Although I think it's pretty evident that even people without the gene can get in and out of their quarters. It would certainly suck if the handful of people with the gene had to go around opening doors and turning on the lights every morning! Although that's a hilarious thought for an AU ... what if NOTHING in Atlantis worked without the gene?
The door to his room swished open, and one Major John Sheppard swept into the room with a bow. "No applause, no applause. I'm here all day."
"Now you are!" Rodney snapped and pointed to the door adjacent to the one the major was currently standing in. "Hurry!"
With a quirk of his lips, John waved his hand over the sensor, and the door to Rodney's bathroom swished open. With a half-laugh, half-sob, McKay rushed by, not noticing or caring as he roughly shoved Sheppard into the wall. "Thank God!"
"You're welcome," John muttered as he rubbed his shoulder.
"And people say I have an ego." McKay's voice drifted from the bathroom.
John quickly palmed the sensor and the door swished shut, thankfully cutting off the sound of the scientist relieving himself in the Atlantean facilities. In retrospect, locking Rodney out of his own bathroom the night before was not as funny as originally envisioned. He glanced at his watch, watching the seconds tick by. It was tempting to leave the frustrating scientist in there, but then he'd get on the radio and then John would never hear the end of it.
"Hurry it up, I've still got half a block after you!" John shouted to be heard through the thick door.
Silence met his statement, and John started to wonder if maybe McKay had fallen in. Finally, he heard a knock and a muffled, "Okay, I'm done."
John palmed the sensor again, and the door opened to reveal a very sheepish McKay, who indicated the interior of the bathroom with a half-fidget.
"Oh, for crying out loud, I'm surprised you didn't ask me to also wipe your--"
"Hey! It's not MY fault the creators of this city forgot to take into account that there might occasionally be visitors!"
"Well they suck as great-grandparents, I'll tell you that," John shot back as he very quickly initiated the flushing mechanism on the toilet and turned back to face Rodney. "Well, my civic duty here is done. Only ten more rooms to go."
"Lucky you," McKay crossed his arms. "And really funny closing the door last night when I wasn't looking."
"It won't happen again, I promise." John wrinkled his nose as he ambled back into the main living area of McKay's quarters. "Turns out, not so funny."
"I could have told you that."
"I've got to go unleash your neighbors on the world, care to join me before this morning's meeting?"
"I've got a previous appointment," Rodney tapped his own watch, unconsciously echoing Sheppard's previous action. "Carson's got the first batch of ATA retrovirus ready."
"Well that sounds promising."
"Tell me about it," Rodney agreed as he bounced out into the hallway. "I'll finally be able to flush my own damn toilet!"
Well you did say nothing worked.