促性腺激素在白蚁脑中的免疫细胞化学定位

Immunocytochemical localization of gonadotropins in termite brains

为研究昆虫卵泡刺激素 (FSH)和黄体生成素 (LH)的存在与分布 ,我们用免疫细胞化学染色技术对FSH和LH在尖唇散白蚁 (Reticulitermesaculabialis)脑中的分布进行了定位研究。结果显示 :FSH免疫阳性神经细胞及神经纤维分布在雌性繁殖蚁分飞期前脑的左叶、右叶及中部 ,雌性末龄若虫前脑的右叶 ,雄性繁殖蚁前脑的右叶 ;LH免疫阳性物质分布在雌、雄繁殖蚁前脑左叶 ;在工蚁和兵蚁中未见有FSH和LH免疫阳性物质存在。研究结果表明 :FSH和LH在白蚁脑中的存在具有发育阶段特异性 ,并且有可能像其在脊椎动物中那样参与调节性腺发育及精卵成熟 ;可能调节繁殖蚁、兵蚁。

To identify the existence and distribution pattern of follicle stimulating hormone(FSH)and luteinizing hormone(LH)in insects, we investigated immunocytochemical localization of FSH and LH in the brain of termite Reticulitermes aculabialis with the SABC (strept avidin-biotin complex)method. The head of termites was fixed in Bouin fixative and embedded in paraffin. Cross sections of 6 μm thickness were cut. Sections with the structure of the brain were identified under a light microscope and selected for immunoreaction. The results indicated that FSH and LH existed in brains of different developmental stages. In the female,FSH immunopositive nerve cells and fibers were localized in the left,right,and middle part of procerebrum at the flying stage and in the right part of the procerebrum during the last instar nymph,LH immunopositive substance was localized in the left part of procerebrum at flying stage. In the male,FSH immunopositive substance was distributed in the right and LH in the left part of the procerebrum at the flying stage. No immunoreactivity for FSH and LH was detected in brains of workers and soldiers. On the other hand,we knew that the oocyte of last instar nymphs were at a growth stage which included follicular differentiation and proliferation,and the oocyte of flying females began to deposit in the cytoplasm,and spermatogenesis of flying males were transformed from spermatogonia to spermatozoa. We showed that FSH and LH are involved in speeding up follicular growth and vitellosensis in the female,and inducing spermatocyte maturation in the male.