By Adam S. Levy - Breaking Celebrity News Staff Writer

Little House on the Prairie star Melissa Gilbert has filed for divorce from her husband of 16 years, actor Bruce Boxleitner, Breaking Celebrity News has learned.

Gilbert, who played Laura Ingalls on the iconic TV series, filed the petition in Los Angeles Superior Court Monday. She cited “irreconcilable differences” as the cause.

Gilbert, 47, is not requesting any spousal support from the Tron: Legacy star, 61; she is asking for joint custody of the couple's 15-year-old son, Michael. (He’s named after Gilbert’s late Little House co-star, Michael Landon.)

The pair separated this past January, according to court docs.

On her Twitter account Thursday, Gilbert chose to focus on her future literary endeavors, as she wrote, “New book, tentative title; Melissa Gilbert's Prairie Memories published by Abrams Image books. Available spring 2012!”

It's been a tough week for the Gilbert clan, as Melissa's sister, Roseanne star Sara, broke up with her partner, TV producer Allison