Morphological abnormalities, impaired fetal development and decrease in myostatin expression following somatic cell nuclear transfer in dogs

• Published in: Molecular reproduction and development 2011-05, Vol.78 (5), p.337-346
• Main Authors: Hong, Il-Hwa, Jeong, Yeon-Woo, Shin, Taeyoung, Hyun, Sang-Hwan, Park, Jin-Kyu, Ki, Mi-Ran, Han, Seon-Young, Park, Se-Il, Lee, Ji-Hyun, Lee, Eun-Mi, Kim, Ah-Young, You, Sang-Young, Hwang, Woo-Suk, Jeong, Kyu-Shik
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cloning, Organism - methods; dog; Dogs; Embryo, Mammalian - abnormalities; Embryo, Mammalian - cytology; Embryo, Mammalian - pathology; Embryology: invertebrates and vertebrates. Teratology; Fundamental and applied biological sciences. Psychology; large offspring syndrome; Macroglossia; Molecular embryology; Muscle Development; Muscles - abnormalities; myostatin; Myostatin - biosynthesis; Myostatin - deficiency; Myostatin - genetics; Nuclear Transfer Techniques; Polymerase Chain Reaction; RNA, Messenger - analysis; somatic cell nuclear transfer
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.21309

Several mammals, including dogs, have been successfully cloned using somatic cell nuclear transfer (SCNT), but the efficiency of generating normal, live offspring is relatively low. Although the high failure rate has been attributed to incomplete reprogramming of the somatic nuclei during the cloning process, the exact cause is not fully known. To elucidate the cause of death in cloned offspring, 12 deceased offspring cloned by SCNT were necropsied. The clones were either stillborn just prior to delivery or died with dyspnea shortly after birth. On gross examination, defects in the anterior abdominal wall and increased heart and liver sizes were found. Notably, a significant increase in muscle mass and macroglossia lesions were observed in deceased SCNT‐cloned dogs. Interestingly, the expression of myostatin, a negative regulator of muscle growth during embryogenesis, was down‐regulated at the mRNA level in tongues and skeletal muscles of SCNT‐cloned dogs compared with a normal dog. Results of the present study suggest that decreased expression of myostatin in SCNT‐cloned dogs may be involved in morphological abnormalities such as increased muscle mass and macroglossia, which may contribute to impaired fetal development and poor survival rates. Mol. Reprod. Dev. 78:337–346, 2011. © 2011 Wiley‐Liss, Inc.