S. Romo

Viability, maturation and embryo development in vitro of immature porcine and ovine oocytes vitrified in different devices.

This study was designed to evaluate the effects of vitrification on immature porcine and ovine oocytes, collected at a slaughterhouse, by performing vitrification in devices with different volumes. Viability was evaluated both before and after vitrification and maturation. Immediately after warming, the percentage of viable pig oocytes was 81% regardless the type of device, while in the control (after oocyte selection) was 95%. The viability of matured pig oocytes after warming, vitrified in beveled edge open straws (BES) was 6%, in small-open-pulled-straw (SOPS) was 17% and in cryotop was 4%, while the viability of the control group was 86%. The viability and maturation results were similar with all devices. Embryo development (ED) was observed in fresh porcine oocytes with 15% 2-8 cell embryos, 7% morulae and 3% blastocysts, and non-embryo cleavage was observed in warmed oocytes. The viability of sheep oocytes immediately after warming averaged 90% in all devices, while that of the control (after oocyte selection) averaged 95%. The viability of warmed oocytes after maturation was: BES 21%, SOPS 30%, cryotop 21% and control group 86%; while maturation values were 11, 21, 34 and 70%, respectively. After vitrification, the highest ED was achieved with ovine oocytes vitrified in SOPS, with 17% morulae development and it was the only device in which blastocysts developed. A direct relationship was observed between viability and actin filament integrity in both species.

Lipid droplet analysis using in vitro bovine oocytes and embryos.

The aim of this study was to quantify the content of lipid droplets in bovine oocytes and embryos from Bos indicus (Bi), Bos taurus (Bt) and Bos indicus × Bos taurus (Bi × Bt). Oocytes were aspirated post-mortem and subjected to in vitro maturation, in vitro fertilization and in vitro development; the medium employed at each stage (TCM-199, TALP, SOF) was supplemented with (i) serum replacement (SR), (ii) foetal calf serum (FCS) or (iii) oestrous cow serum (ECS). The structure and distribution of the lipid droplets were established using electron microscopy, but were quantified using an optical microscope on semi-fine toluidine blue-stained sections. The highest percentage of embryos corresponded to those produced with FCS and ECS, which differed from embryos generated with SR (p < 0.05). The highest percentage of morulae and the lowest percentage of blastocysts were obtained with the SR supplement (p < 0.05). The oocytes cultured in FCS demonstrated a higher number of lipid droplets compared to those cultured in SR and ECS (p < 0.05). Less accumulation of lipids was observed in embryos supplemented with SR. The lowest and highest numbers of lipid droplets in oocytes corresponded to the Bi and Bt strain, respectively. The lowest amount of lipid droplets in embryos was observed in Bi (p < 0.05). In conclusion, supplementation of the in vitro development culture medium (synthetic oviduct fluid) with a synthetic substitute serum produced similar results in terms of embryo development compared to those obtained with FCS, but a decreased degree of lipid droplet accumulation was observed in the in vitro-cultured embryos.

Gamete Therapeutics: Recombinant Protein Adsorption by Sperm for Increasing Fertility via Artificial Insemination

A decrease in fertility can have a negative economic impact, both locally and over a broader geographical scope, and this is especially the case with regard to the cattle industry. Therefore, much interest exists in evaluating proteins that might be able to increase the fertility of sperm. Heparin binding proteins (HBPs), specifically the fertility associated antigen (FAA) and the Type-2 tissue inhibitor of metalloproteinase (TIMP-2), act to favor the capacitation and acrosome reaction and perhaps even modulate the immune system’s response toward the sperm. The objective of this research was to determine the effect on fertility of adding recombinant FAA (rFAA) and recombinant TIMP-2 (rTIMP-2) to bovine semen before cryopreservation for use in an artificial insemination (AI) program in a tropical environment. For this experiment, 100 crossbred (Bos taurus x Bos indicus) heifers were selected based on their estrus cycle, body condition score (BCS), of 4 to 6 on a scale of 1 to 9, and adequate anatomical conformation evaluated by pelvic and genital (normal) measurements. Heifers were synchronized using estradiol benzoate (EB), Celosil® (PGF2α) (Shering-Plough) and a controlled internal drug release (CIDR) device was inserted that contained progesterone. Inseminations were performed in two groups at random, 50 animals per group. The control group was inseminated with conventional semen. The treatment group was inseminated with semen containing rFAA (25 µg/mL) and rTIMP-2 (25 µg/mL). In the control group a 16% pregnancy rate was obtained versus a 40% pregnancy rate for the HBP treatment group, resulting in a significant difference (P = 0.0037). Given the results herein, one may conclude that the HBPs can increase fertility and could be an option for cattle in tropical conditions; however, one needs to consider the environment, nutrition, and the genetic interaction affecting the final result in whatever reproductive program that is implemented.

Carbohydrate affinity chromatography indicates that arylsulfatase-A from capacitated boar sperm has mannose and N-acetylglucosamine/sialic acid residues.

Carbohydrate residues on membrane proteins from sperm are important in gamete interaction. In recent years, Arylsulfatase A (AS-A) has been acquiring an important role from the various putative gamete interaction responsibles in sperm. The aim of this study was to determine if the capacitated boar sperm Arylsulfatase-A (AS-A), contains D-mannose, N-acetylglucosamine and/or sialic acid residues by its purification using affinity chromatography with Concanavalia ensiformis Agglutinin(Con-A) or Wheat Germ Agglutinin (WGA) as ligands. Sperm samples were capacitated in TALP-HEPES medium. Protein extract was added to the affinity columns. Sequencing of retained proteins was done after SDS-PAGE. Total capacitated sperm proteins electrophoresis showed molecular masses between 14 kDa and 102 kDa. A major band of 68 kDa, and 2 minor bands of 52 kDa and 47 kDa were observed. They were AS-A, hyaluronidase and lactadherin, respectively. The Con-A-retained proteins (RP) pattern showed bands from 14 to 98 kDa. After sequencing and BLAST analysis, the 62 kDa band corresponded to Arylsulfatase-A. The WGA RP fraction showed bands from 14 to 100 kDa. The 65 kDa band corresponded to AS-A. This study showed that AS-A has mannose, N-acetylglucosamine and/or sialic acid residues as part of its glycosilation. In this study AS-A was isolated from boar capacitated sperm by affinity chromatography using separately Con-A and WGA, indicating that there are mannose, N-acetylglucosamine and/or sialic acid residues in its glycosilation. AS-A is a membrane protein of capacitated sperm. Further investigation is needed to fully characterize the glycosidic residues bore by AS-A and to determine its function.

Avian cloning: adaptation of a technique for enucleation of the avian ovum

The use of reproductive technologies such as somatic cell nuclear transfer (SCNT) for avian species has been limited by the inability to visualise the pronucleus or pronuclei within the blastodisc or germinal disc region, respectively, primarily due to the opacity of the large, lipid filled yolk. The main objective in the present study was to assess a method for visualising and enucleating the avian ovum, a critical step in developing the capability for cloning birds. The method utilised in the present investigation was epi-fluorescence transmitted light (top-side UV) microscopy (EFTLM), also known as fluorescence/oblique or fluorescence/differential interference contrast (DIC) illumination, combined with vital staining and DNA visualisation techniques. The use of EFTLM combined with micromanipulation methods adapted from mammalian cloning procedures showed that the vitelline membrane of the avian ovum can be pierced and aspiration of the pronucleus, once visualised, can be performed without compromising the ovums structure. Two approaches for domestic chicken ova collection, i.e., in vivo and in vitro, were utilised and ova recovery rates were compared. Based on a statistical analysis, i.e., Fishers exact test, the results of the in vivo versus in vitro ovulation ova recovery methods were significantly different (P < 0.05), with the in vivo ovulation method yielding more viable intact ova. In conclusion, enucleating the avian ovum using EFTLM combined with vital staining, DNA visualisation, and micromanipulation techniques can be a feasible option for future avian cloning endeavours; although it will require further refinement to improve overall efficiency.

58 RADIO-FREQUENCY IDENTIFICATION INTELI-STRAWS: GAMETES AND EMBRYO PACKAGING, STORAGE, AND INFORMATION RECOVERY

The assisted reproduction industry involving sales and services for gametes and embryos for domestic animals of commercial value is a large market totaling millions of dollars annually. The objective of this study was to develop and test gamete and embryo packaging-Inteli-Straws (I-S) equipped with radio-frequency identification (RFID) technology. Specifically, French straws (0.25 and 0.5mL) were modified to include extreme cold-tolerant RFID microchips. Two groups of I-S were formed: Group (G)1: RFID chips that were autoclaved (n=49), and G2: RFID chips that were not autoclaved (n=47). Both groups had a control that was not exposed to liquid nitrogen (LN). Each group was exposed to LN up to 4 times: 2 slow freezes first and then 2 fast (i.e. vitrification) freezes, and I-S RFID chip survival was determined. I-S detection and readability (non-autoclaved) was also measured, placing I-S just above LN (in vapors, n=43) or just below LN (n=38). Statistical differences (α=0.05) were determined using Fishers exact test. The results between G1 and G2 were not significantly different (P=0.108) after 4 rounds of cryopreservation (and thawing). For G1, 98% (48/49) of the I-S RFID chips remained operational, and control and treatment were not significantly different (P=1.000). For G2, 89.4% (42/47) of the autoclaved RFID chips remained operational, and control and treatment not significantly different (P=0.099). RFID chip readability results; that is, the ability to detect the I-S versus not able to detect the I-S, comparing placement just above liquid nitrogen (LN) versus the placement just below LN were not significantly different (P=0.105). Notably, detection differences varied within each group, with I-S in G1 (mean=9.5; SD=3.5cm) readable at a larger distance, 5.2cm farther than the mean of G2 (mean=4.3; SD=1.9cm). During AI or embryo transfer (ET), a technician may not clearly identify the label or colour of straw, may incorrectly record the information, or may take more time than desirable to record it. Increased exposure times may lead to decreased viability of gametes and embryos. The results show that by using the I-S, one may quickly scan the straw within LN or LN vapors, thereby automatically detecting information and even uploading it to a database (e.g. scanner sophistication). We are not aware of comparable device to I-S for locating and retrieving associated information without removing the gamete/embryo packaging from LN or LN vapors; unlike traditionally labelled straws (e.g. laser etched or ink labels). Also, for AI and ET, the I-S can be quickly scanned and the straw information automatically detected and uploaded to a database.