Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2023.02.21.529467

Testing the efficacy of different molecular tools for parasite conservation genetics: a case study using horsehair worms (Phylum Nematomorpha)

De Vivo, M.·Chen, W.-Y.·Huang, J.-P.
View original source ↗Export metadata ↓

Abstract

In recent years, parasite conservation has become a globally significant issue. Because of this, there is a need for standardised methods for inferring population status and possible cryptic diversity. However, given the lack of molecular data for some groups, it is challenging to establish procedures for genetic diversity estimation. Therefore, universal tools, such as double digest restriction-site associated DNA sequencing (ddRADseq), could be useful when conducting conservation genetic studies on rarely studied parasites. Here, we generated a ddRADseq dataset that includes all three described Taiwanese horsehair worms (Phylum Nematomorpha), possibly one of the most understudied animal groups. Additionally, we produced data for a fragment of the cytochrome c oxidase subunit I (COXI) for said species. We used the COXI dataset in combination with previously published sequences of the same locus for inferring the effective population size (Ne) trends and possible population structure. We found that a larger and geographically broader sample size combined with more sequenced loci resulted in a better estimation of changes in Ne. We were able to detect demographic changes associated with Pleistocene events in all the species. Furthermore, the ddRADseq dataset for Chordodes formosanus did not reveal a genetic structure based on geography, implying a great dispersal ability, possibly due to its hosts. We showed that different molecular tools can be used to reveal genetic structure and demographic history at different historical times and geographical scales, which can help with conservation genetic studies in rarely studied parasites.

Source connections

Explore related subjects

zoologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

De Vivo, M., Chen, W.-Y., Huang, J.-P.. 2023-02-22. Testing the efficacy of different molecular tools for parasite conservation genetics: a case study using horsehair worms (Phylum Nematomorpha). https://doi.org/10.1101/2023.02.21.529467

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Sex-linked genomic variation reveals reproductive skew and male-biased dispersal in polygynous sea lions

Sex-biased dispersal and the resulting asymmetry in gene flow are important factors in evolution. However, their quantification in natural populations remains challenging, not least because sex-specific reproductive skew, as reflected in the mating system, further influences the relative contributions of males and females to the genetic pool of subsequent generations. Incorporating information from mitochondria (MT) and sex chromosomes (X, Y) alongside the more commonly used autosomal markers (AUT) provides a promising framework to partly disentangle confounding processes. Here, we exemplify this approach in two closely related, polygynous species with observational evidence for male-biased dispersal, the Galapagos sea lion (GSL) and the Steller sea lion (SSL). Using whole-genome resequencing data, we leveraged genetic variation among all four genomic compartments, representing genetic variation with female-only (MT), mixed (X, AUT) and male-only (Y) inheritance, to obtain information on the mating system and test for sex-specific migration across geographic and environmental boundaries. For GSL, genomic signatures were consistent with mild polygyny and a moderately elevated rate of male migration, particularly across habitat boundaries. In SSL, male reproductive skew was substantially greater, and male-biased migration was more pronounced and less habitat-dependent. Our results align with the species' life history and support a link between mating system and dispersal, but were also impacted by confounding biological processes and bioinformatic choices. This study highlights the value and challenges of population genomic approaches integrating multiple genomic compartments to infer variation in individual behaviours.

zoology↗
bioRxiv2026

Impact of iron-enriched diets on the nutritional composition and microbiome diversity of house crickets (Acheta domesticus)

Iron deficiency (ID) and iron-deficiency anaemia (IDA) pose significant global health challenges. ID and IDA are particularly widespread in Sub-Saharan Africa and South Asian countries, where reliance on plant-based foods is high. Edible insects provide an alternative nutritious food source, rich in both protein and essential minerals and trace elements. Little is known about how dietary iron manipulation affects the trace element bioaccumulation and microbiome community composition of edible insects. This study examined the impact of dietary iron supplementation on the growth, survival, nutrient profile, and microbiome of Acheta domesticus. Experimental diets were formulated using iron (II) sulphate heptahydrate, resulting in final iron concentrations ranging from 333.45 mg Fe/kg (control diet) to 6923.39 mg Fe/kg (100 mM Fe diet). Iron supplementation significantly altered the cricket trace element profile, with iron levels increasing fivefold from basal 21.38 mg/kg to 118.34 mg/kg in the highest iron treatment group. Concurrently, manganese levels showed a strong negative correlation with dietary iron, while zinc and cadmium displayed non-significant downward trends. High-iron diets statistically altered dry matter, chitin, and TBARS, whereas carbohydrates, protein, glycogen, and lipids remained stable. Amino acid profiles shifted progressively, with branched-chain, sulphur-containing, and aromatic amino acids peaking in the 25 mM Fe group. In contrast, the diversity and overall structure of the microbial community remained unaffected across all treatments. In conclusion, tailoring dietary iron can significantly boost the iron content of Acheta domesticus without compromising host survival or altering core microbial structures. To optimize insect rearing strategies aimed at alleviating human micronutrient deficiencies, a feeding dose of 10-25 mmol Fe/kg is recommended.

zoology↗
bioRxiv2026

Tardigrades survive reversible dormancy during spaceflight: In-orbit revival, post-flight recovery, and transcriptomic responses

Long-duration space missions face substantial challenges, including limited resources and prolonged exposure to microgravity and radiation. Transporting organisms in a dormant state and reviving them at their destination could help overcome some of these limitations. However, the feasibility of this strategy has not been experimentally demonstrated in multicellular animals beyond Earth. Here, we investigated this possibility using tardigrades, microscopic invertebrates capable of entering a reversible state of dormancy. We demonstrate that dormant tardigrades can withstand near-absolute-zero temperatures (~12 mK), near-vacuum conditions (10-9 mbar), high doses of ionizing radiation (3000 Gy), and complete desiccation. We transported dormant tardigrades to the International Space Station (ISS). They were revived aboard the ISS, subsequently returned to a dormant state, and successfully revived again following their return to Earth. Approximately 45% of the space-flown tardigrades survived the 64-day experimental period. This included two dormancy-revival cycles, 18 days aboard the ISS, and prolonged periods without food or water. Importantly, surviving tardigrades retained their reproductive capacity. Transcriptomic analysis of ISS-exposed tardigrades revealed upregulation of genes associated with protein folding and stress responses, accompanied by downregulation of genes involved in energy metabolism and protein synthesis, providing insights into their molecular responses to the spaceflight environment. Together, these findings demonstrate the successful revival and re-induction of dormancy in a multicellular animal beyond Earth and establish an experimental foundation for exploring dormancy-based strategies for future long-duration space missions.

zoology↗