title: Protein-coding genes in B chromosomes of the grasshopper Eyprepocnemis plorans.
abstract: For many years, parasitic B chromosomes have been considered genetically inert elements. Here we show the presence of ten protein-coding genes in the B chromosome of the grasshopper Eyprepocnemis plorans. Four of these genes (CIP2A, GTPB6, KIF20A, and MTG1) were complete in the B chromosome whereas the six remaining (CKAP2, CAP-G, HYI, MYCB2, SLIT and TOP2A) were truncated. Five of these genes (CIP2A, CKAP2, CAP-G, KIF20A, and MYCB2) were significantly up-regulated in B-carrying individuals, as expected if they were actively transcribed from the B chromosome. This conclusion is supported by three truncated genes (CKAP2, CAP-G and MYCB2) which showed up-regulation only in the regions being present in the B chromosome. Our results indicate that B chromosomes are not so silenced as was hitherto believed. Interestingly, the five active genes in the B chromosome code for functions related with cell division, which is the main arena where B chromosome destiny is played. This suggests that B chromosome evolutionary success can lie on its gene content.
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Navarro-Domínguez
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Ruiz-Ruano
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Cabrero
authors.affiliation: Leibniz Institute for Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany.|Department of Bioanalytics, Coburg University of Applied Sciences and Arts, Coburg, Germany.
authors.forename: José María
authors.initials: JM
authors.lastname: Corral
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: López-León
authors.affiliation: Leibniz Institute for Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany.|Global Institute for Food Security, 110 Gymnasium Place, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 4J8, Canada.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Sharbel
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Juan Pedro M
authors.initials: JP
authors.lastname: Camacho
mesh_terms: D000818:Animals; D059006:Chromosomes, Insect / Q000235:genetics*; D006110:Grasshoppers / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*
chemical_list: D019476:Insect Proteins