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We successfully produced second-generation cloned cats by somatic cell nuclear transfer (SCNT) using skin cells from a cloned cat. Skin cells from an odd-eyed, all-white male cat (G0 donor cat) were used to generate a cloned cat (G1 cloned cat). At 6 months of age, skin cells from the G1 cloned cat were used for SCNT to produce second-generation cloned cats. We compared the in vitro and in vivo development of SCNT embryos that were derived from the G0 donor and G1 cloned donor cat's skin fibroblasts. The nuclei from the G0 donor and G1 cloned donor cat's skin fibroblasts fused with enucleated oocytes with equal rates of fusion (60.7% vs. 58.8%, respectively) and cleavage (66.3% vs. 63.4%). The 2–4-cell SCNT embryos were then transferred into recipients. One of the five recipients of G0 donor derived NT embryos (20%) delivered one live male cloned kitten, whereas 4 of 15 recipients of the G1 cloned donor cat derived NT embryos (26%) delivered a total of seven male second-generation cloned kittens (four live kittens from one surrogate, plus two stillborn kittens, and one live kitten that died 2 d after birth from three other surrogate mothers). The four second-generation cloned kittens from the same surrogate all had a white coat color; three of the four second-generation cloned kittens had two blue eyes, and one of the second-generation cloned kittens had an odd-eye color. Despite low cloning efficiency, cloned cats can be used as donor cats to produce second-generation cloned cats.

In the present study, we compared in vitro and in vivo development of nuclear transfer (NT) embryos derived from serum-starved or non-serum-starved odd-eyed cat skin fibroblast cells. Flow cytometry analyses revealed that a higher percentage of cells were in the G0/G1 phase after serum starvation (89.3%) as compared with non-serum-starved cells (73.8%, P0.05). Frequency of cleavage and development to the blastocyst stage was not different between the serum-starved or non-serum-starved treatment group, 67.9 and 12.5% versus 73.0 and 10.2%, respectively (P0.05). After transfer of two to four-cell NT embryos derived from starved and non-starved fibroblasts, three of nine (33%) and one of nine (11%) recipients delivered three live male (plus, one dead) and two live male kittens, respectively. Of the five live-cloned kittens, one died from diarrhea at 3 weeks of age and the other four kittens are growing at a normal rate. The cloned kittens are blue-eyed and have functional auditory systems, including clones of the odd-eyed deaf Turkish Angora cat. Subsequent DNA analysis of nine-cat specific microsatellite loci confirmed that all of the cloned kittens were identical to the odd-eyed donor male, but a point mutation occurred in the dead fetus at the FCA 290 marker.

The insulin-like growth factors (IGFs), their receptors, and their binding proteins play key roles in regulating cell proliferation and apoptosis. Insulin-like growth factor binding protein-3 (IGFBP3, OMIM #146732) is one of the proteins that bind to the IGFs. IGFBP3 is a modulator of IGF bioactivity, and direct growth inhibitor in the extravascular tissue compartment. We identified twenty-two novel single nucleotide polymorphisms (SNPs) in IGFBP3 gene in Korean cattle (Hanwoo, Bos taurus coreanae) by direct sequencing of full gene including -1,500 bp promoter region. Among the identified SNPs, five common SNPs were screened in 650 Korean cattle; one SNP in promoter (IGFBP3 G-854C), one in 5'UTR region (IGFBP3 G-100A), two in intron 1 (IGFBP3 G+421T, IGFBP3 T+1636A), and one in intron 2 (IGFBP3 C+3863A). The frequencies of each SNP were 0.357 (IGFBP3 G−854C), 0.472 (IGFBP3 G-100A), 0.418 (IGFBP3 G+421T), 0.363 (IGFBP3 T+1636A) and 0.226 (IGFBP3 C+3863A), respectively. Haplotypes and their frequencies were estimated by EM algorithm. Six haplotypes were constructed with five SNPs and linkage disequilibrium coefficients (|D'|) between SNP pairs were also calculated. The information on SNPs and haplotypes in IGFBP3 gene could be useful for genetic studies of this gene. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 1 : 3-7)

Erratum to ‘‘In vitro production and initiation of pregnancies in inter-genus nuclear transfer embryos derived from leopard cat (Prionailurus bengalensis) nuclei fused with domestic cat (Felis silverstris catus) enucleated oocytes’’ [Theriogenology 66 (2006) 275–282] Xi-Jun Yin , Youngho Lee , Hyosang Lee , Namhyong Kim , Lyoungho Kim , Hyoungdoo Shin , Ilkeun Kong a,* a Department of Animal Science & Technology, Sunchon National University, 315 Megok-dong, Sunchon 540-742, JeonNam Province, South Korea b Department of Animal Science, Chungbuk National University, Cheongju 361-763, Chungbuk, South Korea c Department of Genetic Epidemiology, SNP Genetics Inc., Geumcheon-Gu 153-801, Seoul, South Korea