Life history of Juniperus sabina L. adapted to the sand shifting environment in the Mu Us Sandy Land,China: A review

We have reviewed publications on the physiological and ecological features of the growth and regeneration processes of Juniperus sabina L. which grows in semiarid sandy land in the Ordos plateau in northern China where desertification has progressed over time. J. sabina is a key native plant species used for ecological restoration in this region. The life history of J. sabina in this sandy land that has been revealed through this review includes several unique features: (1) both vegetative and seed propagations are observed, but seed propagation is not successful in the location where the mature J. sabina stands. Instead, seed propagation can occur at a different place with different landscapes from the mature stands. (2) Nurse plants play an important role in providing the microclimatic environment necessary for the growth of J. sabina seedlings and young plants. (3) During the horizontal and vertical growth processes of the J. sabina patch, the root system was affected by burial in shifting sand and consequently acquired greater access to the water supply in deeper soil horizons, which could support larger growth. These characteristics suggested that the regeneration by seed propagation and growth strategy of J. sabina in this region was strongly affected by sand movement and the landscape that is generated by sand movement.

     

UV B-irradiation enhances the racemization and isomerizaiton of aspartyl residues and production of Nε-carboxymethyl lysine (CML) in keratin of skin

UV-B irradiation is one of the risk factors in age-related diseases. We have reported that biologically uncommon D-β-Asp residues accumulate in proteins from sun-exposed elderly human skin. A previous study also reported that carboxymethyl lysine (CML; one of the advanced glycation end products (AGEs)) which is produced by the oxidation of glucose and peroxidation of lipid, also increases upon UV B irradiation. The formation of D-β-Asp and CML were reported as the alteration of proteins in UV B irradiated skin, independently. In this study, in order to clarify the relationship between the formation of D-β-Asp and CML, immunohistochemical analysis using anti-D-β-Asp containing peptide antibodies and anti-CML antibodies was performed in UV B irradiated mice. Immunohistochemical analyses clearly indicated that an anti-D-β-Asp containing peptide antibody and anti-CML antibody reacted at a common area in UV B irradiated skin. Western blot analyses of the proteins isolated from UV B irradiated skin demonstrated that proteins of 50-70 kDa were immunoreactive towards antibodies for both D-β-Asp containing peptide and CML. These proteins were identified by proteomic analysis as members of the keratin families including keratin-1, keratin-6B, keratin-10, and keratin-14.     

Importance of polyadenylation in the selective elimination of meiotic mRNAs in growing S. pombe cells

A number of meiosis‐specific mRNAs are initially weakly transcribed, but then selectively removed during fission yeast mitotic growth. These mRNAs harbour a region termed DSR (determinant of selective removal), which is recognized by the YTH family RNA‐binding protein Mmi1p. Mmi1p directs the destruction of these mRNAs in collaboration with nuclear exosomes. However, detailed molecular mechanisms underlying this process of selective mRNA elimination have remained elusive. In this study, we demonstrate the critical role of polyadenylation in this process. Two‐hybrid and genetic screens revealed potential interactions between Mmi1p and proteins involved in polyadenylation. Additional investigations showed that destruction of DSR‐containing mRNAs by exosomes required polyadenylation by a canonical poly(A) polymerase. The recruitment of Pab2p, a poly(A)‐binding protein, to the poly(A) tail was also necessary for mRNA destruction. In cells undergoing vegetative growth, Mmi1p localized with exosomes, Pab2p, and components of the polyadenylation complex in several patchy structures in the nucleoplasm. These patches may represent the sites for degradation of meiosis‐specific mRNAs with untimely expression.     

RNase E polypeptides lacking a carboxyl-terminal half suppress a mukB mutation in Escherichia coli.

We have isolated suppressor mutants that suppress temperature-sensitive colony formation and anucleate cell production of a mukB mutation. A linkage group (smbB) of the suppressor mutations is located in the rne/ams/hmp gene encoding the processing endoribonuclease RNase E. All of the rne (smbB) mutants code for truncated RNase E polypeptides lacking a carboxyl-terminal half. The amount of MukB protein was higher in these rne mutants than that in the rne+ strain. These rne mutants grew nearly normally in the mukB+ genetic background. The copy number of plasmid pBR322 in these rne mutants was lower than that in the rne+ isogenic strain. The results suggest that these rne mutations increase the half-lives of mukB mRNA and RNAI of pBR322, the antisense RNA regulating ColE1-type plasmid replication. We have demonstrated that the wild-type RNase E protein bound to polynucleotide phosphorylase (PNPase) but a truncated RNase E polypeptide lacking the C-terminal half did not. We conclude that the C-terminal half of RNase E is not essential for viability but plays an important role for binding with PNPase. RNase E and PNPase of the multiprotein complex presumably cooperate for effective processing and turnover of specific substrates, such as mRNAs and other RNAs in vivo.     

Apiology: royal secrets in the queen's fat body

Royalactin, a component of royal jelly, induces queen differentiation in honeybees. Surprisingly, royalactin has a similar effect on growth in fruit flies, highlighting many unexpected features of growth regulation by the insect fat tissue.     

Construction of recombinant monoclonal antibodies from a chicken hybridoma line secreting specific antibody

The chicken is a useful animal for the development of the specificantibodies against the mammalian conserved proteins. We generated twotypes of recombinant chicken monoclonal antibodies (mAbs), using a phagedisplay technique from a chicken hybridoma HUC2-13 which secreted themAb to the N-terminal of the mammalian prion protein (PrP). Althoughthe mAb HUC2-13 is a useful antibody for the prion research, thehybridoma produces a low level of antibody production. In order to producea large amount of the mAb, we have constructed a single chain fragmentvariable region (scF_V) mAb by using the variable heavy(V_H) and light (V_L)genes which were amplified by using the two primer pairs and theflexible linker. The two phage display mAbs (HUC2p3 and HUC2p5)expressed on a M13 filamentous phage and their soluble type mAbs(HUC2s3 and HUC2s5) were reacted with the PrP peptide antigen in theELISA. In the Western blot analysis, the mAbs HUC2p3 and HUC2s3 wereas reactive to PrP^c from mouse brains as the mAb HUC2-13 was. The nucleotide sequences of V_H and V_L genes from HUC2-13 and the two cloneswere identical except for only one residue. These results indicate that themethods presented here provide an effective tool for the improvement ofthe low levels of antibody production in the chicken hybridoma system.     

Regulation of orexin neurons by the monoaminergic and cholinergic systems

Orexins are a pair of neuropeptides implicated in energy homeostasis and arousal. Here we characterize the electrophysiological properties of orexin neurons using slice preparations from transgenic mice in which orexin neurons specifically express green fluorescent protein. Orexin neurons showed high frequency firing with little adaptation by injecting a positive current. The hyperpolarization-activated current was observed in orexin neurons by a negative current injection. The neurotransmitters, which were implicated in sleep/wake regulation, affected the activity of orexin neurons; noradrenaline and serotonin hyperpolarized, while carbachol depolarized orexin neurons in either the presence or absence of tetrodotoxin. It has been reported that orexins directly or indirectly activate the nuclei that are the origin of the neurons containing these neurotransmitters. Our data suggest that orexin neurons have reciprocal neural circuitries between these nuclei for either a positive or negative feedback loop and orchestrate the activity of these neurons to regulate the vigilance states.     

Antagonistic effects of Bacillus natto and Streptococcus faecalis on growth of Candida albicans.

The growth-inhibitory effects of Bacillus natto and Streptococcus faecalis on Canida albicans were investigated. When inoculated into the filtrate of a long-term culture of B. natto strain BN (BN), a stock culture of C. albicans RIMD 0301020 lost its viability completely, whereas C. albicans RIMD 0301011, a fresh isolate from a clinical source, did not. In continuous flow (CF) culture the growth of both strains of C. albicans was suppressed by mixed cultivation with BN. On the other hand, in classical batch culture BN did not suppress the growth of C. albicans. S. faecalis BIO-4R, a multi-drug resistant strain, was also antagonistic to C. albicans RIMD 0301011 but symbiotic with BN in CF culture. These findings suggest that BN in concert with S. faecalis BIO-4R may inhibit the growth of C. albicans in the intestinal tract.     

Replication of ColE2 and ColE3 plasmids: The regions sufficient for autonomous replication

Summary We have localized the regions sufficient for autonomous replication on the genomes of the colicin E2 (ColE2) and colicin E3 (ColE3) plasmids and analyzed the replication functions carried by these regions. A 1.3 kb segment of each plasmid is sufficient for autonomous replication. Plasmids carrying this segment retain the replication properties of the original plasmid. The 1.3 kb segment consists of three functional portions. Firstly, a 0.9 kb region which specifies at least one trans-acting factor required for replication of each plasmid. Secondly, a 0.4 kb region located adjacent to one end of the 0.9 kb region, which is required for expression of the trans-acting factor(s) and probably contains the promoter. The region across the border of these two portions of ColE2 is involved in copy number control of the plasmid. The third portion is a 50 bp region adjacent to the other end of the 0.9 kb region, which contains a cis-acting site (origin) where replication initiates in the presence of the trans-acting factor(s). The action of the trans-acting factor(s) on the origin is plasmid specific. The 50 bp regions functioning as the origins of replication of ColE2 and ColE3 are the smallest among those in prokaryotic replicons so far identified and analyzed.