Publications (15) View all
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Article: Ovarian response and embryo gene expression patterns after nonsuperovulatory gonadotropin stimulation in primiparous rabbits does.
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ABSTRACT: Ovarian stimulation with equine chorionic gonadotropin (eCG) is largely used in animal reproductive technologies to provide a larger number of oocytes and embryos and to improve the reproductive outcome. However, the consequences of maternal treatment with eCG on embryo gene expression patterns are not widely studied. The aim of this work was to assess the ovarian response (preovulatory follicular population, oocyte maturation, ovulation rate, and serum steroid concentrations), the early embryo survival and gene expression patterns of a panel of quality-genes involved in glucose intake, oxidative stress, apoptosis, proliferation, implantation, and fetal growth in embryos of lactating rabbits treated with eCG. A total of 34 primiparous rabbit does (Oryctolagus cuniculus) were randomly distributed at Day 23 postpartum into a treatment group receiving a unique nonsuperovulatory dose (25 IU) of eCG (eCG group; N = 17 does); or a control group without eCG treatment previously to artificial insemination (control group; N = 17 does). After 48 hours, 8 does of each group were euthanized and their ovarian response was studied. The rest of animals were artificially inseminated and their ovulation was induced with a GnRH analogue. Embryos were recovered 3.5 days later. The oocytes retrieved for in vitro maturation showed no differences in metaphase II rate in both experimental groups, although oocyte cytoplasmic maturation, in terms of cortical granule migration rate, was improved in eCG-treated does (P < 0.05). The mean number of preovulatory follicles was similar between groups but the ovulation rate was significantly higher in eCG-treated does compared with does not stimulated (P < 0.05). No differences were found in serum estradiol and progesterone concentrations of does the day of oocyte and embryo recovery, respectively. However, progesterone:estradiol ratio was slightly increased in eCG group on embryo recovery day (P = 0.1). The percentage of embryos recovered at the blastocyst stage was also increased in eCG-treated does (P < 0.05), nevertheless, there were no differences in the gene expression patterns of candidate genes SLC2A4, IGF1R, IGF2R, SHC1-SHC, TP53, PTGS2, and PLAC8; except for the transcripts of SOD1 mRNA which were downregulated in eCG-derived embryos (P < 0.05). In conclusion, the administration of eCG improves ovulation rate, oocyte cytoplasmic maturation, and blastocyst formation in primiparous rabbit does inseminated on Day 25 postpartum. Although it seems not to influence the gene expression patterns studied, a lower antioxidant defense of embryos developed after the maternal eCG treatment is suggested.Theriogenology 11/2012; · 1.96 Impact Factor -
Article: Metabolic and reproductive status are not improved from 11 to 25 day post-partum in non-weaned primiparous rabbit does.
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ABSTRACT: The aim of present work was to analyze the body reserves and ovarian features of lactating primiparous rabbit does under extensive reproductive management (artificial insemination (AI) at 25 days post-partum (dpp)) compared with the common insemination rhythm at 11 dpp. A total of 48 primiparous Californian×New Zealand White rabbit does suckling 8 kits were used to assess liveweight, estimated body composition, serum metabolic and endocrine parameters (oestradiol and progesterone concentrations) and ovarian features like follicle population and atresia rate, and oocyte maturation. Rabbit does were randomly allocated in two experimental groups: (a) lactating does euthanized at early post-partum period (11 dpp) according to a semi-intensive rhythm (n=24), and (b) lactating does euthanized at later post-partum period (25 dpp) according to a more extensive rhythm (n=24). Liveweight, body energy content, lipid depots and serum non-esterified fatty acids (NEFA) concentrations decreased from parturition to post-partum period (P<0.05). In addition, serum protein and glucose concentrations increased in the post-partum period (P<0.05). Similar oestradiol and progesterone levels were found in rhythms as well as similar follicle population and nuclear and cytoplasmic maturation rates measured as metaphase II and cortical granule migration, respectively in both post-partum times. However, the number of preovulatory follicles on the ovarian surface was lower (P<0.05) and the atresia rate tended to be higher with a lower percentage of healthy follicles (P<0.1) in ovaries from females of extensive group. In conclusion, the body reserves, serum metabolic parameters and oocyte quality of primiparous non-weaned rabbits does at the late post-partum time (25 days) were not improved. Thus this reproductive management did not present any advantages compared to earlier post-partum (11 days) reproductive rhythm.Animal reproduction science 03/2012; 131(1-2):100-6. · 1.56 Impact Factor -
Article: 165 SHORT-TIME FASTING AFFECTS METABOLIC MARKERS WITHOUT IMPACT ON FOLLICLE AND OOCYTE DEVELOPMENT IN THE RABBIT MODEL.
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ABSTRACT: Our goal was to elucidate whether acute energy restriction has any influence on ovarian reproductive processes and the relationship with some metabolic markers in the rabbit model. A total of 22 nulliparous rabbits were randomly distributed in 2 groups: control group fed ad libitum (C; n=12) and 72-h fasted group (F; n=10). Before and after the deprivation period, body weight (BW), estimated body composition, serum triglycerides (TG), nonesterified fatty acids (NEFA), and leptin concentrations were measured. After fasting, ovaries were retrieved: one was used to study oocyte in vitro nuclear and cytoplasmic maturation (in terms of granule cortical migration; Arias-Alvarez et al. 2010 Theriogenology 73, 26-35) and the other one was processed histologically to assess follicle categorization and atresia rate by TUNEL and by immunolocalization of procaspase-3 (PC3). Statistical analysis was carried out by MIXED and CATMOD procedures of SAS program. The BW of control rabbits increased at the end of the experiment (3.96±0.06 v. 4.03±0.09kg; P<0.05), but the fasted group showed similar weight compared with 72h before and the C group (3.97±0.09kg). No differences were observed on estimated body composition between C and F animals (61.0±0.52% water, 2.96±0.02% ash, 18.6±0.51% lipids, 18.4±0.05% protein, and 1206±21.6 kJ/100g of energy). The TG was similar between groups (74.4±9.9 v. 49.3±10.4mgdL(-1)), whereas NEFA concentrations were significantly higher in the F group than before fasting (0.29±0.04mmolL(-1) v. 0.17±0.03mmolL(-1); P<0.05) and than in the control group (0.09±0.04mmolL(-1); P<0.05). In opposition, leptin concentrations were lower in the F group than before fasting (2.2±0.6 v. 5.1±0.4; P<0.05) and than in C rabbits after fasting (4.6±0.5ngmL(-1); P<0.05). No differences were found in the number of primordial (192.0±52.9 v. 276.0±88.6), primary (36.7±6.6 v. 45.5±7.8), secondary (37.1±7.5 v. 54.1±14.6), and antral follicles (21.9±2.1 v. 22.3±2.2) between the C and F group. The rates of healthy (53.2±4.3 v. 57.4±5.0), early atretic measured as <50% of apoptotic cells (15.4±2.2 v. 17.2±2.6), and late follicles measured as >50% of apoptotic cells (31.4±3.6 v. 25.4±4.2) did not differ between groups. Cytoplasm staining of PC3 was observed in stroma, follicles of all sizes, and corpora lutea of both groups. Atretic follicles did not exhibit immunoreactivity to PC3. No significant differences were observed in nuclear maturation and migrated cortical granule rates (63.6 v. 53.7% and 12.0 v. 4.7%, respectively). In conclusion, acute fasting affects BW and some metabolic markers (NEFA and leptin), but follicle and oocyte development is not impaired in our rabbit model.Reproduction Fertility and Development 01/2011; 23(1):185. · 2.11 Impact Factor -
Article: Effect of leptin supplementation during in vitro oocyte maturation and embryo culture on bovine embryo development and gene expression patterns.
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ABSTRACT: Leptin is a metabolic hormone related to body condition and nutritional status that influences fertility in assisted reproductive technologies modulating oocyte and embryo quality. The aim of the present study was to establish the effect of various leptin concentrations (0, 10, 100 ng/mL) during in vitro oocyte maturation (IVM) and in vitro embryo culture (IVC) on bovine embryo development and quality in terms of gene expression. The relative mRNA abundance of the genes encoding solute carrier family 2 (facilitated glucose transporter) member 1 (SLC2A1), Bcl-2-associated X protein (BAX), placenta-specific 8 (PLAC8), aldo-keto reductase family 1 member B1 (AKR1B1) and leptin receptor (LEPR) were determined on Day 7 blastocysts by qRT-PCR. Cleavage rate (P < 0.005) and blastocyst yield (P = 0.05) was significantly lower when cumulus-oocyte complexes (COCs) were matured with 100 ng/mL leptin compared to 0 or 10 ng/mL leptin. No significant effect of different concentrations of leptin added during IVC on blastocyst yield was observed. The presence of 100 ng/mL leptin in both IVM and IVC further decreased cleavage rate (P < 0.005) and blastocyst yield compared to the control group without leptin (P = 0.05) and those supplemented with 10 ng/mL leptin or FCS (P < 0.005). There was no evidence of any leptin-induced difference in the relative transcript abundance of SLC2A1, BAX and PLAC8 genes in Day 7 blastocysts. Expression of AKR1B1 was significantly lower in blastocysts from COCs matured with 100 ng/mL leptin compared to those matured with 0 or 10 ng/mL leptin (P < 0.005). LEPR expression was up regulated when leptin concentration was increased from 0 ng/mL during IVM to 10 ng/mL during IVC, but it was down-regulated in the opposite situation (P < 0.005). In conclusion, high leptin concentrations possibly related to obesity seem to be more detrimental rather than the absence of this hormone for preimplantation embryo survival; this effect is independent of LEPR gene expression and it does not influence expression of SLC2A1, BAX and PLAC8 genes in Day 7 blastocysts.Theriogenology 12/2010; 75(5):887-96. · 1.96 Impact Factor -
Article: Body reserves and ovarian performance in primiparous lactating rabbit does submitted to early weaning as a strategy to decrease energy deficit.
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ABSTRACT: The aim of this work was to study the effect on body composition, serum metabolic parameters and ovarian status of early weaning at 25 Days post-partum (dpp) as a strategy to decrease energy deficit of primiparous lactating rabbit does prior to insemination at 32 dpp following an extensive rhythm. A total of 34 primiparous lactating rabbit does were used and distributed in three groups: 10 lactating does euthanized at 25 dpp (group L25), 13 does weaned at 25 dpp and euthanized at 32 dpp (group NL32), and 11 non weaned lactating does euthanized at 32 dpp (group L32). No significant differences were observed in live body weight, ovary weight, serum NEFA and total protein concentration among groups. Although NL32 does had a low feed intake (122+/-23.5g/Day; P<0.001), their estimated lipids (16.9+/-1.09%, P<0.008), protein (19.7+/-0.07%, P<0.0001), and energy (1147+/-42.7MJ/kg, P<0.006) body contents were higher and their serum glucose concentrations (158+/-24.5mg/dl, P<0.04) were lower compared to L25 does (11.9+/-1.3%, 18.5+/-0.08%, 942+/-51.3MJ/kg and 212+/-27.9mg/dl) and L32 does (13.4+/-1.03%, 18.5+/-0.1%, 993+/-40.4MJ/kg and 259+/-29.5mg/dl), respectively. In the ovarian surface of L25 does a lower number of follicles > or =1mm was observed compared to NL32 and L32 groups (12.7+/-1.5 vs. 18.0+/-1.45 and 17.6 +/-1.67; P<0.05). Follicular population in the histological ovarian sections and immunolocalization of prolactin receptor were similar between groups. In group L25, both nuclear maturation of oocytes in terms of Metaphase II rate (67.0 vs. 79.7 and 78.3%; P<0.05) and cytoplasmic maturation measured by percentage of cortical granules (CG) totally or partially migrated in oocytes were significantly lower than in groups NL32 and L32 (16.0 vs. 38.3 and 60.0%; P<0.05). Consequently, a higher rate of oocytes with non-migrated CGs was found in group L25 than in groups NL32 and L32 (76.0 vs. 46.8 and 33.3%; P<0.05). In conclusion, even though early weaning at 25 dpp seemed to improve body energy stores of primiparous does, this fact was not well reflected on the ovarian status at 32 dpp, which was similar regardless of weaning time and it could be performed later.Animal reproduction science 09/2010; 121(3-4):294-300. · 1.56 Impact Factor
