Mitogenomics and phylogenetics of twelve species of African Saturniidae (Lepidoptera).

African Saturniidae (Lepidoptera) include numerous species consumed at the caterpillar stage throughout the continent, and their importance to local communities as a source of nutrition and seasonal income cannot be overestimated. However, baseline genetic data with utility for the characterization of their diversity, phylogeography and phylogenetic relationships have remained scarce compared to their Asian counterparts. To bridge this gap, we sequenced the mitochondrial genomes of 12 species found in southern Africa for comparative mitogenomics and phylogenetic reconstruction of the family, including the first representatives of the tribes Eochroini and Micragonini. Mitochondrial gene content and organization were conserved across all Saturniidae included in the analyses. The phylogenetic positions of the 12 species were assessed in the context of publicly available mitogenomes using Bayesian inference and maximum likelihood (ML) methods. The monophyly of the tribes Saturniini, Attacini, Bunaeini and Micragonini, the sister relationship between Saturniini and Attacini, and the placement of Eochroa trimenii and Rhodinia fugax in the tribes Eochroini and Attacini, respectively, were strongly supported. These results contribute to significantly expanding genetic data available for African Saturniidae and allow for the development of new mitochondrial markers in future studies.

Species Diversity and Phylogenetic Relationships of Olive Lace Bugs (Hemiptera: Tingidae) Found in South Africa.

Olive lace bugs (Hemiptera: Tingidae) are small sap-sucking insects that feed on wild and cultivated Olea europaea. The diversity of olive lace bug species in South Africa, the most important olive producer on the continent, has been incompletely surveyed. Adult specimens were collected in the Western Cape province for morphological and DNA-based species identification, and sequencing of complete mitogenomes. Cysteochila lineata, Plerochila australis, Neoplerochila paliatseasi and Neoplerochila sp. were found at 12 sites. Intra- and interspecific genetic divergences and phylogenetic clustering in 30 species in 18 genera of Tingidae using new and publicly available DNA barcodes showed high levels of congruity between taxonomic and genetic data. The phylogenetic position of the four species found in South Africa was inferred using new and available mitogenomes of Tingidae. Notably, olive lace bugs formed a cluster of closely related species. However, Cysteochila was non-monophyletic as C. lineata was recovered as a sister species to P. australis whereas Cysteochila chiniana, the other representative of the genus, was grouped with Trachypeplus jacobsoni and Tingis cardui in a different cluster. This result suggests that feeding on O. europaea may have a common origin in Tingidae and warrants future research on potential evolutionary adaptations of olive lace bugs to this plant host.

A framework for the development of STR genotyping in domestic animal species: characterization and population study of 12 canine X-chromosome loci.

This study reports the methodology used to search, select and characterize STR loci on the canine X chromosome using publicly available genome resources and following the current guidelines for human and non-human forensic testing. After several rounds of selection, 12 X-STR markers were optimized for simultaneous co-amplification in a single PCR, and genetic profiles were determined in a sample of 103 unrelated dogs. Mendelian inheritance was verified and mutation rates were assessed using family groups. Alleles that varied in size were sequenced to create a standardized nomenclature proposal based on the number of repeats. All loci conformed to Hardy-Weinberg expectations. The resulting panel showed high forensic efficiency, presenting high values of power of discrimination (in males and females) and mean exclusion chance, both in trios involving female offspring and in duos composed of dam and male offspring. Its use may complement the information obtained by autosomal STR analysis and contribute to the resolution of complex cases of kinship in dogs. The presented methodology for the de novo construction of an STR multiplex may also provide a helpful framework for analogous work in other animal species. As an increasing number of reference genomes become available, convenient tools for individual identification and parentage testing based on STR loci selected from autosomes or sex chromosomes' sequences may be created following this strategy.

An assessment of the clonality of the components of canine mixed mammary tumours by mitochondrial DNA analysis.

The aim of this study was to investigate if mutations in the mitochondrial DNA (mtDNA) D-loop fragment control region of canine mammary mixed tumours could be used as clonal markers that identified the cell population of origin. Ten benign mixed mammary tumours and nine carcinomas arising from benign mixed tumours were microdissected and DNA from epithelial and mesenchymal tumour cells and from normal mammary tissue was examined for sequence variations in a fragment of the hypervariable control region. Identical sequence variants in both the epithelial and mesenchymal components (as well as in the corresponding normal tissue) were found in 80% of the benign mixed tumours and in 89% of the carcinomas arising from benign mixed tumours suggesting a shared clonal origin. The distinctive sequence alterations identified in the epithelial and mesenchymal components of 15.8% of all 19 tumours examined, suggests the possibility that a minority of mammary tumours are polyclonal in origin or that early clonal divergence occurs. Increased mutation within the mtDNA D-loop fragment of mixed tumour components was not observed.

Epistatic interactions: how strong in disease and evolution?

When the chimpanzee genome sequence was released, human deleterious alleles associated with simple mendelian diseases were observed as wild-type alleles in six genes (AIRE, MKKS, MLH1, MYOC, OTC and PRSS1). The absence of recognizable phenotypic effects in chimpanzee, contrary to the clinical effect observed in humans, is attributed to epistatic interactions (compensation) between potentially deleterious and compensatory alleles. In this report we investigate the possible evolutionary histories by which substitution of alternative variants in these six genes either ameliorates or avoids pathological consequences.