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Zinc-binding proteins from seminal plasma (ZnBPs) originate in the secretions of different accessory sex glands and are implicated in key events associated with sperm-egg fertilization processes. This study describes the isolation and characterization of the ZnBPs of canine seminal plasma. Ejaculates were collected from three crossbred dogs for a 2-week period. The ZnBPs as well as non zinc-binding proteins (nZnBPs) were isolated by zinc-dependent affinity chromatography. The isolated fractions were subjected to native gel electrophoresis (one-dimensional polyacryamide gel electrophoresis, PAGE) and sodium dodecyl sulphate polyacryamide gel electrophoresis (SDS-PAGE), using denaturing and reducing conditions. Zinc-elution profile using affinity chromatography displayed two protein fractions represented by the nZnBPs and ZnBPs, respectively. Using native gel electrophoresis, it was found that both the nZnBPs and ZnBPs occurred in their native state as aggregates, ranging from 140 to 669 kDa. The nZnBPs were disaggregated into 8 protein bands, with molecular weights ranging from 10.7 to 79.7 kDa, following SDS-PAGE analysis. By contrast, SDS-PAGE analysis of the ZnBPs revealed 13 protein bands, with molecular weights ranging from 11.6 to 152.3 kDa. Densitometric analysis showed that 46-48% of nZnBPs could be accounted by protein fractions with molecular weights of 10.7 and 14.2 kDa. Also, 2 protein fractions with molecular weights of 11.6 and 14.3 kDa, were predominant in ZnBPs, accounting for approximately 28-30% of the total proteins. These results demonstrate the zinc-binding capacity of proteins secreted by the canine prostate. The findings of this study indicate that ZnBPs of canine seminal plasma comprise several protein fractions, which might be implicated in the reproductive processes in the dog.
The purpose of this work was to quantify the impact of spontaneous and X-radiation-induced chromosome rearrangements on survival rate of androgenetic rainbow trout (Oncorhynchus mykiss). Various doses of X irradiation (50, 150, 250, 350 Gy) were used for inactivation of nuclear DNA in oocytes. After the irradiation, eggs were inseminated with normal sperm from 4 males derived from a strain characterized by Robertsonian rearrangements and length polymorphism of the Y chromosome. The haploid zygotes were exposed to a high hydrostatic pressure (7000 psi) to duplicate the paternal DNA. Neither Robertsonian chromosome polymorphism nor the Y chromosome morphology impaired the viability of the androgenetic embryos and alevins. Moreover, survival of eyed embryos of the androgenetic rainbow trout increased significantly with increasing doses of oocyte X irradiation. After 6 months of rearing, only specimens from the 250 and 350 Gy variants survived. The number of fingerlings with remnants of the maternal genome in the forms of chromosome fragments was higher in the 250 Gy group. Intraindividual variation of chromosome fragment number was observed, and some individuals exhibited haploid/diploid mosaicism and body malformations. Individuals irradiated with less than 250 Gy died, presumably because of the conflict between intact paternally derived chromosomes and the residues of maternal genome in the form of chromosome fragments.
Content available Sexual asymmetry in Scots pine seed orchards
In seed orchards of Scots pine Pinus sylvestris L., the reproductive process is affected by the variation among the clones in fertility and abundance of male and female flowering. There were significant differences between the clones in relative proportion of male and female strobili as well as in seed yield. Thus, clones in Scots pine seed orchards may differentiate into "seed" and "pollen" clones. The least fertile clone produce 4.6 times less pollen than the most fertile clone, while cone yield of the least yielding clones was 5.5 times smaller than that of the most yielding clones. Amount of the pollen dispersed at the upper part of the crowns was two times greater than at the base of the crowns. The minimum amount of pollen needed for successful fertilization of an ovule was 1500 grains per cm2. There was no significant relationship between sexual asymmetry of the parental clones and height growth of their progeny.
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