图1 普通针毛蕨颈卵器发育的光学显微镜图。 (A-B): 初生细胞(PC); (C): 中央细胞(CC)和单核颈沟细胞(MNC); (D-E): 幼卵细胞(EC)、腹沟细胞(VCC)与双核颈沟细胞(NCC); (F): 卵细胞发育早期; (G): 卵细胞(EC)与腹沟细胞(VCC)之间分离腔(SC)逐渐形成; (H): 卵细胞与腹沟细胞之间完全分离; (I): 受精孔(FP)形成; (J): 成熟卵时期的颈卵器; (K): 颈卵器壁细胞向基部弯曲; (L): 成熟卵后期, 双核颈沟细胞、腹沟细胞完全退化。FP: 受精孔; SC: 分离腔。

Fig. 1 The generation of the archegonium of the fern Macrothelypteris torresiana under light microscopy. (A-B), A primary cell (PC); (C), The central cell (CC) and mononucleated neck canal cell (MNC); (D-E), The young egg cell (EC), the ventral canal cell (VCC) and the neck canal cell (NCC); (F), The stage of maturing egg cell; (G), The separation cavity (SC) between the egg cell and the ventral canal cells (VCC) gradually formed; (H), Complete separation of the egg cell and the ventral canal cells; (I), Fertilization pore (FP) formation; (J), The archegonium in mature egg stage; (K), Jacket cell of the archegonium bend to the base; (L), At the matured egg anaphase, the neck canal cell and the ventral canal cell have completely degenerated. FP, Fertilization pore; SC, Separation cavity.

图2 普通针毛蕨颈卵器发育和卵发生的电镜图。 (A): 中央细胞(CC)和单核颈沟细胞(MNC); (B): 单核颈沟细胞(MNC)放大及其细胞器; (C): 双核颈沟细胞(NCC)与中央细胞(CC); (D): 幼卵阶段, 颈卵器颈部4-5层细胞高; (E): 腹沟细胞(VCC)呈凸透镜状; (F): 腹沟细胞(VCC)和卵细胞(EC)内细胞器发达。M: 线粒体; N: 核; P: 质体; Ve: 囊泡; Pd: 胞间连丝。

Fig. 2 Electron microscopic charts of archegonium development and the oogenesis of Macrothelypteris torresiana. (A), The central cell (CC) and the mononucleated neck canal cell (MNC); (B), The amplification of the mononucleated neck canal cell (MNC) and its organelles; (C), Neck canal cell (NCC) and central cell (CC); (D), The 4-5 layer height of the archegonium in the young egg stage; (E), The ventral canal cell (VCC) presenting convex lenticular shape; (F), The ventral canal cell (VCC) and the egg cell (EC) have developed organelles. M, Mitochondria; N, Nucleus; P, Plastid; Ve, Vesicles; Pd, Plasmodesmata.

图3 普通针毛蕨卵发生电镜图。 (A): 腹沟细胞(VCC)与双核颈沟细胞(NCC)和卵细胞(EC)之间有胞间连丝相连; (B): 卵细胞细胞核规则, 腹沟细胞的细胞核位于中央; (C): 双核颈沟细胞完全退化, 细胞内出现大量不定型物质; (D): 卵细胞细胞核(N)变形, 卵膜(EE)开始堆积; (E): 卵膜下方线粒体、质体发达; (F): 卵细胞内出现圆形内质网(ER)和嗜锇性囊泡(Veo)。M: 线粒体; N: 核; P: 质体; Ve: 囊泡; ER: 内质网; SC: 分离腔。

Fig. 3 Electron microscopic charts of the oogenesis of Macrothelypteris torresiana. (A), Plasmodesmata are connected between ventral canal cell (VCC), the neck canal cell (NCC) and the egg cell (EC); (B), The nuclear of the egg remain unchanged, the nuclear of the ventral canal cell is located in the center; (C), Ventral canal cell degenerated completely and a large number of amorphous substances appeared in the ventral canal cells; (D), The egg cell have deformed nucleus (N) and the egg envelope (EE) begins to accumulate; (E), Under the egg envelope, there are developed mitochondrial and plastids; (F), Circle endoplasmic reticulum (ER) and vesicle containing the osmiophilic materials (Veo) appeared in the egg. M, Mitochondria; N, Nucleus; P, Plastid; Ve, Vesicles; ER, Endoplasmic reticulum; SC, Separation cavity.

图4 普通针毛蕨卵发生电镜图。 (A): 孔区与腹沟细胞(VCC)分离, 出现受精孔(FP); (B): 卵细胞弓形; (C): 腹沟细胞(VCC)和双核颈沟细胞(NCC)完全退化; (D): 成熟卵细胞内的细胞器; (E): 卵细胞(EC)侧面; (F): 卵细胞与周围颈卵器壁细胞分离。M: 线粒体; N: 核; P: 质体; SC: 分离腔; FP: 受精孔; EE: 卵膜。

Fig. 4 Electron microscopic charts of the oogenesis of Macrothelypteris torresiana. (A), Separation of the pore region from the ventral canal cell (VCC) and a fertilization pore (FP) appears; (B), Arcuate egg; (C), The ventral cancal cell (VCC) and the neck canal cell (NCC) are completely degenerated; (D), Organelles in mature egg cell; (E), A side of egg cell (EC); (F), The separation of the egg from the jacket cell of the archegonium. M, Mitochondria; N, Nucleus; P, Plastid; SC, Separation cavity; FP, Fertilization pore; EE, Egg envelope.

图5 真水龙骨类卵发生可能的演化路径。 (A): 真水龙骨类I, 卵发育后期形成卵膜和受精孔(侧方), 卵核不规则且产生大量核外突; (B): 真水龙骨类II, 卵发育后期形成卵膜和受精孔(侧方), 卵核不规则且产生大量核外突; (C): 桫椤类, 卵发育后期形成卵膜和受精孔(中央), 卵核不规则且产生大量核外突; (D): 里白类, 卵发育后期形成卵膜和受精孔(中央), 卵核外产生少量核外突; (E): 原始薄囊蕨类, 卵发育后期无卵膜、受精孔, 卵核规则且不产生核外突。VCC: 腹沟细胞; EC: 卵细胞; N: 核; SC: 分离腔; FP: 受精孔; EE: 卵膜。

Fig. 5 Potential evolution path of oogenesis of Eupolypods. (A), Eupolypods I, an egg envelope and a fertilization pore (lateral) are formed in the late stage of egg development, the egg nucleus is irregular and produces extensive evaginations; (B), Eupolypods II, an egg envelope and a fertilization pore (lateral) are formed in the late stage of egg development, the egg nucleus is irregular and produces extensive evaginations; (C), Cyatheales, an egg envelope and a fertilization pore (central) are formed in the late stage of egg development, the egg nucleus is irregular and produces extensive evaginations; (D), Gleicheniales, an egg envelope and a fertilization pore (central) are formed in the late stage of egg development, the egg nucleus is regular and produces a few evaginations; (E), Fundamental group of Leptosporangiates, there is no egg envelope and fertilization pore at the later stage of egg development. The egg nucleus is regular and do not produce evaginations. VCC, The ventral canal cell; EC, Egg cell; N, Nucleus; SC, Separation cavity; FP, Fertilization pore; EE, Egg envelope.