A Novel Putative Transporter Maps to the Osteosclerosis (oc) Mutation and Is Not Expressed in theocMutant Mouse

The phenotype of mice homozygous for the osteosclerosis (oc) mutation includes osteopetrosis, and a variety of studies demonstrate that osteoclasts in these mice are present but nonfunctional. We have identified a novel gene that has homology to a family of 12-transmembrane domain proteins with transport functions and maps to proximal mouse chromosome 19, in a region to which theocmutation has been previously assigned. The putative transporter is abundant in normal kidney, but its expression is markedly reduced in kidneys fromoc/ocmice when tested using Northern and Western analyses. Southern analysis of this gene, which we callRoct(reduced inoctransporter), demonstrates that it is intact and unrearranged inoc/ocmice.In situstudies show thatRoctis expressed in developing bone. We propose that the absence ofRoctexpression results in an osteopetrosis phenotype in mice.     

Über die Ursachen der photokapillaren Reaktion der Pflanzen

Zusammenfassung Es wurden Versuche angestellt, die zeigen sollen, daß das Licht in der Pflanze Ladungsverschiebungen verursacht. Es wurde festgestellt, daß das Licht schon nach 3 Tagen die Ladung vermindert, was aller Wahrscheinlichkeit nach einer Ladungszerstreuung zuzuschreiben ist.Es wurde auch gezeigt, daß die photokapillare Reaktion in der Pflanze sowie in vitro (Herík 1928e) auf einer photoelektrischen Erscheinung beruht.     

Estrogen sulfotransferase of the rat liver: complementary DNA cloning and age- and sex-specific regulation of messenger RNA.

Mammalian estrogen sulfotransferase (EST; EC 2.8.2.4) sulfurylates the hydroxyl group of estrogenic steroids by transferring the sulfate from a cosubstrate adenosine 3'-phosphate-5'-phosphosulfate. Sulfurylated steroids do not bind to the estrogen receptor with high affinity and, therefore, are hormonally inactive. We have purified rat liver EST and developed monoclonal antibody to this enzyme. By immunoscreening a lambda gt-11 expression library constructed from male rat liver cDNAs, the cDNA clone corresponding to EST was identified and isolated. A recombinant expression plasmid (pCMV5) containing this cDNA insert when transfected into COS-7 cells generated both immunologically and enzymatically active EST. With the help of this cDNA probe, we have explored the regulation of the EST mRNA in the liver and the possible role of this enzyme in sex hormone action. During the lifespan of male rats, only the young adult animals show hepatic androgen responsiveness. Also, estrogenic hormones strongly antagonize androgen action in the rat liver. Northern blot analysis of liver RNA derived from male rats of different ages shows that the androgen sensitivity of young adult animals is associated with a high expression of EST mRNA. During the same period, mRNA corresponding to dehydroepiandrosterone sulfotransferase is markedly (approximately 10-fold) down-regulated. Such a correlation is in concordance with the role of these enzymes in the maintenance of hepatic androgen sensitivity during young adult life by inactivating the estrogenic and sparing the androgenic steroids. Furthermore, the increase in the hepatic androgen sensitivity of androgen-treated female rats is also associated with the induction of EST.(ABSTRACT TRUNCATED AT 250 WORDS)