title: Overexpression of miR-30b in the developing mouse mammary gland causes a lactation defect and delays involution.
abstract: BACKGROUND
  MicroRNA (miRNA) are negative regulators of gene expression, capable of exerting pronounced influences upon the translation and stability of mRNA. They are potential regulators of normal mammary gland development and of the maintenance of mammary epithelial progenitor cells. This study was undertaken to determine the role of miR-30b on the establishment of a functional mouse mammary gland. miR-30b is a member of the miR-30 family, composed of 6 miRNA that are highly conserved in vertebrates. It has been suggested to play a role in the differentiation of several cell types.
  
  
  RESULTS
  The expression of miR-30b was found to be regulated during mammary gland development. Transgenic mice overexpressing miR-30b in mammary epithelial cells were used to investigate its role. During lactation, mammary histological analysis of the transgenic mice showed a reduction in the size of alveolar lumen, a defect of the lipid droplets and a growth defect of pups fed by transgenic females. Moreover some mammary epithelial differentiated structures persisted during involution, suggesting a delay in the process. The genes whose expression was affected by the overexpression of miR-30b were characterized by microarray analysis.
  
  
  CONCLUSIONS
  Our data suggests that miR-30b is important for the biology of the mammary gland and demonstrates that the deregulation of only one miRNA could affect lactation and involution.
authors.affiliation: INRA, UMR1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Le Guillou
authors.forename: Nezha
authors.initials: N
authors.lastname: Sdassi
authors.forename: Johann
authors.initials: J
authors.lastname: Laubier
authors.forename: Bruno
authors.initials: B
authors.lastname: Passet
authors.forename: Marthe
authors.initials: M
authors.lastname: Vilotte
authors.forename: Johan
authors.initials: J
authors.lastname: Castille
authors.forename: Denis
authors.initials: D
authors.lastname: Laloë
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Polyte
authors.forename: Stéphan
authors.initials: S
authors.lastname: Bouet
authors.forename: Florence
authors.initials: F
authors.lastname: Jaffrézic
authors.forename: Edmond-Paul
authors.initials: EP
authors.lastname: Cribiu
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Vilotte
authors.forename: Fabienne
authors.initials: F
authors.lastname: Le Provost
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D017931:DNA Primers; D005260:Female; D007774:Lactation / Q000235:genetics*; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D035683:MicroRNAs; C534715:Mirn30d microRNA, mouse