A series of ENU-induced single-base substitutions in a long-range cis-element altering Sonic hedgehog expression in the developing mouse limb bud.
Mammal-fish-conserved-sequence 1 (MFCS1) is a highly conserved sequence that acts as a limb-specific cis-acting regulator of Sonic hedgehog (Shh) expression, residing 1 Mb away from the Shh coding sequence in mouse. Using gene-driven screening of an ENU-mutagenized mouse archive, we obtained mice with three new point mutations in MFCS1: M101116, M101117, and M101192. Phenotype analysis revealed that M101116 mice exhibit preaxial polydactyly and ectopic Shh expression at the anterior margin of the limb buds like a previously identified mutant, M100081. In contrast, M101117 and M101192 show no marked abnormalities in limb morphology. Furthermore, transgenic analysis revealed that the M101116 and M100081 sequences drive ectopic reporter gene expression at the anterior margin of the limb bud, in addition to the normal posterior expression. Such ectopic expression was not observed in the embryos carrying a reporter transgene driven by M101117. These results suggest that M101116 and M100081 affect the negative regulatory activity of MFCS1, which suppresses anterior Shh expression in developing limb buds. Thus, this study shows that gene-driven screening for ENU-induced mutations is an effective approach for exploring the function of conserved, noncoding sequences and potential cis-regulatory elements.
Masuya
Hiroshi
H
Mouse Functional Genomics Research Group, RIKEN GSC 3-1-1 Kouyadai, Tsukuba, Ibaraki 305-0074, Japan.
Sezutsu
Hideki
H
Sakuraba
Yoshiyuki
Y
Sagai
Tomoko
T
Hosoya
Masaki
M
Kaneda
Hideki
H
Miura
Ikuo
I
Kobayashi
Kimio
K
Sumiyama
Kenta
K
Shimizu
Aya
A
Nagano
Junko
J
Yokoyama
Haruka
H
Kaneko
Satoko
S
Sakurai
Noriko
N
Okagaki
Yuka
Y
Noda
Tetsuo
T
Wakana
Shigeharu
S
Gondo
Yoichi
Y
Shiroishi
Toshihiko
T
D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D004742:Enhancer Elements, Genetic; D005038:Ethylnitrosourea; D005121:Extremities / Q000196:embryology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005809:Genes, Regulator; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D053823:Hedgehog Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D017880:Limb Deformities, Congenital / Q000196:embryology / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D010641:Phenotype; D017354:Point Mutation; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy
D017931:DNA Primers; D053823:Hedgehog Proteins; C465570:Shh protein, mouse; D005038:Ethylnitrosourea