Canine spermatozoa—What do we know about their morphology and physiology? An overview     

Angelika Chłopik  Anna Wysokińska 《Reproduction in domestic animals》2020,55(2):113-126

Spermatozoa are unique cells because of their morphological and physiological characteristics. They are produced during the process called spermatogenesis. Spermatogenesis consists of three phases: spermatocytogenesis, spermiogenesis and spermiation, during which spermatozoa undergo several changes. Spermatogenesis takes place within the seminiferous tubules containing two types of cells—the germ cells and the Sertoli cells—that alongside the Leydig cells, which play an important role when it comes to normal fertility. Everything is regulated by the hypothalamic–pituitary–gonadal axis and specific hormones due to multi-hormonal feedback systems. Spermatozoa possess morphological and physiological features, which are sometimes completely different from what is observed in various somatic cells. What is more, canine spermatozoa have specific characteristics making them special compared to the spermatozoa of other mammalian species. The metabolic energy production, which is crucial for the appropriate functioning of spermatozoa, can be fuelled by different metabolic pathways utilizing different chemical substrates. Inseparable from the oxidative phosphorylation process is the production of reactive oxygen species, which are both essential and toxic to spermatozoa. Furthermore, epididymis is a very important structure, responsible for the transport and maturation of spermatozoa, which are then stored in the last segment of epididymis—the epididymal cauda. Moreover, the retrieval of spermatozoa from the epididymides is crucial for the development of assisted reproduction techniques and sperm cryopreservation methods. The information gained from the research on domestic dogs might be transferred to their wild relatives, especially those species categorized as endangered.  相似文献   

Aluminium‐induced increase of zeatin riboside and dihydrozeatin riboside in Phaseolus vulgaris L. cultivars     

N. Massot  Ch. Poschenrieder  J. Barcelo 《Journal of plant nutrition》2013,36(2-3):255-265

Toxic effects of aluminium (Al) on root tips are considered to decrease export of cytokinins to shoots, and deficiency of cytokinins has been made responsible for Al‐induced inhibition of shoot growth. But no experimental data on the influence of Al on endogenous cytokinin levels in higher plants have been reported. In this study, the endogenous levels of zeatin riboside (ZR) and dihydrozeatin riboside (DHZR) of roots, stems, and leaves of two bean cultivars (Phaseolus vulgaris L. cv Contender and cv Strike) exposed to Al in continuously flowing nutrient solution (pH 4.5) was analysed. The supply of a high Al concentration (sum of monomeric Al species, 127 μM) caused severe inhibition of root elongation in both cultivars. The cv Strike was more affected by both Al‐induced mineral nutrient disorders and Al‐induced alteration of leaf water relationships. In both cultivars Al‐supply significantly increased ZR and DHZR. Leaves of Al‐treated plants exhibited a more than three times higher concentration of ribosylated cytokinins than controls. Nevertheless, stomatal resistance was significantly increased by Al in both cultivars. Our results support the hypothesis that Al affects plants not by inducing deficiency of cytokinins but of some other factor necessary for the manifestation of cytokinin action.  相似文献   

Effect of aluminum on callose synthesis in root tips of tea (Camellia sinensis L.) plants     

Ch unlan Lian  Yoshihisa Oi wake  Hiromi Yokota  Gang Wang  Shigeki Konishi 《Soil Science and Plant Nutrition》2013,59(4):695-700

Aluminum (Al) toxicity is a major factor limiting yield production on acid soils (Foy 1983). The initial symptom of Al toxicity in many plants is manifested by the inhibition of root elongation (Ownby and Popham 1990; Llugany et al. 1994; Sasaki et al. 1994; Horst et al. 1997), which occurs during a very short period of time after exposure to Al (Llugany et al. 1994; Staß and Horst 1995). In a large number of recent reports, it was shown that the root apex plays a major role in the Al-sensitivity and response mechanisms (Zhang et al. 1994; Sasaki et al. 1997; Sivaguru and Horst 1998). However, it is interesting to note that stimulatory effects of Al on the growth of plants have also been reported in some studies (Chenery 1955; Konishi et al. 1985; Huang and Bachelard 1993; Osaki et al. 1997). In tea plant (Camellia sinensis L.) a stimulatory effect of Al on the growth was also demonstrated in some experiments, using intact plant (Chenery 1955; Konishi et al. 1985), cultured roots (Tsuji et al. 1994), and pollen tubes (Yokota et al. 1997). The growth of tea roots was typically more stimulated than that of shoots by Al (Konishi et al. 1985). It was assumed that Al effects might be due to the amelioration of phosphorus absorption (Konishi et al. 1985), secretion of malic acid from roots to dissolve aluminum phosphate in the rhizosphere (Jayman and Sivasubramaniam 1975), stimulation of growth of microorganisms on the root surface (Konishi 1990) or replacement of some functions of boron (Konishi 1992; Yokota et al. 1997). However, the stimulatory effects of Al on tea plant growth have not yet been el ucidated.

The formation of callose (1,3-β-glucan) has been reported as a common plant response to a variety of stresses, as well as mechanical, biophysical, chemical, and biological injury (Jaffe and Leopold 1984; Zhang et al. 1994). Increased synthesis of callose has been observed upon exposure to excess amounts of some elements, such as boron (McNairn and Currier 1965), cobalt, nickel, zinc (Peterson and Rauser 1979), and manganese (Wissemeier and Horst} 1987, 1992). Callose synthesis was also induced by Al in the roots of Triticum aestivum (Zhang et al. 1994) and Zea mays (Horst et al. 1997; Sivaguru and Horst 1998), suspension-cultured cells of Glycine max (Staß and Horst 1995), and protoplasts of Avena sativa (Schaeffer and Walton 1990) and Zea mays (Wagatsuma et al. 1995). Induction of callose synthesis in roots seems to be a very rapid physiological indicator of Al-induced injury or genotypical differences in Al sensitivity (Wissemeier and Horst 1992; Zhang et al. 1994; Horst et al. 1997). Nevertheless, Al-induced callose synthesis in tea plant, whose growth is stimulated by suitable Al concentrations, has not been described yet. Therefore, to elucidate the physiological basic effects of Al on tea plant, callose synthesis affected by Al in the root tips of intact plants was analyzed in the present study.  相似文献   

Agro-energetic and economic efficiency of technologies for the creation and use of semishrub-grass pasture agrophytocenoses in the Caspian semi-desert     

Z. Sh. Shamsutdinov  V. M. Kosolapov  A. A. Zotov  A. K. Natirov  Yu. B. Kaminov  N. Z. Shamsutdinov  M. M. Shagaipov  Ch. A. Pyurvenov 《Russian Agricultural Sciences》2015,41(6):450-453

The article presents the results of 8 years of research for establishing the economic and agro-energetic efficiency of technologies for the creation and use by sheep of various types of seeded pastures (Kochia–Artemisia, Camphorosma–Artemisia, and Eurotia–Artemisia) in the semi-desert zone of Kalmykia. The technology of creation of Kochia–Artemisia pasture, which differed with high conditionally net income (8785 rub./ha) and the lowest cost of feed (1 rub. 85 kop. per 1 feed un.), showed the highest economic efficiency.  相似文献   

Some biogenetic conclusions from changes in the amount and composition of skin wax of apples during their growth and storage     

Ch. P. Ivanov  M. S. Dodova-Anghelova 《Plant foods for human nutrition (Dordrecht, Netherlands)》1974,24(1-2):37-54

Quantitative and qualitative changes in the chief wax components, isolated from Bulgarian apples (Tetovka variety) were followed up during the period of growth and storage (from August 1st to January 2nd, the following year). After saponification of the soluble in light petroleum wax part, the samples were separated into neutral and acid substances. By means of gas-liquid chromatography of the methyl esters of the isolated acids, the qualitative composition and quantitative content of the individual components in the mixture were established. Using preparative thin-layer chromatography, hydrocarbons, ketones, secondary and primary alcohols were isolated from the neutral part. The individual qualitative and quantitative composition of all these compounds were also estimated by gas-liquid chromatography. On the basis of the results obtained the following biogenetic conclusions were made: 1. The constituents of soluble wax and cutin originate from lipids synthesized in the interior part of the fruit. 2. Paraffin hydrocarbons are formed by fatty acid, especially the C₂₉ hydrocarbon is derived from the C₁₆ acid; 3. Olefines are obtained from respective primary and secondary alcohols, while the diols are derived from primary alcohols; 4. Paraffin hydrocarbons, secondary alcohols and ketones are biogenetically linked and may undergo mutual transformations.  相似文献   

Über den einfluss der düngung auf den pflanzgutwert von kartoffeln     

Ch. Pfeffer 《Potato Research》1959,2(4):238-250

Ohne Zusammenfassung  相似文献   

Effect of virginiamycin supplementation on the performance of young grazing cattle   总被引：1，自引：0，他引：1  

L. O. FIEMS  Ch. V. BOUCQUÉ  B. G. COTTYN  R. J. MOERMANS†  D. L. DE  BRABANDER 《Grass and Forage Science》1992,47(1):36-40

Three experiments have been conducted to study the effect of virginiamycin in young grazing-bulls (Experiment 1) and heifers (Experiments 2 and 3). Rotational grazing on permanent grassland was practised and animals were supplemented with 1 kg dried sugarbeet pulp per head daily. Control groups did not receive virginiamycin via the supplement, while it was incorporated at 120, 300 and 200 mg kg⁻¹ for the treatment groups in Experiments 1 to 3 respectively.
Average daily liveweight gain was significantly increased from 0·59 to 0·72 kg in Experiment 1 and from 0·73 to 0·81 kg in Experiment 3, but was not affected in Experiment 2 (0·51 vs 0·55 kg). Virginiamycin also increased liveweight gain per ha by 12, 7 and 13%, respectively, for the three experiments. Grazed area per animal was not enlarged to the same extent as the calculated daily energy allowances, which may suggest an improved digestibility and/or rumen fermentation.  相似文献   

Fruit morphological descriptors as a tool for discrimination of Daucus L. germplasm     

Najla Mezghani  Imen Zaouali  Wided Bel Amri  Slim Rouz  Philipp W. Simon  Chérif Hannachi  Zeineb Ghrabi  Mohamed Neffati  Béchir Bouzbida  David M. Spooner 《Genetic Resources and Crop Evolution》2014,61(2):499-510

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The effect of land management on carbon and nitrogen status in plants and soils of alpine meadows on the Tibetan plateau     

W. Y. Wang  Q. J. Wang  Ch. Y. Wang  H. L. Shi  Y. Li  G. Wang 《Land Degradation \u0026amp; Development》2005,16(5):405-415

Large‐scale grassland rehabilitation has been carried out on the severely degraded lands of the Tibetan plateau. The grasslands created provide a useful model for evaluating the recovery of ecosystem properties. The purposes of this research were: (1) to examine the relative influence of various rehabilitation practices on carbon and nitrogen in plants and soils in early secondary succession; and (2) to evaluate the degree to which severely degraded grassland altered plant and soil properties relative to the non‐disturbed native community. The results showed: (1) The aboveground tissue C and N content in the control were 105·97 g m⁻² and 3·356 g m⁻², respectively. The aboveground tissue C content in the mixed seed treatment, the single seed treatment, the natural recovery treatment and the severely degraded treatment was 137 per cent, 98 per cent, 49 per cent and 38 per cent, respectively, of that in the control. The corresponding aboveground tissue N content was 109 per cent, 84 per cent, 60 per cent and 47 per cent, respectively, of that in the control. (2) Root C and N content in 0–20 cm depths of the control had an average 1606 g m⁻² and 30·36 g m⁻², respectively. Root C and N content in the rehabilitation treatments were in the range of 26–36 per cent and 35–53 per cent, while those in the severely degraded treatment were only 17 per cent and 26 per cent of that in the control. (3) In the control the average soil C and N content at 0–20 cm was 11 307 g m⁻² and 846 g m⁻², respectively. Soil C content in the uppermost 20 cm in the seeded treatments, the natural recovery treatment and the severely degraded treatment was 67 per cent, 73 per cent and 57 per cent, respectively, while soil N content in the uppermost 20 cm was 72 per cent, 82 per cent and 79 per cent, respectively, of that in the control. The severely degraded land was a major C source. Restoring the severely degraded lands to perennial vegetation was an alternative approach to sequestering C in former degraded systems. N was a limiting factor in seeding grassland. It is necessary for sustainable utilization of seeding grassland to supply extra N fertilizer to the soil or to add legume species into the seed mix. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

河北省主栽小麦品种醇溶蛋白遗传多样性分析     

张茶  梁虹  王睿辉  安浩军  王静华  赵金峰  赵玉新  常文锁 《勤云标准版测试》2008,(1)

【研究目的】为了解河北省40年来不同小麦品种之间的遗传多样性,以及为小麦育种工作提供理论依据;【方法】采用酸性聚丙烯酰胺凝胶电泳（A-PAGE）对河北省40年来的118个主栽小麦品种进行了醇溶蛋白位点特异性检测,分析了这些品种的遗传多样性及其变化情况;【结果】这些品种具有118种醇溶蛋白带型,共分离出101条迁移率不同的醇溶蛋白谱带。绝大多数品种在α、β、γ、ω 4个区中存在着较大差异,其中α区有15条带,87种带型;β区有24条带,110种带型;1区有21条带,90种带型;（1）区有41条带,111种带型,其中（1）区的多态性最大。供试品种的遗传相似性系数（GS）在0．043-43．86之间,平均值为0．35。用非加权成组算术平均法对GS值进行聚类,供试品种在GS值为0．354的水平下可明显聚为6类;【结论】用非加权成组算术平均法对Gs值进行聚类,供试品种在GS值为0．354的水平下可明显聚为6类。讨论了种子醇溶蛋白在品种遗传多样性评价方面的应用价值。  相似文献