SAN CARLOS, California, December 19, 2005 - Deltagen, Inc. (DGEN) today announced that it filed the monthly operating report (MOR) relating to its October 2005 results with the United States Bankruptcy Court for the Northern District of California, San Francisco Division, on December 14, 2005. Deltagen intends to file the November MOR with the Court on or about December 20, 2005. As the Deltagen plan of reorganization became effective on November 29, 2005, the November MOR will be the last MOR Deltagen will file with the Court. Deltagen will continue to file quarterly post-confirmation reports with the Court as and when required.

Although Deltagen has no obligation to make public disclosure with respect to its results of operations or other matters, it currently intends to announce its 2005 financial results sometime during the first quarter of 2006. Deltagen also currently intends to announce quarterly results for 2006.

About Deltagen

Deltagen, Inc. is a leading provider of drug discovery tools to the biopharmaceutical industry. Deltagen offers access to its extensive inventory of knockout mouse lines and related phenotypic data, which enhance the efficiency of target validation and drug discovery. In addition, Deltagen offers target validation data in the areas of immunology and metabolic diseases. Deltagen's products and programs have been validated by customers and partners such as Eli Lilly & Co., GlaxoSmithKline, Merck & Co. and Pfizer Inc. For more information on Deltagen, visit the company's website at www.deltagen.com.