Astrocyte death in organotypic cultures of fetal spinal cord from rats with unilateral micromelia

Growth and differentiation of neurons and glia in spinal cord explants of 16 days old rat fetuses with teratogen-induced left-sided micromelia were studied. Progressive destruction of astrocytes that differentiate in interstitial zone of cultures was observed in 37% of explants of the left side, while the development was normal in cultures of the right side. Possible mechanisms leading to destruction of astrocytes in cultures of spinal cord regions that innervate anomalous limbs are discussed.     

The transformation of the mammalian genome and the teratogenic activity of chloridin

Susceptibility to the effect of teratogen chloridine of three generations produced from transgenic rats with human growth hormone gene was investigated. The offsprings were shown to reveal elevated teratogenic injury as compared with intact animals.     

Alcohol-drug interaction in rat embryogenesis: the effect of separate and combined action of sodium salicylate and ethanol

A combined administration of sodium salicylate and ethanol to female rats in threshold embryotoxic doses on the 9th, 10th, 12th and 13th days of pregnancy results in a sharp increase of embryolethal and teratogenic effects. The embryotoxic effect of sodium salicylate and ethanol at their combined injection exceeds the summational embryotoxic effect at the separate action of the preparations. The spectrum of malformations after their combined effect does not differ from that induced with sodium salicylate.     

Production of DON-related trichothecenes byFusarium graminearum Schw from Krasnodarski krai of the USSR

34Fusarium graminearum Schw isolates produced 4-deoxynivalenol to form significant amounts of 4, 7 — dideoxynivalenol and lesser amounts of 4 — deoxynivalenol monoacetates on grain substratesin vitro. This is the first report on the capability a large group of naturally occurring isolates to produce 4,7-dideoxynivalenol. The average levels of 4,7-dideoxynivalenol on rice, corn, barley, and wheat as a substrate were respectively 26.8, 14.0, 12.8, and 10.5% of the level of 4-deoxynivalenol. 4, 7 — dideoxynivalenol was present in all examined naturally contaminated wheat kernel samples at levels of 1.7 to 7.9% of the level of 4-deoxynivalenol. These findings suggest that more attention should be given to the occurrence of 4,7-dideoxynivalenol in cereals.     

Variation in the ribosomal internal transcribed spacers (ITS1 and ITS2) among eight taxa of the Mimulus guttatus species complex

The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region were sequenced from three individuals in each of eight taxa of the Mimulus guttatus species complex. Three discrete variants, or "types," of ITS sequences were found, among which 30%-40% of sites differed, compared with 1%-2% within types. Dot plots indicate that these types were not related by conspicuous rearrangements or inversions. More than one ITS type was often found in the same taxon, and two of three ITS types span species boundaries, indicating their presence prior to speciation. These ITS sequences showed essentially no positional homology with the nearest sequenced relative, tomato. In contrast, the 5.8S region was relatively unvaried, with 8 of 162 sites varied in the sample among all eight taxa. The phylogeny inferred by the most common ITS sequence type, rooted by the two other ITS types, agreed with isozymes in showing the distinctness of M. nudatus, M. laciniatus, and M. tilingii from the other five taxa.      

Radioautographic and cytofluorimetric analysis of DNA synthesis during the pre-implantation period of rat and mouse embryonic development]

The patterns of DNA synthesis and kinetics of cell population in the rat and mouse embryos were studied by means of 3H-thymidine autoradiography and cytofluorimetry. The rat and mouse embryos during the period of cleavage consist of a heterogenous population of blastomeres. At all the stages under study, all phases of the cell cycle occur in the blastomeres: G1, S, G2 and mitosis. The embryonic cells were distributed into groups containing 2c, 3c, 4c and more DNA. The ratio of cell number in these groups differed in the mouse and rat embryos. The mouse embryos are characterized by the appearance of a considerable amount of polyploid cells in S phase at the morula stage. The stage and species specific quantitative and qualitative patterns were established for DNA synthesis and kinetics of the cell population of blastomeres.     

中国小菇属十个新记录种

报道了小菇科小菇属真菌10个中国新记录种,香菌组：橙盖小菇Mycena aurantiidisca、黄白小菇Mycena flavoalba、粉黄小菇Mycena floridula;棘刺组：异刺小菇Mycena heteracantha;纤柄组：碱味小菇Mycena amygdalina;脆足组：粉被小菇Mycena zephirus;冬生组：绣线菊小菇Mycena speirea、冬生小菇Mycena hiemalis;小菇组：绒柄小菇Mycena flos-nivium,分别来自吉林等11个省份、自治区。提供了每个物种的形态描述和线条图,以及与相近种的讨论。共计90条自测及下载ITS序列,在采用贝叶斯法和最大似然法构建的小菇属系统发育树中,新记录种均得到分子数据支持。凭证标本存放于吉林农业大学菌物标本馆（HMJAU）。