Abstract: Harderian glands (HG) may act as a "standby" structure of the retinal-pineal axis, mediating light signals in vitro and neuroendocrine regulation in vivo. The functions of the gland are variable, and are usually regulated by neural-humoral factors. Somatostatin (SS) is one of the main inhibitors which mediate the growth and the development of vertebrates. In this study, the morphological parameters of HG in striped hamsters (Cricetulus barabensis) were examined. The SS cDNA sequence in HG was cloned and the differential expression levels of SS in HG for sexes and ages were detected by RT- PCR, so as to verify the functions of SS and its effects on the development of HG. The results showed that:(1) Striped hamsters’ body weight increases with age, regardless of gender. The weight and length of HG also increases with age. After the body weight was adjusted for, there were no age differences found for the weight and length of HG, while differences in HG weight were found between genders (P<0.05). (2) A cDNA sequence of SS with 489 bp in size was cloned. SS cDNA in HG of striped hamsters has the typical characteristics of secretory protein cDNAs, and is highly conserved in evolution. (3) SS was expressed in HG and significant differences in relative expression levels existed between sexes and among ages (P<0.05). (4) The relative expression levels of SS in HG declined gradually with tage, and significant negative correlations were detected between the relative expression levels of SS in HG and the morphological parameters of the HG. The above results suggest that sexual dimorphism occurrs in terms of the weight of HG and the SS expression of HG in striped hamsters. SS is an inhibitor, which is closely related to the development and growth of HG.

Key words: Striped hamster (Cricetulus barabensis), Harderian gland, Somatostatin, Real-time PCR, Gender, Age

摘要： 哈氏腺作为“视网膜-松果体轴”的候补结构，介导了体外光信号与体内神经内分泌调控过程，具有多样性和复杂的生理功能，并受神经和体液因素的双重调控。生长抑素（somatostatin, SS）是调控动物生长发育的主要因子之一，检测SS基因在黑线仓鼠哈氏腺的差异表达模式，为光信号调控动物的生长发育机制提供理论依据。以野生黑线仓鼠（Cricetulus barabensis）为研究对象，测量了不同性别和年龄个体哈氏腺的形态学指标，克隆了哈氏腺SS cDNA序列，实时荧光定量PCR方法检测了哈氏腺中SS基因的表达变化。结果显示：（1）黑线仓鼠体重无性别差异，随年龄增长而增加；哈氏腺的长度和重量也随年龄增长而增加；调整体重影响后，哈氏腺的重量和长度没有年龄之间的差异，但哈氏腺重量存在性别间差异（P<0.05）。（2）克隆到黑线仓鼠哈氏腺SS cDNA序列489 bp ，并对序列结构进行分析，黑线仓鼠哈氏腺SS cDNA具有典型分泌蛋白cDNA的特征，并在进化上高度保守；（3）检测到SS mRNA在黑线仓鼠哈氏腺中均有表达，表达量存在年龄和性别差异（P<0.05）；（4）随着个体性成熟和衰老，黑线仓鼠哈氏腺中SS mRNA的相对表达量逐渐降低，其表达量分别与哈氏腺长度和重量的发育变化负相关（r=-0.557，P=0.022；r=-0.806，P＜0.001）。结果表明，黑线仓鼠哈氏腺重量和SS表达量均表现出两性异形，可能是对不同繁殖策略的适应；SS基因作为负调控因子参与野生黑线仓鼠哈氏腺的生长发育过程。

关键词: 黑线仓鼠, 哈氏腺, 生长抑素, 实时荧光定量PCR, 性别, 年龄