Alina V. Fedorova

RPS4 and NAD5 sequences evidenced of polyphyly of ditrichaceae and parallelisms in the evolution of haplolepidous mosses

Molecular phylogenetic analysis of 66 representatives of haplolepidous mosses showed polyphylia of Ditrichaceae. According to the data obtained, the structure of the peristome, as well as features of the gametophyte on which a family traditionally allocated, arose independently in different groups of haplolepideous mosses. At least six genera (Distichium, Saelania, Eccremidium, Garckea, Rhamphidium, and Wilsoniella) should be excluded from the Ditrichaceae family, while Saelania and Distichium should be assigned even to another order. The loss of the peristome and forming of cleistocarpous capsules also occurs independently in at least two lineages of Ditrichaceae s. str., and in representatives of several lineages of Pottiaceae, a family derived from this group. Ditrichum, the type genus of Ditrichaceae, is also polyphyletic, species of this genus belong to two clades. It was concluded that parallel lines of the morphological variability in this group of mosses occur and its phylogeny need to be resolved based on molecular data.

Complete mitochondrial genome sequence of the “copper moss” Mielichhoferia elongata reveals independent nad7 gene functionality loss

The mitochondrial genome of moss Mielichhoferia elongata has been sequenced and assembled with Spades genome assembler. It consists of 100,342 base pairs and has practically the same gene set and order as in other known bryophyte chondriomes. The genome contains 66 genes including three rRNAs, 24 tRNAs, and 40 conserved mitochondrial proteins genes. Unlike the majority of previously sequenced bryophyte mitogenomes, it lacks the functional nad7 gene. The phylogenetic reconstruction and scrutiny analysis of the primary structure of nad7 gene carried out in this study suggest its independent pseudogenization in different bryophyte lineages. Evaluation of the microsatellite (simple sequence repeat) content of the M. elongata mitochondrial genome indicates that it could be used as a tool in further studies as a phylogenetic marker. The strongly supported phylogenetic tree presented here, derived from 33 protein coding sequences of 40 bryophyte species, is consistent with other reconstructions based on a number of different data sets.

On the taxonomic position of the genera Brachydontium Fürnr. and Campylostelium Bruch & Schimp. (Bryophyta, Grimmiales)

The genus Brachydontium was placed in the family Seligeriaceae by most recent authors, in spite of the fact that some of its morphological characters contrast with other genera in this family. The genus Campylostelium was traditionally included in the Ptychomitriaceae, until Hernández-Maqueda et al. (2008) suggested resurrecting the monogeneric Campylosteliaceae De Not. based on data obtained from phylogenetic analyses of two chloroplast markers. Our phylogenetic reconstructions based on chloroplast rps4 and mitochondrial nad5 recovered Brachydontium trichodes (F.Weber) Fürnr. and B. olympicum (E.Britton) T.T.McIntosh & J.R.Spence in a strongly supported clade sister to the Ptychomitriaceae, whereas a well- supported clade composed of Campylostelium saxicola (F.Weber & D.Mohr) Bruch & Schimp. and C. pitardii (Corb.) E.Maier was resolved in a sister position to Brachydontium plus Ptychomitriaceae. The well- supported clade of these three groups is sister to the Grimmiaceae. Results of our phylogenetic analysis and re-evaluation of morphological characters suggest transfer of Brachydontium to the Ptychomitriaceae and confirm the placement of Campylostelium in this family. Based on the inferred affinities of Brachydontium and Campylostelium we propose a new circumscription for the family Ptychomitriaceae.

The mitochondrial genome of the moss Brachythecium rivulare (Hypnales, Brachytheciaceae)

The mitochondrial genome of the pleurocarpous moss Brachythecium rivulare has been sequenced and annotated. The genome consists of 104,460 base pairs and has approximately the same gene set and organization as other bryophyte mitogenomes. Whole mitochondrial genome comparison between B. rivulare and Physcomitrella patens, Tetraphis pellucida, Anomodon rugelii, and Anomodon attenuatus was performed. The primary cause of bryophyte mitochondrial gene length variation was found to be numerous indels in the introns. Bryophyte mitochondrial gene conservation level was estimated, and it was in a good congruence with the overall phylogeny of bryophytes with the percentage of mitogenome similarity being proportional to the age estimated by phylochronologic analysis. Annotation discrepancies in the analyzed mitogenome sequences were identified. The simple sequence repeat (SSR) content was evaluated, and candidate sites of RNA editing were predicted in the B. rivulare mitochondrial genome.