Shanciol B

20337557

The direct transfer of genes into differentiated insect tissues is a useful method of determining gene function because it circumvents the need to perform germ line transformations and of having information on tissue-specific gene promoters. Here in vivo gene delivery is achieved through electroporation of a reporter gene into the pupal forewing of the butterfly Bicyclus anynana (Butler) (Lepidoptera: Nymphalidae). Plasmids containing the coding sequence for enhanced green fluorescent protein (EGFP), driven by the Drosophila heat-shock promoter hsp70, were successfully expressed in epidermal cells after plasmid injection followed by electroporation and heat shock. EGFP expression was restricted to the vicinity of the injection and electroporation site, but the number of transformed cells varied from a few to over 5000 cells. Electroporation parameters were optimized in order to maximize the number of transformed cells while minimizing the extent of damage to the adult wing. While certain electrical parameters were well tolerated by the wing tissue, the physical damage caused by the insertion of the tungsten electrodes led to frequent disruptions of the adult wing pattern around the puncture sites. While this technique can be useful to test the correct expression of marker genes (such as EGFP) in newly build plasmids immediately following their injection, its potential use in testing the function of candidate genes in wing pattern formation is limited.

electroporation, EGFP, Bicyclus anynana, somatic transformation, functional genetics, Lepidoptera, wing patterns

In Vivo Electroporation of DNA into the Wing Epidermis of the Butterfly, Bicyclus anynana

Kyle Golden,1 Veena Sagi,1,,a Nathan Markwarth,1 Bin Chen,1,,2,,b and Antonia Monteiro1,,2,,c

2007

30395332

Evolutionary history is typically portrayed as a branching phylogenetic tree, yet not all evolution proceeds in a purely bifurcating manner. Introgressive hybridization is one process that results in reticulate evolution. Most known examples of genome-wide introgression occur among closely related species with relatively recent common ancestry; however, we present evidence for ancient hybridization and genome-wide introgression between major stem lineages of darters, a species-rich clade of North American freshwater fishes. Previous attempts to resolve the relationships of darters have been confounded by the uncertain phylogenetic resolution of the lineage Allohistium. In this study, we investigate the phylogenomics of darters, specifically the relationships of Allohistium, through analyses of approximately 30,000 RADseq loci sampled from 112 species. Our phylogenetic inferences are based on traditional approaches in combination with strategies that accommodate reticulate evolution. These analyses result in a novel phylogenetic hypothesis for darters that includes ancient introgression between Allohistium and other two major darter lineages, minimally occurring 20 million years ago. Darters offer a compelling case for the necessity of incorporating phylogenetic networks in reconstructing the evolutionary history of diversification in species-rich lineages. We anticipate that the growing wealth of genomic data for clades of non-model organisms will reveal more examples of ancient hybridization, eventually requiring a re-evaluation of how evolutionary history is visualized and utilized in macroevolutonary investigations.

Ancient hybridization, darters, Etheostomatinae, phylogenetic networks, phylogenomics, RADseq

Phylogenomic Signatures of Ancient Introgression in a Rogue Lineage of Darters (Teleostei: Percidae)

Daniel J MacGuigan1 and Thomas J Near1,2

2019 Mar;