Electrophoretic Analysis of Isozymes and Discussion about Species Differentiation in Three Species of Genus Gymnocypris

By using the method of electrophoresis,three isozymes (lactate dehydrogenase,malate dehydrogenase and esterase) of three species of genus Gymnocypris were described and analyzed from North Tibet in this paper. The results showed that all three isozymes presented interspecific difference and distinct differentiation among individuals in the same population,and there was no electrophorectic difference between males and females. Analysis of relationships among three naked carps indicated a high degree of similarity between G. selincuoensis and G. cuoensis ,whereas low degree between G. selincuoensis and G. namensis . Furthermore,three isozymes presented expression of null alleles,and the duplicate genes of LDH A 2,LDH B 2,s MDH A 2 and m MDH B 2 also expressed in some individuals. Compared to other tetraploid fishes,three naked carps retained more functional duplicate genes and null alleles. This suggests fishes of genus Gymnocypris are at the early stage of evolution after polyploidization than that of fishes of Catostomidae,it directly related to the later time of schizothoracine fishes originate as well as severe environment.

DIFFERENTIATION OF SOME YEAST SPECIES BY CAPILLARY GAS CHROMATOGRAPHIC ANALYSIS OF CELLULAR FATTY ACIDS

The cellular fatty acids from a total of 62 strains of Torulopsis glabrata (T. glabrata), Saccharomyces cerevisiae (S. cerevisiae), Rhodotorula rubra (R. rubra), Candida krusei (C. krusei), Candida albicans (C. albicans) and Candida tropicalis (C. tropicalis) were examined by capillary gas chromatography. On the basis of fatty acid composition, all strains could be differentiated as to species. These results indicate that capillary gas chromatographic analysis of cellular fatty acids is likely to be useful for rapid identification or grouping of newer isolates of yeast species.

Chromosomal Studies of Masculinized Hybrids in Bitterlings (Teleostei: Cypriniformes: Acheilognathinae)

The chromosome analysis of the masculinized hybrid between female Tanakia limbata and male T. signifer in bitterlings (Acheilognathinae) was done. It was presumed that they had intermediate karyotype between the parents, and formed sperms with heteroploidy resulting from the incomplete pairing of homologous chromosomes in meiosis. Due to the abundance of species and the ease of artificial fertilization, the study of the factor of the hybrid sterility in bitterlings would lead to the clarification of the mechanism about species differentiation and karyotype differentiation, and also to developing a new variety.

Realgar induces differentiation through ROS-dependent mitochondrial pathway in HL-60 cells

Realgar （As 4 S 4 ）, as a mineral drug in traditional Chinese medicine, is currently used as the remedy for acute promyelocytic leukemia and has been proven to have relatively milder side effects as compared to the arsenolite （As 2 O 3 ）-based drugs. We have previously demonstrated that realgar induces differentiation in HL-60 cells, and the differentiation is associated with serine/threonine protein phosphatases, MAPK signaling pathways, and mitochondrial transmembrane potential decrease. In this study, we further explore the roles of mitochondrial permeability transition pore and reactive oxygen species （ROS） in realgar-induced differentiation in HL-60 cells. The differentiation was preceded by marked changes in the cellular level of ROS, and could be enhanced by SB202190, a p38 MAPK inhibitor. In addition, the efficacy of realgar was suppressed by closing the MPTP with an inhibitor. Taken together, these findings indicate that the opening of MPTP and the alteration of ROS generation were involved in realgar-induced differentiation.

Ectopic expression of VRT-A2 underlies the origin of Triticum polonicum and Triticum petropavlovskyi with long outer glumes and grains

Polish wheat (Triticum polonicum) is a unique tetraploid wheat species characterized by an elongated outer glume. The genetic control of the long-glume trait by a single semi-dominant locus, P1 (from Polish wheat), was established more than 100 years ago, but the underlying causal gene and molecular nature remain elusive. Here, we report the isolation of VRT-A2, encoding an SVP-clade MADS-box transcription factor, as the P1 candidate gene. Genetic evidence suggests that in T. polonicum, a naturally occurring sequence rearrangement in the intron-1 region of VRT-A2 leads to ectopic expression of VRT-A2 in floral organs where the long-glume phenotype appears. Interestingly, we found that the intron-1 region is a key ON/OFF molecular switch for VRT-A2 expression, not only because it recruits transcriptional repressors, but also because it confers intron-mediated transcriptional enhancement. Genotypic analyses using wheat accessions indicated that the P1 locus is likely derived from a single natural mutation in tetraploid wheat, which was subsequently inherited by hexaploid T. petropavlovskyi. Taken together, our findings highlight the promoter-proximal intron variation as a molecular basis for phenotypic differentiation, and thus species formation in Triticum plants.