Figure 3.

The motif pair I2A/B co-occurs in mouse as well as human and is preferentially co-conserved. (A) Representation of five possible models for co-conservation. Lines represent dependencies that are modeled; absence of a line indicates assumption of independence. Model (v) is the maximum entropy model used to define the co-conservation rate. (B) The 23 HM-I2 tetramer pairs that significantly co-occur between the beginning/end of constitutive mouse as well as human introns are shown. (C) I2A/B motif pairs are more conserved than expected. Empirical cumulative distribution functions of chi statistic (higher values indicate increased conservation) for HM-I2 tetramer pairs and control pairs. Controls have similar numbers of co-occurrences in human and mouse constitutive introns as HM-I2 pairs. Vertical black and gray lines indicate mean of statistic over HM-I2 pairs and control pairs, respectively.