Equine embryo research focuses on the early developmental stages of horses, encompassing the formation, growth, and differentiation of the embryo. This area of study is significant for understanding reproductive biology, improving breeding programs, and advancing assisted reproductive technologies in equines. Key aspects include the processes of fertilization, embryonic development, and implantation. Researchers investigate factors influencing embryonic viability, such as genetic and environmental influences, to enhance reproductive success rates. This page aggregates peer-reviewed research studies and scholarly articles that explore the biological mechanisms, technological advancements, and applied methodologies related to equine embryos.
Ginther OJ, Bergfelt DR.Incidence of embryo reduction (natural elimination of one member of a twin set) before d 11 was studied by comparing the number of ultrasonically detected conceptuses per ovulation between single and double ovulators. Effect of unilateral (n = 24) vs bilateral (n = 26) double ovulations on the incidence of embryo reduction also was considered. Each of 50 double-ovulating mares was matched with two single ovulators yielding 100 ovulations, or potential embryos, per group. Frequency with which an ovulation resulted in a conceptus was greater for single ovulators (85%, P less than .01) and for bi...
Enders AC, Lantz KC, Liu IK, Schlafke S.Twelve blastocysts, collected 7-12 days after ovulation (Day 0), were examined by light and electron microscopy to investigate the nature of the relationship of the polar trophoblast (Rauber's layer) to the inner cell mass. On Day 7, the polar trophoblast was intact and formed a flattened layer overlying the epiblast cells of the inner cell mass. As blastocysts enlarged to greater than 1 mm in diameter, small discontinuities appeared in the polar trophoblast, where epiblast cells intruded onto the surface. At this time, trophoblast cells adhered closely to adjacent and underlying epiblast cell...
Bessent C, Ginther OJ.The caracteristics of early intrauterine mobility of the conceptus were compared between ponies (n = 9) and donkeys (n = 9). The extensive mobility of the early conceptus, previously reported for ponies and horses, was found in donkeys as well. There were no significant differences between donkeys and ponies in the characteristics or patterns of mobility. However, the mean day of fixation was approximately one day later (P<0.05) in donkeys (Day 15.6 +/- 0.3) than in ponies (Day 14.7 +/- 0.2).
Ball BA, Shin SJ, Patten VH, Garcia MC, Woods GL.Pony mares which were detected pregnant by transrectal ultrasonography received a single intrauterine infusion of either sterile saline (control, n = 12 mares) or 10(6)Candida parapsilosis (treated, n = 12 mares) between Days 11 to 14 postovulation. Subsequent embryonic loss was studied by daily ultrasonography of the mare's uterus, by serum progesterone levels, by endometrial swabs for cytologic and microbiologic examination and by endometrial biopsies that were taken after embryonic loss was detected. Significantly fewer (P<0.01) embryonic losses occurred in control than in treated mares (4 ...
Sertich PL, Love LB, Hodgson MR, Kenney RM.Equine embryos were collected by transcervical uterine flush 7 d after ovulation. The flush solution was Dulbecco's phosphate buffered saline (PBS) with 1% newborn calf serum and penicillin-streptomycin. Each embryo was washed in modified Dulbecco's PBS with 1% newborn calf serum and 0.4% bovine serum albumin, and placed in 4-ml polystyrene test tube containing this same medium. Embryos were packaged in a commercial semen transport container which cooled (-0.3 degrees C/min) and maintained the embryo at 4 to 6 degrees C. After 24 h, 16 embryos were transcervically transferred into recipient ma...
White KL, Thomson DL, Wood TC.An indirect immunofluorescence assay was used to detect the presence of H-Y antigen on equine blastocysts. A total of 33 blastocyst stage horse embryos were collected 6 to 7 days post-ovulation by trans-cervical flush and were immediately evaluated for the presence of H-Y antigen. Additionally, 17 embryos, were collected and cultured for 72 h to the expanded blastocyst stage and similarly evaluated. Embryos were placed in medium containing monoclonal antibodies to H-Y antigen followed by incubation in medium containing 1/10 (v/v) fluorescein isothiocyanate conjugated goat anti-mouse IgM Fc spe...
Pascoe DR, Pascoe RR, Hughes JP, Stabenfeldt GH, Kindahl H.One hundred mares carrying twin conceptuses between gestation days (GD) 12 and 30 were assigned to 4 groups. Group-1 mares (n = 20) were given a placebo (sterile saline solution, IV, and sesame oil, IM). Group-2 mares (n = 32) were given a single dose of progesterone (625 mg, IM) in sesame oil. Group-3 mares (n = 28) were given multiple progesterone treatments (625 mg, IM) at 6-day intervals until GD 42. Group-4 mares (n = 20) were given a single treatment of flunixin meglumine (500 mg, IV) and progesterone (625 mg, IM). Each group was further assigned to equal subgroups A and B according to t...
Clark KE, Squires EL, McKinnon AO, Seidel GE.Equine embryos were recovered nonsurgically 6.5 d after ovulation (Exp. 1) and those greater than 200 microns were stored in one of three media: 1) Ham's F10 + 10% fetal calf serum (FCS) under 5% CO2, 5% O2 and 90% N2 at 24 C (Ham's F10); 2) Minimal Essential Medium with Hank's balanced salts + 10% FCS in air (MEM) at 24 C or 3) MEM at 5 C n = 10/treatment). Embryos less than or equal to 200 micron (n = 10) were bisected microsurgically; one-half of each embryo was stored in Ham's F10 and the other half in either Dulbecco's phosphate-buffered saline + 10% FCS in air at 24 C (DPBS), or MEM in a...
Kastelic JP, Adams GP, Ginther OJ.Luteal progesterone was removed by an injection of prostaglandin F2alpha or bilateral ovariectomy on Day 12 of pregnancy in pony mares. The embryonic vesicle remained mobile in the uterus until loss occurred on Days 13, 13, 15, or 19 in four prostaglandin-treated mares and Days 15, 17, 19, or 26 in four ovariectomized mares. Exogenous progesterone given daily, starting on Day 12, maintained pregnancy until Day 40 in five of five prostaglandin-treated and three of four ovariectomized mares. During two-hour mobility trials on Day 14, embryonic vesicles in mares without luteal or exogenous proges...
Bousquet D, Guillomot M, Betteridge KJ.The capsule which surrounds the pre-attachment equine embryo has been compared with the zona pellucida (zp) that it replaces, as well as with the rabbit blastocyst coverings, by means of physicochemical and immunological methods. Trypsin solution at pH varying between 7.5 and 9.0 completely solubilized the capsule, as did Na borohydride. However, solutions of pH 2.0 or 12.0, urea, high temperature (65 degrees C, 60 min or 80 degrees C, 30 min), mercaptoethanol and dithiothreitol were able to solubilize the zp but not the capsule at the concentrations used. Indirect immunofluorescence on cryost...
Romagnano A, Richer CL, King WA, Betteridge KJ.To define the time of X-chromosome inactivation in the horse, 122 conceptuses were collected transcervically between Days 6 and 28 (ovulation = Day 0) and subjected to cytogenetic analysis: 59 of the embryos were divided and in 41 of these separate cytogenetic analysis of the embryonic disc and remaining tissues was possible. Conceptuses were measured and photographed before capsule removal, culture in the presence of 5-bromodeoxyuridine and subsequent fixation for cytogenetic analysis. On average, 15 slides were prepared per conceptus. C-banding was used to determine the sex of each conceptus...
Wilson JM, Caceci T, Potter GD, Kraemer DC.Embryos were recovered non-surgically at about Day 6 after ovulation from 15 Quarter horse-type mares and were evaluated for morphological changes which may occur because of exposure to the cryoprotectant and/or cryopreservation. Electron microscopy was used to elucidate the fine structure of intracellular organelles which, if damaged, could cause cellular death. The horse embryo does not totally re-expand in the 10% glycerol freezing medium, nor will it completely re-expand in the isotonic holding medium following glycerol removal whether or not the embryo has been frozen. Embryos in this stu...
Woods GL, Hillman RB, Schlafer DH.To evaluate embryo transfer as a possible method to circumvent infertility in mares, embryos from 14 normal and 14 infertile mares were collected three times and examined. Fewer flushes (p less than 0.05) from normal than infertile mares (1/42 vs 9/42) contained only abnormal embryos whereas more flushes (p less than 0.05) from normal than infertile mares contained one or more normal embryos (28/42 vs 8/42). More flushes (p less than 0.05) from normal than infertile mares contained embryos (29/42 vs 17/42). The embryo diameters (mm) at either day-7 or day-8 post ovulation were greater (p less ...
Czlonkowska M, Boyle MS, Allen WR.Fourteen horse embryos recovered non-surgically on Days 6-8 after ovulation (Day 0) were cooled slowly to - 35 degrees C (7 embryos) or - 40 degrees C (7 embryos) and stored in liquid nitrogen (- 196 degrees C) for 4-98 days. Surgical transfer of the thawed embryos to unmated recipient mares that had ovulated - 2 to + 1 days with respect to the embryo donors resulted initially in the establishment of 4 conceptuses. However, only one mare maintained her pregnancy to term.
Physick-Sheard PW, Maxie MG, Palmer NC, Gaul C.Valvular competency of the foramen ovale (patent foramen ovale) is regarded as a common finding in the neonatal foal and usually occurs in isolation. True atrial septal defects appear to be uncommon and are usually associated with other congenital cardiac lesions. The present report describes a case of atrial septal defect type 1 (persistent ostium primum) complicated by hypoplastic right ventricle, and tricuspid dysplasia, in a Welsh Mountain pony foal, and discusses the embryogenesis of the abnormality. A critical review of the literature suggests that atrial septal defects may occur more fr...
Slade NP, Takeda T, Squires EL, Elsden RP, Seidel GE.Early equine blastocysts and blastocysts were collected nonsurgically at six days post-ovulation. Thirty-two embryos were randomly assigned to a 2x2 factorial design. Factors were: 1) 0.5-ml straws or 1-ml glass ampules; and 2) plunging into liquid nitrogen (IN(2)) at -33 C or -38 C. Cryoprotectant, 10% glycerol in PBS plus 5% fetal calf serum (FCS) was added in two steps, 5% then 10%. Embryos were cooled at 4 C/min to -6 C and then seeded, 0.3 C/min to -30 or -35 C and 0.1 C/min to -33 or -38 C. Samples were thawed in 37 C water and glycerol removed in six steps, 10 min per step. Embryo quali...
Ginther OJ.Twenty-one pregnant pony mares were assigned to one of the following groups: 1) controls, 2) ovariectomy at Day 12, 3) ovariectomy at Day 12 plus daily progesterone treatment on Days 12 to 40, 4) PGF(2alpha) on Day 12, 5) PGF(2alpha) on Day 21, and 6) PGF(2alpha) on Day 30. Based on daily examinations by ultrasound, the embryonic vesicle was maintained to Day 40 in all control mares and in mares that were ovariectomized on Day 12 and given progesterone. The embryonic vesicle was lost in all mares of the other four groups. Administration of progesterone prevented the embryonic loss associated w...
Ginther OJ, Bergfelt DR, Leith GS, Scraba ST.Pregnancy was determined by ultrasound on Days 11, 15, 20, 25, 30, 35, 40, 45, and 50 in 154 ponies and 27 horses. In ponies, the embryonic loss rate for Days 11 to 15 (28 154 , 18.2%) was greater (P<0.01) than for any of the subsequent five-day intervals (0% to 3.3%). There were no losses during Days 11 to 15 in horses (0 27 ), and the difference between ponies and horses was significant. The loss rates for the seven periods encompassing Days 15 to 50 were not significantly different among periods. Pseudopregnancy occurred more frequently (P<0.01) following embryonic loss after Day 20 (...
Romagnano A, King WA, Richer CL, Perrone MA.A technique is described for the preparation of banded chromosomes from early equine embryos cultured for less than 10 h in a medium containing bromodeoxyuridine. In addition to standard Giemsa staining and C-banding, chromosomes thus prepared can also be R-banded by either the RBA or the RB-FPG methods. This technique is rapid, repeatable, and limits cell loss, making it ideal for the preparation of early embryos.
Brockschmidt LD, Loch WE, Sikes JD.An experiment was conducted to test the effect of repeated transcervical (non-surgical) uterine flushing and a prostaglandin analogue (PG) on the estrous cycle of pony mares. Uteri in group A were trancervically flushed for embryos 7 to 9 days post ovulation. In addition, group B mares were given 5 ml of PG by intramuscular injection on the day of flushing. Group C served as controls and were not flushed or given PG but were allowed to cycle normally. All mares (except controls) were bred A.I. every other day during estrus. There was no effect on embryo recovery rate from repeated flushing or ...
Paulo E, Tischner M.The activity of delta (5)3 beta-hydroxysteroid dehydrogenase was examined histochemically in 6 to 10 days aged horse blastocysts. A positive reaction was noted in the blastomeres of all embryos incubated in medium with substrate. Measurable amounts of progesterone, androgens and estrogens were found in blastocysts on day 8th. The presence of enzyme and hormones suggests that steroid hormone production takes place in very early preimplantation horse embryos.
Allen WE, Goddard PJ.The uteri of 13 pony mares were examined daily by ultrasound during the first two months of gestation. The conceptus was first identified between 12 and 16 days after ovulation and the embryo was seen on the ventral surface of the conceptus after Day 21. The foetal heart could be visualised after Day 22 and spontaneous movement of the foetus occurred after Day 39. No consistent pattern was seen in the development of the foetal membranes, although attachment of the umbilical cord to the allantochorion was always on the dorsal aspect of the conceptus. Daily measurements were made of the diameter...
Leith GS, Ginther OJ.Intrauterine mobility patterns of the embryonic vesicle were characterized on Days 9 to 17 after ovulation in pony mares using real-time ultrasonography (n=5 or 7 mares per day). The location of the vesicle was determined by dividing the uterus into right horn, left horn, and body. Each uterine horn was further divided into three approximately equal portions (cranial third, middle third, caudal third), yielding seven segments (body plus three portions of each horn). Location of the vesicle within the uterus was recorded every five minutes for two consecutive hours (25 location determinations p...
Allen WR, Pashen RL.The blastomeres of 192- to 8-cell embryos recovered surgically 1-3 days after ovulation from 23 Pony mares were mechanically separated and inserted, in various combinations, into evacuated pig zonae pellucidae to make 27 'half' and 17 'quarter' micromanipulated embryos. These were embedded in agar and cultured in vivo in the ligated oviducts of ewes for 3.5-5 days to allow development to the late morula/early blastocyst stage. Subsequent surgical or non-surgical transfer of 13 'half' and 17 'quarter' embryos to mares resulted in 10 established pregnancies, including 2 monozygotic pairs. Surgic...
Ginther OJ.The equine embryonic vesicle has been shown to be highly mobile prior to day 15, moving from one horn to the other many times per day. In Experiment 1, intrauterine mobility patterns of the vesicle were compared between barren and postpartum mares on days 12, 13, or 14, using an ultrasound instrument. Location of the vesicle (left horn, right horn, body) was determined every five minutes during six two-hour trials in each group. Averaged over all trials, the vesicle moved from one horn to the other 1.1 times per two-hour trial. There were no significant differences between barren and postpartu...
Zarrilli A, Lacalandra GM, Minoia P.In mare, sheep and bitch the action of PGF2 alpha have been studied in the early pregnancy. Prostin F2 alpha (Upjohn) and Gabbrostim (Vetem ) are commercial names of PGF2 alpha used at doses which are luteolytic in the non pregnant female. Seric progesterone showed a temporaneous decrease but after four or five days the initial values were restored and none of the experimental females aborted. In the opinion of authors, embryo per se and/or with its adnexa might have interacted blocking the mechanism of luteolysis induced by the administration of PGF2 alpha.
Choi YH, Hinrichs K.There is a clinical demand for cryopreservation of both in vivo-recovered and in vitro-produced (IVP) equine embryos. We previously reported successful vitrification of expanded equine blastocysts in fine-diameter microloader pipette tips (MPTs) after blastocoel collapse, in a research setting. Here, we report the results of clinical application of the MPT vitrification technique for both in vivo-recovered and IVP blastocysts. In vivo-recovered blastocysts were obtained by referring veterinarians on Days 6 to 8 after ovulation, and shipped 1 to 10 hours to the laboratory before vitrificat...
Hinrichs K, Riera FL.Ten mares were used to investigate the effect of administration of prostaglandin F2 alpha on uterine tubal motility, as reflected by embryo recovery from the uterus 5 days after ovulation (day 0). Mares were assigned to 3 groups: group A, uterine flush for embryo recovery on day 7; group B, uterine flush for embryo recovery on day 5; and group C, uterine flush for embryo recovery on day 5, after treatment with prostaglandin F2 alpha (10 mg, IM) on day 3. Each mare was assigned to each group once. Embryo recovery rates for the 3 groups were: A, 6 of 10; B, 2 of 8; and C, 0 of 10. The embryo rec...
Azuma T, Choi YH, Hochi S, Oguri N.The development of in-vitro matured and microfertilized horse oocytes was examined in vitro. Fertilized oocytes were produced by 20-h insemination of in-vitro matured and partially zona-removed oocytes with frozen spermatozoa that had been treated with caffeine/calcium ionophore A23187 (fertilization rate 34.2%, monospermy rate 76.9%). Embryonic development was assessed by the number of nuclei stained with Giemsa solution. In Experiment 1, a continuous 8-day culture of the microfertilized oocytes in TCM199 or modified synthetic oviduct fluid (m-SOF) supplemented with 10% fetal bovine serum or ...
Vanderwall DK, Woods GL.To determine the effect on fertility of large-volume uterine lavage with lactated Ringer's solution (LRS) performed immediately prior to insemination in mares. Methods: Prospective randomized controlled study. Methods: 20 mares. Methods: Control mares (n = 10) were inseminated with 1 billion (estimated before cooling) progressively motile spermatozoa that had been cooled in a passive cooling unit for 24 hours. Mares (n = 10) in the treatment group were inseminated with 1 billion progressively motile spermatozoa (cooled as described for control mares) immediately after uterine lavage with 4 L o...
Hinrichs K, Riera FL, Klunder LR.Embryo transfer was performed in three mares with gonadal dysgenesis. Karyotypes of the mares were as follows: Mare 1, 63,XX, 64,XX, 65,XX; Mare 2, 63,X; and Mare 3, 65,XXX. The mares were administered progesterone in oil, 300 mg intramuscularly daily, starting 1 or 2 days after donor mare ovulation. Embryos were transferred on day 7 after donor ovulation. Mare 1 became pregnant after the first embryo transfer and had a normally developing fetus on necropsy on day 45 of gestation. Mare 3 became pregnant after the third embryo transfer, but the embryo was lost between day 14 and day 18 of gesta...
Woods GL, Hillman RB, Schlafer DH.To evaluate embryo transfer as a possible method to circumvent infertility in mares, embryos from 14 normal and 14 infertile mares were collected three times and examined. Fewer flushes (p less than 0.05) from normal than infertile mares (1/42 vs 9/42) contained only abnormal embryos whereas more flushes (p less than 0.05) from normal than infertile mares contained one or more normal embryos (28/42 vs 8/42). More flushes (p less than 0.05) from normal than infertile mares contained embryos (29/42 vs 17/42). The embryo diameters (mm) at either day-7 or day-8 post ovulation were greater (p less ...
Bragulla H, Budras KD, Reilly JD.The fetal development of the white line (Zona alba) in the equine hoof is described. Its specific structure of lamellar and interlamellar horn, which in turn is composed of cap and terminal horn, is formed in the second half of the hoof's fetal development. In equine fetuses with a crown-rump length of less than 550 mm, the hoof capsule lacks a 'characteristic' white line since no borders between stratum medium, stratum internum and sole horn are discernible. In the hoof of an equine fetus with a crown-rump length of 550 mm, a narrow white line has taken shape. Its shallow lamellae are arrange...
Budik S, Tschulenk W, Kummer S, Walter I, Aurich C.Live cell RNA imaging has become an important tool for studying RNA localisation, dynamics and regulation in cultured cells. Limited information is available using these methods in more complex biological systems, such as conceptuses at different developmental stages. So far most of the approaches rely on microinjection of synthetic constructs into oocytes during or before fertilisation. Recently, a new generation of RNA-specific probes has been developed, the so named SmartFlare probes (Merck Millipore). These consist of a central 15-nm gold particle with target-specific DNAs immobilised on i...
Wagner LH, Aurich J, Melchert M, Okada CTC, Gautier C, Kaps M, Claaßen S, Aurich C.High progesterone concentrations in the early luteal phase support pregnancy, whereas subphysiological progesterone concentrations delay embryonic development at least until placentation. In this study, fetal growth and development of pregnancy was investigated in pregnancies with prostaglandin F-induced low progesterone concentrations (PGF) in the early luteal phase and control pregnancies (CON) in the same mares (n = 12). Mares were inseminated and in PGF pregnancies received the prostaglandin F analogue cloprostenol (62.5 µg) on days 0-3 after ovulation to induce subphysiological proges...
Kunanusont N, Taesuji M, Kulthonggate U, Rattanamas K, Mamom T, Thongsri K, Phannithi T, Ruenphet S.African horse sickness (AHS) has become a newly emerging disease after an outbreak in northeastern Thailand in March 2020. Mass vaccination in horses with live-attenuated AHS virus (AHSV) vaccine is essential for AHS control and prevention. This study aimed to monitor the longitudinal humoral immune response before and after a single vaccination using a live-attenuated vaccine against AHS in stallions, mares, and pregnant mares, including maternal immunity in foals born from pregnant mares during the outbreak in Thailand. Unassigned: A total of 13 stallions and 23 non-pregnant and 21 pregnant ...
Li N, Dai S, Wu H, Zhang F, Song S, Guo Y, Wang S, Chang S, Zeng S.The application of embryo recovery and transfer technology in the donkey industry is far lower than that of horses and cattle. Sometimes the recovered embryos could not be transferred in time, which required embryo cryopreservation. The embryo cryopreservation technology is more conducive to the preservation and transportation of recovered embryos with excellent genetic traits. However, this technique for donkey embryos is not efficient and needs further optimization. The objective of this study was to evaluate the effect of different manual puncture methods on the viability and pregnancy rate...
De Coster T, Van Poucke M, Bogado Pascottini O, Angel-Velez D, Van den Branden E, Peere S, Papas M, Gerits I, Govaere J, Peelman L, Vermeesch JR....In addition to fulfilling many breeders' curiosity, equine embryonic sex determination can have a profound commercial impact. However, the application of currently described assays for equine embryonic sexing has rendered variable diagnosis and validation rates, with sensitivity being the main problem. In addition, while pregnancy results of in vivo-flushed equine embryos following a needle aspiration biopsy equal those of non-biopsied embryos, the effect on in vitro-produced embryos is unknown. Here, we aimed to develop a highly sensitive and specific assay for equine sex determination that c...
Newcombe JR, Wilsher S, Silva ESM, Sala-Ayala L, Cuervo-Arango J.Two experiments were conducted in the Northern (UK) and Southern (Brazil) hemispheres to determine the effect of season (month of conception) on the development of supplementary CL (SCL) and the relationship with pregnancy loss. In experiment 1, 199 pregnancies were followed between Day 14 and term, to determine the number of SCL and pregnancy viability (Northern Hemisphere). From the 199 pregnancies, 178 were obtained from inseminations during the breeding season (March-September), while the rest, 21 pregnancies resulted from conceptions in the non-breeding season (October to February). Pregn...
Gille JF, Ginther OJ.The gross and ultrasonic equine embryo morphology are described with emphasis on specific days after ovulation. Included are labeled colored photographs and detailed descriptions of the embryo proper (future fetus and foal) and of the entire embryonic vesicle on Days 21, 24, 30, 35/36, and 40. A few related aspects are included for the early fetus on Days 45 and 50. Regression lines for growth in the length of the embryo proper and diameter of the embryonic vesicle along with the mean days of the morphological event are included. Ultrasonograms of the embryonic vesicle are shown and discussed ...
Fernández-Hernández P, Valero-González M, Fuentes-Romero B, Iglesias-García M, Ezquerra-Calvo LJ, Martín-Cuervo M, Macías-García B.Currently, for in vitro embryo production in live mares, immature oocytes are retrieved by transvaginal follicular aspiration or ovum pick up (OPU). Occasionally, ovarian abscesses have been described after OPU, but no current consensus exists on how to treat this condition. Objective: To describe diagnosis and successful treatment of ovarian abscesses in two mares subjected to OPU. Methods: Case report. Methods: Case records were reviewed and summarised. Results: In the first case, a pony mare showed tachypnoea, tachycardia, high temperature, leukocytosis, left hindlimb lameness and slight in...
Gonzalez-Castro RA, Carnevale EM.Phospholipase C Zeta 1 (PLCZ1) is considered a major sperm-borne oocyte activation factor. After gamete fusion, PLCZ1 triggers calcium oscillations in the oocyte, resulting in oocyte activation. In assisted fertilization, oocyte activation failure is a major cause of low fertility. Most cases of oocyte activation failures in humans related to male infertility are associated with gene mutations and/or altered PLCZ1. Consequently, PLCZ1 evaluation could be an effective diagnostic marker and predictor of sperm fertilizing potential for in vivo and in vitro embryo production. The characterization ...
Podico G, Canisso IF.This study aimed to compare the morphometry of horse and mule embryos. The study's hypothesis was that the micronuclei and nuclear fragmentation indexes are higher in mule embryos than in horse embryos. Twenty-two mares were randomly assigned in a crossover design to receive semen from a horse and a donkey; thirteen horse and thirteen mule embryos were obtained. Embryos were recovered eight days post-ovulation and classified according to the stage of development and quality with a score from 1 (excellent) to 4 (degenerate). Embryos were stained with Hoechst33342, and images were acquired with ...
Pollard CL.Years of sire and dam selection based on their pedigree and athletic performance has resulted in a reduction in the reproductive capability of horses. Mare age is considered a major barrier to equine reproduction largely due to an increase in the age at which mares are typically bred following the end of their racing career. Nicotinamide adenine dinucleotide (NAD) and its involvement in the activation of Sirtuins in fertility are an emerging field of study, with the role of NAD in oocyte maturation and embryo development becoming increasingly apparent. While assisted reproductive technologies ...
Cortez JV, Hardwicke K, Grupen CG, Herrid M, Machaty Z, Vajta G.A 6-year-old mare, a valuable polo horse, died of complications following postcolic surgery. To preserve its genetics, ear skin samples were collected immediately after death and stored in an equine embryo transfer medium at 4°C for 5 days. After trypsin digestion, monolayer fibroblast cultures were established, but signs of massive bacterial infection were found in all of them. As an ultimate attempt for rescue, rigorously and repeatedly washed cells were individually cultured in all wells of four 96-well dishes. New monolayers were established from the few wells without contamination and us...
Piotrowska-Tomala KK, Jonczyk AW, Szóstek-Mioduchowska A, Hojo T, Żebrowska E, Katila T, Ferreira-Dias G, Skarzynski DJ.Intrauterine devices (IUD) are used in the veterinary practice as the non-pharmacological method of oestrus suppression in mares. When placed in the uterus, IUD create a physical contact with the endometrium that mimics the presence of an equine embryo. However, the mechanism of their action has not been fully elucidated. The objective of the present study was to examine the effect of mechanical stimulation of IUD on mare`s endometrium in both in vitro and in vivo study. For this purpose, we demonstrated the effect of IUD on prostaglandin (PG) F and PGE secretion, and mRNA transcription of gen...
Leal Reis I, Lopes B, Sousa P, Sousa AC, Branquinho MV, Caseiro AR, Rêma A, Briote I, Mendonça CM, Santos JM, Atayde LM, Alvites RD, Maurício AC.Horses are high-performance athletes prone to sportive injuries such as tendonitis and desmitis. The formation of fibrous tissue in tendon repair remains a challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance regeneration, retrieving original tissue properties. Multipotent Mesenchymal Stem/Stromal Cells (MSCs) have been successfully used to develop therapeutic products, as they secrete a variety of bioactive molecules that play a pivotal role in tissue regeneration. These factors are released in culture media for producing a conditioned medium (...
Delchiaro SB, Oliveira PVLF, Júnior RJP, Gonçalves GD, Morotti F, Seneda MM.Mares (n = 77) were evaluated by antral follicle count (AFC) and selected as embryo recipients. Cyclic recipients received embryos between days 4-6 after ovulation. The acyclic recipients received an intramuscular (i.m.) protocol with 5mg of estradiol benzoate (EB) on the day of donor ovulation (D0; D-4 recipient), 3mg of EB on the following day (D1; D-3 recipient), and 3mg of EB (D2; D-2 recipient). Furthermore, 1500mg of progesterone (P4) i.m. given on D0 of the recipient (D4 donor) followed by 1500mg of P4 on the day of ET (D4-6 recipient). On the ET day, the AFC and animals' weight, body c...
Sielhorst J, Baade S, Neudeck KC, Tönissen A, Rohn K, Hollinshead F, Sieme H.Transvaginal ultrasound-guided aspiration (TUA) is used for post-fixation twin reduction in mares. However, there is limited information regarding factors that influence pregnancy outcome after TUA. Objective: To evaluate the effect of day of gestation on which TUA is performed, aspiration volume, puncture of the conceptus, medication administered before and after TUA, embryo location, mare age and parity and operator experience on pregnancy and foaling rates after TUA. Methods: Retrospective case series. Methods: Data were collected from case records of 464 TUAs performed by 14 operators in 4...
Sadowska A, Molcan T, Wójtowicz A, Lukasik K, Pawlina-Tyszko K, Gurgul A, Ferreira-Dias G, Skarzynski DJ, Szóstek-Mioduchowska A.The establishment of the fetomaternal interface depends on precisely regulated communication between the conceptus and the uterine environment. Recent evidence suggests that microRNAs (miRNAs) may play an important role in embryo-maternal dialogue. This study aimed to determine the expression profile of endometrial miRNAs during days 26-28 of equine pregnancy. Additionally, the study aimed to predict target genes for differentially expressed miRNAs (DEmiRs) and their potential role in embryo attachment, adhesion, and implantation. Using next-generation sequencing, we identified 81 DEmiRs betwe...
Camargo GS, de Barros LD, Oliveira-Filho JP, Bromberger CR, Dias-Melicio LA, Alves Dos Santos L, Bergfelt DR, Ferraz de Andrade ER, Canesin HS....The present study was designed to evaluate equine blastocyst re-expansion rate, quality, and sex following perforation of the blastocoel, collection of blastocoel fluid (BF), and PCR amplification of free DNA. Experiment 1 tested the feasibility of the BF sample collection with a hand-held, small-gauged needle (26g) and subsequent PCR amplification of the TSP-Y gene for males and AMEL-Y gene for males and AMEL-X gene for females. Experiment 2 tested the application of the technique. Equine embryos were collected via uterine flushes 8d after ovulation. Thereafter, embryos (n = 19) were initia...
Martínez-Boví R, Sala-Ayala L, Querol-Paajanen A, Plaza-Dávila M, Cuervo-Arango J.PGF is commonly given at the end of embryo flushing (EF) to shorten the interval to the next oestrus and ovulation. Objective: To determine the effect of repeated EF on plasma progesterone concentration, percentage of mares with endometritis, unwanted pregnancy and subsequent fertility in mares flushed without the use of PGF . Methods: Controlled experiments. Methods: Nine mares were inseminated in seven consecutive cycles (n = 63), to either perform an EF (n = 54) 7-9 days after ovulation or left pregnant (n = 9). PGF was not used to induce oestrus. Ultrasound examination and bl...
Kovacsy S, Ismer A, Funes J, Hoogewijs M, Wilsher S.Equine embryos >300 μm require puncture before vitrification. Protocols that do not require pre-puncture would make vitrification easier and allow for its widespread use. Objective: To design a successful vitrification protocol for embryos >300 μm without puncture as a pre-treatment. Methods: Experimental in vivo study. Methods: Thirty-eight embryos were divided into 3 groups (G1: ≤300 μm, n = 11; G2: >300-500 μm, n = 20; G3: >500 μm, n = 7). Embryos were vitrified using a human vitrification kit. Following a 15 min exposure to equilibration solution ...
Artificial insemination with cooled-shipped semen is the primary method used in the equine breeding industry; yet, sperm quality and fertility can be suboptimal for some stallions when standard techniques are used. Therefore, there is a critical need to develop alternative approaches for these stallions. Objective: To assess sperm quality parameters and fertility of cooled-stored stallion semen processed by SpermFilter® or centrifugation and resuspended in three extenders. Methods: Controlled and field study. Methods: In Experiment 1, semen was collected from 21 stallions classified as having...
Morris L, Harteveld R, Gibb Z.Insemination of mares with frozen-thawed spermatozoa requires intensive management and results in 40%-60% per cycle pregnancy rates. Objective: To determine if satisfactory fertility is possible for frozen-thawed semen after processing it through a microfluidic device, followed by storage at 17°C for up to 24 h before fixed-time insemination. Methods: Uncontrolled field trials. Methods: A pilot study evaluated the motility of frozen-thawed spermatozoa after centrifugation and storage (17°C) in two different media for up to 48 h. Subsequently, the motility of frozen-thawed semen processed...
Fonte JS, Alonso MA, Junior MPM, Gonçalves MA, Pontes JH, Bordignon V, Fleury PDC, Fernandes CB.This retrospective study aimed at identifying factors that contribute to the success of equine in vitro embryo production by intracytoplasmic sperm injection (ICSI). A total of 7993 ovum pick-up (OPU) sessions were performed, totaling 2540 donor mares and semen from 396 stallions. Oocytes were aspirated at multiple sites in Brazil and were sent to the laboratory, within 6 h from OPU, in pre-maturation medium where they were in vitro matured (IVM) followed by ICSI and in vitro embryo culture for 7-8 days. The number of recovered oocytes, matured oocytes, cleaved embryos and blastocysts were us...
