4 . influence of no on microvascular permeability : specimens from postnatal 1 day showed little immunoreactivity for enos . in contrast , blood vessel endothelium and leydig cells and spermatids in postnatal 3 weeks testes were strongly expressed enos . the number of positive blood vessel endothelium , leydig cells and spermatids in postnatal 3 months was conspicuously increased 饱及枯j代细胞均出现了阳性表达: 3月龄组生精小管靠近若腔的精r细胞出现enos阳性，阳性血管内皮细胞数目增多显著: 12月到24月龄阳性l阳乍今内皮细胞数i ] ‘ . ‘增多的趋势。
Mitochondria and ribosomes are hard to see , and the ribosome are found to adhere on the surface of endoplasmic reticulum ; golgi body and lysosome do not exist , membranous ring emerges at the secondary spermatocyte stage . the organelles change into pre - acrosome vesicles at middle spermatid stage , and finally pre - acrosome forms acrosome . 2 浙江华溪蟹在生精细胞阶段，染色质形态相似，呈不同程度凝集状，核仁在精原细胞期出现;精细胞阶段，染色质分化成纤丝状和致密块状，部分核质延伸入辐射臂内，整个核呈浅杯状。
