Cloned pig fetuses exhibit fatty acid deficiency from impaired placental transport.

Cloned pig fetuses produced by somatic cell nuclear transfer show a high incidence of erroneous development in the uteri of surrogate mothers. The mechanisms underlying the abnormal intrauterine development of cloned pig fetuses are poorly understood. This study aimed to explore the potential causes of the aberrant development of cloned pig fetuses.

Characterization and comparative analyses of transcriptomes of cloned and fertilized porcine pre-implantation embryos.

Somatic cell nuclear transfer (SCNT) is the only method known to rapidly reprogram differentiated cells into totipotent embryos. Most cloned embryos become arrested before implantation and the details of the underlying molecular mechanism remain largely unknown. Dynamic regulation of the transcriptome is a key molecular mechanism driving early embryonic development.

DZNep and UNC0642 enhance in vitro developmental competence of cloned pig embryos.

Somatic cell nuclear transfer in mammalian cloning suffers from a faulty epigenetic reprogramming, which is believed to cause developmental failures in cloned embryos. Regulating the epigenetic-modifying enzymes can rescue the chromatin of cloned embryos from aberrant epigenetic status, thereby potentially promoting cloning efficiency. In this study, we investigated the effect of two histone methyltransferase inhibitors, namely, DZNep and UNC0642, on the in vitro developmental competence of cloned pig embryos.

Identification of amniotic fluid metabolomic and placental transcriptomic changes associated with abnormal development of cloned pig fetuses.

Piglets cloned by somatic cell nuclear transfer (SCNT) show a high incidence of malformations and a high death rate during the perinatal period. To investigate the underlying mechanisms for abnormal development of cloned pig fetuses, we compared body weight, amniotic fluid (AF) metabolome, and placental transcriptome between SCNT- and artificial insemination (AI)-derived pig fetuses. Results showed that the body weight of SCNT pig fetuses was significantly lower than that of AI pig fetuses.

Maternal dietary supplementation of arginine increases the ratio of total cloned piglets born to total transferred cloned embryos by improving the pregnancy rate of recipient sows.

The extremely low full-term developmental efficiency of cloned pig embryos limits the practical application of pig cloning techniques. Maternal dietary supplementation of the nutritionally important amino acid, arginine, can enhance prenatal developmental rate of in vivo fertilization-derived pig embryos. It was hypothesized that maternal dietary addition of arginine can also improve the developmental capacity of cloned pig embryos.

Birth weight, umbilical and placental traits in relation to neonatal loss in cloned pigs.

Cloned piglets generated through somatic cell nuclear transfer (SCNT) have a high rate of neonatal death. Postnatal loss is associated with low birth weight, umbilical status and placental parameters in fertilisation-derived piglets. To investigate whether or not this relationship also exists in cloned piglets, birth weight, umbilical status, placental parameters, placental morphology and gene expression pattern were compared among four piglet groups, namely, SCNT-derived male piglets that died within 4 days (SCNT-DW4), SCNT-derived male piglets that survived over 4 days (SCNT-SO4), artificial insemination (AI)-generated male piglets that died within 4 days (AI-DW4) and AI-generated male piglets that survived over 4 days (AI-SO4).