鳜鱼头肾的组织发生及成鱼头肾B淋巴细胞的分布

通过整体连续切片，研究了鳜鱼不同发育时期的头肾结构，并利用原位PCR方法检测了B淋巴细胞在鳜鱼头肾中的分布。在孵化后第1d观察到了肾组织，主要由肾小管组成。尔后头肾的发育经历了三个结构和功能的转变。第一个阶段为孵化后第1d到第7d，头肾作为滤过性器官存在，由肾小管及少量淋巴细胞组成。第二个阶段从第8d到第36d，是一个功能混合型阶段，头肾中既有肾小管，又有造血组织；随时间推移，肾小管数量减少，淋巴细胞数量剧增。紧接着进入第三个阶段：肾小管完全消失，头肾中开始出现大量的嗜铬细胞，头肾作为淋巴-肾上腺组织而存在。肾上腺首先出现在头肾前端，随发育成熟，集中分布于头肾门静脉周围。IgM在鳜头肾中大量表达，IgM分泌细胞分布于整个头肾组织，在血管周围有集中趋势[动物学报51(3)：440—446，20051。

Ontogenetic development of the pronephros and the distribution of B-lymphocytes in adult pronephros of the mandarin fish Siniperca chuatsi

Ontogenetic development of the pronephros was examined in the mandarin fish Siniperca chuatsi,collected from the first to the 35th day post hatching(dph).Renal tubules and undifferentiated haemopoietic cells were observed on the 1st dph.The development of the pronephros was subjectively divided into three stages according to changes in its composition.At the first stage(from the 1st to 7 dph),the pronephros mainly consisted of renal tubules and some haemopoietic cells;at the second stage(from the 7th to 35th dph)with the composition of lymphocytes and renal tubules.Afterwards,the number of renal tubules decreased and then disappeared,and the number of lymphocytes increased and adrenal gland was found surrounding the blood vessels.In situ PCR technique was successfully used to detect the distribution of B-lymphocytes expressing IgM mRNA in the pronephros of adult mandarin fish.It is shown that lymphocytes are distributed in the whole pronephros,with some of them located around the blood vessels.