Variation of PGM and IDH isozymes for identification of alfalfa varieties   总被引：1，自引：0，他引：1  

M.R. Morales Corts  M.C. Crespo Martinez 《Euphytica》2000,112(2):137-143

Growth habit, heading date and Vrn genotypewere examined for wheat landraces cultivated in China,Korea and Japan, to study their ecogeographicaldifferentiation in east Asia. Spring type landracesaccounted for 43.6% of the whole, and the frequencyvaried between the localities, being closely relatedto the degree of winter coldness. Spring typelandraces mainly adapted to north and south Chinawhere average January temperature is under –7 ^°Cand over 4 ^°C, respectively. On the contrary,winter type adapted to areas of average Januarytemperature from –7 ^°C to 4 ^°C. As toheading date, significant difference was not observedbetween spring and winter type landraces but betweenlocalities, and those cultivated in north China weresignificantly later in heading. It is thereforeindicated that spring type mainly adapts to areaswhere wheat is sown in spring to avoid frost injury,and where winter temperature is not low enough tovernalize winter type wheat. Genetic analysis forspring type landraces showed that the relativefrequency of four Vrn genes was different witheach other. Vrn3 was most widely and frequentlyfound among the four genes, followed by Vrn1 andVrn2. Only seven landraces proved to be thecarrier of Vrn4. The frequency was alsodifferent between localities. Genotype with Vrn1plus other dominant gene(s) adapted to spring sowingto avoid severely cold winter in north China, whilegenotype with only Vrn3 adapted to winter sowingin south China and southwest Japan. It is thereforeconcluded that at least three ecotypes, differing ingrowth habit and Vrn genotype, areallopatrically distributed in east Asia, as a resultof adaptation to winter coldness in each locality.  相似文献   

Colloid Centrifugation Selects Normal Spermatozoa from Polymorphic Bull Ejaculates: A Case Study     

JM Morrell  H Rodriguez‐Martinez  M Andersson 《Reproduction in domestic animals》2014,49(2):281-284

Semen from a Western Finncattle bull exhibiting a highly polymorphic spermiogram was processed by colloid centrifugation using Androcoll‐B, a species‐specific silane‐coated silica colloid. In the first experiment, Single Layer Centrifugation (SLC) was used to identify which density colloids were needed to separate different cell populations. Colloids of the two chosen densities were then used in a density gradient resulting in two sperm subpopulations, one containing nearly all normally sized spermatozoa and the other enriched for the macrocephalic spermatozoa. Microcephalic spermatozoa did not appear in either of the selected subpopulations. Using a combination of SLC and DGC with this species‐specific colloid, it was possible to separate the spermatozoa into different subpopulations, that is, a subpopulation containing nearly all normally sized spermatozoa, and another one enriched for the macrocephalic spermatozoa. Thus, colloid centrifugation could be used to select sufficient normal spermatozoa from a highly polymorphic ejaculate for AI, if desired.  相似文献   

The Effects of Isoflavones on Androgens and Glucocorticoids During Puberty on Male Wistar Rats     

S Caceres  G Silvan  L Martinez‐Fernandez  MJ Illera  P Millan  B Monsalve  L Peña  JC Illera 《Reproduction in domestic animals》2014,49(4):611-617

Isoflavones are the most common phytoestrogens found in human diets. However, it is still not clear whether isoflavones have effects on the reproductive and the endocrine systems under normal dietary intake and overdose. The aim of this study was to determine how the most important isoflavones, genistein and daidzein, affect androgen and glucorticoid levels on male prepuberal rats. A hundred and seventy‐five 30‐day‐old male Wistar rats were dosed orally by stomach tube every day for 35 days, with saline solution, low and high doses of genistein, daidzein and a mixture of both. Serum samples were analysed by an enzyme immunoassay for hormone determinations. In control group, there was a peak of testosterone (T) and dihydrotestosterone levels associated to the onset of puberty, at the third week. However, in low‐dose groups, the same peak was found at the fourth week (p < 0.05), indicating a delay in the onset of puberty in these groups. Moreover, high doses groups serum androgen levels were significantly lower (p < 0.05) than the control group from the first week until fifth week. This fact was supported by a epididymal histological analysis that indicate in low doses there were several content of spermatozoa at fourth week and in high doses there were few content of spermatozoa. Besides, corticosterone levels followed the same pattern of androgens in all groups. We can conclude that oral administration of isoflavones in male rats decreased the secretion of androgens and glucocorticoids causing a delay in the onset of puberty and may cause physiological and developmental problems.  相似文献   

Systemic Immunosuppression by Methylprednisolone and Pregnancy Rates in Goats Undergoing the Transfer of Cloned Embryos     

C Feltrin  CA Cooper  N Mohamad‐Fauzi  VHV Rodrigues  LH Aguiar  S Gaudencio‐Neto  LT Martins  CEM Calderón  AS Morais  IS Carneiro  TM Almeida  ING Silva  JL Rodrigues  EA Maga  JD Murray  AB Libório  LR Bertolini  M Bertolini 《Reproduction in domestic animals》2014,49(4):648-656

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona‐free cloned embryos into the oviduct of recipient female goats. In Experiment 1, seven does were used to study the systemic immunosuppressant effect of the methylprednisolone administration (for 3 days) on blood cell counts. Whole blood was collected prior to treatment with methyprednisolone and then on Days 1, 2, 3, 4, 7, 14, 21 and 28 after the first dose of methylprednisolone for the analysis of haematological parameters. Methylprednisolone treatment significantly reduced circulating white blood cells and neutrophils in comparison with pre‐treatment levels, demonstrating a systemic immunosuppressant effect. In Experiment 2, a group of 58 does were used as recipient females to study the effect of administration of methylprednisolone for 3 days on the establishment of pregnancies after the transfer of zona‐free cloned embryos into the oviducts. No effects on pregnancy rates on Day 30 were observed regarding the distinct treatment groups (control vs. methylprednisolone), the source of oocytes (in vivo‐ vs in vitro‐matured) or the presence or absence of the zona pellucida in embryos. In summary, methylprednisolone was effective at inducing a systemic immunosuppressed state in goats, but the treatment prior to embryo transfer did not affect pregnancy rates. Moreover, pregnancy rates were similar between zona‐free and zona‐intact goat cloned embryos.  相似文献   

Severe hindlimb lameness and pathological femur fracture in a horse secondary to haemangiosarcoma     

A. T. Mahne  H. J. Marais  L. M. Rubio‐Martinez  J. H. Williams 《Equine Veterinary Education》2014,26(10):552-558

An 18‐year‐old Warmblood stallion was presented for an acute onset nonweightbearing right hindlimb lameness following a mild lameness of 2 weeks' duration. Severe swelling was present in the right femoral area. Despite extensive diagnostic procedures, no definitive diagnosis could be made. Packed red cell volume was persistently low. The horse improved with supportive treatment and was discharged at the owner's request. The horse presented 4 days later for bleeding from a previously made incision on the lateral femoral area. Due to deterioration of his condition, the stallion was subjected to euthanasia. Diagnosis of disseminated haemangiosarcoma, affecting primarily the hindlimb musculature and leading to pathological fracture of the femur was made at necropsy and subsequent histopathology.  相似文献   

Use of Cholesterol‐Loaded Cyclodextrin in Donkey Semen Cryopreservation Improves Sperm Viability but Results in Low Fertility in Mares     

RR Oliveira  DM Rates  G Pugliesi  PG Ker  RP Arruda  EA Moraes  GR Carvalho 《Reproduction in domestic animals》2014,49(5):845-850

The use of cholesterol‐loaded cyclodextrin (CLC) on semen cryopreservation has been related with better sperm viability in several species; however, the effect on fertility is not known in donkey semen. Ejaculates (n = 25) from five donkeys were diluted in S‐MEDIUM with 0, 1, 2 or 3 mg of CLC/120 × 10⁶ spermatozoa. Semen was frozen, and thawed samples were evaluated by computer‐assisted sperm analyser system (CASA), supravital test, hyposmotic swelling test and fluorescent dyes to assess the integrity of sperm membranes. Mares (n = 60) were inseminated with frozen‐thawed semen treated with the doses of 0 or 1 mg CLC. Percentages of sperm with progressive motility and with functional plasma membrane were greater (p < 0.05) in the CLC‐treated groups than in the control. Percentages of intact plasma membrane and intact plasma membrane and acrosome detected by fluorescent dyes were also greater (p < 0.05) in CLC‐treated groups. Although no difference (p > 0.05) in conception rates was detected between groups (control, 3/30, 10%; CLC‐treated, 1/30, 3.3%), fertility was low for artificial insemination programs in mares. Therefore, we firstly demonstrated that frozen semen treated with CLC in S‐MEDIA extender before freezing improves the in vitro sperm viability, but semen treated or not with CLC in S‐MEDIUM extender results in a very low conception rate in mares inseminated with thawed donkey semen.  相似文献   

Relevance of ovarian follicular development to the seasonal impairment of fertility in weaned sows     

Tania P. Lopes  Jonatan Sanchez-Osorio  Alfonso Bolarin  Emilio A. Martinez  Jordi Roca 《Veterinary journal (London, England : 1997)》2014,199(3):382-386

A field study was conducted to estimate seasonal differences in follicular development in weaned sows and to evaluate the implication of these differences on seasonal infertility. A total of 110 sows were selected at weaning during winter–spring (WS, n = 58) and summer–autumn (SA, n = 52). Ovaries were scanned once daily from weaning to the onset of oestrus and twice daily from then until ovulation. Six sows during WS were removed from study for not showing growing follicles at weaning. Oestrus was evaluated twice daily from day 1 after weaning to day 14 post-weaning. One of 52 (1.9%) sows in WS and 9/52 (17.3%) in SA showed no signs of oestrus within 14 days of weaning (P < 0.05). The diameters of the follicles at weaning, at the onset of oestrus and just before ovulation were smaller (P < 0.01) in SA sows than in WS sows. There were fewer follicles in SA sows than in WS sows just before ovulation (P < 0.05). Fifty of 51 (98.0%) sows in WS and 31/43 (72.1%) sows in SA experienced a weaning-to-oestrus interval (WOI) of 3–6 days (P < 0.05). Fifty-one of 52 (98.1%) sows in WS and 43/52 (82.7%) sows in SA were inseminated; the percentage of pregnant sows that failed to farrow was lower in WS (1/51, 2.0%) than in SA (5/43, 11.6%; P < 0.05). The percentage of farrowed sows was greater in WS (46/51, 90.2%) than in SA (32/43, 74.4%; P < 0.05). Sows in WS had on average 1.5 more piglets than sows in SA (P < 0.05). Sows with a WOI of 3–6 days had lower rates of pregnancy losses (P < 0.05) and higher farrowing percentages (P < 0.01) than those with a WOI > 6 days, irrespective of season.  相似文献   

What makes a book a work of science?     

Hewlett M 《Science (New York, N.Y.)》2007,316(5833):1843-1844

  相似文献   

Neuronal pp60c-src contains a six-amino acid insertion relative to its non-neuronal counterpart   总被引：57，自引：0，他引：57  

R Martinez  B Mathey-Prevot  A Bernards  D Baltimore 《Science (New York, N.Y.)》1987,237(4813):411-415

Neuronal cells express a pp60c-src variant that displays an altered electrophoretic mobility and a different V8 peptide pattern relative to pp60c-src expressed in tissues of non-neuronal origin. To determine whether the neuronal form of pp60c-src is encoded by a brain-specific messenger RNA, a mouse brain complementary DNA (cDNA) library was screened with a chicken c-src probe and a 3.8-kilobase c-src cDNA clone was isolated. This clone encodes a 60-kilodalton protein that differs from chicken or human pp60c-src primarily in having six extra amino acids (Arg-Lys-Val-Asp-Val-Arg) within the NH2-terminal 16 kilodaltons of the molecule. S1 nuclease protection analysis confirmed that brain c-src RNA contains an 18-nucleotide insertion at the position of the extra six amino acids. This insertion occurs at a position that corresponds to a splice junction in the chicken and human c-src genes. The isolated c-src cDNA clone encodes a protein that displays an identical V8 peptide pattern to that observed in pp60c-src isolated from tissues of neuronal origin.  相似文献   

Physiological constraint on feeding behavior: intestinal membrane disaccharidases of the starling   总被引：1，自引：0，他引：1  

C Martinez del Rio  B R Stevens 《Science (New York, N.Y.)》1989,243(4892):794-796

Animals clearly choose what they eat and can even choose among chemically different sugars. The physiological and biochemical mechanisms that constrain feeding choices are largely unknown. In this study, European starlings (Sturnus vulgaris) preferred mixture solutions of D-glucose plus D-fructose to equimolar (double molar caloric value) solutions of sucrose. Intubation feeding of sucrose did not increase blood glucose levels. Sucrose is a useless energy source for these birds because they lack a single digestive enzyme (sucrase) on the small intestinal brush border membrane. However, the membranes possessed separate maltase and isomaltase disaccharidases. This expression pattern and expression patterns of membrane disaccharidases among mammals suggest a role for intestinal enzymes in the coevolutionary interactions between vertebrates and their plant food sources.  相似文献