128 Comparison of multiple maturation times on juvenile invitro embryo transfer (JIVET)-derived oocytes and embryo development in the goat

Juvenile invitro embryo transfer (JIVET) is an assisted reproductive technology (ART) with the potential to produce numerous offspring from a single young female goat at 4 to 8 weeks of age. It has been reported in small ruminants that there can be a marked variable response to the administration of exogenous hormones for superovulation, the subsequent number of oocytes generated, and subsequent embryo developmental potential. The industry standard (as well as the recommendation of commercial media suppliers) invitro maturation time is 21 to 24h for conventionally derived oocytes. This study investigated multiple maturation times for JIVET-derived oocytes: 16, 22, and 28h. Oocytes were collected from four JIVET animals at 6 to 8 weeks of age. The hormonal superovulation regimen used on the juvenile animals consisted of 4×40-mg FSH injections at ∼12h apart and a 400IU of PMSG injection given with the first FSH injection. Surgical recovery of the oocytes via a midline laparotomy was performed the day following the last FSH injection. All of the oocytes were collected via aspirating follicles that were 4mm and larger. Oocytes with compact cumulus cells subsequently underwent IVM, IVF, and invitro culture (IVC) utilising IVF Bioscience media and methods. A single straw of identical cryopreserved/thawed semen from the same buck was utilised for each of the IVF procedures. The results were (37/88) 42%, (37/85) 44%, and (39/91) 43% cleaved and (23/88) 26%, (24/85) 28%, and (28/91) 31% blastocyst rate based on respective maturation times for JIVET-derived ova. Development rate during the cleavage stage and blastocyst stage was analysed using a repeated-measures logistic regression model utilising generalized estimating equations (GEE), with maturation time as fixed effect and a compound symmetry within subject (juvenile goat) covariance structure. The main effect of maturation time on the odds of development during the cleavage stage (P=0.8727) and blastocyst stage (P=0.3857) was not significant. These results indicate that the time in maturation media does not have as profound an effect on development to blastocysts as a factor in the variability reported by other laboratories. The development rate of embryos from one juvenile goat produced very high blastocyst rates of (5/12) 42%, (11/12) 92%, and (11/15) 73%, respectively. Additional logistic regression analysis showed that the odds of development in this juvenile donor was significantly different compared with the other donors (pooled) during the cleavage stage at 16h (P=0.0083) and 28h (P=0.0021) maturation times. Likewise, the odds of development in this donor was significantly different than that of the other donors (pooled) during the blastocyst stage at 22h (P=0.0002) and 28h (P=0.0003) maturation times. This further indicates the wide variation of oocyte quality from JIVET-derived oocytes and indicates potential for higher development rates at 22 and 28h in this specific goat.

Synthesis and characterization of photocrosslinkable albumin-based hydrogels for biomedical applications

Protein-based biomaterials are widely used to generate three-dimensional (3D) scaffolds for tissue regeneration as well as compact delivery systems for drugs, genes, and peptides. Specifically, albumin-based biomaterials are of particular interest for their ability to facilitate controlled delivery of drugs and other therapeutic agents. These hydrogels possess non-toxic and non-immunogenic properties that are desired in tissue engineering scaffolds. This work employs a rapid ultraviolet (UV) light induced crosslinking to fabricate bovine serum albumin (BSA) hydrogels. Using four different conditions, the BSA hydrogel properties were modulated based on the extent of glycidyl methacrylate modification in each polymer. The highly tunable mechanical behavior of the material was determined through compression tests which yielded a range of material strengths from 4.4 ± 1.5 to 122 ± 7.4 kPa. Pore size measurements also varied from 7.7 ± 1.7 to 23.5 ± 6.6 μm in the photocrosslinked gels. The physical properties of materials such as swelling and degradation were also characterized. In further evaluation, 3D scaffolds were used in cell encapsulation and in vivo implantation studies. The biocompatibility and degradability of the material demonstrated effective integration with the native tissue environment. These modifiable chemical and mechanical properties allow BSA hydrogels to be fine-tuned to a plethora of biomedical applications including regenerative medicine, in vitro cancer study models, and wound healing approaches.

Generation of goats by nuclear transfer: a retrospective analysis of a commercial operation (1998-2010)

At LFB USA, Inc., the ultimate use for transgenic cloned goats is for the production of recombinant human protein therapeutics in their milk. This retrospective analysis of the Somatic Cell Nuclear Transfer (SCNT) program, spanning from 1998 to 2010, examined parameters potentially affecting the outcomes and efficiencies in this commercial operation. Over 37,000 + ova were utilized in the SCNT protocol producing a total of 203 cloned goats. Fifty one (51) clones were produced from non-transfected (transgenic and non-transgenic animal donor) cell lines and 152 clones were produced from transfected cell lines. Comparisons and summaries of (a) transfected versus non-transfected cell lines, (b) relationship of SCNT parameters to offspring produced, (c) skin versus fetal cells, (d) fresh versus cryopreserved cells, (e) parameters from all cell lines used versus those producing SCNT offspring, (f) variation among cell sources, (g) methods of SCNT parturition management and effects on live offspring, and lastly (h) SCNT variation by program are reported. Findings indicate that (a) non-transfected cell lines were more efficient versus transfected cell lines in generating viable cloned offspring on a per reconstructed embryo transferred basis, (b) transfected fetal fibroblasts had improved efficiency versus transfected skin fibroblasts, (c) the percentage of non-transfected cell lines that produced offspring was statistically higher than transfected cell lines, (d) and induction of parturition improved the percentage of viable offspring. In summary, this retrospective analysis on the SCNT process has identified certain parameters for improved efficiency in producing viable cloned goats in a commercial setting.

154 A method of oviductal semen deposition for use in the goat

The objective of this study was to investigate a method of oviducal semen deposition as a strategy for producing offspring from poor-quality cryopreserved goat sperm. Invitro fertilisation (IVF) and AI are common assisted reproductive technologies used in small ruminants, but they have varied results in the goat. The use of poor-quality cryopreserved-thawed sperm (<50% live/dead ratio at post-thaw) can decrease the rate of success. These procedures were performed in the month of November in Central Massachusetts in the United States (42° N). Seven 10-year-old dairy goats (Saanen, Toggenburg, and Alpine breeds) were synchronised and superovulated using a progesterone implant on Day 0, a prostaglandin injection at Day 7, two daily injections of 36mg of FSH ~12h apart on Days 12-15, and progesterone implant removal on Day 14 followed by an injection of 50µg of gonadotrophin-releasing hormone. Sperm deposition was performed on Day 17 (72 h after implant removal). The animals were anaesthetised using a standardised protocol, intubated, and maintained using isoflurane, and sterile prep was performed before a midline laparotomy procedure. Straws from a single ejaculate from a transgenic founder that was cryopreserved using a commercial two-step glycerol-egg yolk-based extender were used. A straw from this collection was post-thawed 30 days after collection and, using a commercial live/dead stain, 67% live sperm was determined. The optimal type of sperm prep and sperm concentration is unknown and may be dependent on sperm quality. Therefore, different gradient preps using Vitrolife SpermGrad at three volumes (1.5 (used on two animals), 1.0, and 0.5mL) as well as two volumes of IVF Bioscience Bovine BO-SemenPrep (4.0mL (used on two animals) and 2.0mL) were used. All five pellets were diluted in 1.0mL of IVF Bioscience Bovine BO-IVF media. Sperm concentrations ranging from 75×106 to 27×106 spermmL−1 were deposited into one oviduct; then, a 10:1 dilution was performed and 7.5×106 to 2.7×10 spermmL−1 were deposited into the contralateral oviduct. The depositions were performed just proximal to the uterotubal junction in a volume of 0.1mL of diluent via a tuberculin syringe attached to a 20-gauge needle. Two days following the procedure, oviducts were flushed postmortem from three of the seven randomly selected goats. All three had fertilised embryos, and nineteen 8-cell embryos were retrieved. Three of these embryos were surgically transferred to the distal uterine horn of a suitable recipient. The recipient became pregnant and produced a single offspring. The remaining four of seven goats were killed 41 days post-surgery. Two of the four goats were pregnant, with one carrying one fetus and the other carrying five fetuses. Further studies are needed to optimise this method, but these initial results indicate that oviducal semen deposition directly into the oviduct proximal to the uterotubal junction may be a suitable alternative for producing offspring from suboptimal cryopreserved-thawed goat sperm.

194 Superovulation response does not affect embryo development of pronuclear microinjected embryos in the goat

Superovulation of donor animals is essential in the production of transgenic founder goats generated through microinjection. There can be a marked variable response to the exogenous hormones used for superovulation. The objective of this study was to examine how the superovulatory response of individual goats affected the ability of the fertilized, microinjected embryos to develop into offspring. The donors were superovulated using a progesterone implant on Day 0, a prostaglandin injection at Day 7, 2 injections ~12h apart of 32 to 36mg of FSH on Day 12 to 15, progesterone implant removal on Day 14, bred by intact bucks several times starting on Day 15 to 16, an injection of 50μg of gonadotropin-releasing hormone, and surgical collection of 1- to 2-cell embryos from retrograde flushing of the oviduct on Day 17 (~24-48 h, 1-2 days after breeding). Surgical collection allows for an accurate ovulation point (OP) count before the oviduct being retrograde flushed and ova collected and counted. Data from donor animals were grouped by superovulatory response based on OP counts of 1-10, 11-20, 21-30, or >30. The number of donors that contributed per group were 130, 280, 175, and 52, respectively. The recovery rate was 76, 72, 68, and 62%, respectively. After collection, ova were viewed under a dissecting microscope and assessed for fertilization by identifying pronuclei, and 1 pronucleus was microinjected. The fertilization rate was 47, 52, 51, and 56%, respectively. The survivability rate after microinjection was 80, 76, 75, and 76%, respectively. Surviving embryos were transferred (3-5) into recipient goats following a 2- to 6-h in vitro culture (as 1- to 2-cell embryos), allowing for a suitable period to assess viability post-injection. Further in vitro development rates were not assessed because of the short timeframe the embryos stayed in culture. The conception rates were 71, 56, 65, and 53%, respectively, and abortion rates were 23, 10, 14, and 9%, respectively. As some recipients received embryos from multiple donors, this data could not be included in the analysis as identifying which offspring were from the corresponding embryo group could not be confirmed. Data were analysed using SAS software (version 9.4, SAS Institute Inc., Cary, NC, USA). The Wald chi square test under linear regression was used to analyse the number of offspring produced per embryo transferred. No significant differences were found between groups (all P-values were>0.05). This analysis indicated that the range of superovulation response does not affect the developmental competence of the pronuclear microinjected embryo or the ability to produce viable offspring. Table 1.Comparison of the donor ovulation counts, number of embryos transferred, offspring produced and overall efficiency

94 Impact of number of embryos transferred on the number of offspring produced in a commercial transgenic founder production operation

The production of transgenic founder dairy goats (cross-bred Saanens, Alpines, Toggenburgs, and Nubians) involves the collection, microinjection, and transfer of numerous embryos into suitable recipient goats to ultimately produce a transgenic founder(s). The objective of this study was to determine the most efficient number of microinjection embryos to transfer to suitable recipients for transgenic founder generation. This is critically important in a commercial production program, as it impacts the goal for the number of embryos collected from donors, number of recipients utilised, and, hence, the overall number of surgical procedures being performed. The entire embryo collection, transfer, and founder-generation process is continuously being evaluated for ways to become more efficient in producing transgenic animals. During LFB USA’s commercial founder-production campaigns over the years (1997-2017), pronuclear microinjection was performed and 3, 4, or 5 embryos were transferred to female goat recipients. The recipients were synchronized using a progesterone implant on Day 0, a prostaglandin injection at Day 7, an injection of 300-500IU of pregnant mare serum gonadotropin on Day 13, progesterone implant removal on Day 14, and surgical transfer of pronuclear microinjected 1- or 2-cell embryos into the oviduct on Day 17. The individual totals and calculation for offspring per embryos transferred was compared for 3, 4, and 5 embryos transferred per recipient and was determined to be (1659/8637) 0.19, (912/4548) 0.20, and (112/675) 0.17, respectively. These embryo efficacy ratios were not significantly different (P>0.05) using the Wald Chi-squared test under logistic regression, and suggests that the number of offspring born is not impacted by number of embryos transferred. Seasonality was also evaluated in this production environment located in North America, with in-season being considered September to December and out-of-season being January to July. Nulliparous recipients during in-season (September to December) embryo transfer operations produced a significant difference, with totals and calculation for (offspring per embryo transferred) of (470/2346) 0.20, (260/1088) 0.24, and (23/190) 0.12 for 3, 4, and 5 embryo transfers, respectively (Table 1). This data indicates that when using nulliparous recipients during the in-season, transferring 4 embryos is optimal for offspring produced. Table 1.Comparison of the individual totals and the calculation of (offspring/embryo) by parity and season

211 INTRODUCING NEW GENETICS INTO A CLOSED BIOSECURE HERD OF DAIRY GOATS

Transgenic dairy goats expressing recombinant molecules in their milk have been validated as a viable method for producing human therapeutic proteins. Although maintaining a closed herd ensures biosecurity within a facility, the ability to introduce new genetics into the herd can be difficult. In this work we determined the ability to use cryopreserved caprine semen, imported from New Zealand into the United States, for IVF as a method to increase the genetic diversity of the GTC Biotherapeutics closed caprine herd. Semen was collected from bucks owned by GTC Biotherapeutics and maintained in New Zealand. The bucks were serologically screened for goat pathogens prior to collection, and were maintained in quarantine during semen collection. Separate single experiments were performed using cryopreserved semen from each of 2 different bucks (NZ1 and NZ2). One or 2 straws of semen (107/0.25 mL straw) from each buck were thawed and then purified using a Percoll gradient. Ovulated oocytes surgically collected from superovulated does were co-incubated with sperm (5 × 105 mL–1) in Brackett-Oliphant medium supplemented with 10% fetal bovine serum, 7.7 mm calcium lactate plus 2.5 μg mL–1 of heparin for 18 h at 38°C. Presumptive zygotes were transferred to equilibrated SOF plus 0.8% BSA and cultured in vitro for 24 h. On Day 2 cleavage was determined and, as an added precaution, embryos selected for transfer were washed per the IETS protocol for the sanitary handling of embryos. Five 2-cell to 8-cell embryos from individual donors were surgically transferred to a single oviduct of each synchronized surrogate recipient. Pregnancies were determined by ultrasonography. Pregnancy rates for recipients at Day 50 of gestation (71 v. 67% pregnant), at term (100 v. 100%), and the proportion of offspring born from total embryos transferred (17 v. 23% offspring) were comparable for buck NZ1 and buck NZ2, respectively (P > 0.05). A total of 13 offspring (6 bucks and 7 does) were produced from 9 different oocyte donors. These results demonstrate that cryopreserved caprine semen, imported from New Zealand into the United States, can be used for IVF to introduce new genetics into a closed biosecure caprine herd. The use of IVF, compared with AI, allows more offspring to be produced per straw of semen. In addition, IVF offers the advantage of accelerated genetic gain by producing multiple offspring from elite does with more desirable lactation, reproduction, and conformation traits. Beyond the new F1 animals produced by IVF, several techniques (natural mating, AI, or IVF) can then be used to quickly disseminate the new genetics into both the nontransgenic and transgenic herds. Finally, skin cells obtained from the female IVF offspring or fetal cells derived from any pregnancies of the initial IVF offspring could also be used to generate transfected cells as karyoplast donors for future somatic cell nuclear transfer work. Table 1. Summary of caprine IVF

61 GENERATING A HERD OF TRANSGENIC DAIRY GOATS BY SOMATIC CELL NUCLEAR TRANSFER

Transgenic dairy goats expressing recombinant therapeutic molecules in the milk may offer an alternative manufacturing method compared to traditional cell culture. Typically, a herd of transgenic progeny can be efficiently generated by naturally mating a transgenic buck with multiple does. However, the ability to rapidly generate a herd of transgenic progeny from a female transgenic founder by natural mating represents a challenge. While a herd of transgenic progeny can be generated from a female transgenic founder by superovulation and either in vitro fertilization or embryo flushing, the time period required is dependent on the number and gender of progeny needed. In this work we determined the ability of using skin cells from two transgenic founder female dairy goats as karyoplasts for nuclear transfer to produce a herd of transgenic female dairy goats. Two transgenic founder female dairy goats expressing a recombinant therapeutic human protein in the milk were generated by nuclear transfer using a transfected fetal cell line. Primary cultures of transgenic skin cells were established from these two founder lines using tissue samples obtained by biopsy. The cells were used as nuclear donors following three or four days of low-serum culture [0.5% fetal bovine serum (FBS)]. Donor cells were simultaneously fused and activated with in vivo produced oocytes from superovulated does. Nuclear transfer embryos were transferred to synchronized surrogate recipients at 24 to 48 h post-fusion and activation. Pregnancies were determined by ultrasonography starting at approximately Day 28 post-fusion and activation and then monitored weekly. The results of work conducted during two defined breeding periods are summarized in Table 1. While there were no significant differences in the number of Day 50 pregnancies (17 vs. 27), there were significantly more term pregnancies (14 vs. 12) and offspring produced (20 vs. 15) during the traditional (September through December) compared with the nontraditional (January through May) breeding seasons, respectively (P < 0.05). In this work, 35 female NT offspring were produced, requiring 13 months from the start until the last offspring was born. These results demonstrate that somatic cell nuclear transfer using transgenic skin cells as karyoplast donors is an alternative method to produce a herd of transgenic female dairy goats. Table 1. Caprine transgenic herd development by nuclear transfer

105 EXPRESSION OF PLURIPOTENCY-DETERMINING FACTORS Oct-4 AND NANOG IN PRE-IMPLANTATION GOAT EMBRYOS

The objective of this study was to determine the expression patterns of the pluripotency-determining factors, Oct-4 and Nanog, in pre-implantation goat embryos. The POU octamer-binding domain transcription factor Oct-4 and the homeobox transcription factor Nanog have been shown to play key roles in the maintenance of pluripotency in the inner cell mass (ICM) of pre-implantation mouse embryos and in embryonic stem cells. As Oct-4 protein has been observed in human, monkey, bovine, and porcine pre-implantation embryos, its role in embryonic development and differentiation may be conserved across these species. The patterns of mRNA expression for Oct-4 and Nanog have not been reported for ruminant embryos. In this study, total RNA was extracted from 10 in vivo-derived goat embryos at each stage (8-cell, morula, and blastocyst) using an Absolutely RNA Nanoprep Kit (Stratagene, La Jolla, CA, USA). The first-strand cDNAs were synthesized using Superscript III (Invitrogen, Carlsbad, CA, USA) and cDNAs were amplified with PfuUltra hotstart PCR master mix (Stratagene). Oct-4 primers were designed based on bovine Oct-4 open-reading sequence, while Nanog primers were designed based on the human Nanog open-reading sequence. Expression screening by PCR was performed. Oct-4 mRNA expression was detected at the 8-cell, morula and blastocyst stages. Sequencing of the 1.1-kb PCR product with Oct-4 primers revealed 87% homology to human cDNA sequence and 96% homology to the bovine sequence. Protein localization of Oct-4 as observed by immunocytochemistry was diffuse at the morula stage, but moved to a more nuclear location at the blastocyst stage. Oct-4 protein and mRNA expression were detected in both the ICM and trophectoderm of expanded blastocysts. This pattern of protein expression is similar to that reported by others in the pig and cow. As caprine, bovine, and porcine embryos all show extensive proliferation and elongation of the trophectoderm, continued expression of Oct-4 protein in the trophectoderm may be necessary to prevent premature differentiation of the trophectoderm. Nanog mRNA was detected at the morula and blastocyst stages. Nanog mRNA was detected in the ICM but not the trophectoderm of expanded goat blastocysts, a pattern that follows the expression observed in mice. Sequencing of the 698 bp PCR product obtained by RT-PCR from goat blastocysts confirmed that the mRNA detected was Nanog. Sequence alignment (ClustalW) showed that the cDNA sequence identities were 96% between goat and human and 70% between goat and mouse. The amino acid identities were 93% between goat and human and 52% between goat and mouse. To our knowledge this is the first report of detection of Nanog in domestic animals. These results are supportive of the premise that core components involved in the control of pluripotency are analogous across vertebrate species.

114EFFECT OF CYTOCHALASIN B TREATMENT ON VITRIFICATION OF CAPRINE PARTHENOGENIC BLASTOCYSTS

Production of human recombinant proteins in the milk of transgenic animals has been shown to be a viable production system. Protection of the animal genetics involved is paramount. Vitrification of embryos is a simple, time-efficient way of preserving an animal’s genetics without the formation of damaging ice crystals during the freezing process. Cytochalasin B has been shown to increase the viability of porcine blastocysts by reducing damage to microfilaments and other cytoskeletal components. These experiments utilized caprine parthenogenic blastocysts as a model to compare the viability of parthenotes treated with or without cytochalasin B prior to and during vitrification. Abattoir oocytes were in vitro-matured in M199 with 10% goat serum containing FSH, LH and gentamycin for 18 to 21h. Parthenogenic blastocysts were produced by treating in vitro matured abattoir oocytes with ionomycin for 5min (5μM) and with 6-dMAP (3mM) for 3h followed by culturing in SOF+0.8% BSA for 7 to 8 days at 38°C with 6% O2, 5% CO2, and 89% N2 in a modular incubator chamber. The experimental group was treated with cytochalasin B (5μg/mL)in the culture media for 30 to 45min prior to and thereafter throughout the vitrification process. All blastocysts (both the experimental group and the control group) were washed through two ovum culture media (OCM) droplets for 5min each. The blastocysts were incubated in vitrification solutions 1 and 2 (10% glycerol in OCM and 10% glycerol+20% ethylene glycol in OCM, respectively) for 5min each, followed by vitrification solution 3 (25% glycerol+25% ethylene glycol in OCM). They were then aspirated immediately into a 0.25cc cryopreservation straw, followed by an air bubble, and then a 0.25M sucrose solution in OCM. The straws were immediately plunged into liquid nitrogen and stored at −196°C. One to four days later, straws were thawed in air for 5s at room temperature, then in 22°C water for 15s. After thawing, the contents of the straw were expelled, mixed, held for 5min, and finally placed in OCM for 5min. Recovered embryos were placed in SOF+20% FBS and incubated at 38°C with 5% CO2 in air overnight. Viability was determined by re-expanding and subsequent hatching of the blastocyst. As shown in Table 1, there were no significant differences between re-expansion and hatching of blastocysts with cytochalasin B treatment compared to blastocysts not treated with cytochalasin B. These results suggest that, unlike porcine embryos (Dobrinsky et al., 2000 Biol Reprod 62, 564–570), cytochalasin B treatment does not improve the post-thaw viability of vitrified caprine parthenogenic blastocysts. Table 1

58ESTRUS SYNCHRONIZATION OF DAIRY GOATS UTILIZED AS RECIPIENTS FOR CAPRINE NUCLEAR TRANSFER EMBRYOS

The timing of estrus synchrony between donor and recipient does is an important consideration in an embryo transfer program. Experiments were conducted to determine the optimal time of estrus synchrony between donor and recipient dairy goats used in a commercial nuclear transfer (NT) program. Donor and recipient synchronization was achieved by implanting either a 3-mg norgestomet ear implant (Crestar®, Intervet Int. B.V., Boxmeer, Holland) or a 300-mg progesterone vaginal implant (CIDR-G®, Pharmacia and Upjohn Ltd. Co., Auckland, NZ) on Day 0. A single 5mg intramuscular injection of prostaglandin (Lutalyse®, Pharmacia and Upjohn, Kalamazoo, MI, USA) was administered on Day 7. Recipients received a single 200–500IU intramuscular injection of PMSG (Calbiochem, LaJolla, CA, USA) on Day 13. Alternatively, starting on Day 12 donors received twice daily intramuscular injection (64mg/day) of FSH (Folltropin®, Vetrepharm, Ontario, Canada) over four consecutive days. On Day 15 the implants were removed from both donors and recipients and the animals were mated several times daily to vasectomized bucks over two consecutive days. In Experiment 1, estrus synchrony or asynchrony was achieved by removing the implant from recipients at the same time or 12h later than donors, respectively. In Experiment 2, only estrus asynchrony was utilized and was achieved by removing the implant from recipients either 12 or 18h later than donors. In vivo-ovulated MII oocytes surgically recovered from superovulated donors on Day 17 were enucleated and reconstructed with transfected caprine fetal or adult skin cells or transgenic adult skin cells. Couplets were simultaneously fused, activated, and then cultured in SOF/BSA for 48h at 38°C. Two-to-eight-cell NT embryos at 48h post-fusion and activation were surgically transferred to the oviducts of surrogate recipients with similar implant types and PMSG doses. Pregnancies were determined by ultrasonography starting at approximately Day 28 post-fusion and activation and then monitored weekly. In Experiment 1, there were significantly more pregnant asynchronous recipients compared with synchronous recipients (6 of 24 v. 12 of 124 does, respectively). While there were no significant differences, more offspring were produced per embryo transferred to asynchronous recipients compared with synchronous recipients (5 of 135 v. 11 of 690 offspring per embryo transferred, respectively). In Experiment 2, while not significant, there were more pregnant +12-h asynchronous recipients compared with +18-h asynchronous recipients (16 of 72 v. 5 of 36 does, respectively). Again, while there were no significant differences, more offspring were produced per embryo transferred to +12h compared with +18h asynchronous recipients (11 of 424 v. 3 of 224 offspring per embryo transferred, respectively). These results suggest that asynchrony of estrus between recipients and donors is more beneficial in a commercial caprine NT program, and that +12h may be a more optimal period of asynchrony for recipient does receiving NT embryos. Table 1 Summary of recipient estrus synchronization

31EFFECTS OF CYCLOHEXIMIDE ON CAPRINE SOMATIC CELL NUCLEAR TRANSFER EMBRYO AND FETAL DEVELOPMENT

The use of protein synthesis inhibitors to down regulate the levels of Maturation Promoting Factor (MPF) following fusion and activation are widely used in the field of Nuclear Transfer (NT). Cycloheximide is a protein synthesis inhibitor that blocks the levels of cyclin B, a component of MPF which is required to maintain MII stage arrest in oocytes. However, it is unclear what, if any, effects these broadbased inhibitors may have on nonspecific protein expression in the oocytes or karyoplasts. The purpose of this study was to examine the effects of treatment with and without cycloheximide on embryo and fetal development to term. Ovulated in vivo MII oocytes from superovulated does during the traditional breeding season were surgically collected and then enucleated and reconstructed with either transfected fetal or adult skin cell karyoplasts or transgenic primary somatic skin cells. Couplets were simultaneously fused and activated with a single electrical pulse between 2.6 and 3.0kVcm−1 for 20μs. An additional electrical pulse was given to fused couplets and non-fused couplets were re-fused. Reconstructed embryos were either treated with 5μgmL−1 cyclohexamide (Sigma, St. Louis, MO, USA) for a minimum of 3h or cultured directly post-fusion and activation. The embryos were cultured in SOF +BSA at 38°C in a humidified modular incubation chamber (Billrups-Rothenberg, USA) containing 6% O2, 5% CO2, and 89% N2 for 24–48h. Cleavage was assessed, and nuclear transfer embryos, with age appropriate development (up to 2 cells at 24h or 2 to 8 cells by 48h), were surgically transferred to the oviduct of surrogate recipient does. There were 18 and 11 confirmed pregnancies by Day 50 post-fusion and activation from the cycloheximide and non cycloheximide groups, respectively. A total of 12 recipients that received cycloheximide treated embryos produced term pregnancies and yielded 15 offspring. Alternatively, 9 recipients that received untreated embryos produced term pregnancies which yielded 12 offspring. A total of 27 NT offspring were produced and one offspring from a set of quadruplets died several days post-natally. While significantly more cycloheximide treated NT embryos cleaved, there was no significant difference in pregnancy rate or offspring born between treatment groups. These results suggest that the use of cycloheximide for embryo development in somatic cell nuclear transfer may not be necessary for establishing and maintaining caprine NT pregnancies. Table 1

A novel class of endotoxin receptor agonists with simplified structure, toll-like receptor 4-dependent immunostimulatory action, and adjuvant activity

A series of novel, synthetic compounds containing lipids linked to a phosphate-containing acyclic backbone are shown to have similar biological properties to lipopolysaccharide (LPS). These compounds showed intrinsic agonistic properties when tested for their ability to stimulate tumor necrosis factor-alpha in human whole blood and interleukin-6 in U373 human glioblastoma cells without added LPS coreceptor CD14. The presence of the LPS antagonist E5564 completely blocked responses, suggesting that the novel compounds and LPS share a common mechanism of cell activation. Stereoselectivity of the molecules was observed in vitro; compounds with an R,R,R,R-configuration were strongly agonistic, whereas compounds with an R,S,S,R-configuration were much weaker in their activity on human whole blood and U373 cells. We also tested the effect of the compounds in cells transfected with the LPS receptor Toll-like receptor 4 (TLR4), with similar results, further supporting a shared mechanism with LPS. This was confirmed in vivo where the agonists failed to elicit cytokine responses in C3H/HeJ mice lacking TLR4 signaling. Because LPS-like molecules enhance immune responses, the compounds were mixed with tetanus toxoid and administered to mice in an immunization protocol to test for adjuvant activity. They enhanced the generation of specific antibodies against tetanus toxoid. Our results indicate that these unique compounds behave as agonists of TLR4, resulting in responses similar to those elicited by LPS. They display adjuvant activity in vivo and may be useful for the development of vaccine therapies.

Hormonal induced lactation in transgenic goats

The aim of this study was to hormonally induce lactation in prepubertal, nulliparous, and male goats both transgenic and non-transgenic. Analysis of milk quality, recombinant protein expression levels, total amount of recombinant protein produced, and the affect on long-term reproductive capability was assessed. Fifty-one goats (Saanen, Alpine, and Toggenburg), male and non-pregnant females, 2-31 months of age, either non-transgenic or transgenic were evaluated with a total of 10 transgenes (constructs) represented. Animals were given estradiol (0.25 mg/kg, i.m.) and progesterone (0.75 mg/kg, i.m.) on days 1, 3, 5, 7, 9, 11 and 13, while prednisilone (0.4 mg/kg, i.m.) was administered on days 14-16 with mammary massage occurring daily from day 5 onward. Forty of 51 animals, (36 of 38 females and 4 of 13 males) produced milk with total volumes in the 30-day experiment, ranging from 20 microl to 530 mls per day, or approximately 500 microl to 6.8 liters total. Milk composition was analyzed for various parameters (total protein, fat content, total solids and somatic cell count) with no significant differences found between induced and natural milk. Expression levels of recombinant proteins from transgenic animals that were analyzed during the induced lactation, and subsequently during normal lactations, were found to have no significant differences. Total amount of recombinant protein produced was evaluated at different expression levels with no statistical significance seen. While over 90% of the females placed in the regimen became pregnant, there was a correlation between increased age at time of induction and an increase in number of breedings, or reproductive cycles needed to establish a pregnancy after induction. For males, 100% placed in the regimen settled females after hormonal induction of lactation. Semen quality was evaluated prior to, during, and after hormonal treatments. Semen volume and sperm number did not differ; however, for a small percentage of males, there was a decrease in sperm and post thaw motility after hormonal treatments. These levels returned to normal within 4-5 weeks. Subsequent natural lactations showed total milk volumes within breed standards. These findings indicate that hormonal induction of lactation in the caprine species is a viable alternative to pregnancy for initiating lactation and milk production, does not adversely impact reproductive performance long-term, and can benefit the early assessment of recombinant proteins produced in a transgenic founder program.

Cryopreservation of epididymal sperm obtained at necropsy from goats

In the field of transgenic production, the ability to carry a male's genetic contribution beyond its natural life span is remarkably important. The ability to successfully collect and cryopreserve sperm from the epididymis at necropsy may prove to be a useful technique for preserving valuable genes. Thirty-two bucks ranging in age from 13 days to 7 years were examined in this study and 25 had epididymal sperm extracted at necropsy. Seven bucks yielded clear fluid with no spermatozoa; all were under four months of age. Testes were removed from the scrotal sac, small lateral incisions made across the convoluted tubules, pressure applied to the tail of the epididymis and small droplets of sperm pipetted into equilibrated extender. The average initial analysis of wave motion (0 to 5, 5 being rapid wave motion), live/dead sperm percentage and acrosomal integrity of 25 fresh epididymal samples were 5.0, 92%, and 100%, respectively. By comparison, the same parameters obtained from 206 fresh ejaculated samples were 3.0, 86%, and 95%, respectively. After being cryopreserved in liquid nitrogen, one straw from each sample was thawed after 3 to 60 days of cryostorage. Results of post-thaw analysis of 25 cryopreserved epididymal sperm samples for live/dead percentage and acrosomal integrity were 82% and 84%, respectively. By comparison, results of post-thaw analysis of 206 cryopreserved ejaculated sperm samples for live/dead percentage and acrosomal integrity were 60% and 89%, respectively. To assess the competence of the frozen epididymal sperm, IVF and AI were performed. In parallel IVF experiments, 40% of the oocytes showed cleavage patterns, with 6% developing to the blastocyst stage using frozen epididymal sperm, while 37% of the oocytes showed cleavage patterns and 4% developed into blastocysts using frozen ejaculated sperm. One artificial insemination out of 20 resulted in a pregnancy using frozen epididymal sperm, while 7 of 18 artificial inseminations resulted in a pregnancy using frozen ejaculated sperm. This data documents the successful collection and cryopreservation of epididymal sperm from the goat and its use for in vitro fertilization and artificial insemination.

Linguistic experience and phonemic perception in infancy: a crosslinguistic study

English- and Spanish-learning infants were tested for perception of 2 synthetic speech contrasts differing in voice onset time. The 2 pairs were chosen so that they were native to either Spanish or English. Using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm, 6--8-month-old infants were taught to respond to a change in auditory stimuli with a headturn. Correct headturns were reinforced by the activation of a lighted animated toy. While Spanish-learning infants provided evidence of discriminating both English and Spanish contrasts, English-learning infants only provided evidence of discriminating their native contrast. The results are discussed in terms of the role of linguistic experience in the development of speech perception skills in infancy.