Sequence divergence of the mitochondrial DNA of Pacific Ocean salmon

Restriction assay of mtDNA has been made in 6 salmon species form the genus Oncorhynchus and one species from the related genus, i.e. Salvelinus malma. The size of the mitochondrial genome was found to be identical and equal to 16.7 kilobases. The digestion patterns of mtDNA cleaved by 5 restriction endonucleases (Eco RI, Bgl I, Bgl II, Hind III, and Pst I) were used for analysis of the levels of interspecific variation and for estimation the matrix of mtDNA sequence differentiation. It was found that the level of nucleotide sequence divergence (p) in the genus Oncorhynchus varies within 1.7-6.7%. Minimum p value was observed in a pair O. keta--O. gorbuscha, maximum one--between O. masu and other species. With respect to similarity in their mtDNA, three groups may be distinguished: 1) O. gorbuscha--O. keta; 2) O. nerka--O. kisutch, O. tschawytscha; 3) O. masu. Mean value of intergeneric level of sequence divergence between Oncorhynchus and Salvelinus was found to be equal to 8%. On the basis of mtDNA analysis, the dendrogram of similarity of the species was plotted which is consistent in principle with current viewpoints on phylogenetic relations among the Pacific salmon.     

Genome analysis of ground squirrels of the genus Citellus (Rodentia,Sciuridae) II. DNA sequence organization

The organization of the DNA sequences in five specics of Citellus (C. pygmaeus, C. fulvus, C. major, C. parryi and C. undulatus) was determined from the reassociation kineties of DNA fragments of various lengths and the size distribution of SI-nuclease-resistant duplexes of repetitive DNA. Only 15% of the genome of all the species studied consists of short unique and repeated sequences interspersed with a period less than 2 3 kb, whereas the major part of the genome is occupied by much more extensive sequences of two types, moderately long (3–15 kb) and very long (much more than 15 kb). On the basis of the number of moderately long single-copy sequences the species under study are divided into two groups, coinciding with their division into short-tailed and long-tailed ground squirrels: the short-tailed (C. pygmaeus, C. major and C. fulvus) possess far more such sequences (17–24%) than do the long-tailed ones (C. parryi and C. undulatus) (1–7%). The same division is observed in the amount of very long single-copy sequences. The repeated DNA sequences of Citellus vary widely in size, i.e. from 70 up to some thousands of nucleotide pairs, sequences of more than 1200 nucleotide pairs being most common. In addition, part of the repetitions contain between 70 and 150 base pairs. About one-third of C. parryi repeats (10% of the genome) are characterized by such very short sequences whereas their amont is much less in the other Citellus species (1–4% of the genome).     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

Direct intracardiac injection of umbilical cord-derived stromal cells and umbilical cord blood-derived endothelial cells for the treatment of ischemic cardiomyopathy

The development of new therapeutic strategies is necessary to reduce the worldwide social and economic impact of cardiovascular disease, which produces high rates of morbidity and mortality. A therapeutic option that has emerged in the last decade is cell therapy. The aim of this study was to compare the effect of transplanting human umbilical cord-derived stromal cells (UCSCs), human umbilical cord blood-derived endothelial cells (UCBECs) or a combination of these two cell types for the treatment of ischemic cardiomyopathy (IC) in a Wistar rat model. IC was induced by left coronary artery ligation, and baseline echocardiography was performed seven days later. Animals with a left ventricular ejection fraction (LVEF) of ≤40% were selected for the study. On the ninth day after IC was induced, the animals were randomized into the following experimental groups: UCSCs, UCBECs, UCSCs plus UCBECs, or vehicle (control). Thirty days after treatment, an echocardiographic analysis was performed, followed by euthanasia. The animals in all of the cell therapy groups, regardless of the cell type transplanted, had less collagen deposition in their heart tissue and demonstrated a significant improvement in myocardial function after IC. Furthermore, there was a trend of increasing numbers of blood vessels in the infarcted area. The median value of LVEF increased by 7.19% to 11.77%, whereas the control group decreased by 0.24%. These results suggest that UCSCs and UCBECs are promising cells for cellular cardiomyoplasty and can be an effective therapy for improving cardiac function following IC.     

Phylogeography of mitochondrial DNA in South Asian Dolly Varden char Salvelinus curilus Pallas, 1814 (Salmoniformes, Salmonidae): mediated gene introgression?

In 41 individuals of South Asian Dolly Varden char Salvelinus curilus, nucleotide sequences of tRNA-Pro gene fragment (27 bp) and mtDNA control region (483-484 bp) were analyzed. The fish were collected in 20 localities covering virtually the whole range of the species: Kuril Islands, Sakhalin Island. and Primorye. In addition, six individuals of three other char species (S. albus, S. malma, and S. leucomaenis), which are closely related to S. curilus and inhabit the Russian Far East, were examined. In all, we detected 12 different variants of mtDNA haplotypes that formed three distinct groups differing in 14--20 nucleotide positions. The first group consisted of six haplotypes found in S. curilus in Kuril Islands, Sakhalin, and Primorye (mtDNA phylogroup OKHOTSKIA). The second group comprised four haplotypes representing the mtDNA phylogroup BERING, which had been described earlier (Brunner et al, 2001); they were found in S. curilus in Kuril Islands and Sakhalin, as well as in S. albus and S. malma in Kamchatka and northern Kurils. The third group included two haplotypes detected in S. leucomaenis. The existence of two mtDNA lineages (OKHOTSKIA and BERING) in S. curilus from Kurils and Sakhalin was explained by hybridization and DNA transfer from S. malma to S. curilus. The absence of the BERING haplotypes in S. curilus from Primorye water reservoirs is related to the physical isolation of the Sea of Okhotsk and Sea of Japan basins in past epochs. On the basis of comparing phylogenetic trees, constructed from the data on allozyme and mtDNA variation, we suggest that in this case, an indirect transfer of mtDNA in Alpinoid chars--> S. malma-->S. curilus chain could occur.     

Relationship between the study of DNA reassociation kinetics of various chromosomal forms of Ellobius and questions concerning the pathways of chromosome rearrangement during evolution

Fifteen chromosome forms of Ellobius talpinus (from 2n = 31 to 2n = 54) were found in the small area in the Pamirs. Low-chromosome karyotypes evolved from 54-chromosomal ancestral form by Robertsonia centric fusions. The DNA reassociation kinetics of 34- and 54-chromosome forms of E. talpinus have been studied. For comparison DNA of E. lutescens (2n = 17) the karyotype of which seems to have arisen from 54-chromosome ancestor by Robertsonian and other types rearrangements was examined. Reassociation profiles of Ellobius DNA suggest the existence of several repeated sequences families with different frequences of repetitions. The reassociation curves of DNA from 34- and 54-chromosome forms were identical. These data indicate absence of changes in DNA molecular organization during the evolution of E. talpinus karyotypes by Robertsonian fusions. Comparative analysis of DNA reassociation kinetics of E. talpinus and E. lutescens showed identical characteristics of highly repeated sequences and of one from the three intermediate fractions, however Cot 1/2, complexity and repetitive frequencies of two intermediate fractions of E. talpinus and E. lutescens were different. It is possible that non-robertsonian rearrangements of E. lutescens karyotype affected only intermediate repetitions. The alternative explanation of these data is a simple divergence of repeated sequences during the evolution of E. lutescens DNA.     

Airway hyperresponsiveness is associated with airway remodeling but not inflammation in aging Cav1-/- mice

Background

Airway inflammation and airway remodeling are the key contributors to airway hyperresponsiveness (AHR), a characteristic feature of asthma. Both processes are regulated by Transforming Growth Factor (TGF)-β. Caveolin 1 (Cav1) is a membrane bound protein that binds to a variety of receptor and signaling proteins, including the TGF-β receptors. We hypothesized that caveolin-1 deficiency promotes structural alterations of the airways that develop with age will predispose to an increased response to allergen challenge.

Methods

AHR was measured in Cav1-deficient and wild-type (WT) mice 1 to 12 months of age to examine the role of Cav1 in AHR and the relative contribution of inflammation and airway remodeling. AHR was then measured in Cav1^-/- and WT mice after an ovalbumin-allergen challenge performed at either 2 months of age, when remodeling in Cav1^-/- and WT mice was equivalent, and at 6 months of age, when the Cav1^-/- mice had established airway remodeling.

Results

Cav1^-/- mice developed increased thickness of the subepithelial layer and a correspondingly increased AHR as they aged. In addition, allergen-challenged Cav1^-/- mice had an increase in AHR greater than WT mice that was largely independent of inflammation. Cav1^-/- mice challenged at 6 months of age have decreased AHR compared to those challenged at 2 months with correspondingly decreased BAL IL-4 and IL-5 levels, inflammatory cell counts and percentage of eosinophils. In addition, in response to OVA challenge, the number of goblet cells and α-SMA positive cells in the airways were reduced with age in response to OVA challenge in contrast to an increased collagen deposition further enhanced in absence of Cav1.

Conclusion

A lack of Cav1 contributed to the thickness of the subepithelial layer in mice as they aged resulting in an increase in AHR independent of inflammation, demonstrating the important contribution of airway structural changes to AHR. In addition, age in the Cav1^-/- mice is a contributing factor to airway remodeling in the response to allergen challenge.     

Detection of tandem repeats in the genome of Citellus genus using restrictases

DNA from ground squirrels of the Citellus genus (Rodentia, Sciuridae) were analysed by centrifugation in the presence of CsCl followed by digestion by restriction endonucleases. Digestion of DNA of two species C. undulatus and C. fulvus by 10 of the 16 restriction endonucleases used led to formation of electrophoretically discrete fragments that are multiple to 330 b.p. in length which points out the tandem organization of repetitive sequences similar to the satellite DNA of many mammal species. However, upon centrifugation we failed to reveal a satellite band in these species; hence the tandem repeats refer to the class of cryptic satellites in the ground squirrels and do not differ in base composition from the remaining part of DNA. The main fraction of the genome was revealed in the form of discrete fragments by cleavage with HindIII and AluI. Both of these restriction endonucleases were used for comparative analysis of DNA of 12 Citellus species. It has been shown that DNA of all species can be digested by HindIII and yields a series of fragments that are multiple to 330-30 b.p. in length and the total content of which varies from species to species within 4-22%. The fraction of the tandem repeats does not correlate with the systematic position of species nor with the amount of heterochromatin in the chromosomes. AluI cuts the DNA of 11 species yielding 110 and 220 b.p. fragments compared to only 60 and 280 b.p. in the DNA of C. dauricus. Under HindIII digestion we can also reveal the tandem repeats in marmot, which is phylogenetically close to the Citellus of the Marmota genus, but they have another periodicity--180 b.p. We propose that the age of ground squirrels repeats is 2-3 million years and they are significantly younger than the marmot repeats.