Identification and Molecular Characterization of B-Tubulin Gene from Dermatophyte Pathogen Microsporum Canis

 Aumaid U. Uthman

Department of Dermatology, Vienna Medical University and College of Veterinary Medicine, University of Sulaimani

  Microsporum canis is the most common pathogen causing dermatophytosis in dogs and cats, which can transmit the pathogen to humans. The disease is increasing in many European countries. Studies regarding the structure, expression, and organization of M. canis genes have been relatively limited because of it's non-aggressive and non-life threatening nature. Microtubules are essential cytoskeleton polymers in all eukaryotes. They are made of α and β-tubulin heterodimers. In this study the DNA and the structural organization of β-tubulin gene of M. canis is described. The DNA of 2487 bp has been identified and sequenced. The ORF of 1341 bp encoding a protein of 447 amino acids with a molecular weight of 49.8 kD is interrupted by eight introns (56-187bp). The gene is highly homologous to β-tubuli of Trichophyton rubrum (%98) and A spergillus parasticus (%91). This data may form one of the bases for the development of molecular investigation of dermatophyte fungi M. canis.

Keywords: Microsporum canis, Dermatophytes,  β-tubulin, gene expression.

1. Weitzman, I. and Summerbell, D.C. The Dermatophytes. Clin. Microbiol. Rev. 1995, 8; 240-259.
2. Kwon-Chung, K.J and Bennett, J.E. Medical mycology, Lea & Febinger, Philadelphia, PA 1992. 136-137 and 816-  817.
3. Barac,I., Stojnic-Sosa,L., Prpic,L., Loncarek,K., Gruber,F.. The epidemiology of Microsporum canis infections in  Rijeka area,  Croatia. Mycoses. 2004 47; 222-226.
4. Monod,M., Jaccoud,S., Zaugg,C., Lechenne,F., Panizzon,R.. Survey of dermatophyte infections in Lausanne area  Switzerland.  Dermatology 2002, 205; 201-203.
5. Cafarchia,C., Romito,D., Capelli,G., Guillot,J., Otranto,D.. Isolation of Microsporum can's from the hair coat of  pet dogs and  cats belonging to owners diagnosed with M. canis tinca corporis. Vet. Dermatol. 2006,17; 327-331.
6. Okeke,C.N., Tsuboi,R., Kawai,M.. Hiruma,M., Ogawa,H.. Isolation of an Intron-Containing Partial Sequence of  the Gene  Encoding Dermatophyte Actin (AC7) and Detection of a Fragment of the Transcript by Reverse  Transcription-Nested PCR as a  Means of Assessing the Viability of Dermatophytes in Skin Scales. Journal of  Clinical Microbiology 2001, 39; 101-106.
7.Kano,R., Okabayashi,K., Nakamura,Y., Watanabe,S. Hasegawa,A.. Expression of ubiquitin gene in Microsporum  canis and Trichophyton mentagrophytes cultured with fluconazole. Antimicrob. Agents Chemother. 2001, 45,  2559-2562.
8.Brouta,F., Descamps,F., Monod,M., Vermout,S., Losson,B. Mignon,B. Secreted metalloprotease gene family of Microsporum  canis. Infect. Immun. 2002, 70; 5676¬5683.
9.Uthman,A., Rezaie,S., Dockal,M., Ban,J., Soltz-Szots,J. and Tschachler,E. Fluconazole downregulates metallothionein  expression and increases copper cytotoxicity in Microsporum canis. Biochem. Biophys. Res. Commun. 2002, 299; 688-692.
10.Descamps,F., Brouta,F., Monod,M., Zaugg,C., Baar,D., Losson,B. Mignon,B. Isolation of a Microsporum canis gene family encoding three subtilisin-like proteases expressed in vivo. J. Invest. Dermatol. 2002, 119; 830-835.
I1. Jousson,O., Lechenne,B., Bontems,O., Capoccia,S., Mignon,B., Barblan,J., Quadroni,M. and Monod,M. Multiplication of an  ancestral gene encoding secreted fungalysin preceded species differentiation in the dermatophytes Trichophyton and  Microsporum. J. Microbiology.2004, 150; 301-310.
12.Uthman,A., Dockal,M., Soltz-Szots,J. Tschachler,E.. Fluconazole upregulates sconC expression and inhibits sulphur  metabolism in Microsporum canis. Fungal Genet. Biol. 2005, 42; 719-725
13.Rezaie,S., Pourmojib,M., Tschachler,E. Isolation of total RNA from dermatophytes. Mycoses 1999 , 42, 615- 617.
14. Rezaie,S.,Mildner,M., Poitschek,C., Brna,C., Tschachler,E. Characterization of a cDNA clone, encoding a 70  kDa heat shock  protein from the dermatophyte pathogen Trichophyton rubrum. Gene 2000, 241; 27-33.
15. Gurr,S.J., Unkles,S.E, Kinghom, J.R. The structure and organization of nuclear genes of filamentous fungi. In:  Kinghom, J.R.  (Ed), Gene structure in Eukaryotic Microbes. IRL Press, Washington. DC, 1987, 93-139.
16. Piotrowska,M., Natroff,R., Paszewski,A. sconC, agene involved in the regulation of sulphur metabolism in  Aspergillus  nidulans, belongs to the SKP1 gene family. Mol. Gen. Genet 2000, 264; 276-282.