Figure 1
From: Aberrant imprinting may underlie evolution of parthenogenesis
Pseudogamous parthenogenesis in Boechera is accompanied by sexual-like gene expression patterns and deregulation of a MADS-box gene. (a,b) Heterologous mRNA in situ signals of EC1.1 in sexual versus parthenogenetic egg cells. Arrow-heads: red – egg cell, green – synergids, white – central cell nuclei. (c,d) MEA signals in central cells. (e–g) Heterologous signals of PHEL1 in apomictic versus sexual embryo sacs. (h) An apomictic egg cell of Apo-1 (red arrow-head) at 3 days after emasculation. (i–n) Fertilized ovules (dark-blue arrow-heads – pollen tube entry, black arrow-heads – endosperm). (m,n) An unfused sperm nucleus (light-blue arrow-head) is visible proximal to the parthenogenetic egg cell (red arrow-heads). (o,p) Confocal micrographs of Apo-1 ovaries at fertilization. (o) Two sperm cells (light-blue arrow-heads) discharged into an apomictic embryo sac. (p) Sperm cell arrival coincides with polar nuclei fusion (white arrow-head). (q,r) CYCB1;1 mRNA in situ signals at one-celled embryo stage (red arrow-heads). Scale bars in (a-r) 20 µm.
