933 resultados para reproductive seasonality
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To identify genes specifically or predominantly expressed in the stigmas/styles and to establish their possible function in the reproductive process of plants, a tobacco stigma/style cDNA library was constructed and differentially screened, resulting in the isolation of several cDNA clones. The molecular characterization of one of these clones is described here. After sequencing the cDNA and the isolated genomic clone, it was determined that the corresponding gene encodes a protein containing an ATP-binding cassette, characteristic of ABC transporters. This gene, designated as NtWBC1 (Nicotiana tabacum ABC transporter of the White-Brown Complex subfamily), encodes a protein that contains the typical structure of the 'half-transporters' of the White subfamily. To establish the spatial expression pattern of the NtWBC1 gene, northern blot and real-time RT-PCR analyses with total RNA from roots, stems, leaves, sepals, petals, stamens, stigmas/styles, ovaries, and seeds were performed. The result revealed a transcript of 2.5 kb present at high levels in stigmas and styles and a smaller transcript (2.3 kb) present at a lower level in stamens. NtWBC1 expression is developmentally regulated in stigmas/styles, with mRNA accumulation increasing toward anthesis. In situ hybridization experiments demonstrated that NtWBC1 is expressed in the stigmatic secretory zone and in anthers, at the stomium region and at the vascular bundle. NtWBC1 is the first ABC transporter gene with specific expression in plant reproductive organs to be identified and its expression pattern suggests important role(s) in the reproductive process.
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Economic losses caused by enzootic bovine leukosis (EBL) have been of interest since World War II, when the neoplastic form of EEL increased dramatically in Europe. Olson (1974) and House et al. (1975) ed that animals with lymphosarcoma caused by the bovine leukosis virus (BLV) had reduced milk yields. a less efficient reproductive performance and high veterinary costs and mortality rates, while many carcasses were rejected at slaughter. However, the actual impact of BLV infection in cattle without lymphosarcoma is not; clear. The purpose of the study reported here was to compare some productive and reproductive responses of cattle that were antibody-positive (BLV+) or negative (BLV-) for BLV.Holstein dairy cows in commercial dairy farms were used in this study. Blood samples were collected and subjected to BLV serological examination by the agar gel immunodiffusion test of Miller & van der Maaten (1976). Animals were then grouped as BLV+ or BLV- according to their serological response to the BLV antigen. Productive and reproductive histories were obtained from individual animal records and the following factors were considered: milk production, calving interval and birth rate. For milk production, we had the daily milk yields of 547 animals, and for calving interval the time between two successive parturitions for 444 cows. These values were examined by ANOVA and when this was significant a Student's t test was carried out for each age group. Birth rates, the percentage of animals that calved in 1 gear, were available for 557 animals and were examined with the Z-two proportion test. For all analyses, P < 0.05 was considered significant.
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Objective. The purpose of this study was to evaluate the effect of total abdominal hysterectomy on ovarian blood supply using transvaginal color Doppler ultrasonography in women of reproductive age. Methods. This prospective study included 61 women aged 40 years or younger who were divided into 2 groups: group 1, comprising 31 patients who underwent total abdominal hysterectomy (TAH), and group 2, comprising 30 women with no abnormalities. Inclusion criteria included normal ovarian function at baseline, with basal follicle-stimulating hormone levels of less than 15 mUI/mL, normal body weight, no tobacco use, and no history of laparotomy or ovarian disease. Ovarian arterial blood supply by determination of the pulsatility index (PI) on Doppler analysis and ovarian volume on transvaginal ultrasonography were assessed at baseline and at 6 and 12 postoperative months. The Student t test, profile analysis, and Friedman and Mann-Whitney tests were used in the statistical analysis of data. Results. Statistical analysis of baseline data revealed that both groups were homogeneous. At months 6 and 12, greater ovarian volumes and lower PI values were observed in patients who underwent TAH (P < .05). By the end of the study, in 8 of the 31 patients who underwent TAH (25.5%), benign ovarian cysts were observed. in the control group, all the parameters studied remained unchanged. Conclusions. The reduced PI values observed on Doppler ultrasonography suggested a decrease in the resistance flow in the ovarian arteries in women of reproductive age who underwent TAH.
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The present work aimed to estimate heritability and genetic correlations of reproductive features of Nellore bulls, offspring of mothers classified as superprecocious (M1), precocious (M2) and normal (M3). Twenty one thousand hundred and eighty-six animals with average age of 21.29 months were used, evaluated through the breeding soundness evaluation from 1999 to 2008. The breeding soundness features included physical semen evaluation (progressive sperm motility and sperm vigour), semen morphology (major, minor and total sperm defects), scrotal circumference (SC), testicular volume (TV) and SC at 18 months of age (SC18). The components of variance, heritability and genetic correlations for and between the features were estimated simultaneously by restricted maximum likelihood, with the use of the vce software system vs 6. The heritability estimates were high for SC18, SC and TV (0.43, 0.63 and 0.54; 0.45, 0.45 and 0.44; 0.42, 0.45 and 0.41, respectively for the categories of mothers M1, M2 and M3) and low for physical and morphological semen aspects. The genetic correlations between SC18 and SC were high, as well as between these variables with TV. High and positive genetic correlations were recorded among SC18, SC and TV with the physical aspects of the semen, although no favourable association was verified with the morphological aspects, for the three categories of mothers. It can be concluded that the mothers sexual precocity did not affect the heritability of their offspring reproduction features.
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ContentsThe objective of this study is to evaluate the reproductive efficiency in donors and recipient Mangalarga Marchador mares in commercial programmes of embryo transfer (ET) and the effects of some reproductive characteristics and ET methodology on conception rates in the recipient mares. A total of 1140 flushing procedures were performed and 830 embryos (72.8%) were recovered. There were no differences between the rates of embryonic recovery in the different breeding seasons (p > 0.05) and 92.8% of the recovered embryos were 8-9 days old. There was no difference in the embryonic recovery regarding the collection order from the first to the ninth embryo collection along the breeding season, as well as among mares inseminated during the foal heat or subsequent cycles (p > 0.05). Pregnancy rates observed in the total period of all reproductive seasons at 15, 30, 45 and 60 days of pregnancy were 73.4, 69.9, 66.7 and 64.5%, respectively. Differences in pregnancy rate and early embryonic loss rates were not observed between embryos transferred immediately after collection (66.8% and 13.5%) and embryos transported at room temperature for periods of < 1 h (62.9% and 14.4%; p > 0.05). Pregnancy rates were higher when the interval between ovulations of donor and recipient mares remained between -3 and -2 days (p < 0.05), and the lowest rates were observed for intervals of -6 days (p < 0.05) with intermediary values for intervals of -1, 0 and +1 (p > 0.05). Embryonic loss rates, however, did not differ between intervals of ovulation's synchronism between donor and recipient mares (p > 0.05). This flexibilization in the ovulatory synchronism between donor and recipient mares optimizes the use of recipient mares, thus reducing costs and facilitating management of horse breeding farms.
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Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T oreadicus, T itambere, T spinulosus and T Guarani species, collected in different places in the Mato Grosso state, Brazil. The reproductive period is synchronous for males and females and occurs in September, October and November. Reproductive males were characterized. In the testes are seminiferous tubules with germ cells at different stages of spermatogenesis, with a high epithelium, at present light, free spermatozoa in the lumen and reduction of interstitial tissue. For females, the reproduction peak occurs when the oviduct epithelium is high with secretions and basal nucleus. These months are characterized in the sampled areas over a period of heavy rain and high temperatures. The decline of reproductive period was observed in both sexes, between April and August. Low reproduction in males is characterized by ample light, absence of sperm, only germ cells in the early stages of spermatogenesis are observed (a few spermatogonia and spermatocytes) and interstitial tissue wide. In females, the period of reproductive decline is marked by the absence of unicellular glands in the oviduct epithelium, with higher affinity with the dye. This period corresponds to low rainfall periods and lower temperatures. We propose an analysis of zoological samples; this is a proposal to facilitate the work of many researchers through access to the species, especially rare species.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)