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981.
Hatchery selection promotes boldness in newly hatched brown trout (Salmo trutta): implications for dominance 总被引:2,自引:0,他引:2
Sundstrom L. Fredrik; Petersson Erik; Hojesjo Johan; Johnsson Jorgen I.; Jarvi Torbjorn 《Behavioral ecology》2004,15(2):192-198
By using newly hatched (approximately 2 weeks old) brown trout(Salmo trutta) from six families of wild and six families ofsea-ranched origin (seventh generation), we tested the hypothesesthat (1) the hatchery environment selects for increased boldness,and (2) boldness predicts dominance status. Sea-ranched troutspend their first 2 years in the hatchery before being releasedinto the wild at the onset of seaward migration. Trout werepresented with a novel object (tack) and with food (brine shrimp),and their responses were measured and scored in terms of boldness.Siblings with increasing difference in boldness were then pairedin dyadic contests. Fish of sea-ranged origin were on averagebolder than were fish of wild origin, and bolder individualswere more likely to become dominant regardless of origin. Boldnesswas not related to RNA levels, indicating that bold behaviorwas not a consequence of higher metabolism or growth rate. Neitherwas size a predictor of bold behavior or the outcome of dyadiccontests. These results are consistent with studies on olderlife stages showing increased boldness toward predators in hatchery-selectedfish, which suggests that behavioral consequences of hatcheryselection are manifested very early in life. The concordancebetween boldness and dominance may suggest that these behaviorsare linked in a risk prone-aggressive phenotype, which may bepromoted by hatchery selection. However, we also found significantvariation in behavioral and growth-related traits among families,suggesting that heritable variation has not been exhausted bysea-ranching procedures. 相似文献
982.
Sandhya Ravishankar Meera Pandey R. P. Tewari V. Krishna 《World journal of microbiology & biotechnology》2006,22(10):1021-1025
Summary The sporophores of Pleurotus are gymnocarpous and continuously release spores in the atmosphere causing respiratory allergies like hay fever and farmer’s lung disease among workers. The allergy is caused by the antigens present on the walls of the spores. Apart from this, during commercial production, these spores settle on the fruit bodies, germinate and form a velvety film which gives an unpleasant appearance to the mushrooms. The spores emitted may include new genotypes likely to attack wood or trees. Spore allergy is one of the most important limiting factors for the large scale cultivation of this species. Different approaches are being adopted at IIHR for the production of commercial sporeless/low-sporing strains of Pleurotus to alleviate the spore allergy problem. Attempts were made during the present investigation to produce sporeless or low-sporing mutants through u.v. mutation. Mutation of the mycelium did not yield the desired results. Mutation of the spores of Pleurotus sajor-caju yielded an extremely low-sporing mutant after 75 min exposure. The character has been found to be stable for more than 10 generations of subculturing. 相似文献
983.
James L Weber 《Biology direct》2006,1(1):16-10
Applications of Genome Polymorphism Scans range from the relatively simple such as gender determination and confirmation of
biological relationships, to the relatively complex such as determination of autozygosity and propagation of genetic information
throughout pedigrees. Unlike nearly all other clinical DNA tests, the Scan is a universal test – it covers all people and
all genes. In balance, I argue that the Genome Polymorphism Scan is the most powerful, affordable clinical DNA test available
today. 相似文献
984.
The epididymis of buffalo is differentiated into 6 regions. The head represents the first 3 regions, the body the 4th region and the tail the 5th and 6th region. At 3-30 weeks, the epithelium is simple high columnar with few basal cells in region I, simple low columnar with few basal cells in region II, pseudostratified low columnar in regions III, IV, V, and pseudostratified low columar in region VI. As age advances, the epithelium increases in height and shows a tendency toward advanced pseudostratification. The basal cells are greater in number in regions III, IV and V than in the other regions of the epididymis. The epithelial cells contain stereocilia in region I at 3 weeks and regions III, IV and V at 30 weeks, whereas they are absent in regions II and VI. The tubules in region I are the smallest in diameter while the tubules in region VI have the largest diameter. 相似文献
985.
A method for separation and visualization of the different apolipoprotein B species using 0.2% sodium dodecyl sulfate-1.5% agarose gel electrophoresis and immunoblotting is described. The method is capable of demonstrating the different forms of apolipoprotein B (apo B) in plasma volumes of 10-50 microliters without prior ultracentrifugation. After ultracentrifugation of samples, estimation of the ratio between apo B 48 and apo B 100 is possible by scanning of Coomassie-stained gels or immunoblots. 相似文献
986.
E Gomard Y Hénin G Sterkers M Masset R Fauchet J P Lévy 《Journal of immunology (Baltimore, Md. : 1950)》1986,136(11):3961-3967
The clone TA10 is a T3+ T4+ T8- proliferative and cytolytic human T cell clone. This clone has been shown to be specific for the hemagglutinin of influenza A Texas virus and restricted by an HLA class II molecule associated with the DRw8-Dw8.1 phenotype. Here we show that TA10 and all of its subclones can also react with eight HLA-DRw8 negative, Epstein-Barr virus (EBV)-transformed cell lines or phytohemagglutinin blasts in the absence of influenza antigens. All of these cell lines are HLA-DR2/DR4 with a classic DR2 long haplotype. The only nonreactive HLA-DR2/DR4 cell line observed bears a DR2 short haplotype. Only heterozygous HLA-DR2/DR4 but not parental DR2 or DR4 EBV-transformed cell lines can be recognized by TA10, indicating that the cross-reacting determinant is a transcomplementation product between HLA-DR2 and HLA-DR4 haplotypes. DR-specific, but not DQ- or DP-specific monoclonal antibodies, inhibit in the proliferation assay and in the chromium release test both the DRw8-Dw8.1-restricted and the anti-DR2/DR4 reactions. These results show that HLA-DR-restricted, anti-viral human T cell clone can evidence cross-reactivity for allospecific class II molecules of the major histocompatibility complex, and human CTL can recognize transcomplementation products of class II HLA genes. In addition, the results suggest that a beta-chain coded for by an HLA-DR gene and associated with an alpha-chain coded for by a still unidentified but possibly HLA-DQ gene constitute this functional transcomplementation product. 相似文献
987.
988.
989.
Ye. P. Dulepova V. A. Nadtochii L. L. Budnikova 《Russian Journal of Marine Biology》2008,34(7):472-481
The trophic structure of benthic communities in the Sea of Okhotsk and Bering Sea was analyzed based on the results of macrobenthic
survey catches conducted in the Far Eastern seas in the 2000s. The production of trophic levels and entire communities was
determined. It was shown that production of benthic communities is still at a high level and has almost not changed since
the 1980s. The arrangement of the communities of some shelf areas by productivity characteristics was made. 相似文献
990.