We don’t normally cover small-screen fare here at In Contention, but when the show in question is the creation of Christopher Guest, exceptions should be made. Guest, whose irreverent brand of mock-doc comedy includes such films as “This is Spinal Tap” and “Best in Show,” is by no means a newcomer to TV — among many other achievements, he was on the “Saturday Night Live” team way back when, and recently directed a failed pilot for a US spin on Britain’s cult political satire “The Thick of It.”

The British connection — Guest holds a British peerage, after all — continues in his latest project, “Family Tree,” a mockumentary sitcom played in Guest’s customary semi-improvised fashion. Irish comedian Chris O’Dowd headlines as a regular bloke from across the pond who, after losing both his job and his girlfriend, determines to find himself by tracing his family in the US. Guest evidently has the current vogue for genealogy (as evident in such popular shows as “Who Do You Think You Are?”) in his satirical sights.

O’Dowd, of course, is swiftly making a name for himsel in film and television following his breakout performance in “Bridesmaids” two years ago: his TV roster also includes “Girls” and his own UK sitcom “Moone Boy,” and his delightful lead turn in Australian musical comedy “The Sapphires” finally hits US screens on Friday. Look out for my interview with him later this week.

“Family Tree” premieres on HBO in May (and on BBC Two in the UK). Check out the teaser trailer below. Will you be watching?