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Summary Nicotine, administered by sub-cutaneous injection over a period of six weeks, was found to be ineffective in breaking male mouse chromosomes as judged by dominant lethal tests. In addition, no indication of an effect of nicotine on the fertility of female mice, or on the development of the foetusin utero, was found.  相似文献   

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Models of the evolution of gynodioecy assume that inbreeding affects male and female fertility equally and ignore quantitative variation in sex expression. The objectives of this study were to assess inbreeding effects, genetic background, and plant maturity on male and female fertility and the mechanism of male sterility inheritance for Nemophila menziesii (Hydrophyllaceae). Frequency of male-sterile flowers, number of anthers and ovules, and percentage of viable pollen were measured on plants from different pedigrees and five inbreeding levels (F = 0, 0.0625, 0.25, 0.5, and 0.75). Quantitative variation in male sterility was evident. As inbreeding increased, anther and ovule number decreased; the effect on anther number was greater than on ovule number. Pedigrees varied in number of male-sterile flowers and inbreeding effects. Frequency of male-sterile flowers was greatest among first flowers. No trade-off between male and female fertility was detected. A model attributing male sterility to a cytoplasmic locus and restoration to male fertility to a nuclear locus accounted for the distribution of complete sterility and hermaphroditism over the pedigrees. This study suggests that models of the evolution and maintenance of gynodioecy should allow for quantitative variation in male and female fertility components due to inbreeding, pedigree, and plant maturity.  相似文献   

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Male mice homozygous for the hypothyroid gene mutation were compared with normal siblings to determine whether hypothyroidism induced infertility by impairing sexual behaviour. In addition, the fertility of the hypothyroid mice was examined. The experimental results provide unequivocal evidence that genetically-induced hypothyroidism in male mice does not impair sexual behaviour or cause infertility.  相似文献   

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Studies on the genetic variation in marginal populations and differentiation between them are essential for assessment of best gene conservation strategies and sampling schemes. In this study, ISSR markers were used to establish the level of genetic relationships and polymorphism 50 genotypes of Salvadora persica collected from 6 different regions of Hormozgan province. The ISSR analysis with 9 anchored primers also generated 105 scorable loci, of which 85 were polymorphic (80.95%). Parameters of genetic diversity and its partitioning were calculated. The genetic analysis demonstrated that S. persica maintain relatively high genetic diversity (PIC was 0.63, Na was 1.27 and Ho and He were 0.15 and 0.17 respectively). The coefficient of genetic differentiation among populations based on FST equaled 0.20. Genetic identities between population's pairs were high (mean I?=?0.88). These values are high as compared with other widespread congener species. Cluster analysis based on the Unweighted Pair Group Method with Arithmetic Averages (UPGMA) revealed 3 main clusters for the ISSR data. The levels of genetic diversity maintained within populations of S. persica indicate that an appropriate sampling design for ex situ safeguarding should capture the majority of genetic diversity found within these taxa to help ensure the long term viability of this species. Furthermore, it could be inferred that ISSR markers are suitable tools for the evaluation of genetic diversity and relationships within the Salvadora persica.  相似文献   

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Daily administration of cannabis extract (mice: 1 mg/day, rats: 5 mg/day for a period of 64 days) results in a cessation of ovarian cyclic activity as judged by vaginal smear and the absence of corpora-lutea in the ovaries of treated rats and mice. Distinct effects are produced upon uterine tissue. Uterine glands were regressed and the stromal edema was conspicuous. Cannabis extract resulted in a decreased uterine RNA, glycogen, and sialic acid concentration. It also brings about a significant depletion in the level of adrenal ascorbic acid.  相似文献   

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The fertility-inhibiting effects of long-term (8 weeks) consumption of maize infected with a fungus producing F2 toxin (zearalenone) was studied in adult male and female albino rats. The fertility rate was further decreased by 25-30% if the animals were kept on contaminated diet up to 14 weeks. The gonadal weight was decreased, follicular maturation and spermatogenesis were disturbed. The toxic diet consumed by mothers during pregnancy and lactation induced permanent changes in reproductive organs, disorders in vaginal cyclicity and disturbed fertility in the offspring. Neonatal administration of purified F2 toxin provoked similar changes. It is suggested that this fungal toxin may cause sterility syndrome in the offspring, similar to that produced by androgen or estrogen administration.  相似文献   

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BACKGROUND : Natalizumab is a humanized monoclonal immunoglobulin G4 antibody directed against the human α4 integrin subunit disrupting interaction with its ligands. As α4 integrins and/or their ligands appear to be involved in reproductive function, the effects of natalizumab on fertility in male and female guinea pigs were investigated. METHODS : Natalizumab was administered by bolus intravenous injection every other day at doses of 0, 3, 10, and 30 mg/kg. Males began treatment at least 28 days prior to mating until necropsy (approximately 3 to 5 days after mating). Dosing in females was done from gestational day (GD) of an existing pregnancy to GD 30 of a second pregnancy. RESULTS : In male guinea pigs, natalizumab treatment had no effect on sperm parameters, reproductive organ weights, organ-weight ratios, or histology of the testis or epididymis. Natalizumab did not affect the ability of treated males to produce pregnancies in untreated females. In female guinea pigs, no treatment-related changes were seen in uterine weights or ovary weights. Pregnancy rates were reduced in females treated with 30 mg/kg natalizumab, but not those treated with 3 or 10 mg/kg. Pregnancy rates were 63.3, 66.7, 66.7, and 29.6% for groups treated with 0, 3, 10, and 30 mg/kg, respectively. Effects observed at 30 mg/kg were at exposures 36-fold those observed in humans. CONCLUSIONS : Natalizumab had no effects on male fertility, but did result in a reduction in pregnancy rates in females treated with the high dose of 30 mg/kg. Birth Defects Res (Part B)86: 108-116, 2009. © 2009 Wiley-Liss, Inc.  相似文献   

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At different parts of the world, Red Seaweeds are one component of human diets especially at Southeast Asia. Red Seaweeds structurally contain bioactive molecules so; we studied the effect of Chondrus crispus on increasing the male albino rat fertility. Twelve male albino rats are used in this study as two group pre-treated group and post- treated one each with 6 animals. The pretreated group was dissected before the post-treated group injection. Each post treated rat injected intramuscular with 1 mg of Chondrus crispus with dose 0.1 ml/ twice per week for 48 day (Mukhtar et al., 2013).The results showed that increasing on the total testosterone levels insignificantly, sperm motility significantly, and decreasing in both FSH and DPPH levels insignificantly and significantly for the MDA levels in the post-treated group. The morphological appearance and histological examination for the sperm, testis and liver were normal as the pretreated group. The molecular studies showed absence of any DNA fragmentation for the testis of both group.The Red Seaweed has an enhanced effect in the testicular function of the animal which might increase their fertility and sexual activities.  相似文献   

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The effect of an extremely low frequency (ELF) magnetic field on the fertility of adult male and female Swiss mice was investigated. Adult male and female mice were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 microT (rms) for 90 days before they were mated with unexposed counterparts. There were no exposure related effects on the fertility of male or female mice. The number of implantation sites, viable fetuses, and the total number of resorptions were not significantly affected in females impregnated by males exposed to the 50 Hz magnetic field as compared with the control group. The number of implantation sites, viable fetuses and the total number of resorptions in exposed females were also not statistically different from the control group. There were no significant effects on the weights of the testes, seminal vesicles, preputial gland or body weights of males exposed to 50 Hz magnetic field. Furthermore, body and uterine weights were not affected in females exposed to 50 Hz field; however, ovarian weight was significantly increased in females exposed to the same field. These results suggest that exposure of male and female mice to low frequency magnetic field had no adverse effects on fertility and reproduction in mice.  相似文献   

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S Krishnan  R P Maickel 《Life sciences》1991,49(26):2005-2011
Ethanol consummatory patterns of individual male and female rats and the effects of Hoe-427 (Ebiratide), an ACTH4-9 analog, thereon, were studied in a test system using 24 hour, two-bottle free choice consumption between 0.2% saccharin and 10% ethanol in 0.2% saccharin. Single, daily i.p. doses (0.03mg/rat) of either ACTH4-10 or its analog resulted in a significant reduction of daily ethanol consumption with no effects on saccharin consumption. After 4 days of treatment, male rats consistently exhibited a rebound increase in ethanol consumption; this effect was not seen in females. The daily ethanol consummatory patterns of the female animals seemed to exhibit a 4-6 day cyclic rhythymicity, suggesting an interaction with estrous cycles. These results support a role for ACTH4-10 in the initiation of ethanol consummatory behavior in rats and suggests the existence of sex differences in this phenomenon.  相似文献   

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Vaccination of female mice with recombinant fertilization antigen (FA-1) causes a long-term reversible contraceptive effect. Also, a DNA vaccine based upon a dodecamer sequence YLP(12) present in sperm causes a reduction in fertility. In the present study, the effects of FA-1 DNA vaccine alone, and FA-1 and YLP(12) DNA vaccines together were examined. FA-1 495-bp DNA was cloned into pVAX1 vector to prepare the DNA vaccine. Four groups of female mice were immunized intradermally by using a gene gun with FA-1 DNA, FA-1 DNA + YLP(12) DNA, FA-1 DNA + YLP(12) DNA mixed with exogenous synthetic CpG oliogodeoxynucleotide (ODN), or vector DNA alone, respectively. Vaccination with all three formulations caused a significant reduction in fertility, with FA-1 DNA + YLP(12) DNA mixed with exogenous synthetic CpG ODN showing the highest reduction. Vaccination with all three formulations raised antibody response in both the sera as well as locally in the vaginal tract, with ODN mixed group demonstrating the highest titers. There was no antibody response in the mice injected with the vector alone. In sera, the highest titers were obtained for the IgG class for all vaccine formulations followed by the IgA class. In vaginal washing, the highest titers were obtained by the IgA class followed by the IgG class. Within the IgG class, the titers for the IgG2a subclass were significantly greater than the IgG1 subclass. The immunocontraceptive effects were long-lasting over 1 year of the observation period and increased with time. These novel findings indicate that the intradermal immunization with a sperm-specific FA-1 DNA vaccine causes a long-term circulating and local immune response resulting in immunocontraceptive effects in female mice. The anti-fertility effects were enhanced when FA-1 DNA vaccine was combined with YLP(12) DNA vaccine and injected with ODN.  相似文献   

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Few studies were published on the effect of nebkhas (phytogenic mounds) on species diversity and soil resources, but no detailed study has been conducted yet on possible specific influence of nebkhas on growth and survival of the plants associated with them. We studied the nebkhas of Salvadora persica and their effect on growth and survival of three woody species (Prosopis cineraria, Tamarix aphylla, and Capparis decidua) in the Ommanian coast of Hormozgan Province in the south of Iran. The results showed that mean height and mean canopy diameter of P. cineraria and T. aphylla trees and shrubs inhabiting nebkhas of Salvadora persica were considerably higher than those of plants of these species growing outside nebkhas. The reverse occurred in the case of C. decidua. Generally, the percentages of stems with dead parts were significantly lower in plants inhabiting the nebkha sites in comparison to comparable ones growing outside the nebkhas. Salvadora persica nebkhas are enriched with more soil nutrients in comparison to inter-nebkha sites. Soil accumulated per each hectare in the nebkhas of the study area dominated by trees of Salvadora persica amounted to 237.6 m3. This indicates the great importance of nebkhas in the protection of soil and the associating species.  相似文献   

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  本文在实验室条件下通过一次性灌胃的方式研究了左炔诺孕酮-炔雌醚复合不育剂(EP-1)对雌性东方田鼠激素、生殖系统、胎仔数、受孕率的影响及药效持续时间,旨在检验其应用于野外东方田鼠不育控制的价值。结果表明,各浓度EP-1灌胃均能显著提高雌性东方田鼠的子宫系数,使子宫形态发生变化,对卵巢组织造成损伤,影响卵泡和黄体的发育,但是对雌二醇含量和子宫长度没有明显影响;60mg/kg EP-1灌胃能显著提高促卵泡刺激素含量和卵巢系数,而10mg/kg、30mg/kg EP-1灌胃对二者没有明显影响。室内繁殖实验表明,各浓度EP-1灌胃均能不同程度延迟初次怀孕时间,并降低试鼠的怀孕率和胎仔数,但抗生育作用具有可逆性且与药物浓度相关,10mg/kg、30mg/kg和60mg/kg剂量组生殖系统恢复时间分别为16 d、38 d和52 d。  相似文献   

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Previous experiments showed that the length of the photoperiod influences the effectiveness of exogenous estrogen in inducing nest-building behavior in ovariectomized female canaries. Long photoperiods affect this aspect of reproductive behavior in two ways. They influence estrogen output by the classical hypothalamus-pituitary-gonad route, and they allow expression of estrogen-dependent behavior. The question arises, do external sitmuli that affect reproductive development, other than the photoperiod, also influence the effectiveness of exogenous estrogen?In this study tape-recorded male song was found to affect the amount of estrogen-induced nest-building of ovariectomized canaries on three different photoperiods. Females exposed to male canary song built more actively than the controls on all day lengths, but budgerigar song was without effect.  相似文献   

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Energy is stored predominately as lipid in white adipose tissue (WAT) in distinct anatomical locations, with each site exerting different effects on key biological processes, including glucose homeostasis. To determine the relative contributions of subcutaneous and visceral WAT on glucose homeostasis, comparable amounts of adipose tissue from abdominal subcutaneous inguinal WAT (IWAT), intra-abdominal retroperitoneal WAT (RWAT), male gonadal epididymal WAT (EWAT), or female gonadal parametrial WAT (PWAT) were removed. Gonadal fat removal in both male and female chow-fed lean mice resulted in lowered glucose levels across glucose tolerance tests. Female lean C57BL/6J mice as well as male and female lean FVBN mice significantly improved glucose tolerance, indicated by decreased areas under glucose clearance curves. For the C57BL/6J mice maintained on a high-fat butter-based diet, glucose homeostasis was improved only in female mice with PWAT removal. Removal of IWAT or RWAT did not affect glucose tolerance in either dietary condition. We conclude that WAT contribution to glucose homeostasis is depot specific, with male gonadal EWAT contributing to glucose homeostasis in the lean state, whereas female gonadal PWAT contributes to glucose homeostasis in both lean and obese mice. These data illustrate both critical differences among various WAT depots and how they influence glucose homeostasis and highlight important differences between males and females in glucose regulation.  相似文献   

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