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1.
We studied the reactivation of cells and the repair of photomutagenic damage induced by xanthotoxin and visnagin plus NUV in arg-1 cells of Chlamydomonas reinhardii. Maintenance of liquid cultures in the dark resulted only in a slight reactivation of cells, even after 24 h. Repair of photomutagenic damage was more efficient: within 24 h the number of Arg+ revertants was reduced by 50% in cells cultured in the dark at 20°C. The repair was more efficient at 30°C. At the beginning of dark cultivation an after-effect could be observed. Cultivation in standard white light instead of dark after treatment resulted in a very strong after-effect. Therefore it was not possible to detect any photoreactivation.After treatment with xanthotoxin plus standard white light (24 h) neither reactivation of cells nor repair of photomutagenic damage was found. The after-effect was higher than after xanthotoxin plus NUV. It is possible that a small amount of repair could be masked by the after-effect.Treatment with visnagin yielded similar results. The photomutagenic effect of visnagin is described for the first time in this paper. The drug is a much less effective photomutagen than xanthotoxin. The photomutagenesis of visnagin may be attributable to photoproducts similar to those formed after treatment with furocoumarins.No definite conclusion can be drawn from the present results regarding the basis for the observed lack of repair (or reduced repair) after standard white light treatment; a possible cause might be a preferential formation of bi-adducts under these conditions.  相似文献   

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Background  

The study was designed to test the effect of fixed-time artificial insemination (fixed-AI) after the slightly modified Ovsynch protocol on the pregnancy rate in beef cattle in Finnish field conditions. The modification was aimed to optimize the number of offsprings per AI dose.  相似文献   

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Current topics in artificial insemination of sheep   总被引:1,自引:0,他引:1  
There have been developments in several aspects of artificial insemination (AI) in recent years, some of which have been directly responsible for proliferation of AI in the sheep-breeding industries of several countries. The most notable advances have probably been associated with the development of intrauterine insemination by laparoscopy. There is potential for refinement of some of the related techniques, particularly in the area of control of ovulation and definition of appropriate times and optimum doses of spermatozoa for insemination. It is unlikely that laparoscopic AI will be developed sufficiently that it will become readily affordable, and therefore widely practised, by commercial producers. Unfortunately, there has been little progress in the past few years in improvement of the methods of cryopreservation of ram semen. There is considerable potential for AI to have a significant impact on the genetic improvement of sheep, though this has yet to be evaluated in practice. However, if the full potential of AI in sheep is to be realized, it will likely only happen when methods of freezing semen are improved sufficiently that cervical or even vaginal insemination can be widely used with frozen-thawed semen, or when practicable methods of deep cervical or intrauterine insemination through the cervix are developed.  相似文献   

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A method is reported for collection of sperm by electrostimulation or prostatic massage in order to carry out artificial in utero insemination in Lemur fulvus mayottensis. Using fresh sperm, one success out of 7 attempts was obtained, although it was achieved with a vesiculectomized male.  相似文献   

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Summary: Artificial insemination (AI) is a technique to transfer instrumentally sperm from the male into the female's reproductive system. AI is widespread in vertebrates for economical animal breeding and for conservation biology. However, in invertebrates only a few cases of successful AI have been reported. In this paper we describe a new technique to artificially inseminate bumblebee queens (Bombus spp.). Males were dissected and the accessory testes were removed and washed in insect ringer. They were then opened and the outflowing sperm was picked up with a glass capillary mounted on a syringe. For the sperm transfer into the queen we adapted a standard apparatus used for honeybee inseminations. The queen was anaesthetized with CO2, held in place by a queen holder and the sting chamber was opened using two hooks. The sperm containing glass capillary was introduced into the queen's sexual tract. The sperm was released into the bursa copulatrix very near the opening of the spermathecal duct of the queen. Inseminated queens were hibernated for 2 weeks and produced a normal colony under field conditions. Multiple inseminations proved to be successful since different patrilines could be detected in the worker offspring. Successful inseminations were performed for B. terrestris, B. lucorum and B. hypnorum.  相似文献   

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Graffer T  Solbu H  Filseth O 《Theriogenology》1988,30(5):1011-1021
Semen production data from 792 Norwegian Red AI bulls, of 46 sires, were analyzed. Semen production was affected by AI center, year and season of collection, number of months the bull had been collected, and sire (each P < 0.01). Heritability for produced accepted doses was estimated to be 0.34 (+/-0.13). This should allow a successful phenotypic selection for this trait. A negative correlation between number of accepted and number of discarded doses (-0.82+/-0.11) was found. Selection based on number of accepted doses per bull will therefore result in improvement of semen quality.  相似文献   

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Storage of semen and artificial insemination in deer   总被引:9,自引:0,他引:9  
Methods of collection and freezing of semen of some deer species and aspects of controlled reproduction associated with the use of frozen-thawed semen by artificial insemination (AI) are discussed.  相似文献   

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Three successful cases of artificial insemination in chimpanzees   总被引:2,自引:0,他引:2  
Artificial inseminations were performed on two female chimpanzees from July 1981 to April 1983 and three conceptions were obtained. Semen samples collected by rectal probe method of electroejaculation were incubated at 37 degrees C for about 20 minutes for liquefaction. Liquefied portion of the semen was sucked up into polyethylene tube about 30 cm in length attached to a syringe and was inseminated into cervix of each female of which pelvic region was raised in prone position under anesthesia. Ovulation time was speculated by swelling of sex skin in earlier two cases and by urinary LH level in last case. Three offsprings were obtained 234, 235 and 235 days after last insemination, respectively. All of three show normal developments.  相似文献   

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In the present study, polymorphonuclear neutrophils (PMN) were enumerated to evaluate acute uterine inflammation after artificial insemination in the bitch. It was concluded that the canine seminal plasma possessed an immunomodulating action. However, the most commonly used extender for freezing canine semen (Tris glucose with egg yolk and glycerol) was a potential inducer of uterine inflammation.  相似文献   

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The possibility of modifying the sex ratio of rabbit litters was examined in two experiments involving artificial insemination (AI) with fresh semen. Three time periods of AI, relative to ovulation, were used in Experiment 1: (a) control, GnRH was administered immediately after AI with ovulation estimated to occur 10-12h after AI; (b) early AI, GnRH was given 6h after AI so that ovulation was delayed until 16-18 h after AI; (c) late AI, GnRH was administered 6h before AI, which was performed 4-6h before ovulation. There were 13 does per treatment, and each doe was used in the same treatment for three AIs at 42-day intervals. The second experiment involved two treatments in which the does were inseminated as for the control in Experiment 1 and AI was performed using semen prepared in the normal manner (Treatment 1) or after centrifugation through 11 discontinuous Percoll gradients (Treatment 2). There were 20 does per treatment, and each doe was used in the same treatment for three AIs at 42-day intervals. The proportion of female kits produced in Experiment 1 was: control 41.7+/-19.1%, early AI 49.8+/-17.8%, and late AI 41.4+/-16.4%. These proportions did not differ significantly between treatments or from the expected 50:50 sex ratio. Fertility was reduced by the early (60.0%) and late (73.7%) AI treatments relative to control AI (80.0%), and the difference between early and control AI almost achieved statistical significance (P<0.07). In Experiment 2, the proportion of female kits was not affected by treatment (control, 51.1%; Percoll, 54.8%), and there was a similar level of fertility for both treatments (control, 76.0%; Percoll, 74.1%). Prolificacy and perinatal mortality were not affected by treatment in either experiment. It was concluded that neither the timing of insemination nor Percoll centrifugation of semen affected the sex ratio at birth of rabbit litters.  相似文献   

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For some endangered parrot species, captive breeding may be the only insurance for their survival. However, many individuals in captivity do not reproduce. Artificial insemination (AI) may help overcome reproductive failures or geographic distance. For semen collection in birds, massage is the most commonly used method. However, this process, which usually requires capture and restraint, involves risk of stress and injuries. The aim of this experiment was to train large macaws to accept the physical manipulations of their body parts needed for the artificial insemination process. Within 15 weeks, a male and a female Buffon's macaw (Ara ambiguus) learned to accept handling without apparent stress. A pair of green-winged macaws (Ara chloropterus) progressed more slowly and displayed some signs of stress. This stress highlights the need to monitor the birds' possible signs of discomfort during the training in order to adapt the working protocol. These results demonstrate that it is possible to train the AI behaviors, thus avoiding the capture, restraint, and anesthesia. An added benefit to this is the potential for the training to provide a form of behavioral enrichment.  相似文献   

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The first successful artificial insemination (AI) in a rhinoceros was reported in 2007 using fresh semen. Following that success, we decided to evaluate the possibility of using frozen-thawed semen for artificial insemination. Semen, collected from a 35-36 year old Southern white rhinoceros (Ceratotherium simum simum) in the UK was frozen using the directional freezing technique. This frozen semen was used in two intrauterine AI attempts on a 30 years old female rhinoceros in Hungary. The first attempt, conducted 30 days postpartum with an insemination dose of ∼135 × 106 motile cells, failed. The second attempt, conducted two estrus cycles later with an insemination dose of ∼500 × 106 motile cells, resulted in pregnancy and the birth of a healthy offspring. This represents the first successful AI using frozen-thawed semen in a rhinoceros, putting it among very few wildlife species in which AI with frozen-thawed semen resulted in a live birth. The incorporation of AI with frozen-thawed semen into the assisted reproduction toolbox opens the way to preserve and transport semen between distant individuals in captivity or between wild and captive populations, without the need to transport stressed or potentially disease carrying animals. In addition, cryopreserved spermatozoa, in combination with AI, are useful methods to extend the reproductive lifespan of individuals beyond their biological lifespan and an important tool for managing genetic diversity in these endangered mammals.  相似文献   

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