Okonkwo Charles, Singh Mahipal
Animal Science Division, Agricultural Research Station, Fort Valley State University, 1005 State University Drive, Fort Valley, GA, 31030, USA.
In Vitro Cell Dev Biol Anim. 2015 May;51(5):463-9. doi: 10.1007/s11626-014-9856-9. Epub 2014 Dec 25.
Successful cloning of animals using somatic cell nuclear transfer requires undamaged nuclear DNA from desired donor cell types. In vitro culture of cells is one way of ensuring nuclear integrity. The goal of this study was to evaluate the limits of postmortem cell survival/culture in refrigerated goat ear skin tissues which could be used for long-term storage and cloning of animals in future. To achieve this, 60 explants from 6 different goats were cultured after 0, 3, 6, 9, 13, 16, 20, 23, 27, 30, 33, 37, and 41 d postmortem and observed under inverted microscope for outgrowth of fibroblast-like cells, after 10-12 d of culture. Explants from all time points including 19% from 41-dpm tissues exhibited outgrowth. However, the percentage of outgrowth positive explants, as well as culture confluence, reduced with increasing postmortem time interval. Cell cultures established from primary outgrowth of 41-dpm tissues when compared for their growth profile with similarly obtained 0-dpm cultures revealed similar growth curve and cell morphology. Cytogenetic analysis of 41-dpm tissue-derived cell populations revealed a normal female karyotype with 60 XX homologous chromosomes indicating genetic stability of the cell population. In conclusion, these results show that refrigerated skin tissue remains alive for more than a month and that the cells derived from such tissues are normal and can be cryopreserved for long-term storage and future cloning of animals with desired genetics.
利用体细胞核移植成功克隆动物需要来自所需供体细胞类型的未受损核DNA。细胞的体外培养是确保核完整性的一种方法。本研究的目的是评估冷藏山羊耳部皮肤组织中死后细胞存活/培养的限度,这些组织可用于未来动物的长期保存和克隆。为实现这一目标,在死后0、3、6、9、13、16、20、23、27、30、33、37和41天,对来自6只不同山羊的60个外植体进行培养,并在培养10 - 12天后,在倒置显微镜下观察成纤维样细胞的生长情况。包括41天死后组织的19%在内,所有时间点的外植体均有生长。然而,随着死后时间间隔的增加,生长阳性外植体的百分比以及培养汇合度均降低。将41天死后组织的初次生长建立的细胞培养物与同样获得的0天死后培养物的生长曲线进行比较,发现生长曲线和细胞形态相似。对41天死后组织来源的细胞群体进行细胞遗传学分析,发现其具有正常的雌性核型,有60条XX同源染色体,表明细胞群体的遗传稳定性。总之,这些结果表明,冷藏皮肤组织在一个多月内仍保持存活,并且由此类组织衍生的细胞是正常的,可以冷冻保存用于长期保存以及未来对具有所需遗传特征的动物进行克隆。