Differential expression of the secretome during lactation. Top: the ratio of transcripts encoding predicted secretory versus non-secretory proteins is shown in function of time (days) after combining EST sequencing (day 23 pregnant, day 130 and 260 of lactation) and MPSS data (day 151 and day 240). The proportion of secretory gene products increases consistently during lactation fitting a second degree polynomial (black line: R > 0.995). Bottom: proportion of predicted secreted protein gene transcript (blue) and other (red) (normalized to 10000) for the complete data set including library sequencing and MPSS. From left to right: pooled data (day-130 lactation, day-130 lactation subtracted, day-260 lactation, day-23 pregnant, day4 lactation unsucked, normalized library), individual stage specific libraries; day-23 pregnant (libraries 15, 16 and 17) day-4 lactation unsucked gland (libraries 18 and 19), day-130 lactation subtracted (libraries 11 and 12), day-130 lactation (libraries 1,2,3,4 and 13), day-260 lactation (libraries 11 and 12), normalised library, day-151 lactation mpss, day-240 lactation mpss.