山羊乳腺上皮细胞的生长特性

用组织块培养法获得山羊乳腺细胞原代培养物。根据山羊乳腺成纤维细胞与上皮细胞对胰蛋白酶的敏感性不同将二者分离纯化，对细胞生长特性进行了光镜观察。结果如下：细胞可形成闭合型细胞群和开放型细胞群。乳腺上皮细胞与成纤维细胞混生时，细胞之间形成许多腔状结构。纯化的乳腺上皮细胞通过单细胞悬浮后传代，部分细胞形成岛屿状聚集，部分细胞以贴壁的自由单个细胞散在形式存在。上皮细胞增殖可形成圆顶型结构，呈乳头状，称之为乳球体；可产生乳腺上皮细胞并分泌乳汁。山羊乳腺上皮细胞含不同的细胞类型．大多数上皮细胞呈短梭形或多角形。细胞之间紧密相靠。互相衔接。连接成片，呈蜂窝状；细胞核呈圆形或椭圆形．核仁2～4枚；部分细胞呈圆饼状，体积较大；出现部分长形细胞；接触抑制的上皮细胞形态不均一。纯化的山羊乳腺上皮细胞传代至第15代时其生长仍正常，经透射电镜观察发现细胞表面微绒毛极为发达，细胞质中线粒体和粗面内质网丰富，细胞质内有大量脂滴及小泡，表明第15代山羊乳腺上皮细胞增殖活力旺盛。染色体数目分析表明．该细胞系稳定，在离体培养条件下细胞不发生转化。山羊乳腺上皮细胞系的细胞染色体数目为60．染色体组型为2n=60。

Growth characteristics of goat mammary epithelial cells

Primary culture of goat mammary gland cells have been achieved by outgrowth of migrating cells from fragment of tissue.Fibroblast and epithelial cells have been purified according to their different sensibility to trypsin.The characteristics of goat mammary epithelial cells were observed by light microscopy.The results were as follows:The cells formed closed clusters and open clusters.When fibroblast and epithelial cells grew together,many cavity-like construction formed among the cells.The pure mannary epithelial cells were cultured in vitro through single-cell afloat,part of the cells formed island monolayer aggregates and part of the cells exsited in free single cell form.Mammary epithelial cells propagated and formed dome-like construction which looks like nipple and it was called milk orb;mammary epithelial cells produced and were able to secret the milk.The goat mammary epithelial cells bore different type,majority of the cells were short shuttle-like or guboidal,the cells depended on each other closely,connected with each other properly,linked and became slice which looks like a beehive;the cell nucleus were circular or oval which has 2-4 cores;part of the cells looked like a big round flat cakes;part of the cells were long;appearance of the contact repressing cells were not same.The purified goat mammary epithelial cells kept normal characteristics until 15th passages.The growth characteristics of 15th passage cells were observed with transmission electron microscopy which showed:More microvilli appeared on the luminal surface of the epithelial cells.Mitochondria and rough endoplasmic reticulums were rich.The cell cytoplasms had plenty of secretive vesicles and fatty droplets,which showed that the 15th generation goat mammary epithelial cell had vigorous secretive activity.Analysis on chromosome number of the goat mammary epithelial cells indicated that the cells are unchanged during cultivation in vitro.Chromosome number of the cells is 60 with its karyotype of 2n=60.