Microsatellite DNA in peach (Prunus persica L. Batsch) and its use in fingerprinting and testing the genetic origin of cultivars.

We isolated and sequenced 26 microsatellites from two genomic libraries of peach cultivar 'Redhaven', enriched for AC/GT and AG/CT repeats, respectively. For 17 of these microsatellites, it was possible to demonstrate Mendelian inheritance. Microsatellite polymorphism was assayed in 50 peach and nectarine cultivars. Of the 1300 PCRs carried out, all but two produced amplified products of the expected size. All microsatellites were polymorphic, showing 2-8 alleles per locus. Heterozygosity ranged from 0.04-0.74 (mean 0.47); the discrimination power (PD) ranged from 0.04-0.84 (mean 0.60). Cultivar heterozygosity varied greatly, with one cultivar ('Independence') being homozygous at all loci. The set of microsatellites discriminated all cultivars investigated, except several sport mutations, i.e., 'Dixitime' vs. 'Springcrest', 'Compact Redhaven' vs. 'Redhaven', and two pairs of cultivars, 'Venus' vs. 'Orion' and 'Elegant Lady' vs. 'Rome Star', whose pedigrees are controversial. We were able to analyze the paternity of several cultivars. In most cases, the parenthood was confirmed. The comparison of three long-living 'Redhaven' accessions supplied by different repositories did not provide any evidence of somatic instability of microsatellites. Hence, microsatellites, ranked according to their information content, are recommended as markers of choice for peach fingerprinting and suggestions are provided for interpreting band profiles and the correct sizing of alleles.     

Dynorphin A [1-17] induces "reward" in rats in the place conditioning paradigm

Intracerebroventricular (i.c.v.) administration of dynorphin A [1-17] induced significant place preference conditioning in male, Sprague-Dawley rats. Place preferences were induced by 2.3 and 3.5 nmole, but not 1.2 nmole of dynorphin A. Co-administration of naloxone, 27.5 nmole but not 5.5 nmole, antagonized the reward response induced by 2.3 nmole of dynorphin A. Leu-enkephalin, 5 or 25 nmole, and dynorphin A [2-17], 2.3 or 3.5 nmole, had no effect in the place conditioning paradigm.     

Lymphocyte migration in internally irradiated animals. Effect of internal gamma radiation on the migration properties of spleen lymphocytes labeled with 51Cr

In experiments on CBA mice it was shown that migration of 51Cr-labeled spleen lymphocytes, injected intravenously, to lymph nodes of intact recipients was suppressed 6-24 months after the administration of a radiopharmaceutic preparation of selenium-75-selenomethionine in a quantity forming the doses of 1 Gy and 1.5 Gy absorbed within the whole body and lymphoid organs, respectively. Migration of labeled lymphocytes to the liver, kidneys and lungs, as well as their retention in the circulating blood, were increased. As the result of the migration disorders the specific affinity of lymphocytes for peripheral lymphoid tissue decreased.