B6.129S4-Nos1^tm2Plh/J

Stock number: 008519
Research areas: Endocrine Deficiency Research, Neurobiology Research, Reproductive Biology Research

Description

Mice that are homozygous for this targeted mutation of Nos1 (nitric oxide synthase 1, neuronal) have decreased body and gonad weight and are infertile. Female homozygotes have impaired ovulation and male homozygotes do not display mating behavior. This mutant mouse strain may be useful in studies of hypothalamo-pituitary axis and neuroendocrine regulation of reproduction.

Detailed description

In this targeted mutation exon 6, which encodes the heme-binding domain, is deleted. Mice that are homozygous for the targeted mutation are viable only when maintained on a liquid diet and are not fertile. Some truncated gene product (mRNA) containing exon 2 but completely lacking exon 6 is detected by RR-PCR of brain. Nitric oxide synthase activity is only 0.3% of wildtype levels in the brain. Homozygotes have smaller total body and gonad weight and develop pyloric stenosis. Female homozygotes have fewer ovarian corpora lutea and increased hypothalmic gonadotropin-releasing hormone and circulating luteinizing hormone. Homozygous males have decreased follicle stimulating hormone levels and do not display mating behavior. Mice that are heterozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. This mutant mouse strain may be useful in studies of hypothalamo-pituitary axis and neuroendocrine regulation of reproduction.

Development

A targeting vector containing a loxP site flanked neomycin resistance and herpes simplex virus thymidine kinase cassette was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 6 of the targeted gene, and another loxP site was inserted upstream of exon 6. The construct was electroporated into 129S4/SvJae derived J1 embryonic stem (ES) cells, which were transiently transfected with a Cre recombinase vector to remove the selection cassette. ES cells that had successfully undergone Cre-mediated recombination and no longer retained the cassette were injected into recipient blastocysts. The mice were backcrossed to C57BL/6J for 10 generations before arriving at The Jackson Laboratory.

Allele

Symbol: Nos1^tm2Plh
Name: targeted mutation 2, Paul L Huang
MGI accession ID: MGI:3621899
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Nos1
Marker name: nitric oxide synthase 1, neuronal
Chromosome: 5
Strain of origin: Not Specified
Molecular note: Exon 6 was removed via cre-mediated recombination. This exon encodes the heme-binding domain. RT-PCR confirmed the loss of exon 6 in mutants, demonstrating presence of some mRNA containing exon 2, but none containing exon 6. Immunohistochemistry failed to detect any staining in the cytoplasm, neurites, varicosities, cortex or striatum of mutants.