Chapter 9: Aquatic Macroinvertebrates, Section A: Aquatic Macroinvertebrates (Exclusive of Mosquitoes)

Final Report. Excerpt (Chapter 9, Section A) from The Des Plaines River Wetlands Demonstration Project, Volume II, Baseline Survey, edited by Donald L. Hey and Nancy S. PhilippiReport issued on: October 1985INHS Technical Report prepared for Wetlands Research, Inc

The comparative morphology and evolution of the internal female reproductive system of Trichoptera

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Soybean spiders : species composition, population densities and vertical distribution /

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Pitfall Trapping in Ecological Studies of Wandering Spiders

Volume: 3Start Page: 101End Page: 11

Identification of Macroinvertebrate Samples for State E.P.A.

Final ReportINHS Technical Report prepared for Illlinois Department of Transportation, Bureau of Location and Environmen

\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu