Acta Veterinaria et Zootechnica Sinica ›› 2020, Vol. 51 ›› Issue (7): 1563-1572.doi: 10.11843/j.issn.0366-6964.2020.07.009

• ANIMAL GENETICS AND BREEDING • Previous Articles     Next Articles

Study of Biosafety Evaluation on Melatonin Synthase AANAT/ASMT Overexpressed Sheep

YANG Ailing1,2, LI Guangdong2, WU Hao2, JI Pengyun2, ZHANG Lu2, ZHANG Jinlong3, ZHANG Xiaosheng3, WUSIMAN Abulizi1, LIAN Zhengxing2, LIU Guoshi1,2*   

  1. 1. College of Animal Science, Xinjiang Agricultural University, Urumqi 830052, China;
    2. College of Animal Science and Technology, China Agricultural University, Beijing 100193, China;
    3. Institute of Animal Husbandry and Veterinary, Tianjin Academy of Agricultural Sciences, Tianjin 300192, China
  • Received:2019-12-16 Online:2020-07-25 Published:2020-07-22

Abstract: The purpose of this experiment was to study the biological safety of sheep with melatonin synthase genes AANAT and ASMT (HIOMT) over-expressed in mammary gland. Based on the sheep models with AANAT and ASMT (HIOMT) over-expressed in mammary gland established in the previous study, we tracked the growth traits of positive transgenic sheep, analyzed the physiological and biochemical indexes of the blood and urine samples, and detected the intestinal microorganisms, melatonin levels in milk and milk composition. The results showed that:1) The body weight, body length, height and bust of positive transgenic sheep at 0, 6 and 12 months of age were not significantly different from those of ordinary sheep (P>0.05); 2) The total protein levels, albumin, globulin and cholesterol levels in blood of positive transgenic sheep as well as the number of various types of cells were not significantly different from those of ordinary sheep(P>0.05). Meantime, the levels of nitrite, protein, glucose and some other factors in urine were normal and not significantly different from those of ordinary sheep (P>0.05); 3) The sequencing results of microbiota showed that there was no significant difference in the composition of intestinal microbial communities and dominant bacteria between positive transgenic sheep and ordinary sheep(P>0.05); 4) The expression level of melatonin in blood of positive transgenic sheep was not significantly different from that of ordinary sheep (P>0.05), the level of melatonin at night was significantly higher than that at daytime (P<0.05); while the level of melatonin in milk of positive transgenic sheep was extremely significantly higher than that of ordinary sheep (P<0.01), the lactose content was significantly higher than that of ordinary sheep (P<0.05), in addition, the number of somatic cells of positive transgenic sheep was extremely significantly lower than that of ordinary sheep (P<0.01). In summary, the growth performance, many physiological and biochemical indexes and intestinal microbiota of positive transgenic sheep with AANAT and ASMT (HIOMT) over-expressed in the mammary gland were not significantly different compared with the ordinary sheep. Furthermore, the content of melatonin and lactose in milk of positive transgenic sheep were higher and the number of somatic cells was lower, which might be that melatonin in the mammary gland played an anti-inflammatory effect, reducing the number of somatic cells in the milk.

Key words: sheep, transgene, AANAT, ASMT, safety evaluation

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