RESUMO
Follicle diameter deviation has been identified as the pivotal morphological manifestation of follicle selection, however, many of the hormonal mechanisms leading to this key event and regulating variation between individual follicular waves remain undefined. This study compared circulating FSH, LH, and P4 with the follicular dynamics during three different physiological conditions. We hypothesized that these end-points would: 1) be similar for a spontaneous wave 2 vs one induced by follicular aspiration, 2) but would differ between wave 1 and 2, and 3) between conventional (F2â¯>â¯7.0 mm at deviation) vs undersized (F2â¯<â¯7.0 mm) deviations in either wave. Holstein dairy heifers (Nâ¯=â¯24) were studied daily during an interovulatory interval. All heifers were evaluated during wave 1 and randomized 6 days after ovulation into an induced wave 2 and a spontaneous wave 2. Values were normalized to the day of expected diameter deviation (day 0) and compared for day -2 to 0 and 0 to 2. Hypothesis 1 was supported that an induced wave 2 from ablation of follicles of wave 1 and spontaneous wave 2 have similar follicle dynamics. However, the peak FSH surge was more prominent at emergence of an induced wave 2 (Pâ¯<â¯0.003). Hypothesis 2 was supported that waves 1 and 2 differ in follicle and hormone dynamics. Circulating P4 was lower and LH was greater (Pâ¯<â¯0.01) with no difference in diameter of F1 but with a greater (Pâ¯<â¯0.01) diameter of F2 on day 0 in wave 1 (7.3⯱â¯0.2â¯mm) than in wave 2 (6.6⯱â¯0.2â¯mm). Differences between waves were not found when each follicular wave was categorized into conventional vs undersized deviation and analyzed separately. Hypothesis 3 was supported as there were differences in circulating hormones between conventional and undersized deviations. Growth rate of F2 differed (Pâ¯<â¯0.0005) during days -2 to 0 (conventional, 2.6⯱â¯0.2â¯mm/2d; undersized, 1.4⯱â¯0.3â¯mm/2d). However, circulating FSH and P4 concentration on days -1 and 0 tended to be greater (Pâ¯<â¯0.06) in undersized than conventional deviations. In conclusion, the effect of different hormonal conditions on follicle dynamics was observed for F2 and not for F1. Furthermore, understanding the physiology that produces conventional vs undersized deviations is crucial since these categories explained most differences in follicular dynamics and circulating FSH observed in these different physiological conditions. In addition, future studies of wave 2 may be facilitated by using an induced wave 2 since it was similar to a spontaneous wave 2.
Assuntos
Bovinos/fisiologia , Folículo Ovariano/fisiologia , Animais , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Progesterona/sangue , Distribuição AleatóriaRESUMO
This short communication reports the impact of endometrial biopsies, uterine flushings and follicular fluid aspiration procedures at day 6 post artificial insemination (AI) on pregnancy rates. In Experiment 1, cows were timed AI (TAI) and assigned to the following treatment groups: control (n = 37), uterine flushing (n = 35) and endometrial biopsy (n = 38). On day 30 post AI, pregnancy rates were 40.5%, 33% and 28.5%, respectively (p > 0.1). Pregnancy rate on day 60 was lower (p < 0.004) in flushed cows than in the controls. In Experiment 2, oestrus was detected and cows were assigned to flushing (n = 32) or biopsy (n = 33) treatments 6 days after AI, which resulted in pregnancy rates of 31% and 36%, respectively (p > 0.1). In Experiment 3, cows were, 6 days after TAI, randomly assigned to the following treatments: control (n = 84) or aspiration of the largest follicle (n = 73). Pregnancy rates on day 30 post AI were 63.5% for the control group and 53% for the aspirated group (p > 0.1). In conclusion, uterine flushing and endometrial biopsy negatively affect pregnancy rates, but neither procedure can be considered to be incompatible with pregnancy maintenance. Follicular aspiration during pregnancy does not interact with pregnancy success. The amount and quality of samples obtained are compatible with the use of cellular and molecular analysis of uterine variables from cows that failed or succeeded on maintaining pregnancy.
Assuntos
Biópsia/efeitos adversos , Fertilidade , Irrigação Terapêutica/efeitos adversos , Útero/fisiologia , Animais , Bovinos , Desenvolvimento Embrionário , Endométrio/irrigação sanguínea , Endométrio/patologia , Feminino , Líquido Folicular , Inseminação Artificial/veterinária , Folículo Ovariano , Gravidez , Taxa de Gravidez , Sucção , Fatores de Tempo , Ultrassonografia Pré-Natal/veterináriaRESUMO
AIMS: To establish protocols for the simultaneous detection and identification of Xanthomonas species causing tomato bacterial spot. METHODS AND RESULTS: We verified the specificity and sensitivity of the previously reported sets of primers designed for strains of the four species of Brazilian tomato bacterial spot xanthomonads, consisting of 30 of Xanthomonas euvesicatoria, 30 of X. vesicatoria, 50 of X. perforans and 50 of X. gardneri. Furthermore, we tested a multiplex PCR protocol for the purpose of concurrent species identification. The possibility of direct detection of the pathogens in diseased leaf samples was also verified. The primers were highly specific, amplifying only target DNA. The sensitivity of the primers in conventional PCR was 50 pg µl(-1) for purified DNA and ranged from 5 × 10(2) to 5 × 10(4) CFU ml(-1) when bacterial suspensions were analysed. The multiplex PCR was suitable for the detection of all four species and showed similar sensitivity to conventional PCR when tested on purified DNA. When using bacterial suspensions, its sensitivity was similar to conventional PCR only when a biological amplification step (Bio-PCR) was included. Both methods were able to detect the pathogens in symptomatic tomato leaves. CONCLUSIONS: Brazilian Xanthomonas strains causing tomato bacterial spot can be differentiated and identified at species level by a PCR-based method and by a multiplex PCR. SIGNIFICANCE AND IMPACT OF THE STUDY: This protocol may be a feasible alternative tool for the identification and detection of these pathogens in plant material and may be used for routine diagnostic purposes in plant pathology laboratories.