中华蜜蜂工蜂嗅叶的胚后发育

Postembryonic development of olfactory lobe in worker bees of Apis cerana cerana

通过形态解剖、免疫组织化学、原位细胞凋亡检测技术,对中华蜜蜂工蜂嗅叶的胚后发育过程进行了系统的比较研究。结果表明:(1)中华蜜蜂工蜂的嗅叶由神经纤维网区和外围的中脑神经细胞体层组成,在幼虫早期,神经纤维网的腹外侧和背外侧区内有几个大型的成神经细胞,呈现出典型的不对称分裂模式;在随后的发育过程中,神经纤维网的体积逐渐增加,神经细胞逐渐分散,细胞层变薄;分裂细胞主要集中在背外侧细胞区;在3龄幼虫期,触角嗅觉神经元的传入纤维开始进入嗅叶;在蛹发育的第3天,神经纤维网内的神经纤维球开始出现;(2)嗅叶发育过程中的细胞凋亡发生较少,增殖细胞和凋亡细胞数量的相对比率基本恒定;细胞凋亡的高峰期出现在幼虫末期;蛹发育的第4天左右,凋亡细胞完全消失;(3)中华蜜蜂的嗅叶存在雌雄异形现象。

Apis cerana cerana （Hymenoptera： Apidae） is a subspecies of Apis cerana and is the main subspecies in China, Development of the olfactory lobe was studied, based on the studies of anatomy, immunohistochemistry （5-Bromo-2-deoxyuridine, BrdU immunostaining） and in situ cell death detection. The characteristics of the proliferation and programmed cell death （PCD） of olfactory lobe cells, and patterns of cell divisions during growth were studied. Results showed that the adult olfactory lobe of Apis cerana cerana emerges from a precursor, the larval antennal lobe. Some interneurons of the adult olfactory lobe are derived from a lateral neuroblast which started to divide early in the 4th larval instar. The multilayered larval olfactory lobe cortex becomes gradually thinner and ultimately forms a unicellular flattened layer in front of the lobe neuropil. Most of its cells move to their adult locations, dorsolaterally and ventrolaterally. Olfactory afferents inervate the olfactory lobe during the 3rd larval instar. Glomeruli are first identifiable on pupal day 3. During olfactory lobe development, numbers of cells lost by apoptosis were few. Subsequently, the number of apoptotic nuclei increased. Apoptotic nuclei disappeared during days 4 of pupal development. Our study also showed that the olfactory lobes of Apis cerana cerana are sexually dimorphic .