Pronuclear Embryo Yield in Canindé and Saanen Goats for DNA Microinjection     

RR Moura  ES Lopes‐Junior  DIA Teixeira  IA Serova  LE Andreeva  LM Melo  VJF Freitas 《Reproduction in domestic animals》2010,45(5):e101-e106

The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.  相似文献   

Insecticide resistance in the bollworm,Helicoverpa armigera from Indonesia     

Alan R. McCaffery  Andrew J. Walker  Clive P. Topper 《Pest management science》1991,32(1):85-90

Helicoverpa armigera collected from cotton growing areas of South Sulawesi, Indonesia in 1987 and early 1988 were resistant to cypermethrin. It is suggested that the 86-fold resistance to cis-cypermethrin in 1987 and the 65-fold resistance to cis/trans-cypermethrin in 1988 are consistent with this being a major cause of failure to control the insects in cotton in this area. The second laboratory generation showed a 20-fold resistance to fenvalerate. The larvae collected in 1988 additionally had a 203-fold resistance to DDT and a 5.6-fold resistance to endosulfan. The results are discussed in relation to the fact that this is a further region in which Helicoverpa armigera has developed resistance to a number of pyrethroids.  相似文献   

Seed dormancy and germination in the summer annual Galeopsis speciosa     

LM KARLSSON  JAL ERICSSON  & P MILBERG 《Weed Research》2006,46(5):353-361

This study examined germination and dormancy in Galeopsis speciosa (Lamiaceae), a common summer annual weed in cold‐temperate areas. Seeds collected in southern Sweden were subjected to several experiments. The seeds were dormant at maturity. Seeds sown outdoors after collection produced a small number of seedlings that emerged early in the spring. After long cold stratification or stratification outdoors over two winters, the maximum germination was 40–50%; germination occurring over a wide range of temperatures. Warm stratification preceding cold stratification had no effect on germination, but repeated warm and cold periods seemed to promote germination. Gibberellic acid (GA) stimulated germination, but full germination was only achieved after more than 2 months of incubation at the most suitable temperature regime tested. Excised embryos grew and developed into normal seedlings. With these results, the species does not fit into the currently used system for seed dormancy classifications. The response to GA and the growth of excised embryos indicate non‐deep or intermediate physiological dormancy, but dormancy alleviation by stratification was not in line with the guiding principles for these classifications. Galeopsis speciosa has a strong dormancy that is sufficiently alleviated during the winter to allow germination of only part of a seed batch each year; hence a stepwise germination pattern occurs over a period of several years.  相似文献   

The Equine Manual     

LM Begg 《Australian veterinary journal》2006,84(8):300-300

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Lymphocystis disease in captive barramundi     

M PEARCE  JD HUMPHREY  AD HYATT  LM WILLIAMS 《Australian veterinary journal》1990,67(4):144-145

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Essential role of insulin in transcription of the rat 25,000 molecular weight casein gene   总被引：4，自引：0，他引：4  

P Chomczynski  P Qasba  Y J Topper 《Science (New York, N.Y.)》1984,226(4680):1326-1328

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Mammary alveolar epithelial cells: effect of hydrocortisone on ultrastructure   总被引：4，自引：0，他引：4  

E S Mills  Y J Topper 《Science (New York, N.Y.)》1969,165(898):1127-1128

Hydrocortisone is necessary for the formation of rough endoplasmic reticulum in mammary alveolar epithelial cells. This membrane system is required for the synthesis of the milk protein, casein, but it is not required for the synthesis of a nonmilk protein fraction.  相似文献   

Mycobacterial Ku and ligase proteins constitute a two-component NHEJ repair machine     

Della M  Palmbos PL  Tseng HM  Tonkin LM  Daley JM  Topper LM  Pitcher RS  Tomkinson AE  Wilson TE  Doherty AJ 《Science (New York, N.Y.)》2004,306(5696):683-685

In mammalian cells, repair of DNA double-strand breaks (DSBs) by nonhomologous end-joining (NHEJ) is critical for genome stability. Although the end-bridging and ligation steps of NHEJ have been reconstituted in vitro, little is known about the end-processing reactions that occur before ligation. Recently, functionally homologous end-bridging and ligation activities have been identified in prokarya. Consistent with its homology to polymerases and nucleases, we demonstrate that DNA ligase D from Mycobacterium tuberculosis (Mt-Lig) possesses a unique variety of nucleotidyl transferase activities, including gap-filling polymerase, terminal transferase, and primase, and is also a 3' to 5' exonuclease. These enzyme activities allow the Mt-Ku and Mt-Lig proteins to join incompatible DSB ends in vitro, as well as to reconstitute NHEJ in vivo in yeast. These results demonstrate that prokaryotic Ku and ligase form a bona fide NHEJ system that encodes all the recognition, processing, and ligation activities required for DSB repair.  相似文献   

Hormone-dependent differentiation of mammary gland: sequence of action of hormones in relation to cell cycle   总被引：6，自引：0，他引：6  

D H Lockwood  F E Stockdale  Y J Topper 《Science (New York, N.Y.)》1967,156(3777):945-946

Differentiation of mouse mammary gland in vitro requires insulin, hydrocortisone, and prolactin. The epithelial cells must first divide in order to synthesize casein in response to these hormones. Insulin is required for the initiation of DNA synthesis and is also necessary during G(1) phase (after mitosis). Prolactin can elicit the overt differentiative responses after mitosis. Activity of hydrocortisone precedes that of prolactin, that is, after mitosis it is not capable of eliciting the differentiative response.  相似文献   

Evaluation of auditory evoked potentials to predict depth of anaesthesia during fentanyl/fluanisone−midazolam anaesthesia in rats     

LM Antunes MSc  DVM    JV Roughan BSc  PhD  & PA Flecknell MA  Vet MB  PhD  DLAS  Dip ECVA 《Veterinary anaesthesia and analgesia》2001,28(4):196-203

Objectives To assess a method for monitoring depth of anaesthesia using components of middle latency auditory evoked potential (AEP) waveforms during anaesthesia with fentanyl/fluanisone and midazolam. Study design Prospective observational study. Animals Five female Wistar rats weighing between 210 and 250 g. Methods Implanted electrodes were used to record AEPs in animals receiving five doses of anaesthetic. Recordings were made at 5 minutes post‐injection (deep anaesthesia; no pedal withdrawal response, PWR) and then at 25 minutes (light anaesthesia; strong PWR). Responses showed five characteristic peaks occurring at 11, 14, 23, 42 and 68 ms that were measured for latency of occurrence and peak amplitude. Results Auditory evoked potential peaks P14, N23 and P42 were increased significantly in latency with successive anaesthetic injections [avg. F(1,4) = 12.53, p < 0.001; avg. F(1,4) = 10.6, p < 0.001; avg. F(1,4) = 3.9, p = 0.02, respectively]. Peak N23 showed a significant reduction in latency during the 20 minute recovery period following both the first and second anaesthetic injections (t(3) = 7.52, p = 0.005; t(4) = 5.17, p = 0.007, respectively). Peak P42 occurred significantly earlier 20 minutes following the second anaesthetic injection (t(4) = 4.75, p = 0.009). The mean overall depth of anaesthesia assessed using PWR scores was significantly correlated with the mean latency of peak N23, such that as the strength of PWR increased, N23 occurred significantly earlier (r = ?0.99, p = 0.01). The amplitude difference between peaks N23 and P42 increased after the second and third drug administrations [avg. F(1,4) = 10.65, p = 0.031 and avg. F(1,4) = 11.24, p = 0.028, respectively]. Conclusion The characteristics of these peaks, and in particular latency of peak N23, may provide a useful tool for assessing depth of anaesthesia produced by this, and possibly other anaesthetic agents.  相似文献