Caenorhabditis tropicalis

Caenorhabditis tropicalis is a species of Caenorhabditis nematodes, belonging to the Elegans super-group and Elegans group within the genus.[2] It is a close relative of C. wallacei. C. tropicalis is collected frequently in tropical South America, Caribbean islands, and various islands in the Indian and Pacific Oceans from rotting fruit, flowers and stems. C. tropicalis was referred to as "C. sp. 11" prior to 2014.[1]

Caenorhabditis tropicalis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Nematoda
Class: Chromadorea
Order: Rhabditida
Family: Rhabditidae
Genus: Caenorhabditis
Species:
C. tropicalis
Binomial name
Caenorhabditis tropicalis
Felix, Braendle & Cutter, 2014[1]
Synonyms

Caenorhabditis sp. 11

Anatomy

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The mean body lengths of adult hermaphroditic and adult male C. tropicalis were calculated as 1378.63 μm and 992.85 μm, respectively, making C. tropicalis males and hermaphrodites on average larger than other hermaphroditic species like C. elegans and C. briggsae.[3]

Spicule shape

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The spicules of C. tropicalis males consist of a long, slender, pointed, and simple morphology, which is a common feature among Caenorhabditis species outside of the Elegans super-group (with the exception of C. japonica and C. afra).[2]

Reproduction

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C. tropicalis demonstrates a hermaphroditic mode of reproduction.[1] Similar to C. elegans and C. briggsae, androdioecious populations of C. tropicalis are made up of protandrous hermaphrodites (XX sex chromosome karyotype) and X0 males. These three species are not each other's closest relatives, supporting the independent evolutionary origins of hermaphroditism and androdioecy.[1] The self-fertile hermaphroditic reproductive strategy of these species is an example of convergent evolution.

Ecology

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C. tropicalis was first discovered from La Reunion island in the Indian Ocean in 2008, with subsequent collection in Puerto Rico and Cape Verde Islands in the Atlantic Ocean, French Guiana and Brazil in South America, and Hawaii in the Pacific Ocean. C. tropicalis has only been sampled from tropical regions thus far.[2] It is one of the most commonly-sampled Caenorhabditis species in the Nouragues Nature Reserve of French Guiana, where it has been isolated both in litter samples and from rotting fruits and flowers.[4]

Like other Caenorhabditis species found in the tropical rainforest of French Guiana, C. tropicalis is commonly found among rotting flower substrates. This species demonstrates a preferential association with rotting flowers in earlier stages of decay, indicated by a decrease in association with flowers in later stages of decay.[4]

C. tropicalis has shown inter-species associations with Nematocida major, an intracellular pathogen that has also been observed to associate with C. elegans and C. briggsae, two other hermaphroditic Caenorhabditis nematode species. N. major infections of these nematodes have only been observed in tropical regions even though C. elegans is predominantly found in temperate regions.[5]

Genetics

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The genome of C. tropicalis reference strain JU1373 consists of around 79.32 million base pairs and 22,326 protein coding genes. These genome characteristics make it shorter than the C. elegans genome, which consists of around 100.29 million base pairs and 20,326 protein coding genes.[6] Like all known Caenorhabditis species, the genome of C. tropicalis is partitioned into six chromosomes (five autosomes and one "X" sex chromosome).

Outbreeding Depression

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Like the other Androdioecious Caenorhabditis species, C. tropicalis demonstrates outbreeding depression mediated by Medea like elements, which can result in lethality in C. tropicalis offspring, which results in smaller population sizes, it is likely due to this why C. tropicalis faces an evolutionary pressure to demonstrate high rates of inbreeding. Crosses between strains of C. tropicalis isolated from different locations resulted in a higher frequency of defective offspring in comparison to crosses between strains of C. tropicalis from the same location.[7] High inbreeding rates in C. tropicalis has subsequently resulted in a significant decrease in genomic diversity in this species compared to other Caenorhabditis nematodes.[8] C. tropicalis, along with C. briggsae and C. elegans, the other two hermaphroditic Caenorhabditis species demonstrate 20-40% smaller genome sizes compared to gonochoristic or male-female Caenorhabditis species.[9]

References

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  1. ^ a b c d Félix, Marie-Anne; Braendle, Christian; Cutter, Asher D. (11 April 2014). "A Streamlined System for Species Diagnosis in Caenorhabditis (Nematoda: Rhabditidae) with Name Designations for 15 Distinct Biological Species". PLOS ONE. 9 (4): e94723. Bibcode:2014PLoSO...994723F. doi:10.1371/journal.pone.0094723. PMC 3984244. PMID 24727800.
  2. ^ a b c Kiontke, Karin C; Félix, Marie-Anne; Ailion, Michael; Rockman, Matthew V; Braendle, Christian; Pénigault, Jean-Baptiste; Fitch, David HA (2011). "A phylogeny and molecular barcodes for Caenorhabditis, with numerous new species from rotting fruits". BMC Evolutionary Biology. 11 (1): 339. doi:10.1186/1471-2148-11-339. PMC 3277298. PMID 22103856. S2CID 3170363.
  3. ^ Vielle, Anne; Callemeyn-Torre, Nicolas; Gimond, Clotilde; Poullet, Nausicaa; Gray, Jeremy C.; Cutter, Asher D.; Braendle, Christian (November 2016). "Convergent evolution of sperm gigantism and the developmental origins of sperm size variability in Caenorhabditis nematodes" (PDF). Evolution. 70 (11): 2485–2503. doi:10.1111/evo.13043. PMID 27565121. S2CID 16937726.
  4. ^ a b Ferrari, Céline; Salle, Romain; Callemeyn-Torre, Nicolas; Jovelin, Richard; Cutter, Asher D.; Braendle, Christian (December 2017). "Ephemeral-habitat colonization and neotropical species richness of Caenorhabditis nematodes". BMC Ecology. 17 (1): 43. doi:10.1186/s12898-017-0150-z. PMC 5738176. PMID 29258487.
  5. ^ Zhang, Gaotian; Sachse, Martin; Prevost, Marie-Christine; Luallen, Robert J.; Troemel, Emily R.; Félix, Marie-Anne (12 December 2016). "A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes". PLOS Pathogens. 12 (12): e1006093. doi:10.1371/journal.ppat.1006093. PMC 5179134. PMID 27942022.
  6. ^ Slos, Dieter; Sudhaus, Walter; Stevens, Lewis; Bert, Wim; Blaxter, Mark (23 February 2017). "Caenorhabditis monodelphis sp. n.: defining the stem morphology and genomics of the genus Caenorhabditis" (PDF). BMC Zoology. 2 (1): 4. doi:10.1186/s40850-017-0013-2. S2CID 20541147. ProQuest 2348204867.
  7. ^ Ben-David, Eyal; Pliota, Pinelopi; Widen, Sonya A.; Koreshova, Alevtina; Lemus-Vergara, Tzitziki; Verpukhovskiy, Philipp; Mandali, Sridhar; Braendle, Christian; Burga, Alejandro; Kruglyak, Leonid (March 2021). "Ubiquitous Selfish Toxin-Antidote Elements in Caenorhabditis Species". Current Biology. 31 (5): 990–1001.e5. doi:10.1016/j.cub.2020.12.013. PMID 33417886. S2CID 230972352.
  8. ^ Noble, Luke M; Yuen, John; Stevens, Lewis; Moya, Nicolas; Persaud, Riaad; Moscatelli, Marc; Jackson, Jacqueline L; Zhang, Gaotian; Chitrakar, Rojin; Baugh, L Ryan; Braendle, Christian; Andersen, Erik C; Seidel, Hannah S; Rockman, Matthew V (11 January 2021). "Selfing is the safest sex for Caenorhabditis tropicalis". eLife. 10: e62587. doi:10.7554/elife.62587. PMC 7853720. PMID 33427200.
  9. ^ Bird, David McK.; Blaxter, Mark L.; McCarter, James P.; Mitreva, Makedonka; Sternberg, Paul W.; Thomas, W. Kelley (December 2005). "A White Paper on Nematode Comparative Genomics". Journal of Nematology. 37 (4): 408–416. PMC 2620993. PMID 19262884.
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