TMNT2014 movie (+spoiler)

[Meowazziel]

Back when I as a kid, I was a big fan of the TMNT.
Now that there is a new movie released, it brings a lot of nostalgia for me.
I havent seen it yet, but plan to do so (in the movies/dvd).

I googled a lot about the movie and read how they altered the story a bit.
In this movie, the turtles are turtles that were in April's father's laboratory for example.
This is a change from earlier versions, where they were not.
I dont mind with such changes tbh, however, what I wonder is, where
did splinter come from in this movie?

In some versions of the turtles, he was Hamato Yoshi, a ninja master, who was banished (unfairly) from his ninja clan, where he was a teacher. When he lived in the sewers, he got affected by mutagen. This turned him into a humanoid rat.

In some other versions he was pet rat, from a ninja called Hamato Yoshi. This Hamato Yoshi got
killed by the schredder. His pet rat Splinter, was from that point on homeless got affected in the sewers by mutagen
and turned into a humanoid rat.

My question is, regarding the tmnt 2014 movie, where did splinter come from in this version?
Was he human and did he turn into a rat? Was he among the creatures (as a rat) in the laboratory of April's father?
I cant find that info on the net and I would really like to know.

 

[Meowazziel]

If splinter, in the 2014 movie version, was from the laboratory as well (just as the turtles), than how did he become a ninja master, who could teach the turtles?

In previous comic, movies and animated versions, he was either a human ninja master called Hamato Yoshi, who became a mutant rat or he was a pet rat called splinter, from a ninja master called Hamato Yoshi (who splinter tried to copy when he saw him train and such).
In both those versions, there are explanations how splinter was able to be a ninja master.

IF he is from the laboratory too in the 2014 movie version, than I wonder, how did he learn to be a ninja master?