Abstract. The cryopreservation of ovarian tissues is a technology with significant potential for the preservation of the genetic resource materials of working dogs, including guide dogs for the blind. However, no attempt has been reported on cryopreservation of the canine ovary. Thus, we evaluated a vitrification method for cryopreservation of canine ovaries and determined the potential functionality of vitrified-warmed canine ovaries by means of transplantation into non-obese diabeticsevere combined immunodeficiency (NOD-SCID) mice. All ovarian tissues cryopreserved by vitrification were morphologically normal in terms of histology. Cryopreserved ovaries were transplanted into the ovarian bursa of the NOD-SCID mice, and the xenografts were recovered from 23 of 23 mice (100%) 4 weeks after the operation. The transplanted canine tissue was tightly adhered to the mouse ovary. Although antral follicle formation did not occur after grafting, proliferating cell nuclear antigen immunoreactivity was detectable in many of the granulosa cells in the primary follicles of the grafts. These results indicate that cryopreservation of the canine ovary by vitrification appears to have the potential to restore endocrine function and ovulation potential.

Purpose The main drawback of ovarian cryopreservation followed by transplantation is that a large proportion of follicles are lost after transplantation. Thus, effects of erythropoietin (EPO) and desialylated EPO administration on the frozen-thawed canine ovarian xenotransplantation were examined. Methods The protective and survival-promoting effects of EPO and desialylated EPO on the follicles of frozen-thawed canine ovaries after transplantation were examined using NOD-SCID mice. Frozen-thawed dog ovarian tissue with 400 U/kg of EPO or asialo EPO was placed into the ovarian bursa.Results At 4 weeks after the transplantation, the ovaries were removed and subjected to histological examination. The survival rate of early primary follicles was 15.2% in the EPO group and 157.6% in the asialo EPO group, in contrast to 10.1% in the untreated group. Conclusions These results demonstrate that administration of asialo EPO could be effectively used to enhance the survival of the follicles of transplanted cryopreserved ovaries.

The assisted reproductive techniques (ARTs) such as in vitro fertilization, embryo transfer, and cryopreservation of gametes have contributed considerably to the development of biomedical sciences in addition to improving infertility treatments in humans as well as the breeding of domestic animals. However, ARTs used in canine species have strictly limited utility when compared with other mammalian species, including humans. Although successful somatic cell cloning has been reported, artificial insemination by frozen semen to date is only available for the improved breeding and reproduction for companion and working dogs as well as guide dogs for the blind. We describe here the successful cryopreservation of embryos and subsequent embryo transfer in dogs. Canine embryos were collected from excised reproductive organs after artificial insemination and subsequently cryopreserved by a vitrification method. When the 4-cell to morula stage of cryopreserved embryos were nonsurgically transferred into the uteri of nine recipient bitches using a cystoscope, five recipients became pregnant and four of them delivered a total of seven pups. The cryopreservation of embryos in canine species will facilitate the transportation and storage of genetic materials and will aid in the elimination of vertically transmitted diseases in dogs. In addition, this technique will contribute to the improved breeding of companion and working dogs such as guide dogs, drug-detecting dogs, and quarantine dogs.

BackgroundVarious factors impact the severity of malaria, including the nutritional status of the host. Vitamin E, an intra and extracellular anti-oxidant, is one such nutrient whose absence was shown previously to negatively affect Plasmodium development. However, mechanisms of this Plasmodium inhibition, in addition to means by which to exploit this finding as a therapeutic strategy, remain unclear.Methodsα-TTP knockout mice were infected with Plasmodium berghei NK65 or Plasmodium yoelii XL-17, parasitaemia, survival rate were monitored. In one part of the experiments mice were fed with a supplemented diet of vitamin E and then infected. In addition, parasite DNA damage was monitored by means of comet assay and 8-OHdG test. Moreover, infected mice were treated with chloroquine and parasitaemia and survival rate were monitored.ResultsInhibition of α-tocopherol transfer protein (α-TTP), a determinant of vitamin E concentration in circulation, confers resistance to malarial infection as a result of oxidative damage to the parasites. Furthermore, in combination with the anti-malarial drug chloroquine results were even more dramatic.ConclusionConsidering that these knockout mice lack observable negative impacts typical of vitamin E deficiency, these results suggest that inhibition of α-TTP activity in the liver may be a useful strategy in the prevention and treatment of malaria infection. Moreover, a combined strategy of α-TTP inhibition and chloroquine treatment might be effective against drug resistant parasites.

Abstract. It is well-known that there are considerable strain differences in the relative copulation rates between male and superovulated female mice. In particular, the C57BL/6J strain of mice has a lower rate of successful copulation. We examined the effect of exposure to an electric field on sexual behavior in C57BL/6J male mice. When C57BL/6J males were exposed to a 50 Hz, 45 kV/m electric field for 30 min per day for 11 days and placed in a cage with a superovulated female of the same strain, the successful copulation rates of males was significantly improved compared with unexposed males (P<0.05). These results suggest that the exposure of C57BL/6J male mice to an electric field improves their sub-fertility activity in mating with superovulated females.