Based on the partial nucleotide sequence analysis of 16S ribosomal ribonucleic acid (rRNA), presence of unique sphingoglycolipids in cellular lipid, and the major type of ubiquinone (Q10), we propose Sphingomonas gen. nov. with the type species Sphingomonas paucimobilis (Holmes et al, 1977) comb. nov. From the homology values of deoxyribonucleic acid‐deoxyribonucleic acid hybridization and the phenotypic characteristics, three new species, Sphingomonas parapaucimobilis, Sphingomonas yanoikuyae, Sphingomonas adhaesiva, and one new combination, Sphingomonas capsulata, are described. S. par apaucimobilis JCM 7510 (=GIFU 11387), S. yanoikuyae JCM 7371 (=GIFU 9882), and S. adhaesiva JCM 7370 (=GIFU 11458) are designated as the type strains of the three new species. Emended description of the type strain of S. capsulata is presented.

Severe childhood autosomal recessive muscular dystrophy (SCARMD) is a progressive muscle-wasting disorder common in North Africa that segregates with microsatellite markers at chromosome 13q12. Here, it is shown that a mutation in the gene encoding the 35-kilodalton dystrophin-associated glycoprotein, gamma-sarcoglycan, is likely to be the primary genetic defect in this disorder. The human gamma-sarcoglycan gene was mapped to chromosome 13q12, and deletions that alter its reading frame were identified in three families and one of four sporadic cases of SCARMD. These mutations not only affect gamma-sarcoglycan but also disrupt the integrity of the entire sarcoglycan complex.

Cocaine conditioned place preference (CPP) is intact in dopamine transporter (DAT) knockout (KO) mice and enhanced in serotonin transporter (SERT) KO mice. However, cocaine CPP is eliminated in double-KO mice with no DAT and either no or one SERT gene copy. To help determine mechanisms underlying these effects, we now report examination of baselines and drug-induced changes of extracellular dopamine (DA ex ) and serotonin (5-HT ex ) levels in microdialysates from nucleus accumbens (NAc), caudate putamen (CPu), and prefrontal cortex (PFc) of wild-type, homozygous DAT-or SERT-KO and heterozygous or homozygous DAT/SERT double-KO mice, which are differentially rewarded by cocaine. Cocaine fails to increase DA ex in NAc of DAT-KO mice. By contrast, systemic cocaine enhances DA ex in both CPu and PFc of DAT-KO mice though local cocaine fails to affect DA ex in CPu. Adding SERT to DAT deletion attenuates the cocaine-induced DA ex increases found in CPu, but not those found in PFc. The selective SERT blocker fluoxetine increases DA ex in CPu of DAT-KO mice, while cocaine and the selective DAT blocker GBR12909 increase 5-HT ex in CPu of SERT-KO mice. These data provide evidence that (a) cocaine increases DA ex in PFc independently of DAT and that (b), in the absence of SERT, CPu levels of 5-HT ex can be increased by blocking DAT. Cocaine-induced alterations in CPu DA levels in DAT-, SERT-, and DAT/SERT double-KO mice appear to provide better correlations with cocaine CPP than cocaine-induced DA level alterations in NAc or PFc.

Dystrophin is purified as a complex with several proteins from the digitonin-solubilized muscle cell membrane. Most of dystrophin-associated proteins (DAPs) are assumed to form a large oligomeric transmembranous glycoprotein complex on the sarcolemma and link dystrophin with a basement membrane protein, laminin. In the present study, we found that the purified dystrophin-DAP complex was dissociated into several groups by n-octyl-P-~-glucoside treatment. In particular, we found that the glycoprotein complex stated above was dissociated into two distinct groups: one composed of 156DAG and 43DAG (A3a) and the other composed of SODAG, 35DAG and A3b. We confirmed by crosslinking and immunoaffinity chromatography that these two groups existed in a complexes. We thus concluded that the glycoprotein complex consists of these two subcomplexes. Furthermore, A3b and 43DAG, which had been formerly treated simply as the 43DAG doublets due to their similar electrophoretic mobilities in SDS/PAGE, were shown to be present in two different subcomplexes. Based on the analyses by two-dimensional gel electrophoresis, peptide mapping and immunoblotting, we concluded that A3b is a novel DAP different from 43DAG. Dystrophin, the protein responsible for Duchenne muscular dystrophy [ l , 21, is purified as a complex with several proteins called dystrophin-associated proteins (DAPs) from digitonin-solubilized rabbit skeletal muscle membrane [3, 41. At least four DAPs, given the symbols 156DAG, SODAG, 43DAG doublets (A3a and A3b) and 35DAG, were shown to exist in the transmembranous glycoprotein complex (GPC) [5, 61. In the structural study of dystrophin or the complex of dystrophin and its associated proteins (dystrophin-DAP complex) by limited calpain digestion [7], we showed that the locus of GPC binding on the dystrophin molecule is confined to the cysteine-rich domain and the first half of the Cterminal domain [6]. Since this locus is known to be the region whose loss is responsible for Duchenne muscular dystrophy [8], this finding was the first experimental evidence showing that the interaction of GPC with dystrophin is essential to prevent muscle degeneration.Among the components of GPC, 156DAG [9, 101 and 43DAG [ l l ] were shown to bind directly to laminin and dystrophin, respectively. However, the molecular organization of GPC has not yet been clarified. Thus, its study is indispensable in order to clarify the molecular basis behind muscular dystrophy. We showed immunochemically that the components of GPC (50DAG and 35DAG) are expressed in striated muscles but not in smooth muscles such as uterus and aorta, whereas 43DAG is rather ubiquitously expressed in various tissues [12, 131. On the other hand, it was reported that in the muscles of patients with severe childhood autosoma1 recessive muscular dystrophy (SCARMD), 5ODAG is lost and 35DAG is reduced, while dystrophin and other DAPs are preserved [ 141. Similar observations were made in the skeletal muscle of dystrophic hamster [15, 161. We also observed that in the skeletal...

Serotonergic axons from the raphe nuclei in the brainstem project to every region of the brain, where they make connections through their extensive terminal arborizations. This serotonergic innervation contributes to various normal behaviors and psychiatric disorders. The protocadherin-␣ (Pcdha) family of clustered protocadherins consists of 14 cadherin-related molecules generated from a single gene cluster. We found that the Pcdhas were strongly expressed in the serotonergic neurons. To elucidate their roles, we examined serotonergic fibers in a mouse mutant (Pcdha ⌬CR/⌬CR ) lacking the Pcdha cytoplasmic region-encoding exons, which are common to the gene cluster. In the first week after birth, the distribution pattern of serotonergic fibers in Pcdha ⌬CR/⌬CR mice was similar to wild-type, but by 3 weeks of age, when the serotonergic axonal termini complete their arborizations, the distribution of the projections was abnormal. In some target regions, notably the globus pallidus and substantia nigra, the normally even distribution of serotonin axonal terminals was, in the mutants, dense at the periphery of each region, but sparse in the center. In the stratum lacunosum-moleculare of the hippocampus, the mutants showed denser serotonergic innervation than in wild-type, and in the dentate gyrus of the hippocampus and the caudateputamen, the innervation was sparser. Together, the abnormalities suggested that Pcdha proteins are important in the late-stage maturation of serotonergic projections. Further examination of alternatively spliced exons encoding the cytoplasmic tail showed that the A-type (but not the B-type) cytoplasmic tail was essential for the normal development of serotonergic projections.