China has successfully cloned both Zhangmu cattle and Apeijiaza cattle, two endangered breeds found in southwest China's Xizang Autonomous Region, scientists announced on Monday.

Four male calves of each breed were recently born in Yunyang County, southwest China's Chongqing Municipality, marking the world's first successful cloning of cattle from Xizang.

The researchers collected the ear tissues of the two cattle breeds, and established fibroblast cell lines in the laboratory, Yu Dawei, a researcher at the Institute of Animal Sciences of Chinese Academy of Agricultural Sciences, told China Media Group.

"Then we used somatic cell nuclear transfer technology to prepare cloned embryos, and transplanted the cloned embryos into surrogate cattle. After full-term pregnancy, we got eight cloned calves," said Yu.

The endangered Zhangmu cattle and Apeijiaza cattle are native to the Qinghai-Xizang Plateau. In 2022, a rescue and protection initiative was launched by the Ministry of Agriculture and Rural Affairs, National Animal Husbandry Station and relevant local departments in Xizang, during which the researchers collected the cattle breeds' blood samples, completed whole-genome resequencing data collection, and finally realized the rescue and protection of the endangered breeds through technologies including somatic cell conservation and cloning embryo restoration.

"Next, we will carry out cloned embryo transplantation of Zhangmu cattle and Apeijiaza cattle in Xizang, and integrate cloning technology with conventional breeding technology to build a complete system for the protection and utilization of genetic resources," said Yu.

(WIth input from Xinhua)