Alternative splicing types observed in five most studied species.

ES – exon skipping; IR – intron retention; A3 –
alternative 3′ splice site; A5 – alternative 5′
splice site; ME – mutually exclusive exons; N – number
of alternatively spliced genes; A – alternative splicing ratio
(proportion of alternatively spliced genes); R – ratio of the
total number of protein products to the total number of protein
genes; H – Shannon's index;
Hmax – maximum possible
value of Shannon's index, where for a given n,
H is a maximum and equal to
logn, when all the Pi are
equal (i.e., 1/n);E –
Shannon's equitability
(E = H/Hmax).
Complex cases are denoted as combinations of these abbreviations.
Pr - proportion (ratio) of the type to all
types.