title: Targeted JAM-C deletion in germ cells by Spo11-controlled Cre recombinase.
abstract: Meiosis is a crucial process for the production of functional gametes. However, the biological significance of many genes expressed during the meiotic phase remains poorly understood, mainly because of the lethal phenotypes of the knockout mice. Functional analysis of such genes using the conditional knockout approach is hindered by the lack of suitable Cre transgenic lines. We describe here the generation of transgenic mice expressing Cre recombinase under the control of the meiotic Spo11 gene. Using LacZ-R26(loxP) and EYFP-R26(loxP) reporter mice, we show the specific expression and activity of Cre during meiosis in males and females. Spo11(Cre) mice were then crossed with floxed Nbs1 and JAM-C mice to produce conditional knockouts. A strong reduction of Nbs1 and JAM-C protein levels was found in the testis. Although Nbs1-deleted mice developed minor gonadal abnormalities, JAM-C-knockout mice showed a spermiogenetic arrest, as previously described for the null mice. These results provide strong evidence that Spo11(Cre) transgenic mice represent a powerful tool for deleting genes of interest specifically in meiotic and/or in postmeiotic germ cells.
authors.affiliation: Department of Public Health and Cellular Biology, University of Rome 'Tor Vergata', 00133 Rome, Italy. manuelapellegrini@libero.it
authors.forename: Manuela
authors.initials: M
authors.lastname: Pellegrini
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Claps
authors.forename: Valeria V
authors.initials: VV
authors.lastname: Orlova
authors.forename: Florencia
authors.initials: F
authors.lastname: Barrios
authors.forename: Susanna
authors.initials: S
authors.lastname: Dolci
authors.forename: Raffaele
authors.initials: R
authors.lastname: Geremia
authors.forename: Pellegrino
authors.initials: P
authors.lastname: Rossi
authors.forename: Gabriele
authors.initials: G
authors.lastname: Rossi
authors.forename: Bernd
authors.initials: B
authors.lastname: Arnold
authors.forename: Triantafyllos
authors.initials: T
authors.lastname: Chavakis
authors.forename: Lionel
authors.initials: L
authors.lastname: Feigenbaum
authors.forename: Shyam K
authors.initials: SK
authors.lastname: Sharan
authors.forename: Andre
authors.initials: A
authors.lastname: Nussenzweig
mesh_terms: D000818:Animals; D004706:Endodeoxyribonucleases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D018390:Gene Targeting / Q000379:methods*; D005854:Germ Cells / Q000166:cytology / Q000201:enzymology*; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D015877:Miosis; D011401:Promoter Regions, Genetic; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D004706:Endodeoxyribonucleases; D019426:Integrases; D000099257:Meiotic Recombination Protein SPO11; C045073:Cre recombinase