A cloned monkey has survived for over two years, according to reports. 

In a landmark development in reproductive cloning, a team of international researchers say their successfully cloned healthy rhesus monkey has been thriving.  

Previously, somatic cell nuclear transfer (SCNT) technology, a method used in cloning mammals like Dolly the sheep and cynomolgus monkeys, faced challenges in cloning most mammalian species due to high foetal and neonatal mortality rates. 

Earlier attempts to clone a rhesus monkey using this technology resulted in the cloned animal's demise shortly after birth.

But a breakthrough came when Qiang Sun and colleagues undertook a detailed analysis of the genetic functioning in embryos. 

They compared embryos derived from in vitro fertilisation (IVF) and those created through SCNT. 

This comparison revealed significant abnormalities in how the genetic information was accessed and read by the developing cloned embryo and its placenta. Additionally, there were notable differences in the size and shape of the placentas in cloned monkeys growing in surrogate mothers.

To counter these challenges, the researchers innovated a method to provide the developing cloned embryo with a healthy placenta. 

This technique proved to be key, enabling the birth and survival of a healthy male rhesus monkey for more than two years.

The study offers insights into the reprogramming mechanism of monkey SCNT, unearthing challenges like widespread decrease in DNA methylation and loss of imprinting in maternally imprinted genes within SCNT monkey blastocysts. 

These findings were accompanied by abnormalities in SCNT placentas, such as hyperplasia and calcification, identified through histological examination.

Although this success story involves only one healthy rhesus monkey clone so far, the findings open promising avenues for future primate cloning strategies. 

This scientific feat not only deepens the understanding of reproductive cloning mechanisms but also paves the way for potential improvements in cloning efficiency for various species, including primates. 

The research holds significant implications for the broader field of reproductive technology and genetic research, offering a beacon of hope for addressing complex reproductive challenges in the future.

More details are accessible here.