Comparison of Conventional Freezing and Vitrification with Dimethylformamide and Ethylene Glycol for Cryopreservation of Ovine Embryos     

FC Varago  VS Moutacas  BC Carvalho  RV Serapião  F Vieira  H Chiarini‐Garcia  FZ Brandão  LS Camargo  M Henry  MA Lagares 《Reproduction in domestic animals》2014,49(5):839-844

The aim of this work was to evaluate the efficiency of the cryoprotectants dimethylformamide and ethylene glycol for cryopreservation of ovine embryos using vitrification and conventional freezing. The recovered embryos were distributed randomly in three treatment groups: Gr. 1: conventional freezing (n = 44), Gr. 2: vitrification with ethylene glycol (n = 39) and Gr. 3: vitrification with dimethylformamide (n = 38). Quality of fresh embryos in control group as well as of frozen and vitrified embryos was examined by three methodologies: staining with propidium iodide and Hoechst 33258 and evaluation under fluorescent microscopy, evaluation of re‐expansion and hatching rates after culture, and determination of apoptotic index with TUNEL technique. It was established that re‐expansion rate in all treatment groups was similar. In the same time, hatching rates were higher in Gr. 1 (40.5%) and Gr. 2 (35.3%) in comparison with Gr. 3 (15.5%, p < 0.05). The number of dead cells in vitrified embryos of Gr. 2 and Gr. 3 was higher (42.6 ± 26.2 and 63.2 ± 34.65, respectively) in comparison with Gr. 1 (conventional freezing, 10.1 ± 8.5, p < 0.05). Embryos vitrified with dimethylformamide included the same quality of apoptotic cells that Gr. 1 (conventional freezing) and fresh embryos. In conclusion, the dimethylformamide and ethylene glycol used as cryoprotectant to vitrify ovine embryos, in the concentrations and exposition time tested in this work, were not as efficient as the conventional freezing for cryopreservation of ovine embryos Thus, the conventional freezing with ethylene glycol was the most efficient method to cryopreserve ovine embryos in comparison with vitrification.  相似文献   

Cytological mechanism of 2n pollen formation and unilateral sexual polyploidization in Lolium     

C. A. Sala  E. L. Camadro  M. T. Salaberry  A. O. Mendiburu 《Euphytica》1989,43(1-2):1-6

Summary Plants of Lolium perenne, L. multiflorum and L. hybridum (331, 51 and 18, respectively) were screened for 2n pollen production. The screening was based on the size differences that are expected to be found between n and 2n pollen of a plant. It was found that 28 plants of perennial ryegrass-belonging to 13 cultivars-produced produced pollen grains of heterogenous size (big and small). The estimated frequency of big pollen grain production was higher than 10% in ten out of 28 plants and in three of them it reached a value of 100%. Eight plants obtained from two 4x × 2x crosses, in which the male parent had been previously identified as producing pollen grains of heterogenous size, was tetraploid. The cytological mechanism of big pollen grain formation observed in three plants consists in the lack of spindle formation and, consequently, of chromosome migration in anaphase II. From these breeding and cytological results, it was concluded that the big pollen grains observed were viable 2n pollen grains. The nuclei of the 2n pollen grains produced by this mechanism are genetically equivalent to those formed by the restitution of the second meiotic division. The value of these gametophytes in a breeding program of Lolium is discussed.  相似文献   

Polyketide Synthases in the Microbiome of the Marine Sponge Plakortis halichondrioides: A Metagenomic Update     

Gerardo Della Sala  Thomas Hochmuth  Roberta Teta  Valeria Costantino  Alfonso Mangoni 《Marine drugs》2014,12(11):5425-5440

Sponge-associated microorganisms are able to assemble the complex machinery for the production of secondary metabolites such as polyketides, the most important class of marine natural products from a drug discovery perspective. A comprehensive overview of polyketide biosynthetic genes of the sponge Plakortis halichondrioides and its symbionts was obtained in the present study by massively parallel 454 pyrosequencing of complex and heterogeneous PCR (Polymerase Chain Reaction) products amplified from the metagenomic DNA of a specimen of P. halichondrioides collected in the Caribbean Sea. This was accompanied by a survey of the bacterial diversity within the sponge. In line with previous studies, sequences belonging to supA and swfA, two widespread sponge-specific groups of polyketide synthase (PKS) genes were dominant. While they have been previously reported as belonging to Poribacteria (a novel bacterial phylum found exclusively in sponges), re-examination of current genomic sequencing data showed supA and swfA not to be present in the poribacterial genome. Several non-supA, non-swfA type-I PKS fragments were also identified. A significant portion of these fragments resembled type-I PKSs from protists, suggesting that bacteria may not be the only source of polyketides from P. halichondrioides, and that protistan PKSs should receive further investigation as a source of novel polyketides.  相似文献   

Global trajectories of the long-term decline of coral reef ecosystems   总被引：1，自引：0，他引：1  

Pandolfi JM  Bradbury RH  Sala E  Hughes TP  Bjorndal KA  Cooke RG  McArdle D  McClenachan L  Newman MJ  Paredes G  Warner RR  Jackson JB 《Science (New York, N.Y.)》2003,301(5635):955-958

Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.  相似文献   

Ecological forecasts: an emerging imperative   总被引：1，自引：0，他引：1  

Clark JS  Carpenter SR  Barber M  Collins S  Dobson A  Foley JA  Lodge DM  Pascual M  Pielke R  Pizer W  Pringle C  Reid WV  Rose KA  Sala O  Schlesinger WH  Wall DH  Wear D 《Science (New York, N.Y.)》2001,293(5530):657-660

Planning and decision-making can be improved by access to reliable forecasts of ecosystem state, ecosystem services, and natural capital. Availability of new data sets, together with progress in computation and statistics, will increase our ability to forecast ecosystem change. An agenda that would lead toward a capacity to produce, evaluate, and communicate forecasts of critical ecosystem services requires a process that engages scientists and decision-makers. Interdisciplinary linkages are necessary because of the climate and societal controls on ecosystems, the feedbacks involving social change, and the decision-making relevance of forecasts.  相似文献   

A Legume Ethylene-Insensitive Mutant Hyperinfected by Its Rhizobial Symbiont   总被引：3，自引：0，他引：3  

RV Penmetsa  DR Cook 《Science (New York, N.Y.)》1997,275(5299):527-530

Development of the Rhizobium-legume symbiosis is controlled by the host plant, although the underlying mechanisms have remained obscure. A mutant in the annual legume Medicago truncatula exhibits an increase of more than an order of magnitude in the number of persistent rhizobial infections. Physiological and genetic analyses indicate that this same mutation confers insensitivity to the plant hormone ethylene for multiple aspects of plant development, including nodulation. These data support the hypothesis that ethylene is a component of the signaling pathway controlling rhizobial infection of legumes.  相似文献   

Gravity Waves in Jupiter's Thermosphere     

LA Young  RV Yelle  R Young  A Seiff  DB Kirk 《Science (New York, N.Y.)》1997,276(5309):108-111

The Atmosphere Structure Instrument on the Galileo probe detected wavelike temperature fluctuations superimposed on a 700-kelvin temperature increase in Jupiter's thermosphere. These fluctuations are consistent with gravity waves that are viscously damped in the thermosphere. Moreover, heating by these waves can explain the temperature increase measured by the probe. This heating mechanism should be applicable to the thermospheres of the other giant planets and may help solve the long-standing question of the source of their high thermospheric temperatures.  相似文献   

抗草甘膦大豆的遗传研究   总被引：5，自引：2，他引：5  

陈新  朱成松  顾和平  Francisco Firpo  Carlos Sala 《江苏农业科学》2002,(6):21-23

以3个大面积推广的春大豆品种（宁镇3号、灰荚2号和日本晴3号）为母本与3个转基因抗草甘膦品种（ARG4、ARG5和ARG6）杂交，对杂交后代F1、F2、F3和BC1的抗除草剂特性进行遗传分析，结果表明大豆对除草剂的抗性受一对显性核基因控制。  相似文献   

Fatty acid digestibility in gilthead sea bream fed diets containing native,re‐esterified or acid vegetable oils          下载免费PDF全文

C. Trullàs  R. Fontanillas  A. Tres  R. Sala 《Aquaculture Nutrition》2017,23(3):537-547

Re‐esterified vegetable oils are obtained from a chemical esterification reaction between vegetable acid oils and glycerol. Due to their properties, it is expected that they have a higher nutritive value than their corresponding acid oils and a better digestibility than their native counterparts. The aim of this study was to determine the effect of re‐esterified oils with a different monoacylglycerol (MAG) and diacylglycerol (DAG) content, produced from palm or rapeseed, on fatty acid digestibility in gilthead sea bream (Sparus aurata). Triplicate groups of fish were fed nine experimental diets containing different oils during 28 days. For each source, four different types of oil were used: native, re‐esterified low or high in MAG and DAG and acid. A commercial fish oil was used for the control diet. Diets containing re‐esterified oils had better apparent digestibility coefficients (ADC) of total fatty acids than acid oil diets. Re‐esterified oils do not negatively affect apparent digestibility coefficients of fatty acids when compared to their corresponding native oils and could be incorporated as a source of energy in diets for gilthead sea bream. An improvement in digestibility compared to the native oil diet was only obtained in palm re‐esterified oil high in MAG and DAG.  相似文献   

Exploring Chemical Diversity of Phorbas Sponges as a Source of Novel Lead Compounds in Drug Discovery     

Alessia Caso  Fernanda Barbosa da Silva  Germana Esposito  Roberta Teta  Gerardo Della Sala  Laura P. A. Nunes Cavalcanti  Alessandra Leda Valverde  Roberto Carlos C. Martins  Valeria Costantino 《Marine drugs》2021,19(12)

Porifera, commonly referred to as marine sponges, are acknowledged as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention over the years. They are widespread in all continents, and several structurally unique compounds have been identified from this species. Terpenes, mainly sesterterpenoids, are the major secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have presented interesting biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial, and anti-inflammatory activities have been isolated and structurally characterized. This review provides an overview of almost 130 secondary metabolites from Phorbas sponges and their biological activities, and it covers the literature since the first study published in 1993 until November 2021, including approximately 60 records. The synthetic routes to the most interesting compounds are briefly outlined.  相似文献