ArticleBMC evolutionary biology2016
Evidence of positive selection associated with placental loss in tiger sharks.
Article in BMC evolutionary biology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.
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Who cites it
8 citing papers in PubMed.
- Fishing for DNA? Designing baits for population genetics in target enrichment experiments: Guidelines, considerations and the new tool supeRbaits.Molecular ecology resources · 2022Article
- Retrospective genomics highlights changes in genetic composition of tiger sharks (Galeocerdo cuvier) and potential loss of a south-eastern Australia population.Scientific reports · 2022Article
- Global shifts in species richness have shaped carpet shark evolution.BMC ecology and evolution · 2021Article
- Gene Expression and Functional Analyses of Odorant Receptors in Small Hive Beetles (International journal of molecular sciences · 2020Article
- Bridging disciplines to advance elasmobranch conservation: applications of physiological ecology.Conservation physiology · 2019Article
- Phylotranscriptomics suggests the jawed vertebrate ancestor could generate diverse helper and regulatory T cell subsets.BMC evolutionary biology · 2018Article
- Sequencing and characterization of the complete mitochondrial genome of Japanese Swellshark (Cephalloscyllium umbratile).Scientific reports · 2017Article
- Identification of Genes under Positive Selection Reveals Differences in Evolutionary Adaptation between Brown-Algal Species.Frontiers in plant science · 2017Article
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Authors and funding
9 authors.
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No grant is acknowledged in the PubMed record.
Abstract
backgroundAll vertebrates initially feed their offspring using yolk reserves. In some live-bearing species these yolk reserves may be supplemented with extra nutrition via a placenta. Sharks belonging to the Carcharhinidae family are all live-bearing, and with the exception of the tiger shark (Galeocerdo cuvier), develop placental connections after exhausting yolk reserves. Phylogenetic relationships suggest the lack of placenta in tiger sharks is due to secondary loss. This represents a dramatic shift in reproductive strategy, and is likely to have left a molecular footprint of positive selection within the genome.
resultsWe sequenced the transcriptome of the tiger shark and eight other live-bearing shark species. From this data we constructed a time-calibrated phylogenetic tree estimating the tiger shark lineage diverged from the placental carcharhinids approximately 94 million years ago. Along the tiger shark lineage, we identified five genes exhibiting a signature of positive selection. Four of these genes have functions likely associated with brain development (YWHAE and ARL6IP5) and sexual reproduction (VAMP4 and TCTEX1D2).
conclusionsOur results indicate the loss of placenta in tiger sharks may be associated with subsequent adaptive changes in brain development and sperm production.
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