors.lastname: Qu
authors.forename: Li-Gang
authors.initials: LG
authors.lastname: Ma
authors.forename: Stefan
authors.initials: S
authors.lastname: Scholten
authors.forename: Meng-Xiang
authors.initials: MX
authors.lastname: Sun
mesh_terms: D018076:DNA, Complementary; D020224:Expressed Sequence Tags; D018392:Genomic Imprinting; D006824:Hybridization, Genetic; D011110:Polymorphism, Genetic; D012639:Seeds / Q000254:growth & development*; D014026:Nicotiana / Q000196:embryology / Q000235:genetics*
chemical_list: D018076:DNA, Complementary