Assignment of human prochymosin pseudogene to chromosome 1

A genomic analysis of rat proteases and protease inhibitors

Proteases perform important roles in multiple biological and pathological processes. The availability of the rat genome sequence has facilitated the analysis of the complete protease repertoire or degradome of this model organism. The rat degradome consists of at least 626 proteases and homologs, which are distributed into 24 aspartic, 160 cysteine, 192 metallo, 221 serine, and 29 threonine proteases. This distribution is similar to that of the mouse degradome but is more complex than that of the human degradome composed of 561 proteases and homologs. This increased complexity of rat proteases mainly derives from the expansion of several families, including placental cathepsins, testases, kallikreins, and hematopoietic serine proteases, involved in reproductive or immunological functions. These protease families have also evolved differently in rat and mouse and may contribute to explain some functional differences between these closely related species. Likewise, genomic analysis of rat protease inhibitors has shown some differences with mouse protease inhibitors and the expansion of families of cysteine and serine protease inhibitors in rodents with respect to human. These comparative analyses may provide new views on the functional diversity of proteases and inhibitors and contribute to the development of innovative strategies for treating proteolysis diseases.

The human ribosomal protein S6 gene: isolation, primary structure and location in chromosome 9

Using PCR cloning we isolated the first intron of the human ribosomal protein S6 gene (hRPS6). By screening the human HeLa cell cDNA library in lambda ZAPII vector (Stratagene, La Jolla, CA), we identified and sequenced a partially spliced pre mRNA copy of hRPS6. The complete hRPS6 gene was isolated from a lambda DASH library with an intron-specific probe. The gene and flanking regions were sequenced, and the mRNA 5' end was mapped by primer extension experiments. The hRPS6 gene has 6 exons and 5 introns and is 3.6 kb long. Using intron-specific primers in PCR and a panel of human-hamster cell lines we localized the hRPS6 gene in human chromosome 9.

Assignment of eight loci to bovine syntenic groups by use of PCR: extension of a comparative gene map

The polymerase chain reaction (PCR) has been combined with hybrid somatic cell technology to extend the bovine physical map. Eight bovine loci--glycoprotein hormone alpha (CGA), coagulation factor X (F10), chromogranin A (CHGA), low-density lipoprotein receptor (LDLR), human prochymosin pseudogene (CYM), oxytocin (OXT), arginine-vasopressin (ARVP), and cytochrome oxidase c subunit IV pseudogene (COXP)--were assigned to bovine syntenic groups with this approach. CGA was assigned to bovine syntenic group U2, F10 to U27, CHGA to U4 [bovine Chromosome (Chr) 21], LDLR to U22, CYM to U6, OXT and ARVP to U11, and COXP to U3 (bovine Chr 5). Seven of these genes, CGA, F10, CHGA, LDLR, OXT, ARVP, and CYM, further delineate regions of chromosomal conservation on human Chrs 6, 13, 14, 19, 20, 20, and 1, respectively. CHGA, OXT, and ARVP are unmapped in the mouse. Comparative mapping predicts the mouse CHGA will map to Chr 12, and mouse OXT and ARVP will map to mouse Chr 2. Furthermore, human CYM is predicted to be sublocalized to 1p32-q21. The primers developed for these eight loci will be useful for the development of hybrid somatic cell panels in the future as well as establishing a collection of bovine expressed sequence tags.

Human spermidine synthase gene: structure and chromosomal localization

The human spermidine synthase (EC 2.5.1.16) gene was isolated from a genomic library constructed with DNA obtained from a human immunoglobulin G (IgG) myeloma cell line. Subsequent sequence analyses revealed that the gene comprised of 5,818 nucleotides from the cap site to the last A of the putative polyadenylation signal with 8 exons and 7 intervening sequences. The 5'-flanking region of the gene was extremely GC rich, lacking any TATA box but containing CCAAT consensus sequences. No perfect consensus sequence for the cAMP-responsive element for the AP-1 binding site was found, yet the gene contained seven AP-2 binding site consensus sequences. The putative polyadenylation signal was an unusual AATACA instead of AATAAA. Polymerase chain reaction analysis with DNA obtained from human x hamster somatic cell hybrids indicated that human spermidine synthase genomic sequences segregate with human chromosome 1. Transfection of the genomic clone into Chinese hamster ovary cells displaying a low endogenous spermidine synthase activity revealed that the gene was transiently expressed and hence in all likelihood represents a functional gene.