Cloning of the mouse steroid sulfatase (Sts) gene
- UCSF School Medicine, San Francisco, CA (United States)
- UCSF Sch. Medicine, San Francisco, CA (United States); and others
In humans, the STS gene is located on the distal short arm of the X chromosome, proximal to the pseudoautosomal region (PAR). STS activity can be detected in mouse tissues using the same substrates as for the human STS assay, and quantitative differences in STS levels among various mouse strains allowed the mapping of Sts to the PAR. However, several attempts to clone the mouse Sts gene using human reagents have failed, which has been taken as evidence of substantial divergence between these genes. We report the cloning of the mouse Sts gene by using the Sts cDNA from an intermediate species, the rat. The coding region of the rat Sts cDNA was used as a probe to screen mouse fibroblast and liver cDNA libraries, and 5 clones were isolated. DNA sequence of the 2.5 kb cDNA revealed 75% similarity with rat Sts, while it was only 63% and 60% similar to the human STS at the DNA and protein levels, respectively. Interestingly, the mouse Sts cDNA revealed a high GC content, including 225 CpG dinucleotides in the coding region, compared to 88 and 44 CpGs in the same regions of the rat and human STS genes, respectively. Despite the low degree of conservation between these genes, all the point mutations described so far in human STS-deficient patients occur at amino acid residues that are conserved between these three species. Using a panel of mouse-hamster somatic cell hybrids, the mouse Sts cDNA sequences were mapped to the mouse X and Y chromosomes, with restriction fragments of the same size for both chromosomes, consistent with localization of Sts in the PAR. The pseudoautosomal pattern of inheritance was ascertained in back-crosses between C3H/An and SW mice, making use of STS activity assays and RFLPs. RT-PCR experiments using cDNA from a panel of hamster-mouse somatic cell hybrids containing either the inactive or the active X chromosome indicated that the mouse Sts gene escapes X-inactivation, as expected for a pseudoautosomal gene.
- OSTI ID:
- 133869
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
Similar Records
The human C/EBP{delta} (CRP3/CELF) gene: Structure and chromosomal localization
Sequence divergence and chromosomal rearrangements during the evolution of human pseudoautosomal genes and their mouse homologs
Related Subjects
BASIC STUDIES
AMINO ACIDS
COMPARATIVE EVALUATIONS
DNA SEQUENCING
DNA-CLONING
GENE MUTATIONS
GENES
GENETIC MAPPING
GENETICS
HETEROCHROMOSOMES
HUMAN POPULATIONS
HYBRIDIZATION
MICE
NUCLEOTIDES
POLYMERASE CHAIN REACTION
PROBES
PROTEINS
RATS
RFLPS
SOMATIC CELLS
STEROIDS
STRUCTURE-ACTIVITY RELATIONSHIPS