The evolution of dimorphism and separate sexes in schistosomes

Després, Laurence; Maurice, Sandrine

doi:10.1098/rspb.1995.0193

Cited by 16 publications

(2 citation statements)

References 19 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Once we better understand the full diversity of schistosomes, we will gain a better perspective from which to answer other important questions. For example, what will a more complete and accurate accounting of schistosome diversity tell us about the evolution of dioecy and of patterns of snail or vertebrate host use (e.g., Després and Maurice, 1995;Platt and Brooks, 1997;Morand and Muller-Graf, 2000;Lockyer et al, 2003)? Griphobilharzia amoena from crocodiles (Platt et al, 1991) and Macrobilharzia from cormorants and anhingas (Carmichael, 1984;Morand and Muller-Graf, 2000) are considered to represent ancient lineages (Carmichael, 1984;Platt et al, 1991), yet no molecular information thus far has been available for either genus.…”

mentioning

confidence: 99%

An Approach to Revealing Blood Fluke Life Cycles, Taxonomy, and Diversity: Provision of Key Reference Data Including Dna Sequence From Single Life Cycle Stages

Brant¹,

Morgan

Mkoji

et al. 2006

Journal of Parasitology

101

View full text Add to dashboard Cite

Revealing diversity among extant blood flukes, and the patterns of relationships among them, has been hindered by the difficulty of determining if specimens described from different life cycle stages, hosts, geographic localities, and times represent the same or different species. Persistent collection of all available life cycle stages and provision of exact collection localities, host identification, reference DNA sequences for the parasite, and voucher specimens eventually will provide the framework needed to piece together individual life cycles and facilitate reconciliation with classical taxonomic descriptions, including those based on single life cycle stages. It also provides a means to document unique or rare species that might only ever be recovered from a single life cycle stage. With an emphasis on the value of new information from field collections of any available life cycle stages, here we provide data for several blood fluke cercariae from freshwater snails from Kenya, Uganda, and Australia. Similar data are provided for adult worms of Macrobilharzia macrobilharzia and miracidia of Bivitellobilharzia nairi. Some schistosome and sanguinicolid cercariae that we recovered have peculiar morphological features, and our phylogenetic analyses (18S and 28S rDNA and mtDNA CO1) suggest that 2 of the new schistosome specimens likely represent previously unknown lineages. Our results also provide new insights into 2 of the 4 remaining schistosome genera yet to be extensively characterized with respect to their position in molecular phylogenies, Macrobilharzia and Bivitellobilharzia. The accessibility of each life cycle stage is likely to vary dramatically from one parasite species to the next, and our examples validate the potential usefulness of information gleaned from even one such stage, whatever it might be.The Schistosomatidae is one of the best known of parasite families, yet even within this group much remains to be learned about global species diversity, biogeography, patterns of vertebrate and snail host usage, and evolutionary relationships. Our knowledge of schistosome origins and diversification also will be improved by better understanding the diversity inherent in closely-related digenean families, including the 2 other families of blood flukes (the Spirorchiidae of turtles and the Sanguinicolidae of fishes), and the Clinostomidae. Blood fluke systematics, particularly of schistosomes, has received considerable attention in the last several years (e.g., Carmichael, 1984;Rollinson et al., 1997;Snyder and Loker, 2000;Attwood et al., 2002;Lockyer et al., 2003;Morgan et al., 2003; Agatsuma et al., 2004). These studies have examined morphology, DNA sequence diversity, and patterns of host use. The molecular studies, in particular, have yielded intriguing new hypotheses that delineate the broad patterns of relationships within the family and have provided an invaluable framework to examine overall schistosome and blood fluke diversity.One of the long-standing impediments to assessing diversi...

show abstract

mentioning

confidence: 99%

An Approach to Revealing Blood Fluke Life Cycles, Taxonomy, and Diversity: Provision of Key Reference Data Including Dna Sequence From Single Life Cycle Stages

Brant¹,

Morgan

Mkoji

et al. 2006

Journal of Parasitology

101

View full text Add to dashboard Cite

show abstract

“…In addition, and in contrast with most other plathyhelminth species, schistosomes are gonochoric [16]. This suggests that, in general, being hermaphrodite is an advantage in this phylum, probably through minimizing the risk that is associated with finding a mate inside the host [17]. In Schistosomatidae, the acquisition of separated sexes was concomitant with the invasion of warm-blooded animals [16].…”

Section: Introductionmentioning

confidence: 99%

Chromatin structure changes around satellite repeats on the Schistosoma mansoni female sex chromosome suggest a possible mechanism for sex chromosome emergence

et al. 2012

View full text Add to dashboard Cite

show abstract

The varied ways of being male and female

Schärer

2017

Molecular Reproduction Devel

View full text Add to dashboard Cite

SUMMARYOur understanding of sexual reproduction is mainly informed by research on gonochorists (i.e., species with separate sexes), including insects, birds, and mammals. But the male and female sexes are not two types of individuals; they actually represent two different reproductive strategies, and in many organisms, these two strategies are distributed among individuals in a population in a variety of ways. For example, sequential hermaphrodites (or sex-changers) exhibit one strategy early in life and later switch to the other, while simultaneous hermaphrodites exhibit both strategies at the same time. There are also many intermediate sexual systems that mix gonochorists and hermaphrodites in the same species and within many organismal groups, shifts occur between these sexual systems. A fascinating collection of six articles in this special issue on Hermaphroditism & Sex Determination impressively documents some important challenges to our understanding of sex determination, and the specification of male and female reproductive function when these need to occur within the same individual rather than in two separate individuals. Moreover, hermaphroditism changes how we need to think about reproductive allocation to sexual functions, how such allocation can be specified, as well as how the sexual system affects sexual conflict and the resulting antagonistic coevolution. Our understanding of sexual reproduction will profit greatly from exploring the varied ways of being male and female.

show abstract

The evolution of dimorphism and separate sexes in schistosomes

Cited by 16 publications

References 19 publications

An Approach to Revealing Blood Fluke Life Cycles, Taxonomy, and Diversity: Provision of Key Reference Data Including Dna Sequence From Single Life Cycle Stages

An Approach to Revealing Blood Fluke Life Cycles, Taxonomy, and Diversity: Provision of Key Reference Data Including Dna Sequence From Single Life Cycle Stages

Chromatin structure changes around satellite repeats on the Schistosoma mansoni female sex chromosome suggest a possible mechanism for sex chromosome emergence

The varied ways of being male and female

Contact Info

Product

Resources

About