Citation
Maupas E: 1900. Modes et formes de reproduction des nematodes.
Archives de Zoologie Experimentale et Generale 8: 463-624. Translation provided by Marie-Anne Felix.
Download: English translation [PDF], Foreword [PDF; DOC]
Foreword
This article by Maupas (1900) is interesting for two reasons. First, it describes and names Caenorhabditis elegans as
a new species which then got much fame after it was chosen by Sydney Brenner in the late 1960s to become a model system in
biology. Second, this study is of historical interest for the biological questions it addresses, namely the diversity and
evolution of modes of reproduction.
The introduction (pp. 1-14) reviews previous work on modes of reproduction in nematodes, emphasizing that there has
been a lack of recognition and acceptance of the hermaphroditic and parthenogenetic modes of reproduction in described
species.
The article continues with a short method section on worm culture (pp. 14-16). This leads to a defense of nematodes as
elementary research subjects to study biological questions regarding complex organisms, ciliates being the choice for studies
of cellular phenomena (Maupas is actually best known for his work on ciliates).
The main part of the article (pp. 16-130) is then divided into 18 sections, each corresponding to a nematode species,
either hermaphroditic or parthenogenetic. Because most of the species had not been described previously, most sections start
with a precise species description that conforms to a constant scheme. Each section then continues with observations and
experiments on the lifecycle, mode of reproduction, frequency of males, mating of males with hermaphrodites and successful
propagation of selfing lines for several generations. The first and most detailed section concerns C. elegans. It is clear
that it already constituted for Maupas a favorite species among nematodes.
The discussion (pp. 131-165) is divided into 16 subsections (their titles are given in the table of contents at the
end), which place Maupas' observations in a broader context, for example by establishing a clear distinction between germ line
and somatic sex determination or the equivalence of male and female gamete nuclei. It is a great piece to read.
The plate legends are on pp. 170-174, and the plates on pp. 175-185.
The table of contents is at the end, on p. 186.
Notes:
- Rhabditis is used here as genus name rather than Caenorhabditis, which came later (Osche, 1952). The definition of genera is
somewhat arbitrary. Even now, Caenorhabditis is a subgenus name, one among many in the Rhabditis genus, and C. elegans should
formally be called Rhabditis (Caenorhabditis) elegans.
- In zoological nomenclature, the name of the author who first describes a species is placed after the species name, as a
reference. "mihi" after the new species' names refers to Maupas ("mine" in Latin).
- Maupas then lived in Algiers, Algeria (at that time under French administration). Bone is today called Annaba, in the
Northeast of Algeria.
- The word "evolution" was used at that time to mean "development". For the sake of clarity for modern readers, I translated
it as "development" when appropriate.
- "Lateral membranes" are alae.
- "Encysted" larvae are dauer larvae. Maupas had published the previous year (1899) an article on molts and dauers in
nematodes, where the first historical mention of R. elegans is made.
- Although Maupas is clearly a great observer, I have some doubt on one point: the way he interprets degenerate
oocytes/embryos that are laid by the mother as a definitive indicator of the absence of sperm in one or both gonadal arms of
the mother (with consequences on the interpretation of crosses and of dissogony).
Acknowledgements
I thank W. Sudhaus for inducing me to translate this (short) text, E. Schwarz and D. Fitch for correcting it and Wormbase for
publishing it.
Marie-Anne Felix, May 2005
