3.4 Cell-type-specific programs of division and expansion
The final form of an organ reflects the pattern of cell proliferation, expansion, and differentiation of the constituent tissues and their cell type. For every cell type, cell counts along X-, and Y- axes (Figure3AB ) and cell width, cell length and cell depth were quantified in mm along X-, Y-, and Z-axes, respectively (Figure 3E-G ) at least in 12 anthers per stage with ˃ 10 replicates. We analyzed the cell ratio of Y-axis and X-axis (Figure 3I ). These values were multiplied to estimate the cell size and cell counts per anther, resolved by the tissue type (Figure 3CH ). Additionally, percentage in every anther locule was calculated as well (Figure3J ). As shown in Figure 3A, Table 1 , EPI cells have consistently more cells counts along X-axis then other cell types and their ratio increased more rapidly from 200-400 µm anthers moves towards the stability until to maturation, where pollen grains released. The cell counts of all other cell types increased gradually as anther undergoes development. In Figure 3B, Table 1,EN cells has greater cell counts then all other type of cells along Y-axis. Results showed that the cell counts of EN cells along Y-axis increased extensively during the anther development from 400-800 µm compared to other length of development. EPI increased more rapidly from 200-400 µm and then become stable. As shown in Figure 3C, Table1 , the total cell/locule (X*Y) of EN cells was more than all other cell types during anther development, except from 200-700 µm, where cell counts of EPI was more. Moreover, total cell/locule of SPL, ML, TA, PMC, MP and PG increased as the anther increased in size. Interestingly, the percentage of locule cell count of EPI cells decreased during development, but increased in EN cells with the anther development. However, almost irregular response was noted in SPL, ML, TA, PMC, MP and PG (Figure 3D, Table 1 ). As shown in Figure 3E, Table 2, width (X-axis) of all cell types increased as anther goes to development. The maximum cell width noted in EN cells, but interestingly PG got more width suddenly in anthers 2000-2300 µm than other cell types. In addition, width of SPL cells only recorded in 200-400 µm anthers and then disappear. The irregular pattern of cell width of all cell types was recorded in EPI, ML, TA and PG during cell development. The maximum cell length (Y-axis) was recorded in EPI cells compared to all other cell types. However, in EN, ML, TA, PMC and MP length increased gradually during anther development. PG developed more rapidly especially from 1700-2000 µm. Additionally, the length of SPL cells increased slowly, then cells become disappear by differentiating into ML and TA after division (Figure 3F, Table2 ). Likewise, width and length, the cell depth (Z-axis) of all cell types significantly influenced during the division and expansion. Results demonstrated that cell depth of EPI, EN, SPL, ML, TA, PMC and PG increased gradually as anther increased in size during development, but in PG depth increased more rapidly from 1700-2000 µm long anthers and then moves towards stability (Figure 3G, Table 2 ). The cell volume (X*Y*Z) was calculated for all cell types sizes and more cell volume was observed in the PG compared to others cell types. While in ML and TA suppressed proliferation of cells were noted (Figure3H, Table 2 ). Length/ width (Y/X) ratio was calculated for all cell types. EPI cells showed more percentage during their expansion and division, while all other cells showed gradual response during the division (Figure 3I, Table 2). Percentage of locule volumes were calculated as well and PG has maximum in later stage of development (Figure 3J, Table 2 ).