Fig. 2.

Expression of cowpea meiosis-related genes SPO11-1, REC8 and OSD1, and protein localization in cowpea. a Expression of SPO11-1, REC8 and OSD1 genes in laser-captured cell types originating from cowpea reproductive tissues [17] represented as normalized read counts in a heat map. Pink indicates high abundance, and blue indicates low abundance. Additional file 6: Table S7 provides expression metrics. b Absolute expression levels of SPO11-1, REC8 and OSD1 in leaves and anthers collected at different developmental stages determined by quantitative PCR and normalized to the ADF gene. Asterisks indicate significant expression differences (*p < 0.05; Student’s t-test, X ± SE; n = 3 replicates). c Localization of meiosis gene transcripts (order as indicated in d), by in situ hybridization in developing ovules undergoing meiosis. Expression is evident in sporophytic and gametophytic tissues. d Protein localization determined by whole mount immunolocalization. e Detection of nuclei in images shown in d using propidium iodide (cyan). Scale bars: 10 µm. ADF actin depolymerizing factor 4, PMC.E early pollen mother cell, PMC.L late pollen mother cell, mTET male tetrads, MIC uninucleate microspore, SC mature pollen with sperm cells, MMC megaspore mother cell, fTET female tetrads, ES2n mitotic embryo sac with 2 nuclei, ES4n embryo sac with 4 nuclei, MES mature embryo sac at anthesis, containing the egg cell (EC) and central cell (CC), EM embryo