Sampling of visceral tissues from Bovines in the Qinghai-Tibet Plateau and techniques of their RNA preservation

The habitat and biological behavior of yaks are considerably different from those of indigenous cattle. It is not easy to obtain samples, in particular. The preservation method of the hard-won samples for long periods is important. Yaks and indigenous cattle served as tissue donors for developing an effective method for the storage and quality monitoring of RNA. Three yaks and cattle each, were slaughtered to obtain samples of gastrointestinal, liver, and kidney tissues, and RNA were extracted using a TRizol Kit; additionally, RNA concentration and the degree of RNA degradation were analyzed as per the Food and Drug Administration (FDA) regulations with Gel-pro Analyzer after the RNA samples were stored for 1 and 23 months at -80 ℃, respectively. The results indicated that after 23 months, RNA concentration increased in all the yak gastric tissue samples; however, it decreased in the rumina and omasa of the cattle. RNA was relatively stable in jejunal and ileal tissues of the yaks and cattle. There were significant differences in RNA concentration in the large intestine between the yaks and cattle(P<0.05). Gel-pro Analyzer results indicated that 5S bands were clear; however, 28S and 18S bands were vague in all the gastric, liver, and kidney tissues. The 28S:18S ratio ranged from 0.34 to 0.72 for the gastric, liver, and kidney tissues: however, it ranged from 0.43 to 2.15 for intestinal tissues after storing for 23 months at -80 ℃. It was feasible to obtain RNA of high quality from the gastrointestinal samples of ruminants in the Qinghai-Tibet plateau. However, the RNA samples were degraded during storage by the conventional method. Additionally, the degradation degree was affected by several factors, such as genotype and tissue type.