Disney XD will launch a dedicated Marvel programming block featuring the premiere of “Ultimate Spider-Man” on April 1.

In a newsy day for the Disney Universe, it was also announced that Disney Junior’s expansion from a programming block on Disney Channel to also become a 24-hour network replacing SoapNet will take place March 23 (though agreements with some distributors, such as DirecTV, remain to be negotiated). New animated series “Doc McStuffins” will premiere on the day the new network launches.

In June, Disney XD will bow animated series “Motor City” and “Tron Uprising,” while Disney Channel (which could celebrate 9.8 million viewers for last Friday’s series finale of “Wizards of Waverly Place”) will launch toon “Gravity Falls” as a new companion to hit “Phineas and Ferb.” New musical telepic “Let It Shine,” with Tyler James Williams, Courtney B. Vance, Dawnn Lewis and Coco Jones, also premieres that month.

The Marvel Universe block will be the latest manifestation of Disney’s 2009 acquisition of Marvel. In addition to “Ultimate Spider-Man,” the block will also offer such Marvel content as the return of “The Avengers: Earth’s Mightiest Heroes,” as well as new short-form animation series and live-action interstitials.

Iron Man, Hulk, Thor and Captain America will be among the characters featured in the Marvel Universe programming.

Drake Bell will voice the lead character of “Ultimate Spider-Man” and will be joined in the voice cast by Chi McBride, JK Simmons, Clark Gregg, Steven Weber and Stan Lee. The show puts Peter Parker on a team with four other teenage superheroes.

Marvel Animation is producing with a team including chief creative officer Joe Quesada, Paul Dini (“Batman: The Animated Series,” “Lost”), Brian Michael Bendis (“Ultimate Spider-Man” comic) and Joe Casey, Joe Kelly, Duncan Rouleau and Steven T. Seagle of Man of Action Studios (“Ben 10”).

The cabler also plans to premiere “Lab Rats” on Feb. 27 and to run a second cycle of reality series “Fort Boyard – Ultimate Challenge” beginning Jan. 16. The latter will air every weeknight leading to a season finale Jan. 27.

“Fort Boyard,” in which teens from the U.S. and U.K. compete against each other at a 19th-century sea fort off the coast of France, is a 22-year-old French format that has been adapted in more than 30 territories. Nigel Pickard and Ged Allen exec produce for The Foundation, Pierre Godde for Adventure Line Productions (both companies owned by Zodiak Media) and Jamila Metran for CiTV. Geno Segers and Laura Hamilton host.

“Lab Rats,” a new comedy about a regular teenager and his super-human step-siblings, will have a one-hour premiere following Disney XD standby “Kickin’ It.” A preview will be available Feb. 17 on Disney XD on Demand.

Series creators Chris Peterson and Bryan Moore (“That ’70s Show”) are exec producing with Mark Brazill (“That ’70s Show,” “3rd Rock from the Sun”) for It’s a Laugh Prods.

Disney XD set channel records in 2011 in the 2-11, 6-14, 6-11 and 9-14 demos, growing from the previous year by double-digit percentages.