Biomedical subjects

D Rath

Publications and source records attributed to D Rath.

At least 37 records · Page 2Linked to original sources

PubMed2003

In vitro fertilisation of in vivo matured porcine oocytes obtained from prepuberal gilts at different time intervals after hCG injection.

The goal of the present study was to find out the best interval after hCG injection in PMSG primed prepuberal gilts for retrieval of in vivo matured oocytes for in vitro fertilisation (IVF). Altogether 66 gilts were superovulated with 1500 IU PMSG and 500 IU hCG 72 h later. Ovum pick up was performed endoscopically 24, 28, 32 or 36 h after hCG and a total of 869 cumulus-oocyte-complexes (COCs) were aspirated from 1400 follicles. COCs were tested for quality, and an aliquot was immediately fixed and stained to determine meiotic configuration. The remaining COCs were fertilised in vitro using frozen-thawed epididymal semen. Quality and developmental stage of embryos were tested after IVF, and the number of nuclei was counted. At 24 to 32 h after hCG only few oocytes have entered the second meiotic cycle (18 to 25% vs. 58% at 36 h, p < 0.05). The overall cleavage rate was significantly influenced by insufficient maturation rate at the early collection times (14% at 24 h vs. 49% at 36 h). Additionally, when oocytes were collected 24 to 32 h vs. 36 h the cleavage rate based on mature oocytes was lower (26 vs. 62%, p < 0.05). Once embryonic development has been initiated, the further in vitro development to blastocyst stages did not differ between groups. However, the number of cells was lower at collection times 24 to 32 h as compared to 36 h after hCG (12 to 15 cells vs. 22 cells, p < 0.05). The results indicate that the time of COC collection affects the in vitro developmental competence up to the blastocyst stage and should not be performed earlier than 36 h after hCG treatment.

Animals↗

PubMed2002

Low dose insemination in the sow--a review.

Artificial insemination (AI) in pigs has been established for about four decades but ejaculates are still used insufficiently. Higher demand of semen for AI and new techniques that involve low sperm concentration require the optimization of insemination protocols. Based on the knowledge of the physiology of sperm transportation and events in the female genital tract prior to fertilization, new strategies are under development to minimize sperm losses. One goal is to deposit the semen into the uterine horn rather than into the proximal cervix. It was shown that the minimal number of spermatozoa necessary for surgical AI at the utero-tubal junction (UTJ) were at least 1 x 10(6) diluted in 0.5 ml of a special extender. Artificial insemination into the distal part of the uterine horn required about 1 x 10(7) million sperm in 20 ml of extender. Meanwhile, first insemination devices for non-surgical intra-uterine AI are commercially available. Using similar sperm concentrations as for surgical AI, non-surgical uterine insemination did not differ significantly from control inseminations in terms of pregnancy rate and litter size. With respect to the fertilizing capacities of their ejaculates, boars have to be selected more strictly for sperm quality parameters as most of the compensatory effects of sperm cells disappear in maximally extended semen samples.

Animals↗

PubMed2001

Progress in reproductive biotechnology in swine.

This article summarizes recent progress in reproductive biotechnology in swine with special reference to in vitro production of embryos, generation of identical multiples, and transgenic pigs useful for xenotransplantation. In vitro production (in vitro maturation, in vitro fertilization, and in vitro culture) of viable porcine embryos is possible, although with much lower success rates than in cattle. The main problems are insufficient cytoplasmic maturation of porcine oocytes, a high proportion of polyspermic fertilization and a low proportion of blastocysts that, in addition, are characterized by a low number of cells, hampering their development in vivo upon transfer to recipients. Microsurgical bisection of morula and blastocyst stage embryos leads to a 2 to 3% monozygotic twinning rate of the transferred demiembryos, which is similar to that in rabbits and mice but considerably lower than in ruminants. It was found that with decreasing quality an increasing proportion of demi-embryos did not possess an inner cell mass. Porcine individual blastomeres derived from 4- and 8-cell embryos can be cultured in defined medium to the blastocyst stage. Leukemia inhibitory factor has been shown to be effective at defined embryonic stages and supports the formation of the inner cell mass in cultured isolated blastomeres in a concentration-dependent manner. For maintaining pregnancies with micromanipulated porcine embryos, it is not necessary to transfer extraordinarily high numbers of embryos. Porcine nuclear transfer is still struggling from the inefficiency of producing normally functioning blastocysts. Blastomeres, blastocyst-derived cells, fibroblasts and granulosa cells have been employed as donor cells in porcine nuclear transfer and have yielded blastocysts. Recently, the generation of the first piglets from somatic cell nuclear transfer has been achieved. DNA-microinjection into pronuclei of porcine zygotes has reliably resulted in the generation of transgenic pigs, which have special importance for the production of valuable pharmaceutical proteins in milk and xenotransplantation. It has been demonstrated that by expression of human complement regulatory proteins in transgenic pigs the hyperacute rejection response occurring after xenotransplantation can be overcome in a clinically relevant manner. Although biotechnological procedures in swine have recently undergone tremendous progress, the development is still lagging behind that in cattle and sheep. With regard to genetic engineering, considerable progress will originate from the possibility of employing homologous recombination in somatic cell lines and their subsequent use in nuclear transfer. In combination with the increasing knowledge in gene sequences this will allow in the foreseeable future widespread use in the pig industry either for agricultural or biomedical purposes.

Animals↗

PubMed2001

Gene expression during pre- and peri-implantation embryonic development in pigs.

Embryo technological procedures such as in vitro production and cloning by nuclear transfer are not as advanced in pigs as in cattle and cannot yet be applied under field conditions. The present paper focuses on genome activation in in vivo-derived, in vitro-produced and nuclear transfer pig embryos with special emphasis on the development of embryonic nucleoli, where the ribosomal RNA (rRNA) genes transcribed can be used as markers for genome activity. In addition, contemporary data on gene expression in in vivo-derived pig embryos are reviewed. In in vivo-derived pig embryos, pronounced transcription is initiated at the four-cell stage (the third cell cycle after fertilization), when nucleoli develop. In parallel with the development of the nucleoli as a result of rRNA gene activation, a cascade of other genes is also likely to be transcribed. However, apart from identification of transcripts for the oestrogen receptor at the blastocyst stage, reports on mRNAs resulting from initial transcription of the pig embryonic genome are lacking, in contrast to the situation in cattle and, in particular, mice. More information is available on gene expression during elongation of pig conceptuses, when the genes for steroidogenic enzymes, extracellular matrix receptors, oestrogen receptors, growth factors and their receptors, as well as retinol binding protein and retinoic acid receptors, are expressed. Nucleolus development appears to be disturbed in in vitro-produced pig embryos and in pig embryos reconstructed by nuclear transfer of granulosa cells to enucleated metaphase II oocytes produced by oocyte maturation in vivo or in vitro, which is indicative of disturbances in activation of rRNA genes.

Animals↗

PubMed2000

Activation of ribosomal RNA genes in preimplantation cattle and swine embryos.

Transcription of ribosomal RNA (rRNA) genes occurs in the nucleolus resulting in ribosome synthesis. In cattle and swine embryos, functional ribosome-synthesizing nucleoli become structurally recognizable towards the end of the fourth and third post-fertilization cell cycle, respectively. In cattle, a range of important nucleolar proteins become localized to the nucleolar anlage over several cell cycles and this localization is apparently completed towards the end of the fourth cell cycle. In swine, the localization of these proteins to the anlage is more synchronous and occurs towards the end of the third cell cycle and is apparently completed at the onset of the fourth. The rRNA gene activation and the associated nucleolus formation may be used as a marker for the activation of the embryonic genome in mammalian embryos and, thus, serve to evaluate the developmental potential of embryos originating from different embryo technological procedures. By this approach, we have demonstrated that in vitro produced porcine embryos display a lack of localization of nucleolar proteins to the nucleolar anlage as compared with in vivo developed counterparts. Similarly, bovine embryos produced by nuclear transfer from morulae display such deviations as compared with in vitro produced counterparts. Collectively, this information may help to explain the appearance of abnormalities seen in a certain proportion of offspring derived from in vitro produced embryos and after cloning.

Animals↗

PubMed2000

Intrauterine insemination in sows with reduced sperm number.

Usually 2-3 x 10(9) sperm per insemination are used in pigs. In other species it has been shown that changing the site of insemination allows a reduction in the amount of sperm per insemination dose. The goal of this study was to determine the minimal number of sperm that can be used, without a reduction in either the pregnancy rate or the mean litter size, using surgical deep intrauterine insemination in sows after weaning. Three different sperm concentrations (5 x 10(8), 1 x 10(8) and 1 x 10(7) sperm cells extended in 0.5 mL Androhep) were inseminated into the tip of each uterine horn. In addition two groups of control sows were inseminated once intracervically 24-32 h after the first signs ofoestrus with 1 x 10(9) and 3 x 10(9) sperm in 80 mL Androhep extender. Animals that became pregnant were allowed to farrow normally. No significant differences were observed between groups inseminated surgically with the three different sperm dosages with respect to pregnancy or farrowing rate. There was also no significant difference between the results of these groups and the results obtained from the non-surgically inseminated control groups. Neither the mean number of live-born nor stillborn piglets was significantly different between the surgically inseminated groups and the control groups. The total number of piglets born in each group was also not statistically different. The data show that the sperm number to be used for surgical insemination can be lowered without loss of the fertilization potential and may be used in the field as soon as a suitable insemination device is available.

Animals↗

PubMed2000

Risks of in-vitro production of cattle and swine embryos: aberrations in chromosome numbers, ribosomal RNA gene activation and perinatal physiology.

In cattle, in-vitro production (IVP) of embryos has become a standardized technique; however, increased frequencies of calving problems and larger calves have been reported. In swine, IVP has resulted in only a limited number of piglets. In this paper we present information on cattle and swine embryos produced in vitro by oocyte maturation, fertilization and further embryo culture to the blastocyst stage in vitro. Control in-vivo developed embryos were collected after superovulation. The cattle embryos were processed for fluorescence in-situ hybridization (FISH) with two chromosome-specific probes to detect numerical chromosome aberrations. The swine embryos were processed for transmission electron microscopy and immunocytochemistry with an antibody against RNA polymerase I [essential for ribosomal RNA (rRNA) gene transcription] in order to highlight the post-fertilization development of the nucleolus as a marker for rRNA gene activation. The FISH analyses of the cattle embryos revealed that 72% of IVP blastocysts were mixoploid, i.e. contained both diploid and polyploid cells, versus 25% in vivo. Chromosome abnormalities were observed from the 2-cell stage onwards. The immunocytochemical analyses of the swine embryos revealed that during in-vivo development, RNA polymerase I became localized to multiple foci in the developing nucleoli late during the 4-cell stage. This focal localization of RNA polymerase I was not observed in IVP embryos. In conclusion, IVP embryos may display aberrations in chromosome numbers and rRNA gene activation. The significance of these deviations for fetal and perinatal viability, however, remains unknown. The survival of most calves derived from IVP indicates that a considerable number of these embryos are able to compensate for the adverse effects of the in-vitro procedures.

Animals↗

PubMed2000

Nucleolar proteins and ultrastructure in preimplantation porcine embryos developed in vivo.

Ribosomal RNA genes are transcribed in the nucleolus. The formation of this organelle after fertilization is essential for embryonic protein synthesis and viability. We have examined nucleolus formation in in vivo-derived porcine embryos by light microscopical autoradiography following 20 min of (3)H-uridine incubation, transmission electron microscopy (TEM), and immunocytochemical localization by confocal laser scanning microscopy of key nucleolar proteins involved in rRNA transcription (nucleolin, upstream binding factor, topoisomerase I, and RNA polymerase I) and processing (fibrillarin, nucleophosmin). During the first two postfertilization cell cycles, TEM revealed fibrillar spheres as the most prominent intranuclear entity of the blastomeres. Fibrillogranular nucleoli were established during the third cell cycle. Initially, fibrillar centers, a dense fibrillar component, and a granular component were formed on the surface of the fibrillar spheres. At the same time, autoradiographic labeling over the nucleoplasm and in particular the nucleoli was detected for the first time. The nucleolar proteins were, in general, not immunocytochemically localized to the presumptive nucleolar compartment until late during the third or early during the fourth cell cycle.

Animals↗

PubMed2000

[The short bowel syndrome].

The authors demonstrate on case-histories their experience with short-loop syndrome which develops after extensive resections of the small intestine. The clinical picture of the syndrome is characterized by diarrhoea, steatorrhoea, maldigestion and malabsorption with loss of body weight. Non-surgical treatment of the syndrome copies its different stages. The objective of conservative therapy is above all to preserve the nutritional integrity of the organism and gradual adaptation of the gut which will make eventually a change to oral intake possible. This adaptation takes 1 to 2 years. Last not least, treatment should eliminate the diarrhoea. The authors demonstrate on examples that properly conducted treatment prevented the development of malnutrition, contrary to another case where the sequelae of surgery were underestimated and the patient developed cachexia and pernicious anaemia.

Adult↗

PubMed1999

Low dose insemination in synchronized gilts.

Conventional insemination techniques in pigs require 2 to 3 x 10(9) sperm/dose. When using the latest high-speed sperm-sorting technology, one can still sort only about 5 to 6 million sperm of each sex per hour. The objective of the present study was to find the minimal sperm concentration at a low-insemination volume in pigs without diminishing fertilization rate and litter size using surgical deep intra-uterine insemination (IUI). Semen from 3 boars was collected and diluted with Androhep to 5 x 10(8), 1 x 10(8), 1 x 10(7), 5 x 10(6) or 1 x 10(6) sperm/0.5 ml. In trial 1, 109 prepuberal gilts were synchronized and surgically inseminated into the tip of each uterine horn 32 h or 38 h after hCG treatment or at the time of ovulation, respectively. Pregnant gilts were allowed to go to term. Pregnancy and farrowing rates did not differ significantly except at the lowest sperm concentration if inseminated 32 h or 38 h after hCG treatment (p < 0.05). No differences were found among insemination groups for the total number of piglets, number of piglets born alive, stillborn piglets, and mummified fetuses. In trial 2, 34 gilts were inseminated as described above 32 h after hCG. Additionally, 9 gilts were inseminated once nonsurgically with 1 x 10(9) sperm as controls. Gilts were slaughtered 48 h after insemination, and embryos were recovered. Embryos were cultured in NCSU 23 (120 h), evaluated morphologically and stained with fluorescent dye (Hoechst 33342) to visualize nuclei. Recovery rates varied between 71.4% and 84.4%. Fertilization rate of the lowest sperm concentration (1 x 10(6) sperm/horn) differed significantly (p < 0.05) from all other groups. Cleavage rates at specific developmental stages did not differ. After 5 days of in vitro culture, embryos developed to morulae and blastocysts. No differences were found for these stages. In conclusion, no major differences were found between insemination groups as long as the sperm dosage was at least 10 million sperm per gilt. The low volume was sufficient for successful deep intra-uterine insemination. Embryo development was comparable to the controls.

Animals↗

PubMed1999

In vitro production of sexed embryos for gender preselection: high-speed sorting of X-chromosome-bearing sperm to produce pigs after embryo transfer.

The objectives for the present experiments were to apply sperm sexing technology to an in vitro production system with porcine oocytes obtained from slaughterhouse material. On six experimental days, ovaries were obtained from an abattoir, and cumulus-oocyte-complexes were matured in vitro. Semen was collected from mature boars of proven fertility and was sorted for X-chromosome-bearing sperm, using the Beltsville Sperm Sexing Technology incorporating the use of high-speed sorting. A total of 5,378 oocytes were submitted for in vitro fertilization (IVF). Of these, 559 ova were stained for cytogenetic analysis 18 h after IVF. From the remaining 4,819 ova, 1,595 cleaved, and 1,300 of the cleaved embryos were transferred into 26 synchronized recipients (5 control gilts for unsorted sperm, 21 gilts for X-sorted sperm). In a test of two fertilization media (FERT-A vs FERT-B) higher cleavage rates (P<.05) were obtained when FERT-B was used as a fertilization medium for unsorted (43.4+/-5.1%) and sorted sperm (43.1+/-1.1%;), whereas in FERT-A unsorted sperm gave a cleavage rate of 17.9+/-4.4% and sorted sperm gave 30.4+/-1.4%. Additionally, cleavage rates were higher (P<.05) after fertilization with sorted sperm vs unsorted sperm, independent of fertilization medium. Cytogenetic analysis of ova revealed that more oocytes with unsorted than with sorted sperm remained in Metaphase 2 arrest (P<.05). This was also independent of the fertilization medium. Monospermic fertilization rates were the same for IVF with unsorted or sorted sperm, independent of the fertilization system, except FERT-A with unsorted sperm (P<.05). Polyspermic fertilization rates were highest in FERT-B (37.6+/-6.6). A total of 57 pigs were born from nine litters. Six litters from sexed sperm (X-sorted) produced 33 females (97%) and one male. Three litters from control transfers produced 23 pigs, 11 of which were female (48%). The sex ratio of the offspring was predicted based on the sort reanalysis of the sorted sperm for DNA content.

Animals↗

PubMed1998

Evaluation of a patient file folder to improve the dissemination of written information materials for cancer patients.

BACKGROUND: Many cancer centers make available to patients written information material to supplement verbal information provided by clinicians. Randomized trials have demonstrated that providing such information can increase patient knowledge and satisfaction. However, little data are available regarding effective means of dissemination of such materials. The purpose of this study was to determine whether providing patients with a personal file folder after their first clinic appointment would improve the dissemination of written information materials and increase patient satisfaction. METHODS: A before/after study was performed. Consecutive patients with newly diagnosed cancer attending the Hamilton Regional Cancer Centre were selected randomly and interviewed by telephone within 1-2 weeks of the first clinic appointment regarding the number of information pamphlets received, patient satisfaction, and general preference for written information materials. The preintervention evaluation (T1) occurred over a 4-month period followed by the introduction of the personal file folder into the clinical practice. Six weeks after its introduction, the postintervention (T2) evaluation took place over the ensuing 4 months. RESULTS: A total of 300 patients completed the evaluation (150 each in T1 and T2). Responding patients in the two time periods were comparable with respect to background demographic variables. The mean number of information pamphlets received by patients increased with the introduction of the personal file folder from 2.4+/-2.0 standard deviations (SD) in T1 to 3.6+/-2.5 SD in T2 (P=0.0001). The percentage of patients planned for treatment who received treatment-related information increased from 36% (42 of 116 patients) in T1 to 65% (68 of 105 patients) in T2 (P=0.002). Mean patient satisfaction increased from 3.3+/-1.1 SD to 3.8+/-1.0 SD over the 2 time periods (P=0.0001). The majority of patients (87%) believed it was important to receive written information materials. CONCLUSIONS: The patient file folder increased the dissemination of written information materials and currently is being incorporated into routine practice.

Attitude↗

PubMed1998

Commitment of a cancer organization to a program for training in communication skills.

An Ontario cancer agency started an initiative to improve and promote effective communications between health care providers and their patients, using a 4.5-hour workshop developed by the Bayer Institute for Health Care Communications. Each of the eight regional cancer centers in Ontario sent two people, one physician and one other health care professional, for training in delivery of the workshop. Subsequently, each center provided workshops for physicians, nurses, pharmacists, physicists, social workers, psychologists, radiotherapists, and secretarial staff. The ongoing workshops are multiprofessional in composition and interactive and participatory in design. Between September 1996 and September 1997, the workshops involved over 400 cancer care professionals. Their success has been attributed to the knowledge, skills, and enthusiasm of the trained pair of facilitators; the interactive and participatory nature of the workshop design; the multiprofessional participation; and the support of the board of directors and senior management and the administration of each cancer center.

Communication↗

PubMed1998

[Poisoning in patients treated during 4 years at the Metabolic Unit of the Second Internal Medicine Clinic of the Charles University Medical School in Prague].

The authors summarize their experience with intoxicated patients who were treated between 1994 and 1997 at the metabolic unit of the Medical Clinic, Second Medical Faculty Charles University, Prague. The group of intoxicated patients comprises 165 subjects, incl. 76 men and 89 women. 107 intoxications were committed with suicidal intentions, in another 27 cases intoxication was accidental, in 14 toxicomania was involved and 17 patients were chronic alcohol addicts. From the total number 57 patients suffered from serious psychiatric disease of the type of psychosis, but only 22 patients had a psychiatric case-history. In 46 instances suicide was a demonstrative deed or hysterical reaction to partnership conflicts. In this group women predominate over men. The group comprises 14 toxicomaniacs, incl. 9 dependent on hard drugs. The patients were most frequently intoxicated with alcohol which they took either alone or combined with medicaments. 56 of the patients consumed ethyl alcohol. The next most frequently used intoxicating substance is flunitrazepam (Rohypnol), which was taken by 48 subjects. In 113 cases medium severe intoxications were involved, 31 were mild and 21 intoxications were severe.

Adult↗

PubMed1998

[Plasma homocysteine levels in patients with indications for cardiac revascularization].

The amino acid homocysteine is a further possible risk factor for the development of atherosclerosis. The authors examined at the First Medical Clinic, Second Medical Faculty Charles University in the course of 1994-1996 59 patients with manifest IHD who were examined by coronarography and because of a major finding were indicated for revascularization surgery. This group was compared with a control group of subjects of equal age without major findings on the coronary circulation. The control group differed from the former group significantly only as regards the triglyceride level which was higher in the former group and the group comprised a larger number of diabetic patients. As regards cholesterol, HDL-cholesterol, uric acid, fibrinogen levels there was no significant difference. The authors found an insignificant difference in homocysteine levels. In the investigated group of patients indicated for revascularization surgery the mean homocysteinaemia was 12.3 mumol/l (sigma 4.3 mumol/l) and in the control group 11.8 mumol/l (sigma 3.8 mumol/l). The mean homocysteine level in the investigated group did not exceed the level of 15 mumol/l reported in the literature as the borderline of normal homocysteine blood levels. The authors did not reveal a statistically significant correlation between homocysteine levels, diabetes mellitus type II and smoking.

Arteriosclerosis↗

PubMed1998

[Thyroid hormones in Old German Black Pied- and Holstein-Friesian suckling calves. Effects of parturition and postpartum adaptation].

The present trial deals with the effects of birth stress on the thyreoidea respectively on the thyroxine- and triiodthyronine-concentration as well as on their unbound fraction (FT4 and FT3) of suckler calves and the evolution of those parameters in the first three months of life. T4- and T3 concentrations in blood serum of calves were beyond maternal levels increasing significantly in the first 24 hours with strong individual specificity and reaching levels of adult animals at the end of the three-month-period. The different increasing rates of the four parameters show a stimulation of the thyreoideal activity and of the monodejodinase-system as well and they show also a greater decomposition rate of the binding proteins. An influence of the course of parturition on the T3 level p.n. and the T4/T3 ratio in the first 24 hours could be disclosed. The hormone concentrations p.n. showed correlations to the pH and pCO2 of the neonatal calves. For T4 and T3 a strong influence of maternal levels on the hormone levels of the calves p.n. could be ascertained. Effects of breed, surrounding temperatures and type of husbandry on the investigated parameters could be established.

Acclimatization↗

PubMed1997

In vitro fertilization of porcine oocytes with fresh and frozen-thawed ejaculated or frozen-thawed epididymal semen obtained from identical boars.

The objective of this study was to compare the in vitro fertilizing capacity of porcine spermatozoa from fresh and frozen-thawed semen and frozen-thawed epididymal spermatozoa obtained from identical boars. Prior to IVF, fresh spermatozoa were capacitated in TCM 199. Frozen semen samples were stored in 0.25-ml plastic straws using a lactose/glycerol/orvus-es-paste extender. Cumulus-oocyte-complexes (COC) obtained from superovulated prepuberal gilts were fertilized in vitro within 2 h after aspiration with one of the semen samples. After final dilution for IVF, frozen-thawed epididymal semen samples showed motility rates (72.2 +/- 5.6%) similar to those of spermatozoa in fresh semen (76.4 +/- 4.5%), while sperm motility decreased in frozen-thawed ejaculated semen (40.2 +/- 9.4%). Considerable individual differences in sperm motility between boars were observed for ejaculated semen but not for epididymal semen. Enhanced fertilizing capacity of frozen-thawed epididymal spermatozoa was confirmed by pronucleus formation and cleavage rates, with significantly more embryos developing to the 2- and 4-cell stages compared with the groups fertilized with fresh or with frozen-thawed ejaculated semen (59.7 vs 14.6 and 16%). In conclusion, consistent in vitro fertilization rates with minimal semen variability are obtained using frozen-thawed epididymal semen. Following a modified freezing protocol, epididymal spermatozoa can easily be frozen in small containers for IVF, with higher resultant motility and fertilization rates than with ejaculated semen.

Journal Article↗

PubMed1997

Production of piglets preselected for sex following in vitro fertilization with X and Y chromosome-bearing spermatozoa sorted by flow cytometry.

In vivo-matured porcine oocytes were fertilized in vitro with X and Y chromosome-bearing spermatozoa, and sorted for sex on the basis of DNA content by flow cytometry. Developmental competence of the sexed embryos was determined through established pregnancies after embryo transfer. Spermatozoa were stained with Hoechst 33342 and sorted using a flow cytometry cell sorter. Purity of sorting was 83% for Y spermatozoa and 92% for X spermatozoa. A total of 387 mature cumulus-oocyte-complexes (COC) was collected from 18 superovulated prepuberal gilts shortly before ovulation. In vitro fertilization with sorted spermatozoa was performed in 4 replicates. After 18 h of sperm- oocyte co-culture at 39 degrees C, the zygotes were placed into culture medium (NCSU-23) for another 24 h. The average cleavage rate was 56.2%. Ninety-two embryos produced from X-sorted sperm cells were transferred surgically into the uterus of 2 recipients. Two gilts farrowed and delivered 6 and 4 healthy female piglets, respectively. Additionally, 2 gilts were inseminated intratubally via surgical laparotomy with either X or Y sorted spermatozoa (2 x 10(5)) per oviduct. The 2 sows farrowed producing 15 piglets. Thirteen of the 15 piglets were of the predicted gender (85%).

Journal Article↗