Edinburgh revealed the signing of powerful and athletic Sharks lock Anton Bresler, on a three-year deal.
Owen Williams, who sustained significant neck and spinal injuries during the inaugural World Club 10s in Singapore, has returned home to Wales
Cai Griffiths has re-signed with the welsh region and is looking to add to his 123 regional appearances from two prior spells in the black jersey.
Edinburgh's backline resources for the new season were boosted with the signing of Highlanders utility back Phil Burleigh.
Wales centre Owen Williams suffered a potential career-ending injury at the weekend.
Veteran Scotland flyhalf Dan Parks has announced that he will retire from the game.
The Scarlets received a boost with the signing of destructive Tongan No.8 Chris Hala'ufia.
Edinburgh have extended the contracts of trialists Sam Beard and Carl Bezuidenhout to 2016 and 2015 respectively.
The Irish Rugby Football Union, Connacht and Leinster have agreed a loan deal that will see two high-profile players swap provinces.