Effect Of Myostatin Genetically Engineered Meishan Pork On Growth And Development Of Rats

As the lastest biological technology,gene editing techniques has been improving,and had been used in medicine and livestock production research with its target specificity and broad applicability.Our laboratory recently produced genetically engineered(GE)Meishan pigs containing a loss-of-function myostatin(MSTN)mutant introduced using ZFN technology.These GE pigs develop and grow as normal as wild type pigs but produce pork with greater lean yield and lower fat mass.Although gene editing techniques can be more precise positioning to the target gene,but if there are some potential hazards,we have not yet known.To assess any potential subchronic toxicity risks of this GE pork,a 90-day feeding study was conducted in male and female Sprague– Dawley rats.Rats were randomly divided into five group(10 males and 10 females every group),and fed for 90 days with basic diet(baseline),basic diets containing 0.9%(low dose)and 15%(high dose)pork produced by wild type Meishan pigs(negative controls)and genetically engineered Meishan pigs(treatments),respectively.Animal behaviors and clinical signs weremonitored twice daily,and body weight and food consumption were measured andrecorded weekly.At days 45 and 90,blood tests(lipid panel,electrolytes,parametersrelated to liver and kidney functions,and complete blood counts)were performed.Additionally,gross pathology and histopathological analyses were performed for major organs ineach group.Data analysis shows that there were no significant differences in growth rate,food consumption,and blood test parameters between rat groups fed with GE pork andwild type pork.Although differences in some liver function parameters(such as aspartateaminotransferase,total proteins,albumin,and alkaline phosphatase)and white blood cellproportion(such as lymphocyte percentage and monocyte percentage)were observedbetween rats fed with high dose GE pork and basic diet,all test results in rats fed with GEpork are in the normal range.Additionally,there are no apparent lesions noted in all organsisolated from rats in all five feeding groups on days 45 and 90.Overall,our results clearlyindicate that food consumption of GE pork produced by ZFN-edited myostatin loss-of-function mutant pigs did not have any long-term adverse effects on the health status in rats.