Genus' signing was first reported by Matthew Elder of BuffaloBillsDraft.com, who was on top of things all night with the UDFA locations. From just looking at the roster, the Packers only have one true center in Scott Wells, and Genus' versatility with playing guard earlier in his USF career had to have helped in the Pack bringing him to Green Bay.
Bogan announced his signing with the 49ers on his Twitter account, and it reunites him with former USF HC Jim Leavitt, who is now the linebackers coach at San Fransisco. Although there are seven WR currently on the roster, Bogan is in a unique position because no one was able to get a playbook of Jim Harbaugh's new offense. Bogan also looks like a sure bet to make the final roster as he signed a 3-year contract that paid more than some contracts of players drafted in the 7th round.
Marshall's signing was first reported by 620 WDAE's Justin Pawlowski. Marshall will be reunited with former teammates Jason Pierre-Paul and Jacquian Williams, who were drafted in the last two seasons. Marshall had a solid senior year for USF before injuries hampered the 2nd half of the season. The Giants are pretty stacked at DE this year, so it will be tough for Marshall to earn a spot on the final roster.
Congrats to all three, and good luck at the next level guys!