title: Expression of X-linked genes in deceased neonates and surviving cloned female piglets.
abstract: Animal cloning through somatic cell nuclear transfer (NT) is very inefficient, probably due to insufficient reprogramming of the donor nuclei, which in turn would cause the dysregulation of gene expression. X-Chromosome inactivation (XCI) is a multi-step epigenetic process utilized by mammals to achieve dosage compensation in females. Our aim was to determine if any dysregulation of X-linked genes, which would be indicative of unfaithful reprogramming of donor nuclei, was present in cloned pigs. Real time reverse transcription polymerase chain reaction (RT-PCR) was performed to quantify the transcript levels of five X-linked genes, X inactivation-specific transcript (XIST), TSIX (the reverse spelling of XIST), hypoxanthine guanine phosphoribosyltransferase 1 (HPRT1), glucose-6-phosphate dehydrogenase (G6PD), V-raf murine sarcoma 3,611 viral oncogene homolog 1 (ARAF1), and one autosomal gene, alpha-1 type IV collagen (COL4A1) in major organs of neonatal deceased and surviving female cloned pigs as well as their age-matched control pigs from conventional breeding. Aberrant expression level of these genes was prevalent in the neonatal deceased clones, while it was only moderate in cloned pigs that survived after birth. These results suggest a correlation between the viability of the clones and the normality of their gene expression and provide a possible explanation for the death of a large portion of cloned animals around birth.
authors.affiliation: Department of Animal Science and Center for Regenerative Biology, University of Connecticut, Storrs, Connecticut, USA.
authors.forename: Le
authors.initials: L
authors.lastname: Jiang
authors.forename: Liangxue
authors.initials: L
authors.lastname: Lai
authors.forename: Melissa
authors.initials: M
authors.lastname: Samuel
authors.forename: Randall S
authors.initials: RS
authors.lastname: Prather
authors.forename: Xiangzhong
authors.initials: X
authors.lastname: Yang
authors.forename: X Cindy
authors.initials: XC
authors.lastname: Tian
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D003001:Cloning, Molecular; D024141:Collagen Type IV / Q000235:genetics; D017931:DNA Primers; D005260:Female; D005786:Gene Expression Regulation; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D009928:Organ Specificity; D012313:RNA / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics; D014960:X Chromosome
chemical_list: D024141:Collagen Type IV; D017931:DNA Primers; D014157:Transcription Factors; D012313:RNA; D007041:Hypoxanthine Phosphoribosyltransferase