Cloning,characterization and overproduction of nuclease S1 gene (nucS) from Aspergillus oryzae

The nuclease S1 gene (nucS) from Aspergillus oryzae was isolated using a polymerase-chain-reaction-amplified DNA fragment as a probe, and a 2.6-kb SalI-EcoRI fragment containing the nucS gene was sequenced. It was deduced that the nucS gene had two short introns, 49 and 50 nucleotides in lenght. The nucS gene had an open-reading frame of 963 base pairs and coded for a protein of 287 amino acid residues, comprising the signal peptide of 20 amino acids and a mature protein of 267 amino acids. The deduced amino acid sequence agreed well with the published amino acid sequence except for one substitution. Southern hybridization analysis showed that the nucS gene existed as a single copy in the A. oryzae chromosome. When the structural gene of nucS was fused with the promoter of the glaA gene and introduced into A. oryzae, the yield od secreted nuclease S1 increased about 100-fold compared with the recipient strain.     

Methodology in the study of seabass (Lates calcarifer Bloch): nutritional requirements in Singapore

This paper describes the effort of the Marine Aquaculture Section of the Primary Production Department in Singapore and the Institut Francais de Recherche pour l'Exploitation de la Mer in developing adequate facilities for fish nutritional requirement studies in Singapore, and in introducing appropriate nutritional methodology so that results are reliable and accurate. One of the first achievements was the demonstration of homogeneous fish (tropical seabass, Lates calcarifer Bloch) growth response in a newly established tank system before any nutritional experiments were initiated. The application of statistical procedures that take into consideration the power of a test and number of replications required has allowed for more accurate interpretation of results. This can be seen in the results of the first nutritional requirement experiment on the optimal dietary protein level of the seabass at constant energy.     

中国大陆若干群体的黑果蝇的线粒体DNA多态性研究

本文研究了果蝇Ｄ．ｖｉｒｉｌｉｓ种群Ｄ．ｖｉｒｉｌｉｓ线粒体ＤＮＡ（ｍｉｔｏｃｈｏｎｄｒｉａｌＤＮＡ,ｍｔＤＮＡ）的多态性。用９种限制性内切酶ＸｂａⅠ,ＥｃｏＲⅠ,ＰｓｔⅠ,ＨｉｎｄⅢ,ＢｇｌⅡ,ＳａｃⅠ,ＳｃａⅠ,ＥｃｏＲＶ和ＰｕｖⅡ,对青岛、南京、上海、宁波与泉州５个Ｄ．ｖｉｒｉｌｉｓ群体的ｍｔＤＮＡ进行了限制性片段长度多态性（ｒｅｓｔｒｉｃｔｉｏｎｆｒａｇｍｅｎｔｓｌｅｎｇｔｈｐｏｌｙｍｏｒｐｈｉｓｍ,ＲＦＬＰ）的研究。在５群体中,发现５种不同的酶切图谱,它们彼此之间的遗传差异π为０．４６％－１．７６％,群体内遗传差异πｉｊ为０．００％－０．３３％,群体间的差异ｄｘｙ,为０．００％－０．８２％。分布于中国大陆的Ｄ．ｖｉｒｉｌｉｓ的群体间遗传差异在总遗传差异中所占比例γｓｔ值为２４．６２％。我们发现,Ｄ．ｖｉｒｉｌｉｓ的栖息环境对ｍｔＤＮＡ的遗传变异有十分明显的影响,而不同地理纬度的群体之间其遗传距离并无倾群（ｃｌｉｎｅ）表现。     

Desaturation, dioxygenation, and monooxygenation reactions catalyzed by naphthalene dioxygenase from Pseudomonas sp. strain 9816-4.

The stereospecific oxidation of indan and indene was examined with mutant and recombinant strains expressing naphthalene dioxygenase of Pseudomonas sp. strain 9816-4. Pseudomonas sp. strain 9816/11 and Escherichia coli JM109(DE3)[pDTG141] oxidized indan to (+)-(1S)-indanol, (+)-cis-(1R,2S)-indandiol, (+)-(1S)-indenol, and 1-indanone. The same strains oxidized indene to (+)-cis-(1R,2S)-indandiol and (+)-(1S)-indenol. Purified naphthalene dioxygenase oxidized indan to the same four products formed by strains 9816/11 and JM109(DE3)[pDTG141]. In addition, indene was identified as an intermediate in indan oxidation. The major products formed from indene by purified naphthalene dioxygenase were (+)-(1S)-indenol and (+)-(1R,2S)-indandiol. The results show that naphthalene dioxygenase catalyzes the enantiospecific monooxygenation of indan to (+)-(1S)-indanol and the desaturation of indan to indene, which then serves as a substrate for the formation of (+)-(1R,2S)-indandiol and (+)-(1S)-indenol. The relationship of the desaturase, monooxygenase, and dioxygenase activities of naphthalene dioxygenase is discussed with reference to reactions catalyzed by toluene dioxygenase, plant desaturases, cytochrome P-450, methane monooxygenase, and other bacterial monooxygenases.     

Structure and evolution of teleost mitochondrial control regions

We amplified and sequenced the mitochondrial control region from 23 species representing six families of teleost fish. The length of this segment is highly variable among even closely related species due to the presence of tandemly repeated sequences and large insertions. The position of the repetitive sequences suggests that they arise during replication both near the origin of replication and at the site of termination of the D-loop strand. Many of the conserved sequence blocks (CSBs) observed in mammals are also found among fish. In particular, the mammalian CSB-D is present in all of the fish species studied. Study of potential secondary structures of RNAs from the conserved regions provides little insight into the functional constraints on these regions. The variable structure of these control regions suggests that particular care should be taken to identify the most appropriate segment for studies of intraspecific variation. Correspondence to: T.D. Kocher     

Iron Regulation in the Developing Rat Brain: Effect of In Utero Ethanol Exposure

Abstract: Fetal alcohol syndrome produces defects that parallel abnormalities associated with early iron deficiency. Hence, we examined the effects of prenatal exposure to ethanol on iron, transferrin, and ferritin concentrations. The subjects were the offspring of pregnant rats fed an ethanol-containing diet (Et), pair-fed an isocaloric control diet (Ct), or fed chow and water. The amounts of iron, transferrin, and ferritin were assessed in three CNS regions (cerebral cortex, subcortical forebrain, and brain-stem). In all three segments of the control rats, iron, transferrin, and ferritin levels decreased during the first 2 postnatal weeks, reached a minimum during week 3, and then rose to adult levels. This pattern was delayed by ethanol treatment, e.g., the minimal concentrations in iron, transferrin, and ferritin in the Et-treated rats were achieved later (3 days, 7 days, and 2 weeks, respectively) than they were in the Ct-treated rats. Ethanol-induced alterations in iron homeostasis persisted into adulthood; iron concentration was reduced, transferrin concentration was unaffected, and ferritin concentration was increased. The net result was that the timely delivery and bioavailability of iron were compromised by ethanol exposure. The defects in iron regulation are permanent and may underlie ethanol-induced abnormalities in iron-dependent growth processes such as myelination.     

The Distribution and Biochemical Properties of a Cdc2-Related Kinase, KKIALRE, in Normal and Alzheimer Brains

Abstract: The biochemical properties and distribution of a Cdc2-related kinase, KKIALRE, were studied in brain tissues and cultured cells with antibodies to a subregion of KKIALRE protein deduced from cDNA. In adult human brain, the KKIALRE-immunoreactive protein consisted of four or five isoforms having a molecular size of 40–52 kDa, whereas in fetal brain, there was one protein of ∼48 kDa. Cultured astrocytes, neuroblastoma cells, and mouse brains contained the fetal form of KKIALRE protein. KKIALRE-immunoreactive proteins were capable of phosphorylating histone and synthetic peptides with the X-Ser-Pro-X motif, indicating that these proteins belong to the proline-directed Ser/Thr protein kinase family. The KKIALRE immunoreactivity was detected primarily in fibrous astrocytes in white matter and perivascular and subpial spaces, as well as in Bergmann glia in the cerebellum. In fetal brains radial glia were weakly immunoreactive. Reactive astrocytes were more intensely labeled than other glia. Neurons in normal brains and brains with Alzheimer's disease (AD) displayed no KKIALRE immunoreactivity. KKIALRE immunoreactivity was similar in neurons with and without neurofibrillary tangles. The results indicate that in CNS, the KKIALRE protein is mainly a glial protein that is up-regulated in gliosis and that it probably plays no role in the hyperphosphorylation of τ in AD brains.     

Predictions of protein backbone bond distances and angles from first principles

A procedure is described, based on a spline-function representation of ab initio peptide conformational geometry maps, that allows one to predict backbone bond distances and angles of proteins as functions of the peptide ?(N-C^α)/Ψ(C^α-C′) torsions with an accuracy comparable to that of high-resolution protein crystallography. For example, for the more than 40 residues of crambin, the rms deviation between predicted and crystallographic values of N-C^α-C′ is 1.9° for the 1.5 Å resolution structure and 1.9° for the 0.83 Å resolution structure, compared with angle variations of < 10°. Accurate information on protein backbone geometries is important for establishing dictionaries of flexible geometry functions for use in empirical peptide and protein modeling. © 1995 John Wiley & Sons, Inc.