Molecular evolution in Panagrolaimus nematodes: origins of parthenogenesis, hermaphroditism and the Antarctic species P. davidi
2009

Evolution of Reproductive Modes in Panagrolaimus Nematodes

Sample size: 31 publication Evidence: moderate

Author Information

Author(s): Samantha C. Lewis, Leslie A. Dyal, Caroline F. Hilburn, Stephanie Weitz, Wei-Siang Liau, Craig W. LaMunyon, Dee R. Denver

Primary Institution: Oregon State University

Hypothesis

What are the evolutionary origins of parthenogenesis and hermaphroditism in Panagrolaimus nematodes?

Conclusion

The study reveals a single origin of parthenogenesis in Panagrolaimus and suggests that the Antarctic species P. davidi arrived in Antarctica recently.

Supporting Evidence

  • Phylogenetic analyses showed that Panagrolaimus species form a paraphyletic group.
  • Parthenogenesis was found to have a single evolutionary origin from a gonochoristic ancestor.
  • P. davidi was closely related to two strains from southern California.
  • Cold tolerance mechanisms in P. davidi were highlighted as unique among nematodes.

Takeaway

This study looks at how different types of reproduction evolved in a group of tiny worms called Panagrolaimus, showing that some can reproduce without males.

Methodology

The study involved collecting and analyzing nuclear ribosomal RNA and mitochondrial gene sequences from 31 Panagrolaimus species and strains.

Limitations

The study's conclusions are limited by the small number of strains analyzed and the need for broader sampling.

Digital Object Identifier (DOI)

10.1186/1471-2148-9-15

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