The genus Cylindrotheca consists of a small group of marine diatoms with a few species described. Eleven isolates of diatoms identified as Cylindrotheca closterium morphologically were obtained from Jiaozhou Bay with their nuclear-encoded small-subunit ribosomal RNA (SSU rDNA) and chloroplast-encoded rbcL gene sequences determined in this study. Interestingly, very high sequence divergences of SSU rDNA and rbcL gene were found among these isolates, and numerous nucleotide variation of rbcL gene caused relatively few variation of deduced amino acid sequence. Phylogenetic analyses based on SSU rDNA and rbcL gene, respectively, grouped the isolates into 6 clades. Phylogenetic tree of SSU rDNA placed all the Cylindrotheca isolates together, separating them into two lineages clearly. Lineage I was composed of the eleven C. closterium isolates obtained in this study together with another C. closterium isolate, but some clades were not well supported. Lineage II contained two C. closterium isolates and one C. fusiformis isolate. Phylogenetic analysis of rbcL gene also separated the Cylindrotheca isolates into two well-defined lineages. The eleven C. closterium isolates formed a lineage and all clades were supported strongly. Statistical comparisons of SSU rDNA indicated that the average distance within lineageⅠwas significantly higher than that of other microalgae species (P < 0.01). These results suggested the existence of cryptic species within C. closterium.
Background
The placental anticoagulant protein Annexin A5 is highly expressed on the apical surfaces of syncytiotrophoblasts and plays an important role in maintaining blood fluidity in the placental circulation. We investigated the expression of Annexin A5 in maternal blood and placentas from pregnancies complicated by preeclampsia compared with uncomplicated pregnancies.
Materials and Methods
Placental tissue and maternal blood were collected from pregnancies complicated by preeclampsia. They were classified into two groups: early-onset group (n = 10), late-onset group (n = 10) .10 women without perinatal complications who accepted elective term cesarean section were chosen as the control group. Western blot and immunohistochemistry were used to detect the expression and localization of Annexin A5 in the placenta. Annexin A5 mRNA expression was quantified by Real-Time PCR. Annexin A5 and coagulation factor Xa in maternal blood was measured by an enzyme-linked immunosorbent assay. Prothrombin time, activated partial thromboplastin time, Thrombin time, fibrinogen were detected in each groups.
Results
(1) The expression of Annexin A5 in maternal blood were: 5.54±0.29 in early-onset group; 5.10±0.28 in late-onset group; 4.5±0.19 in control group. They were significantly higher in preeclampsia groups than in control group (P = 0.013). However, there was no significant difference among preeclampsia groups (P > 0.05). The mean ±SD coagulation factor Xa expression in the early-onset and late-onset group were 1229.23±45.33 and 1366.96±56.30 versus 1372.95±45.44 in the control group, which has not statistically significant(P=0.072). (2) The protein expression of Annexin A5 in placenta was not statistically significant between the early-onset, late-onset, and control groups (mean ± SD): 0.01 ± 0.02, 0.95±0.03vs.0.99 ± 0.02, p = 0.071.(3) The Annexin A5 mRNA levels in placenta were: 0.79±0.23 in early-onset group; 1.18±0.53 in late-onset group; respectively. All were significantly lower than that in control group (6.19±1.68, P =0.024), and no significant difference was found among preeclampsia groups (P > 0.05). (4) Prothrombin time, activated partial thromboplastin time, Thrombin time, fibrinogen levels were: (11.9 ± 0.23), (33.38± 0.85) s, (16.88 ± 0.45) g/L and 3.85 ± 0.23 in early-onset group; (11.65 ± 0.12), (33.15 ± 0.36) s, (16.13 ± 0.19) g/L and 4.91 ± 0.14 in late-onset group; (12.01 ± 0.09), (32.08 ± 0.41) s, (16.34 ± 0.24) g/L and 4.32 ± 0.20 in control group. The first three were no significant difference among preeclampsia groups and control group (P > 0.05), fibrinogen was statistically significant among all groups (P < 0.05).
Conclusion
These results suggest that Annexin A5 plays an important role in the pathogenesis and progression of preeclampsia by affecting coagulation.
The full length cDNA of a prion protein (PrP) encoding gene of guppy (Poecilia reticulata) and the corresponding genomic DNA were cloned. The cDNA was 2245 bp in length and contained an open reading frame (ORF) of 1545 bp encoding a protein of 515 amino acids, which held all typical structural characteristics of the functional PrP. The cloned genomic DNA fragment corresponding to the cDNA was 3720 bp in length, consisting of 2 introns and 2 exons. The 5' untranslated region of cDNA originated from the 2 exons, while the ORF originated from the second exon. Although the gene was transcribed in diverse tissues including brain, eye, liver, intestine, muscle and tail, its transcript was most abundant in the brain. In addition, the transcription of the gene was enhanced by 5 salinity, implying that it was associated with the response of guppy to saline stress.
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