Cloning of the KcURA3 gene and development of a transformation system for Kluyveromyces cicerisporus

KcURA3 was cloned from Kluyveromyces cicerisporus CBS4857 by complementation of the ura3 mutation in Saccharomyces cerevisiae. KcURA3 encodes a 267-amino-acid protein with 80% sequence identity to that of S. cerevisiae. An ura3 mutant strain from K. cicerisporus CBS4857, named Y179U, was obtained by selection on 5-fluoroorotic acid plates. Sequence analysis of this mutated gene revealed that it contained a point mutation at nucleotide position +277. Two vectors, pUK1 and pUKD, bearing KcURA3 were constructed. Either the lithium acetate method or electroporation could be used to transform pUK1 and pUKD intoY179U. The transformation efficiency using electroporation was higher than that using the lithium acetate method.

A human homolog of the yeast gene encoding tRNA 2'-phosphotransferase: cloning, characterization and complementation analysis

The Saccharomyces cerevisiae TPT1 gene plays a role in removing the 2'-phosphate from ligated tRNA during the maturation of pre-tRNA. Here we reported the cloning and characterization of the human TRPT1 gene as a homolog of yeast TPT1. The TRPT1 gene is located at human chromosome 11q13 and encodes a polypeptide of 253 amino acids. BLAST searches with its amino acid sequence revealed the ubiquitous occurrence of TRPT1 homologs and their functional relationships with the presence of the DUF60/KptA domain. Northern analysis demonstrated that the gene is primarily expressed in heart and skeletal muscle, with lower or undetectable levels in other tissues studied. A plasmid-shuffling experiment showed that the human TRPT1 gene could complement the tpt1 mutation in S. cerevisiae

[Construction of Cryptococcus neoformans cap70 transformation system]

OBJECTIVE

To construct a transformation system of Cryptococcus neoformans capsule-deficient strain cap70.

METHODS

(1)Obtained ura5 mutants by screening the Cryptococcus neoformans cap70 using 5-fluoroorotic acid counter selection method, analyzed the obtaining strain by Southern blot and PCR; (2)Through the plasmid pCXJ18 and pCXJU which contained ura5 gene from Cryptococcus neoformans and ura3 from Kluyveromyces fragilils. as a selective marker, the ura5 strains were transformed by electrotransformation and chemical transformation.

RESULTS

Obtained ura5 mutants, they were detected as lack of ura function. The chemical transformation method was first be used in Cryptococcus neoformans transformation.

CONCLUSION

A transformation system of Cryptococcus neoformans cap70 has been established, which provides not only the basis for gene cloning from the species for studying gene function and gene expression.

[Factor analysis on the intelligence of patients with schizophrenia]

The authors made a factor analysis on the intelligence of patients with schizophrenia. 119 patients with schizophrenia were measured by Wechsler Adult Intelligence Scale-Revised China (WAIS-RC). The results revealed the average full intelligence quotient (IQ) of schizophrenia was 79.70, the verbal intelligence quotient(VIQ) 84.43, and the performance intelligence quotient(PIQ) 74.10. Multiple regression showed the regression coefficient of educational level for IQ was 8.6721. The regression coefficient of the course of disease for IQ was negative 0.1519. Factor analysis showed that the cumulative percent of three-factor solution of schizophrenia was 73.5. In conclusion, the IQ of most patients with schizophrenia was lower than norm, VIQ > PIQ(P = 0.0000). Educational level had greater influence on IQ. The longer the course of disease was, the worse the intelligence came to be. Factor analysis indicated that three-factor solution of schizophrenia was similar to that of norm, but each subtest value was lower than norm.

[Development of an expert system for assessment of criminal responsibility capacity of mentally ill offenders]

The objective of this study was to develop an expert system for the assessment of legal capacity (ESALC). Visual Basic for Windows 3.0 was employed in establishing ESALC, and 281 cases were assessed by the system. The results were in substantial agreement with those of expert assessment. Kappa = 0.68 (P < 0.01); accuracy 90.04%, sensitivity, 85.63% and specificity 96.49%. ESALC can be used as a supplementary instrument in forensic psychiatric assessment.

Cloning and expression of Kluyveromyces fragilis LAC4 gene

The genomic library of Kluyveromyces fragilis was constructed in E. coli TG1, and 5 beta-galactosidase gene (LAC4) clones have been obtained from the library by complementation of the Kluyveromyces lactis lac4-8 mutation. The studies on the structure and the function of the LAC4 gene revealed that (i) the gene can also complement E. coli lacZ mutation; (ii) the physical map of the K. fragilis LAC4 gene was very similar to that of K. lactis; (iii) the beta-galactosidase levels expressed by the clone strains were much higher than that expressed by the original strain; (iv) the variation of the beta-galactosidase level of different clone strains induced by lactose or galactose was related to the retained degree of the 5' flanking region of LAC4 gene, suggesting that there might be a lactose specific transcription activating element in the region.

[Survey of suicidal mortality rate in several districts of Sichuan province]

A survey of the suicidal mortality rates in two cities and six districts in Sichuan province was carried out from 1980 to 1988 by the authors. The average suicidal mortality rate (ASMR) in these districts from 1980 to 1988 was 15.5/10(5), and the population and suicidal mortality rate positively correlated, r = 0.53. The ASMR in the male was 14.9/10(5), in the female 17.1/10(5), in the urban area 9.4/10(5), in the rural area 21/10(5), and the ASMR in the urban area was higher than that in the rural area (P < 0.05). The peak age of suicidal mortality was around twenty years.