title: Insertion of a knockout-first cassette in Ampd1 gene leads to neonatal death by disruption of neighboring genes expression.
abstract: AMPD1 is an adenosine monophosphate deaminase that catalyzes the deamination of AMP to IMP. To understand the physiological function of AMPD1, we obtained a strain of Ampd1 mutant mice from KOMP repository, which was generated by a knockout-first strategy. An elevated AMP level and almost complete lack of IMP was detected in the skeletal muscle of E18.5 Ampd1tm1a/tm1amice. However, Ampd1tm1a/tm1amice died in 2 days postnatally, which was contradicting to previous reports. After removal of the knockout-first cassette and critical exon, mice homozygous for the Ampd1tm1c/tm1cand Ampd1tm1d/tm1dalleles survived to adulthood. RNA-seq analysis indicated that the expression of two neighboring genes, Man1a2 and Nras, were disrupted in the Ampd1tm1a/tm1amice, but normal in the Ampd1tm1c/tm1cand Ampd1tm1d/tm1dmice. The neonatal lethality phenotype in the Ampd1tm1a/tm1amice was consistent with the Man1a2-deficient mice. Our results indicated the knockout-first cassette may cause off-target effect by influence the expression of neighboring genes. This study, together with other reports, strongly suggests that removal of targeting cassette by site-specific recombinases is very important for the accurate phenotypic interpretation on mice generated by target mutations.
authors: Key laboratory of Hunan Province in Neurodegenerative Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China.|The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Yongcheng
authors: Y
authors: Pan
authors: Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.|The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Lusi
authors: L
authors: Zhang
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Qiong
authors: Q
authors: Liu
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Ying
authors: Y
authors: Li
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Hui
authors: H
authors: Guo
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Yu
authors: Y
authors: Peng
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Hexiang
authors: H
authors: Peng
authors: Key laboratory of Hunan Province in Neurodegenerative Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China.|The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.|Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors: Beisha
authors: B
authors: Tang
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.
authors: Zhengmao
authors: Z
authors: Hu
authors: Mental Health Institute of the Second Xiangya Hospital, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, Hunan, China.
authors: Jingping
authors: J
authors: Zhao
authors: The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.|College of Life Science and Technology, Xinjiang University, Xinjiang, China.|Collaborative Innovation Center for Genetics and Development, Shanghai, China.
authors: Kun
authors: K
authors: Xia
authors: Key laboratory of Hunan Province in Neurodegenerative Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China.|The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China.|Collaborative Innovation Center for Genetics and Development, Shanghai, China.
authors: Jia-Da
authors: JD
authors: Li
mesh_terms: D000659:AMP Deaminase / Q000235:genetics*; D000249:Adenosine Monophosphate / Q000032:analysis; D000818:Animals; D000831:Animals, Newborn; D005786:Gene Expression Regulation; D055786:Gene Knockout Techniques; D007291:Inosine Monophosphate / Q000032:analysis; D051379:Mice; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000473:pathology; D016254:Mutagenesis, Insertional
chemical_list: D007291:Inosine Monophosphate; D000249:Adenosine Monophosphate; D000659:AMP Deaminase; C577245:AMPD1 protein, mouse