Chromosomal assignment of canine THADA gene to CFA 10q25

Jan T Soller^*¹^,2 , Claudia Beuing^*² , Hugo Murua Escobar¹^,2 , Susanne Winkler¹ , Nicola Reimann-Berg¹ , Norbert Drieschner¹ , Gaudenz Dolf³ , Claude Schelling⁴ , Ingo Nolte² and Jörn Bullerdiek¹^,2

¹Centre for Human Genetics, University of Bremen, Leobener Straße ZHG, 28359 Bremen, Germany

²Small Animal Clinic and Research Cluster of Excellence "REBIRTH", University of Veterinary Medicine Hanover, Bischofsholer Damm 15, 30173 Hannover, Germany

³Institute of Genetics, Vetsuisse Faculty, University of Berne, Bremgartenstrasse 109a, PO Box 8466, 3001 Bern, Switzerland

⁴Department of Animal Science, Swiss Federal Institute of Technology Zurich, Vetsuisse-Faculty Zurich, University of Zurich, Winterthurerstrasse 204, 8057 Zürich, Switzerland

author email corresponding author email* Contributed equally

Molecular Cytogenetics 2008, 1:11doi:10.1186/1755-8166-1-11


Published:	3 June 2008

Abstract

Background

Chromosomal translocations affecting the chromosome 2p21 cluster in a 450 kb breakpoint region are frequently observed in human benign thyroid adenomas. THADA (thyroid adenoma associated) was identified as the affected gene within this breakpoint region. In contrast to man tumours of the thyroid gland of dogs (Canis lupus familiaris) constitute mainly as follicular cell carcinomas, with malignant thyroid tumours being more frequent than benign thyroid adenomas. In order to elucidate if the THADA gene is also a target of chromosomal rearrangements in thyroid adenomas of the dog we have physically mapped the canine THADA gene to canine chromosome 10.

A PCR was established to screen a canine genome library for a BAC clone containing the gene sequence of canine THADA. Further PCR reactions were done using the identified BAC clone as a template in order to verify the corresponding PCR product by sequencing.

Canine whole blood was incubated with colcemid in order to arrest the cultured cells in metaphases. The verified BAC DNA was digoxigenin labeled and used as a probe in fluorescence in situ hybridization (FISH). Ten well spread metaphases were examined indicating a signal on canine chromosome 10 on both chromatids. A detailed fine mapping was performed indicating the canine THADA gene locus on the q-arm of chromosome 10.

Results

The canine THADA gene locus was mapped on chromosome 10q25. Our mapping results obtained in this study following the previously described nomenclature for the canine karyotype.

Conclusion

We analysed whether the THADA gene locus is a hotspot of canine chromosomal rearrangements in canine neoplastic lesions of the thyroid and in addition might play a role as a candidate gene for a possible malignant transformation of canine thyroid adenomas. Although the available cytogenetic data of canine thyroid adenomas are still insufficient the chromosomal region to which the canine THADA has been mapped seems to be no hotspot of chromosomal aberrations seen in canine thyroid adenomas.