Tokyo stocks opened higher Tuesday after an overnight rise on Wall Street, with export-related issues lifted by a weaker yen against the U.S. dollar. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 545.55 points, or 1.43 percent, from Thursday to 38,781.62. Japanese financial markets were closed Friday and Monday for national holidays. The broader Topix index was up 14.47 points, or 0.53 percent, at 2,743.00. On the top-tier Prime Market, gainers were led by securities house, machinery and electric appliance issues. At 9 a.m., the dollar fetched 154.23-26 yen compar…