Systematics of Scleranthus (Caryophyllaceae)

<p>Scleranthus is a genus of about 12 species of herbaceous flowering plants or small shrubs with a disjunct Eurasian/Australasian distribution. Monophyly of the genus is supported by the close similarity of gynoecial development of all species and consistent with nuclear ITS DNA sequence analysis. Traditionally the genus had been divided into two sections, section Scleranthus and section Mniarum. Section Mniarum is exclusively Australasian while section Scleranthus has been circumscribed to contain exclusively European species or a combination of European and Australasian species. Pollen and floral characters align the species into Australasian and Eurasian groups also supported by nuclear ITS DNA sequence analysis. Section Scleranthus as more broadly defined (i.e., sensu West and Garnock-Jones, 1986) is therefore at least paraphyletic or at worst polypyhyletic. Phylogenetic reconstructions based on morphological characters differ from those based on ITS sequences in supporting different relationships within the Australasian species of Scleranthus. Hybridisation and introgression within the genus are discussed and suggested as the cause of discordance between morphology and DNA sequence based trees. Low sequence divergence among Scleranthus ITS sequences suggests that the European and Australasian clades within the genus diverged within the last l0 million years. Biogeographic implications of these dating and competing hypotheses explaining the disjunct North-South distribution of the genus are discussed. Nuclear ITS and chloroplast ndhF DNA sequences both suggest that Scleranthus belongs to a clade within the family Caryophyllaceae consisting of members of subfamilies Alsinoideae and Caryophylloideae. Phylogenetic relationships between genera belonging to the three subfamilies of Caryophyllaceae (Alsinoideae, Caryophyloideae, and Paronychioideae) are addressed in this thesis through ndhF sequence analysis, which provides no support for the monophyly of traditionally recognised groups. Morphological character data sets are likely to always encompass multiple incongruent data partitions (sensu Bull et al. 1993). It may therefore be appropriate to combine data from DNA sequence and morphology for parsimony analysis even where the two are significantly incongruent.</p>

Systematics of Scleranthus (Caryophyllaceae)

<p>Scleranthus is a genus of about 12 species of herbaceous flowering plants or small shrubs with a disjunct Eurasian/Australasian distribution. Monophyly of the genus is supported by the close similarity of gynoecial development of all species and consistent with nuclear ITS DNA sequence analysis. Traditionally the genus had been divided into two sections, section Scleranthus and section Mniarum. Section Mniarum is exclusively Australasian while section Scleranthus has been circumscribed to contain exclusively European species or a combination of European and Australasian species. Pollen and floral characters align the species into Australasian and Eurasian groups also supported by nuclear ITS DNA sequence analysis. Section Scleranthus as more broadly defined (i.e., sensu West and Garnock-Jones, 1986) is therefore at least paraphyletic or at worst polypyhyletic. Phylogenetic reconstructions based on morphological characters differ from those based on ITS sequences in supporting different relationships within the Australasian species of Scleranthus. Hybridisation and introgression within the genus are discussed and suggested as the cause of discordance between morphology and DNA sequence based trees. Low sequence divergence among Scleranthus ITS sequences suggests that the European and Australasian clades within the genus diverged within the last l0 million years. Biogeographic implications of these dating and competing hypotheses explaining the disjunct North-South distribution of the genus are discussed. Nuclear ITS and chloroplast ndhF DNA sequences both suggest that Scleranthus belongs to a clade within the family Caryophyllaceae consisting of members of subfamilies Alsinoideae and Caryophylloideae. Phylogenetic relationships between genera belonging to the three subfamilies of Caryophyllaceae (Alsinoideae, Caryophyloideae, and Paronychioideae) are addressed in this thesis through ndhF sequence analysis, which provides no support for the monophyly of traditionally recognised groups. Morphological character data sets are likely to always encompass multiple incongruent data partitions (sensu Bull et al. 1993). It may therefore be appropriate to combine data from DNA sequence and morphology for parsimony analysis even where the two are significantly incongruent.</p>

Osteogenesis imperfecta: a literature review and a clinical case of a perinatal-lethal type of disease

The article presents the modern views of clinicians and geneticists on one of the most severe genetic disorders of skeletal and connective tissues - osteogenesis imperfecta. The review provided the literature data that showed the incidence rates, genetic heterogeneity of osteogenesis imperfecta, as well as the role of some proteins involved in the construction of bone tissue, as well as a clinical classification of the main types of the disorder. The authors described a clinical case: a girl with typical clinical and radiological manifestations of the rarest of all types of osteogenesis imperfecta - type II (perinatal-lethal, congenital osteogenesis imperfecta, Vrolik’s syndrome). The child’s diagnosis was verified by a parallel DNA sequence analysis which showed a heterozygous mutation in exon 29 (c.1966G> A) of COL1A1 gene not previously described in the literature. It caused the substitution of glycine for serine at position 656. The role of antenatal diagnostics and the importance of medical genetic counselling of the family before planning the next pregnancy due to the existing risk of re-birth of a sick child is outlined. Due to the fact that majority of the patients with the most prognostically unfavourable type II osteogenesis imperfecta, as a rule, die in utero, the described case of observation of the girl with typical clinical and X-ray signs of the disorder for almost 3 months of postpartum period is extremely rare and highly indicative. The detection of the heterozygous mutation in exon 29 (c.1966G > A) of COL1A1 gene by a parallel DNA sequence analysis which was not previously described in the literature gives an additional significance to the described observation.

Effects of Culture Conditions on Growth and Cyclooligomer Depsipeptides Biosynthesis of Cordyceps sp. CPA14V

Cordyceps sp. CPA14V was isolated from insect-fungi sample that was collected from Copia - Son La Nature Reserve. The strain was able to biosynthesize cyclooligomer depsipeptides (CODs). This study aimed to identify Cordyceps sp. CPA14V to species using DNA sequence analysis and to estimate the effects of carbon, nitrogen, pH of culture broth on its growth and COD producing capacity. The results showed that the studied strain was Cordyceps cateniannulata CPA14V. This is the first record of the species in Vietnam. Glucose, yeast extract and pH=8.0 were the most suitable for growth and CODs synthesis of C. cateniannulata CPA14V. This is also the first report of CODs produced by a C. cateniannulata.