[Modality and structure of Japanese eel (Anguilla japonica) during spermiogenesis].

The special process and special structure which bring organelle during the spermiogenesis of Japanese eel, Anguilla japonica were observed by scanning electron microscope and transmission electron microscope. The process which spermatoblast became sperm including four special stages, the early stage, the middle stage, the later stage and the spermic stage, then came into being a normal mature sperm. In the early stage, cell nucleus became long form gradually by the oval form. In one side of the cell nucleus, there was a big and special globoid structure dyeing lower, account for 1/3 of cell nucleus cubage. It contains a little of deep dyeing grain form and the lines form material, the outside is wrapped by plasmalemma separated with the cell nucleus, the outside of that structure and cell nucleus still lay a plasmalemma. The spermiogenesis of early stage did not form independent centriolar complex and mitochondria. In the middle stage, the cell nucleus presented a long form with the globoid structure on the top of the nucleus, and the down side had no globoid structure where the flagellum primordium appears. The globoid structure changed with the spermiogenesis. The inner part of the globoid differentiated a centriolar complex and mitochondria step by step. The lysosomes distributed in the medium segment of the cell nucleus obviously. In the late stage, the cell nucleus was similar with the shape of eyebrow or crescent. The centriolar complex released from the globoid structure, then became an independent structure. There were mitochondria which had not become the independent structure still in the globoid structure. Under the karyon, there was flagellum primordium where sent a rather long flagellum. The flagellum formed a typical "9+0" microtubular structure at that time. The spermatozoa in this phase has movable ability. In the spermic stage, the cell nucleus was round in shape. The centriolar complex was inside implantation fossa. Mitochondria were under karyon. And under the mitochondria was the central space of the sleeve. The flagellum formed a typical "9+2" microtubular structure at that time. The spermatozoa of Japanese eel, A. japonica became complete mature spermatozoa must pass through four phases for abnormality.

[Multiple nuclear pseudogenes of mitochondrial cytochrome oxidase I gene in Scylla paramamosain (Decapoda : Portunidae)].

Nuclear mitochondrial pseudogenes (Numts), widely existing in nuclear genomes of many organisms, are those nuclear DNA sequences which have high similarity with mtDNAs. In this study, we identified 14 different multiple nuclear pseudogenes of mitochondrial cytochrome oxidase I gene from an individual Scylla paramamosain (Decapoda: Portunidae). Of these sequences, ninety-six variable sites were detected, accounting for 15.7%. Nucleotide diversity (Pi) index and Haplo-type diversity (Hd) index were 0.05682 and 0.8800, respectively. Among the 14 pseudogenes, the copies of sequence one were the most, occupying 30.8% of total copies, and sequence two run the second one (occupying 19.2%). These sequences were divided into two groups compared with their homologues. In Group 1, there were no insertion or deletion sites, while 8 deletion and 5 insertion sites were detected in Group 2, resulting in frame-shift mutations. It was proved that these two groups of pseudogenes were evolved from at least two independent mtDNA integrations into S. paramamosain nuclear genomes through Chi-square and homogeneity tests.

[Separation and characterization of mitochondrial COI pseudogenes in Scylla paramamosain].

Mitochondrial DNA marker has been applied in genetic structure and phylogenetic analysis, but the differences between nuclear mitochondrial pseudogenes (Numts) and mitochondrial DNA complicate phylogenetic analysis. Using the universal and special primers, 34 pseudogene sequences (Numts) and 5 real mtDNA COI sequences were amplified respectively from 34 individuals of Scylla paramamosain from the coast of southeast China. Twenty-nine haplotypes were identified and two groups (Group I and Group II) were determined according to the homology of the 34 pseudogene sequences. Two insertions and an 8-bp deletion were found in some sequences of Group I, but no indel (insertion and deletion) was found in Group II. Compared to mtDNA COI sequences, the two groups had their conservative sites respectively. At least two independent nuclear transfer events are required to explain the codon position biases revealed through the pairwise comparisons of the 34 Numts, one for Group I and one for Group II. The results showed the necessity of great care in interpreting PCR-generated mtDNA sequences using universal primers when used in population or evolutionary studies in genus Scylla.

Study on toxicity mechanism(s) of ifosfamide in suspending cultured rat hepatocytes / 军事医学科学院院刊

Objective：To study the toxicity mechanism(s) of ifosfamide(Ifo) in suspending cultured rat hepatocytes.Methods：Hepatocytes of adult rat were isolated using two-step perfusion method and cultured suspendingly. Cell viability,intracellular enzyme leakage, contents of sulfhydryl groups and MDA contents of hepatocytes were examined 3 hours after ifosfamide was administered at 5,10,20 mmol/L. Surface and ultrastructure of hepatocytes were also observed. Results：Cell viability and TSH,NPSH,PSH contents of hepatocytes significantly declined, and LDH,AST activities in media increased due to the leakage of intracellular enzymes. The decrease in PSH content was ascribed to depletion of TSH. The higher the dose was, the more serious these changes became. However, MDA contents of the hepatocytes were not found increased at any ifo dose groups. In pathological examination, “bulla" formation was found on the surface of the hepatocytes, deformation，swelling even vacuolation of mitochondria and dilation of rough，smooth endoplasmic reticulum were also observed. Conclusions：Ifo has toxic effect on suspending cultured rat hepatocytes. The decrease in sulfhydryl groups contributes to the hepatotoxicity induced by Ifo.