Contrasting patterns of the 5S and 45S rDNA evolutions in the Byblis liniflora complex (Byblidaceae).

To clarify the evolutionary dynamics of ribosomal RNA genes (rDNAs) in the Byblis liniflora complex (Byblidaceae), we investigated the 5S and 45S rDNA genes through (1) chromosomal physical mapping by fluorescence in situ hybridization (FISH) and (2) phylogenetic analyses using the nontranscribed spacer of 5S rDNA (5S-NTS) and the internal transcribed spacer of 45S rDNA (ITS). In addition, we performed phylogenetic analyses based on rbcL and trnK intron. The complex was divided into 2 clades: B. aquatica-B. filifolia and B. guehoi-B. liniflora-B. rorida. Although members of the complex had conservative symmetric karyotypes, they were clearly differentiated on chromosomal rDNA distribution patterns. The sequence data indicated that ITS was almost homogeneous in all taxa in which two or four 45S rDNA arrays were frequently found at distal regions of chromosomes in the somatic karyotype. ITS homogenization could have been prompted by relatively distal 45S rDNA positions. In contrast, 2-12 5S rDNA arrays were mapped onto proximal/interstitial regions of chromosomes, and some paralogous 5S-NTS were found in the genomes harboring 4 or more arrays. 5S-NTS sequence type-specific FISH analysis showed sequence heterogeneity within and between some 5S rDNA arrays. Interlocus homogenization may have been hampered by their proximal location on chromosomes. Chromosomal location may have affected the contrasting evolutionary dynamics of rDNAs in the B. liniflora complex.

Does daily Naikan therapy maintain the efficacy of intensive Naikan therapy against depression?

AIM: Naikan Therapy, which has been applied to treating patients with various mental difficulties, can be classified into two major categories: intensive Naikan therapy, which lasts for seven days in a Naikan center or a clinical institute secluded from the outside world for the purpose of deep introspection, and daily Naikan therapy, which can be integrated into regular daily activities. The aim of this research is to evaluate daily Naikan therapy as a maintenance treatment for depression. METHODS: Forty-seven patients, who were diagnosed as having major depressive disorder using DSM-IV criteria and who practiced intensive Naikan therapy participated in the present study. Two groups of patients were compared: 24 patients who conducted daily Naikan therapy and 23 patients who did not, after practicing intensive Naikan therapy. To evaluate efficacy, the Beck Depression Inventory was used as a primary outcome measure for the assessment of depression. The State-Trait Anxiety Inventory and the Cornell Medical Index were also used as secondary outcome measures to evaluate anxiety and psychosomatic conditions before, immediately after and three months after intensive Naikan therapy. RESULTS: Significant between-group differences were obtained in the time course change of depression, anxiety and psychosomatic scores within three months following the completion of intensive Naikan therapy. CONCLUSION: The current study indicates that conducting daily Naikan therapy is effective for maintaining the psychological and psychosomatic state at 3 months following the intensive Naikan therapy, while a lack of therapy may allow the patients to exacerbate their conditions to the level they held before practicing intensive Naikan therapy.

Specific interactions of three proliferating cell nuclear antigens with replication-related proteins in Aeropyrum pernix.

Proliferating cell nuclear antigen (PCNA) is a well-known multifunctional protein involved in eukaryotic and archaeal DNA transactions. The homotrimeric PCNA ring encircles double-stranded DNA within its central hole and tethers many proteins on DNA. Plural genes encoding PCNA-like proteins have been found in the genome sequence of crenarchaeal organisms. We describe here the biochemical properties of the three PCNAs, PCNA1, PCNA2 and PCNA3, from the hyperthermophilic archaeon, Aeropyrum pernix. PCNA2 can form a trimeric structure by itself, and it also forms heterotrimeric structures with PCNA1 and PCNA3. However, neither PCNA1 nor PCNA3 can form homotrimers. The DNA synthesis activity of DNA polymerase I and II, the endonuclease activity of FEN1, and the nick-sealing activity of DNA ligase were stimulated by the complex of PCNA2 and 3 or PCNA1, 2 and 3. These results suggest that the heterotrimeric PCNA at least including PCNA2 and 3 function as the clamp in the replisome. However, PCNA2 is the most abundant in the cells throughout the growth stages among the three PCNAs, and therefore, PCNA2 may perform multitasks by changing complex composition.