Production of cloned sei whale (Balaenoptera borealis) embryos by interspecies somatic cell nuclear transfer using enucleated pig oocytes

In this study, we examined the feasibility of using subzonal cell injection with electrofusion for interspecies somatic cell nuclear transfer (iSCNT) to produce sei whale embryos and to improve their developmental capacity by investigating the effect of osmolarity and macromolecules in the culture medium on the in vitro developmental capacity. Hybrid embryos produced by the electrofusion of fetal whale fibroblasts with enucleated porcine oocytes were cultured in modified porcine zygote medium-3 to examine the effects of osmolarity and fetal serum on their in vitro developmental capacity. More than 66% of the whale somatic cells successfully fused with the porcine oocytes following electrofusion. A portion (60~81%) of the iSCNT whale embryos developed to the two- to four-cell stages, but no embryos were able to reach the blastocyst stage. This developmental arrest was not overcome by increasing the osmolarity of the medium to 360 mOsm or by the addition of fetal bovine or fetal whale serum. Our results demonstrate that sei whale-porcine hybrid embryos may be produced by SCNT using subzonal injection and electrofusion. The pig oocytes partly supported the remodeling and reprogramming of the sei whale somatic cell nuclei, but they were unable to support the development of iSCNT whale embryos to the blastocyst stage.

Relationship between Yearly Changes in Serum Calcium Level and Calcium Intake / 日本農村医学会雑誌

Yearly changes in serum electrolytes, especially calcium (Ca), and Ca intake which may influence such changes were studied for 2 years from 1979 to 1980 in the same inhabitants of a rural area with a tendency to low Ca intake, and the following results were obtained.<BR>1) Among different components of electrolytes, yearly changes in Ca were greater than in magnesium and inorganic phosphorus.<BR>2) Yearly changes in serum Ca level from 9 mg/dl or lower level to higher level or vice versa were more frequent in men than in women and the number of women with not more than 9 mg/dl showed a tendency to decrease.<BR>3) Yearly changes in serum Ca were closely correlated with Ca intake. It was supposed that serum Ca level in those who took about 400 mg/day of Ca was fluctuating above or below 9 mg/dl level in proportion to amount of intake.