Transcriptional regulation of heat shock protein 70 genes by class I histone deacetylases in the red flour beetle, Tribolium castaneum

The regulatory function of histone acetylation in the expression of genes encoding heat shock proteins (Hsps) has been documented in Drosophila melanogaster; however, knowledge of the role of acetylation in modulating Hsps in other insect pests is limited. In this study, two full-length cDNAs encoding inducible Hsp70 (designated TcHsp70) and heat shock cognate 70 (TcHsc70) were isolated and characterized in the red flour beetle, Tribolium castaneum. TcHsp70 and TcHsc70 cDNAs were 2256 and 2132 bp and encoded 1941- and 1893-bp open reading frames, respectively. The deduced TcHsp70 and TcHsc70 proteins contained 646 and 630 amino acids, respectively, and contained sequences typical of the Hsp70 family, including the EEVD motif for cytoplasmic localization. Expression patterns after heat shock indicated that TcHsp70 was strongly heat-inducible, whereas the expression level of TcHsc70 remained unchanged under heat shock. RNA interference-mediated knock-down of three genes encoding class I histone deacetylases differentially influenced both basal and heat shock inducible expression of TcHsp70 and TcHsc70, suggesting the involvement of histone acetylation in epigenetic regulation of Hsp70 transcription in T. castaneum.

[Genetic complementation group analysis of xeroderma pigmentosum patients in China]

OBJECTIVE

To establish skin fibroblast cell strains derived from Chinese xeroderma pigmentosum(XP) patients and to analyze the genetic complementation group and distribution.

METHODS

From four XP patients, skin fibroblast cell strains were derived and used for the complementation group analysis by autoradiography and cell-fusion technique.

RESULTS

Of the four XP patients from apparently independent families, three were assigned to group C, and one belonged to group E. This is the first report on XP-E patient in China.

CONCLUSION

Based on the data from the previous 7 cases and the present 4 cases, the distribution of complementation group in Chinese XP patients known at present is: nine XP-C, one XP-F and one XP-E. Although the number of cases is still limited, XP-C appears to be more frequent in China. This forms a marked contrast to Japanese XP patients, who are dominated by XP-A with infrequent presence of XP-C.

[Cytogenetic study in eight cases of Fanconi anemia]

OBJECTIVE

To study the clinical, hematological and cytogenetical characteristics in Fanconi anemia (FA).

METHODS

Culture the peripheral lymphocytes with Mitomycin C (MMC) induction to count the chromosome breakages and to count the sister chromatid exchanges (SCE) in FA.

RESULTS

The clinical and hematological manifestations in FA varied at all. Spontaneous chromosome break and MMC induced break in FA were significantly higher than those in normal. Spontaneous and induced SCE were also higher in FA.

CONCLUSION

Owing to genetic heterogeneity in FA, the phenotypes in FA are diversified also. So, chromosome breakage study is a very important method in the diagnosis of FA, and gene complementation analysis may identify which complementation group the patient carries.