FIG. 2.

The T-box transcription factor Tbx-2 is expressed in melanocytes and melanoblasts. (A) Northern blot of 5 μg of poly(A)⁺ mRNA derived from the indicated cell lines or from mouse kidney probed with either Tbx-2 or G3PDH cDNA. Tbx2 mRNA is present as two species of approximately 2.6 and 3.6 kb. The same blot was also probed for G3PDH message as a loading control. Note that the HeLa lane was deliberately overloaded to illustrate that these cells do not express Tbx2 message. M6 and M4 are premelanoblast cell lines; melan-a and melan-M5 are mouse melanocyte cell lines; melb-M5 is a mouse melanoblast cell line. (B) Northern blot of mRNA derived from the indicated cell lines and probed with radiolabeled Tbx-2 cDNA. Each lane was loaded with the same amount of RNA, as judged by staining with ethidium bromide and visualization under UV. melan-a and melan-S1 are mouse melanocyte cell lines; melb-a, melb-P3, and melb-S1 are mouse melanoblast cell lines; XB2 is a mouse keratinocyte cell line.