Platinum mineralization has been studied within two zoned clinopyroxenitedunite massifs of the Urals Platinum Belt. Within the Svetloborsky massif, platinum group minerals (PGM) occur directly in serpentinized dunite. The ore-forming system demonstrates the features of an early evolutionary stage: a significant portion of PtFe alloys belongs to ferroan platinum; native osmium is depleted in Ir; an isoferroplatinumosmium paragenesis is present. Within the Kamenushinsky massif, PGM are genetically related to chromitite and belong to the late-magmatic stage of the ore-forming system evolution: osmium and isoferroplatinum are rich in Ir; both isoferroplatinumosmium and isoferroplatinumiridium magmatic parageneses are present. The elevated Pt in the dunite of the Svetloborsky massif and in the chromitite of the Kamenushinsky massif is the result of two events: the primary-magmatic crystallization of PGM and later hydrothermal overprint.

The findings of the present study indicate ontogenetic dissociations between taste reactivity to ethanol and saccharin and intake of these solutions, and suggest that high acceptance of ethanol early in ontogeny may not be associated with its orosensory properties but rather with the pharmacological effects of ethanol.

Earlier we showed that human genome contains many evolutionarily young or novel genes with tumor-specific or tumor-predominant expression. We suggest calling such genes Tumor Specifically Expressed, Evolutionarily New (TSEEN) genes. In this paper we performed a study of the evolutionary ages of different classes of human genes, using homology searches in genomes of different taxa in human lineage. We discovered that different classes of human genes have different evolutionary ages and confirmed the existence of TSEEN gene classes. On the other hand, we found that oncogenes, tumor-suppressor genes and differentiation genes are among the oldest gene classes in humans and their evolution occurs concurrently. These findings confirm non-trivial predictions made by our hypothesis of the possible evolutionary role of hereditary tumors. The results may be important for better understanding of tumor biology. TSEEN genes may become the best tumor markers.

Earlier we suggested a new hypothesis of the possible evolutionary role of hereditary tumors (Kozlov, Evolution by tumor Neofunctionalization, 2014), and described a new class of genes – tumor specifically expressed, evolutionarily novel (TSEEN) genes - that are predicted by this hypothesis (Kozlov, Infect Agents Cancer 11:34, 2016). In this paper we studied evolutionarily novel genes expressed in fish tumors after regression, as a model of evolving organs. As evolutionarily novel genes may not yet have organismal functions, we studied the acquisition of new gene functions by comparing fish evolutionarily novel genes with their human orthologs. We found that many genes involved in development of progressive traits in humans (lung, mammary gland, placenta, ventricular septum, etc.) originated in fish and are expressed in fish tumors and tumors after regression. These findings support a possible evolutionary role of hereditary tumors, and in particular the hypothesis of evolution by tumor neofunctionalization.Research highlightsEarlier we described a new class of genes that are tumor-specifically expressed and evolutionarily novel (TSEEN). As the functions of TSEEN genes are often uncertain, we decided to study TSEEN genes of fishes so that we could trace the appearance of their new functions in higher vertebrates. We found that many human genes which are involved in development of progressive traits (placenta development, mammary gland and lung development etc.,) originated in fishes and are expressed in fish tumors.

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The hypothesis of evolution by tumor neofunctionalization (the main hypothesis) describes the possible role of hereditary tumors in evolution. The present article examines the relationship of the main hypothesis to other biological theories. As shown in this paper, the main hypothesis does not contradict to the existing biological theories, but fills the lacunas between them and explains some unexplained (or not completely understood) questions. Common features of embryonic development and tumorigenesis are described by several recognized theories. Similarities between normal development and tumorigenesis suggest that tumors could participate in the evolution of ontogenesis and in the origin of new cell types, tissues and organs. A wide spectrum of non-trivial explanations and non-trivial predictions in different fields of biology, suggested by the main hypothesis, is an indication of its fundamental nature and the potential to become a new biological theory, a theory of the role of tumors in evolution of development, or carcino-evo-devo.

The present study was designed to test the hypothesis that sensitivity of ingestive behavior of infant rat to the pharmacological effects of ethanol changes between postnatal (P) days 9 and 12. The intake of 0.1% saccharin and water, general motor activity, and myoclonic twitching activity were assessed following administration of three doses of ethanol (0, 0.25, 0.5g/kg) while fluids were free available to the animals. The 0.5g/kg dose of ethanol attenuated saccharin intake in P9 pups and enhanced saccharin intake in P12 rats. On P12 some sex-related differences emerged at 0.5g/kg of ethanol, with saccharin intake being higher in females than in their male counterparts. Taste reactivity probe revealed that 0.5 g/kg of ethanol increased taste responsiveness to saccharin on P12 but only to infusions presented at a high rate. The results of the present study indicate that ontogenetic changes in sensitivity to the effects of ethanol on ingestive behavior occur during the second postnatal week, with P9 animals being more sensitive to the inhibitory (sedative) effects on saccharin intake and P12 rats being more sensitive to the stimulatory effects of ethanol. We suggest that acute ethanol enhanced saccharin intake via sensitization of oral response to appetitive taste stimulation.

Mineralization in the platinum-group elements occurs in lodes in the dunite-clinopyroxenite-gabbro Gal'moenan complex, in the Koryak-Kamchatka Platinum Belt of Russia, and in associated placers, namely those along the Levtyrinyvayam River and Ledyanoy and Penistiy creeks at different distances from the source. The grains of Pt-Fe alloy in lode deposits are isoferroplatinum and have Pt 3 Fe compositions, whereas those in the Levtyrinyvayam River placer range in composition from native to ferroan platinum and having iron contents generally higher than in the lodes (30-35 at.% Fe). Platinum grains from the Ledyanoy Creek placer are larger and more commonly intergrown with chromite than those from the Levtyrinyvayam River. Minor elements, which are indicators of conditions of formation of the Pt-Fe alloy, exhibit different concentrations in lodes and in the nearby placers. Platinum-iron alloy from the Levtyrinyvayam placer, the farthest from the source, represents the eroded upper apical part of the intrusion, and contains mainly Pd. The Penistiy placer receives platinum from dunite and pyroxenite of a marginal facies of the complex, and thus platinum-iron alloy bearing Rh-Ir and Pd-Rh. Placer isoferroplatinum deposited in the Ledyanoy Creek, which drains dunite and chromite-bearing rocks in the south of the intrusion, is rich in Ir (up to 6.98 wt.%), as is the Pt-Fe alloy in the Gal'moenan complex (4.34 wt.% Ir). Most grains contain also a relatively high Rh content. Isoferroplatinum + iridium and isoferroplatinum + osmium are two main primary magmatic parageneses revealed in both placers and lodes, though the first is more commonly found in lodes and in the Ledyanoy Creek placer, and the latter in the Levtyrinyvayam River placer. Lodes mostly contain laurite, RuS 2 , and the Levtyrinyvayam placer bears all varieties of (Ru,Os)S 2 , including Ru-free Rh-rich erlichmanite (Os,Rh)S 2. The irarsite-hollingworthite series predominates in lodes, and the irarsite-platarsite and osarsiteplatarsite series predominate in the Levtyrinyvayam placer. Sperrylite in lodes may contain up to 6.94 wt.% Sb, and thus differs from that in placers. The phase (Pt 0.96 Fe 0.02) ⌺0.98 (As 1.17 Sb 0.75 S 0.09) ⌺2 , a member of the sperrylite-geversite solid solution, has been found in a lode. Complete solid-solution between RuS 2 and RuAsS on one hand, and PtAsS and PtAs 2 on the other, is demonstrated. In the Gal'moenan complex, concentrations of Ir decrease, and those of Pd and Os increase, toward the upper or apical parts of the complex.