Swine Generated by Somatic Cell Nuclear Transfer Have Increased Incidence of Intrauterine Growth Restriction (IUGR)

Abstract

While somatic cell nuclear transfer (SCNT) has been successful in several species, many pregnancies are lost and anomalies are found in fetal and perinatal stages. In this study SCNT and artificial inseminations (AI) populations were compared for litter size, average birth weight, piglets alive at birth, stillborn, mummies, dead at the first week, intrauterine growth restriction (IUGR) and large for gestational age (LGA). Twenty-three SCNT litters (143 individuals) were compared to 112 AI litters (1300 individuals). Litter size average was 11.5 for AI and 6.2 for SCNT. Litter weight and average birth weight adjusted by litter size were significantly (p < 0.05) higher in AI than in SCNT litters. The SCNT population had a significant (p < 0.01) increase in the number of IUGRs per litter with LSmeans 7.2 +/- 1.4 versus 19.4 +/- 3.5 and means 8.0 +/- 10.8 versus 15.5 +/- 24.5 for AI and SCNT, respectively. Additionally, there was a trend for higher postnatal mortality and stillbirths in the SCNT population. These findings demonstrate that there are some differences between SCNT-derived and AI litters. SCNT-derived pigs are excellent models to study epigenetic factors and genes involved in IUGRs, and to develop effective means to improve fetal growth in humans and animals.

39 Factors Influencing the Efficiency of Generating Genetically Engineered Pigs by Nuclear Transfer: Multi-Factorial Analysis of a Large Data Set

“…In our data set, more than half of cloned pigs were stillborn (23.6%) or died soon after birth (31.4%). Associated pathological changes, such as underweight (average weight of the cloned piglets born under 1000 g: 686.4 +/− 181.0 g; range: 375 -973 g), which is one of the major causes of early neonatal death, or cleft palate, contracted tendons, or enlarged tongues, have also been observed by other groups [43][44][45][46][47]. We have the impression that the percentage of underweight piglets (among normal weight littermates) is higher in cloned litters.…”

Identification and cloning of the porcine ROSA26 promoter and its role in transgenesis

“…Couples were exposed to two DC pulses of 140 V for 50 ms in 280 mM Mannitol, 0.001 mM CaCl 2 , and 0.05 mM MgCl 2 . One hour later, reconstructed oocytes were activated by two DC pulses of 120 V for 60 ms in 280 mM Mannitol, 0.1 mM CaCl 2 , and 0.05 mM MgCl 2 [14]. After activation, oocytes were placed back in NCSU-23 medium with 0.4% bovine serum albumin BSA and cultured at 38.5ºC, 5% CO 2 in a humidified atmosphere, for less than 1 h before being transferred into the recipient.…”

Successful Cloning of the Yucatan Minipig Using Commercial/Occidental Breeds as Oocyte Donors and Embryo Recipients

“…At 70-90% confluence, cells were removed from the plate by trypsin, centrifuged, and suspended in NCSU-23 (Petters and Wells, 1993) supplemented with 0.8 mM CaCl 2 and 10% FBS. In addition, fetal fibroblasts collected as described in Estrada et al, (2007) were used as nuclear donors to generate control day 30 pregnancies.…”

“…HILE CLONING SWINE by SCNT is progressing at a rapid rate with increases in efficiency continually being reported (Estrada et al, 2007;Lai et al, 2006;Li et al, 2006;Walker et al, 2002) the incorporation of this technology into mainstream biomedical investigation will require its application to breeds of swine that are more amenable to study under a biomedical environment. The conventional occidental commercial breeds such as Yorkshire, Hampshire, Large White, Duroc, Landrace, etc., and their crossbreds have the advantage of high prolificacy, ease of management, low cost, and extensive availability.…”