In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 B and C1 fusions with yeast GAL4 DNA - binding and transcriptional activation domains were also found to interact when synthesized and assayed in yeast .
C1 fusions

 We have previously described the partial purification of Ap4A hydrolase from S . pombe [ Robinson , de la Pena and Barnes ( 1993 ) Biochim .
Ap4A hydrolase

 The Polycomb group proteins are involved in maintenance of the silenced state of several developmentally regulated genes .

Polycomb group proteins