Why no Jennie Garth, Tori Spelling and Shannen Doherty, all stars of the original? They're guest stars, not cast regulars, who'll appear in multiple episodes. 90210 is filming its third episode; only Garth has shot any scenes to date.

Here's a first look at the cast photo for the fall series, with a description of each character and comments from executive producer Gabe Sachs.

• Annie Wilson (Shenae Grimes, Degrassi: The Next Generation)

Pretty, cool and popular in Kansas, Annie must start from scratch in Beverly Hills. Sachs and fellow executive producer Jeff Judah had seen Wilson's work "and knew she had the acting chops. But she did a dramatic scene for us and it just killed," Sachs says. "She can act, she's beautiful, and she can give this sweet cuteness (that lets us see) through her eyes into this world."

• Dixon Wilson (Tristan Wilds, The Wire)

Dixon, adopted by the Wilsons, was a star athlete and student in Kansas. He and Annie, who face similar hurdles in adapting to their new environment, support each other as "best friends," Sachs says. The producers wanted to cast Wilds from the start. "We were huge fans of The Wire and huge fans of Tristan. … We said if we could ever get Tristan onto our show, it would be amazing."

•Harry Wilson (Rob Estes, Women's Murder Club, Melrose Place)

Harry, who grew up in Beverly Hills as the son of a '70s TV star, returns with his family to become principal at West Beverly Hills High School. Sachs, who went to the University of Southern California with Estes, says the actor initially wasn't available because he was on Women's Murder Club. When that was canceled, "I said, 'Get Rob on the phone,' " Sachs says. "He loved it. He just thought this would be so great. And I said, 'I promise you won't be furniture,' " as in the seldom seen or heard parents who populate many youth-centric series, like the Walsh parents on the original 90210.

•Debbie Wilson (Lori Loughlin, Full House, Summerland)

Debbie, "a cool mom," struggles with when she should be her children's friend and when she should be the parental disciplinarian. She and Harry come from a generation that has a good idea of what their kids might be up to. Sachs figured Loughlin was too established to read for the part, but she came in to read, and she understood the role immediately. "She can look at something and just 'Boom!' " Sachs says. "She only had to do it once. We knew it was her."

•Tabitha Wilson (Jessica Walter, Arrested Development)

Harry's mother, hip, feisty Tabitha, is a faded TV star familiar with the Betty Ford Clinic. Harry, back to keep an eye on her, moves with his family into her home. The producers were Walter fans. "Play Misty for Me. That's all you had to say to me and Jeff. And then you have to explain to the kids what that (movie) is," Sachs says. "She knows pieces of scenes. She'll suggest stuff that works."

•Naomi Clark (AnnaLynne McCord, Nip/Tuck)

Naomi is described in press notes as "a hot, spoiled, rich girl," but Sachs says she's not a stereotype, and the series will peel back layers of her character to show why she is the way she is. "AnnaLynne is very smart. She's someone who is worldly, and there's a sophistication to her that's interesting."

•Ethan Ward (Dustin Milligan, The Land of Women)

Ethan, a lacrosse star who goes out with Naomi, has West Beverly "wired." But the arrival of Dixon, another top athlete with a friendly personality, could shake up his high school world. "Dustin is really funny. That's something you don't know when you're meeting them and working with them for the first time. Then you see this and say, 'We have to write to that.' "

•Silver (Jessica Stroup, Prom Night)

"Silver" — introduced only by her last name — is a quirky kid who moves to her own beat. As for a rumored connection to original 90210 character David Silver, Sachs would only say, "We'll know that very soon." As for Stroup, "We kept looking at people for this. Jessica came in dressed for the part, artsy and quirky, and she had her hair up and she had a bandana. She nailed it."

•Navid Shirazi (Michael Steger, guest on NCIS,Criminal Minds)

Navid, who does the school newscast, "has a passion for it. He wants to be the guy who has the scoop. It's a fun character, because you're not always the most popular kid when you're trying to get the scoop," Sachs says. As for Steger, cast by Tim Burton for the music video of The Killers' song Bones: "He's just great."

•Ryan Matthews (Ryan Eggold, Dirt)

Matthews, a teacher, is only a few years older than his students; he connects with them but is also an authority figure. Eggold "is such a sophisticated actor, and he's also very funny. He plays a great mix between a teacher and a real guy in this world. Every time he's on the screen, people are going to go, 'Wow!' "