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Biology subjects

Timmermeyer, N.

Publications and source records attributed to Timmermeyer, N..

2 recordsLinked to original sources

An open source microfluidic sorter for Caenorhabditis nematodes

Rapid and accurate sorting of biological samples is extremely useful in a wide variety of applications. The model nematode Caenorhabditis elegans lends itself to automated fluid-flow based sorting because of its ability to live in aqueous solutions. Here, we build upon previous developments to construct a microfluidic device capable of sorting individuals based on a variety of characteristics, with a specific application toward differentiating fluorescently marked individuals. We find that our new design generates highly repeatable pools of sorted individuals. In general, there tends to be a tradeoff between precision and speed that can be optimized based on several different factors. Importantly, sorting does not decrease offspring production, and individuals can be sorted multiple times for increased precision. We provide detailed parts lists, schematics and software to allow implementation of these methods in other laboratories. Our results demonstrate that custom-made sorter chips can be a flexible and versatile addition to the nematode experimental toolbox.

bioengineering↗

Proteomic and Evolutionary Analyses of Sperm Activation Identify Uncharacterized Genes in Caenorhabditis Nematodes

BackgroundNematode sperm have unique and highly diverged morphology and molecular biology. In particular, nematode sperm contain subcellular vesicles known as membranous organelles that are necessary for male fertility, yet play a still unknown role in overall sperm function. Here we take a novel proteomic approach to characterize the functional protein complement of membranous organelles in two Caenorhabditis species: C. elegans and C. remanei.\n\nResultsWe identify distinct protein compositions between membranous organelles and the activated sperm body. Two particularly interesting and undescribed gene families--the Nematode-Specific Peptide family, group D and the here designated Nematode-Specific Peptide family, group F--localize to the membranous organelle. Both multigene families are nematode-specific and exhibit patterns of conserved evolution specific to the Caenorhabditis clade. These data suggest gene family dynamics may be a more prevalent mode of evolution than sequence divergence within sperm. Using a CRISPR-based knock-out of the NSPF gene family, we find no evidence of a male fertility effect of these genes, despite their high protein abundance within the membranous organelles.\n\nConclusionsOur study identifies key components of this unique subcellular sperm component and establishes a path toward revealing their underlying role in reproduction.

evolutionary biology↗