Molecular phylogeny of cave dwelling Eremogryllodes crickets (Orthoptera, Myrmecophilidae) across Zagros Mountains and Southern Iran

Recently, several new species and subspecies from the genus Eremogryllodes Chopard, 1929 (Insecta: Orthoptera: Myrmecophilidae) inhabiting caves of Iran, have been described based on morphology. The high variation of genitalia structure along with high similarity of external morphology between populations hamper the precise species identification. Thus, molecular approaches are critical to determine the taxonomic positions of species/subspecies of this genus. Here we provide the molecular phylogeny, based on the 16S rRNA mitochondrial gene, of recently described species of Eremogryllodes along with some unidentified specimens from the same region. The results support the monophyly of the family Myrmecophilidae. The topology of the 16S rRNA tree did not completely support the five morpho-species. The three main recovered clades mainly grouped specimens by their geographical locations. Our study suggests the possibility of more than one species in one cave and the presence of cryptic species among cave dwelling crickets, based on the 16S rRNA marker.

Morphological and molecular characterisation of Coslenchus persicus n. sp. (Nematoda: Tylenchidae) from Iran

Summary A new species of Coslenchus from north-western Iran is illustrated and described using morphological, morphometric and molecular data. Coslenchus persicus n. sp. is characterised by a medium-sized body of 694-810 μm, often 18 (seldom 20-22) longitudinal ridges excluding lateral field, head with four distinct annuli, stylet 9.6-10.8 μm long, pharyngeal basal bulb large and cylindrical, spermatheca offset and ovate, without sperm, vulval flaps extending for two annuli, 5-7 μm in length, tail striated with finely to bluntly rounded tip, 110-153 μm long and without males. The new species comes close to C. assamensis, C. diversus, C. japonicus, C. leiocephalus, C. maritus, C. multigyrus, C. paramaritus, C. pastor, and C. polonicus, but can be distinguished from all by differences in body length, stylet length and shape of basal bulb, post-vulval uterine sac, tail and certain morphometric data. Molecular data are provided for the characterisation of the new species using ribosomal genes (18S and 28S rRNA). In the 18S rRNA tree, the new species was placed in a clade including one isolate of Coslenchus sp. from Iran. In the reconstructed 28S rRNA phylogenetic tree, C. persicus n. sp. clustered with other known Coslenchus species.

Morphological and molecular characterisation of Telotylenchus tamariscus n. sp. (Nematoda: Telotylenchinae) recovered from Khuzestan, south-western Iran

Summary An undescribed species from the rhizosphere of tamarisk, Tamarix passerinoides, Telotylenchus tamariscus n. sp., is illustrated and described based on morphological, morphometric and molecular approaches. The new species is characterised by female characters including body size of ca 1 mm, areolated lateral fields, cephalic region rounded, distinctly set off from the body contour, stylet 19.5 (18.5-20.5) μm long with posteriorly directed basal knobs, pharyngeal glands overlapping intestine dorso-laterally, subcylindrical tail bearing 32 (25-37) cuticular annuli and ending in an annulated terminus, and male spicules and gubernaculum 27 (25-29) and 13 (12.5-14.5) μm long, respectively. Morphologically, our population comes close to several known species of the genus, including T. avaricus, T. aerolatus, T. indicus, T. ventralis, T. paaloofi and T. namibiensis. In the 18S rRNA phylogenetic tree, it occupied a phylogenetic position in close affinity with two sequences of T. ventralis. In the 28S rRNA tree, the genus Telotylenchus did not form a monophyletic group, our isolate clustering with an unknown population of Histotylenchus and four isolates of Tylenchorhynchus mediterraneus in a clade well separated from another clade that included three other isolates tentatively named as Telotylenchus sp.

An ectosymbiosis-based mechanism of eukaryogenesis

The findings of a deep branching Microsporidia clade on the SSU rRNA tree, and diversity of sequence motifs in eukaryotic Hsp70s rendered invalid the endosymbiosis-first theory that mitosome- and hydrogenosome-containing amitochondriate eukaryotes (AMIs) arose from mitochondriate eukaryotes (MTEs) via reductive evolution. Instead, evidence of widespread ectosymbioses indicated that eukaryogenesis was started by an archaeal parent via its acquisition of archaeal proteins through ‘accelerated gene adoption’, and bacterial proteins from ectosymbionts including a clostridial ectosymbiont that supplied its [Fe] hydrogenase and pyruvate:ferredoxin oxidoreductase genes to the AMIs. Subsequent endosymbiosis with Tistrella gave rise to mitochondria with the participation of other alphaproteobacteria. The high frequencies of top similarity bitscores displayed by Giardia, Edhazardia and Trichomonas toward Aciduliprofundum boonei (Abo) pertaining to the enzymes of DNA biology, far surpassing the frequencies toward any Asgard or TACK archaeon, established Abo as the source of these enzymes in eukaryotes, and the archaeal parent of Eukarya.

Molecular taxonomy of some sponges (Demospongiae) using ribosomal (18s rrna) and partial mitochondrial (coi) genes

Sponges, the most ancient multicellular metazoan, were widely distributed across habitats. Vietnam is known to possess a high biodiversity of sponges, however, they are mostly identified based on morphological characteristics and lack the molecular data. In the current study, the phylogenetic relationship of some sponges (Demospongiae) in Vietnam was constructed using two independent markers (COI and 18S rRNA). In this paper the individual markers (COI and 18S rRNA) were successfully used to identify some sponge taxa at the species level. The obtained results showed the congruence of molecular taxonomy using two independent markers. However, our study showed that a combination of the two markers provided more information and supported better for sponge identification. At order level, the COI tree and 18S rRNA tree also recovered the same clades, indicating the congruence of COI and 18S rRNA genes in sponge classification. However, branching order of the clades in COI tree was weakly supported and slightly different from those in 18S rRNA tree.

Natural Communities of Novel Archaea and Bacteria Growing in Cold Sulfurous Springs with a String-of-Pearls-Like Morphology

ABSTRACT We report the identification of novel archaea living in close association with bacteria in the cold (approximately 10°C) sulfurous marsh water of the Sippenauer Moor near Regensburg, Bavaria, Germany. These microorganisms form a characteristic, macroscopically visible structure, morphologically comparable to a string of pearls. Tiny, whitish globules (the pearls; diameter, about 0.5 to 3.0 mm) are connected to each other by thin, white-colored threads. Fluorescent in situ hybridization (FISH) studies have revealed that the outer part of the pearls is mainly composed of bacteria, with a filamentous bacterium predominating. Internally, archaeal cocci are the predominant microorganisms, with up to 107 cells estimated to be present in a single pearl. The archaea appear to be embedded in a polymer of unknown chemical composition. According to FISH and 16S rRNA gene sequence analysis, the archaea are affiliated with the euryarchaeal kingdom. The new euryarchaeal sequence represents a deep phylogenetic branch within the 16S rRNA tree and does not show extensive similarity to any cultivated archaea or to 16S rRNA gene sequences from environmental samples.