title: HP1 knockdown is associated with abnormal condensation of almost all chromatin types in a grasshopper (Eyprepocnemis plorans).
abstract: Heterochromatin protein 1 (HP1) is a highly conserved family of eukaryotic proteins required for heterochromatic gene silencing and euchromatic gene transcription regulation. In addition, HP1 is involved in chromatin organization and protection of chromosome integrity during cell division. Here, we present a cytological and molecular analysis of the effects of HP1 knockdown in Eyprepocnemis plorans, a grasshopper species polymorphic for supernumerary heterochromatic chromosomes. Our results revealed contrasting effects of HP1 knockdown on gene activity. While the Bub1 gene decreased in expression level in HP1 knockdown animals, NOR activity, rRNA and, contrarily to previous reports in Drosophila, Hsp70 gene expression remained unchanged. Furthermore, HP1 knockdown resulted in abnormal chromatin condensation, chromosomal bridges, higher frequency of macrospermatids, loss of muscle mass and hemolymph amount as well as a low number of dividing cells and survival reduction. All these phenotypes are very likely due to the chromatin condensation disruption observed for almost all kinds of chromatin.
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Ruiz-Estévez
authors.forename: Mohammed
authors.initials: M
authors.lastname: Bakkali
authors.forename: Josefa
authors.initials: J
authors.lastname: Cabrero
authors.forename: Juan Pedro M
authors.initials: JP
authors.lastname: Camacho
authors.forename: María Dolores
authors.initials: MD
authors.lastname: López-León
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D059006:Chromosomes, Insect / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D006110:Grasshoppers / Q000378:metabolism*; D008297:Male; D008540:Meiosis; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013087:Spermatids / Q000166:cytology / Q000378:metabolism
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D012333:RNA, Messenger; D000090266:Chromobox Protein Homolog 5