The growth and reproductive endocrinology of adult triploid Pacific salmonids     

Tillmann J. Benfey  Helen M. Dye  Igor I. Solar  Edward M. Donaldson 《Fish physiology and biochemistry》1989,6(2):113-120

This paper describes the effect of triploidy on growth and reproductive endocrinology in the months leading up to and including spawning in rainbow trout,Salmo gairdneri, and pink salmon,Oncorhynchus gorbuscha. Growth rates were the same for diploid and triploid rainbow trout, but triploid female pink salmon were smaller than maturing diploid females and diploid and triploid males of the same age. Triploid males of both species developed typical secondary sexual characteristics and had normal endocrine profiles, although their cycle appeared to be delayed by about one month. Triploid females remained silvery in appearance and showed no endocrine signs of maturation, even at the level of the pituitary. Thus, although triploids of both sexes are genetically sterile, only the females do not undergo physiological maturation.Reported in part at the Third International Symposium on Reproductive Physiology of Fish, St. John's, Newfoundland, August 2–7, 1987.  相似文献   

Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children     

Marques RC  Dórea JG  McManus C  Leão RS  Brandão KG  Marques RC  Vieira IH  Guimarães JR  Malm O 《Public health nutrition》2011,14(4):661-669

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Health screening of free-ranging European brown hares (Lepus europaeus) on the German North-Sea island Pellworm     

Annika Posautz  Igor Loncaric  Marie Lundin  Daniel Hoffmann  Antonio Lavazza  Zsofia Kelemen  Christoph Beiglb?ck  Christian Walzer  Anna Kübber-Heiss 《Acta veterinaria Scandinavica》2015,57(1)

Background

A sudden decline of the European brown hare (Lepus europaeus) population in one of the best hunting districts for small game species in northern Germany, the German North-Sea island Pellworm, in the years 2007/08 following marked habitat changes led to the implementation of a thorough health assessment program of the population. 110 animals were collected during the normal hunting season in the years 2010 and 2011. A post-mortem examination and histopathological investigation was performed on all animals. Additionally, routine bacteriology of the small intestine and parasitology were carried out. Sera of hares were tested for European Brown Hare Syndrome (EBHS) by enzyme linked immunosorbent assay, and for Treponema sp. by indirect immunofluorescent test. Additional testing was performed when deemed necessary.

Results

The most striking result was a shift in the intestinal bacterial flora towards Gram-negative Enterobacteriaceae with a predominance of either Escherichia coli, or Aeromonas sp., or a high-grade double-infection with these two pathogens with subsequent catarrhal enteritis. Additionally, a marked coccidiosis, and varying infestations with the nematode Trichostrongylus retortaeformis were found. The sero-prevalence for EBHS was 78.1%, and for Treponema 43.9%.

Conclusions

The shift and decrease in diversity of the intestinal flora was the main and most consistent result found. In the authors’ opinion the change of the habitat combined with other stressors increased the animals’ sensitivity to ubiquitous bacterial species and parasites which usually would not have such fatal effects.  相似文献   

Diversity and function of adaptive immune receptors in a jawless vertebrate     

Alder MN  Rogozin IB  Iyer LM  Glazko GV  Cooper MD  Pancer Z 《Science (New York, N.Y.)》2005,310(5756):1970-1973

Instead of the immunoglobulin-type antigen receptors of jawed vertebrates, jawless fish have variable lymphocyte receptors (VLRs), which consist of leucine-rich repeat (LRR) modules. Somatic diversification of the VLR gene is shown here to occur through a multistep assembly of LRR modules randomly selected from a large bank of flanking cassettes. The predicted concave surface of the VLR is lined with hypervariable positively selected residues, and computational analysis suggests a repertoire of about 10(14) unique receptors. Lamprey immunized with anthrax spores responded with the production of soluble antigen-specific VLRs. These findings reveal that two strikingly different modes of antigen recognition through rearranged lymphocyte receptors have evolved in the jawless and jawed vertebrates.  相似文献   

The Fusarium graminearum genome reveals a link between localized polymorphism and pathogen specialization     

Cuomo CA  Güldener U  Xu JR  Trail F  Turgeon BG  Di Pietro A  Walton JD  Ma LJ  Baker SE  Rep M  Adam G  Antoniw J  Baldwin T  Calvo S  Chang YL  Decaprio D  Gale LR  Gnerre S  Goswami RS  Hammond-Kosack K  Harris LJ  Hilburn K  Kennell JC  Kroken S  Magnuson JK  Mannhaupt G  Mauceli E  Mewes HW  Mitterbauer R  Muehlbauer G  Münsterkötter M  Nelson D  O'donnell K  Ouellet T  Qi W  Quesneville H  Roncero MI  Seong KY  Tetko IV  Urban M  Waalwijk C  Ward TJ  Yao J  Birren BW  Kistler HC 《Science (New York, N.Y.)》2007,317(5843):1400-1402

We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts.  相似文献   

Pinpointing the source of a lunar meteorite: implications for the evolution of the Moon     

Gnos E  Hofmann BA  Al-Kathiri A  Lorenzetti S  Eugster O  Whitehouse MJ  Villa IM  Jull AJ  Eikenberg J  Spettel B  Krähenbühl U  Franchi IA  Greenwood RC 《Science (New York, N.Y.)》2004,305(5684):657-659

The lunar meteorite Sayh al Uhaymir 169 consists of an impact melt breccia extremely enriched with potassium, rare earth elements, and phosphorus [thorium, 32.7 parts per million (ppm); uranium, 8.6 ppm; potassium oxide, 0.54 weight percent], and adherent regolith. The isotope systematics of the meteorite record four lunar impact events at 3909 +/- 13 million years ago (Ma), approximately 2800 Ma, approximately 200 Ma, and <0.34 Ma, and collision with Earth sometime after 9.7 +/- 1.3 thousand years ago. With these data, we can link the impact-melt breccia to Imbrium and pinpoint the source region of the meteorite to the Lalande impact crater.  相似文献   

Design of new α-conotoxins: from computer modeling to synthesis of potent cholinergic compounds     

Kasheverov IE  Zhmak MN  Khruschov AY  Tsetlin VI 《Marine drugs》2011,9(10):1698-1714

A series of 14 new analogs of α-conotoxin PnIA Conus pennaceus was synthesized and tested for binding to the human α7 nicotinic acetylcholine receptor (nAChR) and acetylcholine-binding proteins (AChBP) Lymnaea stagnalis and Aplysia californica. Based on computer modeling and the X-ray structure of the A. californica AChBP complex with the PnIA[A10L, D14K] analog, single and multiple amino acid substitutions were introduced in α-conotoxin PnIA aimed at compounds of higher affinity and selectivity. Three analogs, PnIA[L5H], PnIA[A10L, D14K] and PnIA[L5R, A10L, D14R], have high affinities for AChBPs or α7 nAChR, as found in competition with radioiodinated α-bungarotoxin. That is why we prepared radioiodinated derivatives of these α-conotoxins, demonstrated their specific binding and found that among the tested synthetic analogs, most had almost 10-fold higher affinity in competition with radioactive α-conotoxins as compared to competition with radioactive α-bungarotoxin. Thus, radioiodinated α-conotoxins are a more sensitive tool for checking the activity of novel α-conotoxins and other compounds quickly dissociating from the receptor complexes.  相似文献   

Synchronous fluorescence spectroscopy of edible vegetable oils. Quantification of tocopherols     

Sikorska E  Gliszczyńska-Swigło A  Khmelinskii I  Sikorski M 《Journal of agricultural and food chemistry》2005,53(18):6988-6994

The study demonstrates the application of front face and right angle synchronous fluorescence spectroscopy for the characterization of edible oils. The method enables monitoring of tocopherols, pheophytins, and other fluorescent components in edible oils. Principal component analysis of synchronous fluorescence spectra revealed sample clustering according to the type of oil. Partial least-squares regression was utilized to develop calibration models between fluorescence spectra and total tocopherol content determined by HPLC. The regression models showed a good ability to predict tocopherol content. The best fitting results were obtained for 1% v/v diluted oils and for bulk samples using the entire spectrum, yielding the regression coefficient, r, of 0.991, and root mean square error of cross-validation of approximately 8%. The results presented confirm the capabilities of the fluorescence techniques as a tool for the analysis of edible oils.  相似文献   

Über einige Fragen der Heterosis und des Leistungsabfalls bei den Ertragsmerkmalen von Mais     

Igor Grebenščikov 《Genetic Resources and Crop Evolution》1972,19(1):151-162

Zusammenfassung Bei der Anwendung einer neuen Methodik konnte gezeigt werden (abweichend von den Ergebnissen des Autors von 1968), daß eine Tendenz zu negativem Zusammenhang zwischen Heterosisindex in F₁ und Leistungsabfall-index in F₂ für die Merkmale Pflanzenhöhe (PH), Grünmasse (PG) und Kornertrag (KrG) bei Mais besteht; dieser Zusammenhang ist aber sehr locker und zeigte signifikante Werte nur unter ungünstigeren Jahresbedingungen.Ferner wurde ein Versuch unternommen, die genotypischen Varianzkomponenten der Heterosis und des Abfalls bei den genannten Merkmalen zu schätzen. Für die Merkmale, die stärker zu Heterosis neigen (PG und KrG) war diese Heritabilität für Abfall überhaupt nicht signifikant, während sie für Heterosis gut gesicherte Werte von etwa 40% ergab.

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On some problems referring to heterosis and the reduction in vigour of yield characters in maize

Summary Using a new method it could be demonstrated, in difference to the author's results published in 1968, that there is a tendency to negative correlation between the index of heterosis in F₁ and the index of reduction in vigour in F₂ for the characters plant height (PH), green matter (PG), and grain yield (KrG) of maize. This mutual relation, however, is rather weak and proved significant only under conditions of unfavourable years.Also an attempt was made to estimate for the above-mentioned characters the genotypic components of variance of both heterosis and reduction in vigour. As to the characters which tend to more strongly marked heterosis (PG and KrG), this heritability was not at all significant for reduction in vigour, but gave sufficiently significant values of about 40% for heterosis.

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F₁ F₂

1968 ., , , F₁ F₂ . (PH), (PG) (KrG) , , . , , (PG KrG), «» , 40%.

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Detection of Gibellina cerealis infection on winter common wheat in Ukraine     

Retman  Sergiy  Kyslykh  Tetiana  Shevchuk  Olga  Kozub  Natalia  Sozinov  Igor  Karelov  Anatolii  Chernychenko  Sergiy 《植物病害和植物保护杂志》2021,128(6):1479-1485

Journal of Plant Diseases and Protection - False eyespot disease caused by Gibellina cerealis (Pass.) Pass. was first detected in Ukraine during field inspections of wheat canopies in...  相似文献