HMG-17 is an early marker of inductive interactions in the developing mouse kidney.
We studied the relationship between proliferation, differentiation, and the expression of high-mobility-group protein 17 (HMG-17) during metanephric kidney development. Proliferating cells were found homogenously throughout the early kidney rudiment. The expression pattern of HMG-17 mRNA, on the other hand, was distinctly uneven: In the undifferentiated mesenchyme, the cells in the cranial "tail" part of the mesenchyme showed only a weak signal, whereas a group of cells lying close to the tip of the ureteric bud showed strong HMG-17 expression. The region distinctly positive for HMG-17 is known to contain the first cells to undergo mesenchyme-to-epithelium transition. Using the transfilter model system, strong expression of HMG-17 mRNA, followed by mesenchyme-to-epithelium transition, could be induced also in the "tail" part of the mesenchyme. The upregulation of HMG-17 in the metanephrogenic mesenchyme thus results from interaction with an inductor tissue. Throughout the renal development, the HMG-17 mRNA was also abundant in those epithelial and mesenchymal cells that were undergoing active cell differentiation, and the transcript was downregulated in mature cells. HMG-17 expression thus correlated with the processes of induction and differentiation rather than with proliferation. The present results suggest that HMG-17 could have a role in the activation of the genes regulating kidney organogenesis.
Lehtonen
S
S
Department of Pathology, Haartman Institute University of Helsinki, Finland.
Lehtonen
E
E
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002455:Cell Division; D004627:Embryonic Induction / Q000235:genetics; D005314:Embryonic and Fetal Development; D005260:Female; D020869:Gene Expression Profiling; D024242:HMGN2 Protein / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007668:Kidney / Q000166:cytology / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D015415:Biomarkers; D024242:HMGN2 Protein; D012333:RNA, Messenger