@article{didion_hauser_eisen_1991, title={Use of in vitro fertilization and embryo transfer to circumvent infertility caused by an inherited imperforate vagina in mice}, volume={8}, DOI={10.1007/BF01131709}, abstractNote={An autosomal recessive mutation (ipv) causing infertility in homozygous females (ipv/ipv) because of imperforate vaginae was discovered in a line of mice selected for low lean tissue mass as a proportion of body weight. The aim of this study was to determine if the mutation could be propagated in offspring following embryo transfer of oocytes collected from mutant females and fertilized in vitro with sperm from males known to carry the gene (ipv/?). Caudal epididymal sperm were incubated with cumulus-enclosed oocytes for 8-10 hr in tissue culture medium 199 + 5% fetal calf serum + 0.4% bovine serum albumin. Oocytes possessing at least two pronuclei were transferred to recipient CD-1 females which had been mated 24 hr earlier to vasectomized males. A total of 683 oocytes was collected from 27 superovulated mutant females. A large proportion of the oocytes was abnormal as evidenced by cytoplasmic fragmentation (259/683, 38%). Seventy-eight percent (331/424) of the normal oocytes were fertilized and 181 of these were transferred to 10 recipients. Six of 10 recipients delivered 38 offspring (24 females, 14 males). Fifty-eight percent (14/24) of the female offspring displayed an imperforate vagina. The results demonstrate that in vitro fertilization and embryo transfer can be used for propagating a mutant gene that causes infertility in females.}, number={3}, journal={Journal of In Vitro Fertilization and Embryo Transfer}, author={Didion, B. A. and Hauser, M. E. and Eisen, E. J.}, year={1991}, pages={167} }
 @article{didion_pomp_martin_homanics_markert_1990, title={Observations on the cooling and cryopreservation of pig oocytes at the germinal vesicle stage}, volume={68}, DOI={10.2527/1990.6892803x}, abstractNote={This study examined the viability of pig oocytes at the germinal vesicle stage following cooling or cryopreservation. Cumulus-intact oocytes (n = 641) were collected from slaughterhouse pig ovaries and used in two experiments. In Exp. I the viability of 1) control, 2) cryoprotectant control (CC, 1.5 M glycerol/.5 M sucrose), 3) cooled (0 degrees C) and 4) cryopreserved (-196 degrees C) oocytes was assessed after no incubation or a 24-h incubation. Survivability was judged by morphological appearance, trypan blue exclusion and fluorescein diacetate staining. Survival rate of control oocytes (90%; based primarily on morphological appearance of the cumulus) incubated 0 h was greater (P less than .05) than that of all other groups, whereas survival rate of -196 degrees C oocytes (57%) was less (P less than .05) than that of all other groups. However, vital staining of 0 degrees C and -196 degrees C oocytes showed 0% survival rate as evidenced by trypan blue uptake and lack of fluorescence. The cumulus cells surrounding oocytes that were stored at 0 degrees C or -196 degrees C survived freezing as evidenced by trypan blue exclusion and intense fluorescence. Similar differences among treatment groups were found for oocytes incubated 24 h. Exp. 2 examined the temperature at which oocytes became sensitive to cooling. Oocyte death occurred when oocytes were cooled to 15 degrees C or lower. These results demonstrate that pig oocytes at the germinal vesicle stage did not survive cooling to 15 degrees C or below. When assessing the viability of cryopreserved cumulus enclosed oocytes it is important to use vital stains in conjunction with morphological appearance.}, number={9}, journal={Journal of Animal Science}, author={Didion, B. A. and Pomp, D. and Martin, M. J. and Homanics, G. E. and Markert, C. L.}, year={1990}, pages={2803} }
 @article{didion_martin_markert_1990, title={PARTHENOGENETIC ACTIVATION OF MOUSE AND PIG OOCYTES MATURED INVITRO}, volume={33}, ISSN={["0093-691X"]}, DOI={10.1016/0093-691X(90)90035-R}, abstractNote={The objective of this study was to determine if mouse and pig oocytes matured in vitro undergo parthenogenetic activation following exposure to various activation stimuli. Cumulus-intact, germinal vesicle-stage mouse oocytes (n = 151) were collected from pregnant mare serum gonadotropin primed mice and incubated overnight in Brinster's medium. This culture system allowed an 85% maturation to Metaphase II. Pig oocytes (n = 242) were gathered from ovaries collected at an abbattoir and incubated in vitro for 48 h to allow maturation to occur (51% maturation to Metaphase II). Following maturation, mouse and pig oocytes were exposed to various activation stimuli. Mouse oocytes were treated with medium containing ethanol (7%), electricity (85 V, 30 us, one time), or medium; then they were incubated for 6 to 8 h to allow for activation. Pig oocytes were treated with medium containing ethanol (10%), electricity (85 V, 30 us once or twice), ethanol followed by electricity, or medium then incubated for 18 h to allow for activation. A portion of the mouse and pig oocytes were fixed immediately after maturation to serve as a control. The nuclear status of the oocytes was examined after staining with Hoechst 33342. Chi-square procedures were used to analyze the data. The proportion of mouse oocytes which underwent activation was higher (P<0.01) for ethanol and electricity than for the medium (22, 30 and 0%, respectively). The proportion of pig oocytes which underwent activation was higher (P<0.05) for two current exposures (14%) and ethanol followed by current (16%) than for the medium (0%). There was no evidence of spontaneous activation occurring in mouse or pig oocytes during the maturation period. Most of the activated mouse oocytes contained a single haploid pronucleus, as evidenced by two polar bodies and one pronucleus. In contrast, most of the activated pig oocytes were diploid parthenotes, as evidenced by one polar body and one pronucleus. The results show that a portion of in vitro matured mouse and pig oocytes undergo parthenogenetic activation following exposure to activation stimuli.}, number={6}, journal={THERIOGENOLOGY}, author={DIDION, BA and MARTIN, MJ and MARKERT, CL}, year={1990}, month={Jun}, pages={1165–1175} }