Cardiff Blues and the Ospreys provide the bulk of the Wales squad for the 2010 Six Nations.
A total of 13 Blues and 14 Ospreys were today named in a 35-man set up that features just two non-Magners League players.
Wales coach Warren Gatland has selected four uncapped players in Ospreys backs Tom Prydie and Kristian Phillips, Blues scrum-half Richie Rees and Saracens prop Rhys Gill.
Gatland has also recalled British & Irish Lions stars Lee Byrne and Adam Jones after the Ospreys duo missed the autumn internationals.
Scarlets hooker Matthew Rees and fly-half Stephen Jones are both included despite currently being injured, while Ian Gough, Deniol Jones and Gareth Williams all return.
"We are now at the beginning of our countdown to the world cup and this slightly larger squad reflects that," said Gatland.
"We have brought in some youngsters to put some pressure on some of our senior players and to help increase the depth we have in certain positions.
"Kristian is a good example of an exciting young player, he has just won the Principality player of the month award and scored five tries in one match for Neath. He is skilfull and very quick.
"Elsewhere we are very happy to welcome back the likes of Adam (Jones) and Lee (Byrne) who were both obviously missed in the autumn, although at full-back in particular a certain James Hook provided more than ample cover.
"Our first match at Twickenham could set the tone for the Championship for both sides, we will both be desperate to win that first up match.
"We then come to the Millennium Stadium for two home matches and the support we have there will make a huge difference to us."
Sale scrum-half Dwayne Peel joins first-choice No9 Mike Phillips on the sidelines after picking up an injury last weekend, leaving Gareth Cooper, Martin Roberts and Richie Rees to battle for a starting spot against England on February 6.
Wales squad for the Six Nations
Cardiff Blues: Gareth Cooper, Bradley Davies, Leigh Halfpenny, Tom James, Gethin Jenkins, Deiniol Jones, Andy Powell, Richard Rees, Jamie Roberts, Tom Shanklin, Sam Warburton, Gareth Williams, Martyn Williams
Newport Gwent Dragons: Luke Charteris, Dan Lydiate
Ospreys: Huw Bennett, Dan Biggar, Andrew Bishop, Lee Byrne, Ian Gough , James Hook, Paul James, Adam Jones, Alun Wyn Jones, Ryan Jones, Kristian Phillips, Tom Prydie, Jonathan Thomas, Shane Williams
Sacrlets: Jonathan Davies, Stephen Jones, Matthew Rees, Martin Roberts
Sale Sharks: Eifion Lewis-Roberts
Saracens: Rhys Gill