Molecular phylogeny and species delimitation of the genus Tonkinacris (Orthoptera, Acrididae, Melanoplinae) from China

Tonkinacris is a small group in Acrididae. While a few species were occasionally sampled in some previous molecular studies, there is no revisionary research devoted to the genus. In this study, we explored the phylogeny of and the relationships among Chinese species of the genus Tonkinacris using the mitochondrial COI barcode and the complete sequences of ITS1 and ITS2 of the nuclear ribosomal DNA. The phylogeny was reconstructed in maximum likelihood and Bayesian inference frameworks, respectively. The overlap range between intraspecific variation and interspecific divergence was assessed via K2P distances. Species boundaries were delimitated using phylogenetic species concept, NJ tree, K2P distance, the statistical parsimony network as well as the GMYC model. The results demonstrate that the Chinese Tonkinacris species is a monophyletic group and the phylogenetic relationship among them is (T. sinensis, (T. meridionalis, (T. decoratus, T. damingshanus))). While T. sinensis, T. meridionalis and T. decoratus were confirmed being good independent species strongly supported by both morphological and molecular evidences, the validity of T. damingshanus was not perfectly supported by molecular evidence in this study.

Molecular evidences confirm the taxonomic separation of two sympatric congeneric species (Mollusca, Gastropoda, Neritidae, Neritina)

A reliable taxonomy, together with more accurate knowledge of the geographical distribution of species, is a fundamental element for the study of biodiversity. Multiple studies on the gastropod family Neritidae record three species of the genus Neritina in the Brazilian Province: Neritina zebra (Bruguière, 1792), Neritina virginea (Linnaeus, 1758), and Neritina meleagris Lamarck, 1822. While N. zebra has a well-established taxonomic status and geographical distribution, the same cannot be said regarding its congeners. A widely cited reference for the group in Brazil considers N. meleagris a junior synonym of N. virginea. Using a molecular approach (phylogenetic, species delimitation, and statistical parsimony network analyses), based on two mitochondrial markers (COI and 16S), this study investigated if N. virginea and N. meleagris are distinct species. The molecular results confirmed the existence of two strongly supported distinct taxonomic entities in the Brazilian Province, which is consistent with the morphological descriptions previously proposed for N. virginea and N. meleagris. These species occur in sympatry in the intertidal sandstone formations of Northeastern Brazil. Despite the great variation in the colour patterns of the shells, the present study reinforced previous observations that allowed the differentiation of these two species based on these patterns. It also emphasized the importance of the separation of these two clades in future studies, especially those conducted in the Brazilian Province, since these species may cohabit.

Introducing improvements in the mass rearing of the housefly: biological, morphometric and genetic characterization of laboratory strains

Understanding the biology of the housefly (Musca domestica L.) is crucial for the development of mass-rearing protocols in order to use this insect as a degradation agent for livestock waste. In this study, the biological and genetic differences between different laboratory strains of M. domestica were analysed. Additionally, hybrids were obtained by mixing the strains and their biological parameters were also measured. The three strains of M. domestica presented differences in their biological and morphological parameters, the main differences were: size, egg production and developmental time. The strain A (specimens from Central Europe) had the best qualities to be used in mass-rearing conditions: it produced the largest quantities of eggs (5.77±0.38 eggs per female per day), the individuals were larger (12.62±0.22 mg) and its developmental time was shorter (15.22±0.21 days). However, the strain C (specimens from SW Europe) produced the fewest eggs (3.15±0.42 eggs per female per day) and needed 18.16±0.49 days to develop from larva to adult, whilst the females from strain B (from South America) produced 4.25±0.47 eggs per day and needed 17.11±0.36 days to complete its development. Genetic analysis of the original laboratory strains showed four different mtDNA cytochrome c oxidase subunit I haplotypes. Statistical parsimony network analysis showed that the SW Europe and South-American strains shared haplotypes, whereas the Central Europe strain did not. Upon hybridizing the strains, variations in egg production and in developmental time were observed in between hybrids and pure strains, and when mixing Central European and South-American strains only males were obtained.

Origin and evolution of the Italian subterranean termite Reticulitermes lucifugus (Blattodea, Termitoidae, Rhinotermitidae)

The Holarctic genus Reticulitermes shows seven species within the Mediterranean Basin. While phylogeny and systematics at continental level has been deeply investigated, a few studies concentrated on local ranges. To gain a clearer picture of the diversity and evolution of the Italian species Reticulitermes lucifugus, we analyzed the mitochondrial cytochrome oxidase II (COII) gene marker in newly collected colonies across the Peninsula. Data were gathered with all R. lucifugus sequences available from previous studies; COII sequences of the closely related Iberian taxa were also added to the data set. Maximum-likelihood, median-joining and statistical parsimony network elaborations on the resulting 119 colonies all agreed in indicating that: (i) the Sardo-Corsican subspecies R. lucifugus corsicus, strictly related to Southern Italian populations (including the Sicilian ones), is phylogenetically closer to the Iberian Reticulitermes grassei; and (ii) R. lucifugus lucifugus peninsular populations are structured into three clusters. The phylogenetic relationships and the biogeography of extant taxa suggest a scenario in which R. lucifugus ancestors colonized the Italian region through the Sardo-Corsican microplate during its Oligocene-Miocene anticlockwise rotation. Moreover, well after the colonization took place, northward range expansion might have produced the presently observed genetic diversity, as inferred from haplotype and nucleotide diversity estimates. On the whole, this study highlights the evolution of Italian Reticulitermes taxa and supports the importance of a wide taxon sampling especially when dealing with organisms easily dispersed by human activities.

A study on the phylogeny and phylogeography of a marine cosmopolite diatom from the southern Black Sea

A single-cell PCR method was applied to Pseudo-nitzschia pungens strains from the southern Black Sea. Based on the aligment set of the LSU D1-D3 region, a Bayesian molecular phylogeny analysis and a parsimony network analysis were used to investigate phylogenetic clades (Clades I-III) in P. pungens and to determine the ancestral clades. The parsimony network analysis also demonstrated that ancestral haplotypes belonged to Clade II, residing around the northeastern Pacific, while Clade I was distributed globally but antitropicaly. According to the findings of this study, the Black Sea strain (Clade III) shows a global phylogeographic pattern.

Development and characterization of chloroplast microsatellite markers in Macaranga (Euphorbiaceae)

As part of our study on the phylogeography of the ant-plant genus Macaranga, we have screened for polymorphic regions in the chloroplast genome. Initially, ten universal PCR primer pairs targeted at chloroplast microsatellite loci were applied to a small set of specimens, covering various taxonomic levels from intrafamilial to intraspecific. Eight primer pairs produced PCR fragments that behaved as single and discrete bands on agarose gels. The five most promising candidate pairs were further analysed with an extended set of DNA templates, and PCR products were separated on sequencing gels. The number of size variants per locus varied from two to eight, combining into 17 haplotypes among 29 Macaranga accessions from 10 species. Comparative sequencing demonstrated that microsatellites were responsible for the observed size variation at three of five loci, whereas variation at the other loci was caused by larger insertions and (or) deletions (indels). In addition to poly(A) and poly(T) repeats, which are typically found in chloroplast DNA, we also identified a variable (CT)n repeat, with n = 4 to n = 8. Sequencing revealed three examples of size homoplasy, one of which was caused by a single base substitution that raised the actual number of haplotypes to 18. Relationships between haplotypes were assessed by phenetic analyses of size variants and by constructing a parsimony network based on sequence variation. For both types of analysis, the distribution of haplotypes correlated with geographically circumscribed regions rather than with taxonomic boundaries.Key words: chloroplast microsatellites, ccmp primers, Macaranga, haplotype network, interspecific gene flow.