The genes that encode the α- and β-chain subunits of vertebrate hemoglobin have served as a model system for elucidating general principles of gene family evolution, but little is known about patterns of evolution in amniotes other than mammals and birds. Here, we report a comparative genomic analysis of the α- and β-globin gene clusters in sauropsids (archosaurs and nonavian reptiles). The objectives were to characterize changes in the size and membership composition of the α- and β-globin gene families within and among the major sauropsid lineages, to reconstruct the evolutionary history of the sauropsid α- and β-globin genes, to resolve orthologous relationships, and to reconstruct evolutionary changes in the developmental regulation of gene expression. Our comparisons revealed contrasting patterns of evolution in the unlinked α- and β-globin gene clusters. In the α-globin gene cluster, which has remained in the ancestral chromosomal location, evolutionary changes in gene content are attributable to the differential retention of paralogous gene copies that were present in the common ancestor of tetrapods. In the β-globin gene cluster, which was translocated to a new chromosomal location, evolutionary changes in gene content are attributable to differential gene gains (via lineage-specific duplication events) and gene losses (via lineage-specific deletions and inactivations). Consequently, all major groups of amniotes possess unique repertoires of embryonic and postnatally expressed β-type globin genes that diversified independently in each lineage. These independently derived β-type globins descend from a pair of tandemly linked paralogs in the most recent common ancestor of sauropsids.
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Globins in the marine annelid Platynereis dumerilii shed new light on hemoglobin evolution in bilaterians
How vascular systems and their respiratory pigments evolved is still debated. While many animals present a vascular system, hemoglobin exists as a blood pigment only in a few groups (vertebrates, annelids, a few arthropod and mollusk species). Hemoglobins are formed of globin sub-units, belonging to multigene families, in various multimeric assemblages. It was so far unclear whether hemoglobin families from different bilaterian groups had a common origin.
To unravel globin evolution in bilaterians, we studied the marine annelid
We uncover a complex “pre-blood” evolution of globins, with an early gene radiation in ancestral bilaterians. Circulating hemoglobins in various bilaterian groups evolved convergently, presumably in correlation with animal size and activity. However, all hemoglobins derive from a clade I globin, or cytoglobin, probably involved in intracellular O2transit and regulation. The annelid
- NSF-PAR ID:
- 10207762
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- BMC Evolutionary Biology
- Volume:
- 20
- Issue:
- 1
- ISSN:
- 1471-2148
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Premise Despite the fast pace of exploration of the patterns and processes influencing Neotropical plant hyperdiversity, the taxa explored are mostly from large groups that are widely distributed, morphologically diverse, or economically important. Vochysiaceae is an example of an undersampled taxon, providing an excellent system for investigating Neotropical biogeography. We present a phylogenomics‐based hypothesis of species relationships in Vochysiaceae to investigate its evolutionary history through space and time.
Methods We inferred a phylogeny for 122 species from Vochysiaceae and seven other families of Myrtales. Fossils from four myrtalean families were used to estimate the divergence times within Vochysiaceae. Historical biogeography was estimated using ancestral range probabilities and stochastic mapping.
Results Monophyly of all genera was supported except for
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Abstract Premise The ~140 species of
Lonicera are characterized by variously fused leaves, bracteoles, and ovaries, making it a model system for studying the evolution and development of organ fusion. However, previous phylogenetic analyses, based mainly on chloroplast DNA markers, have yielded uncertain and conflicting results. A well‐supported phylogeny ofLonicera will allow us to trace the evolutionary history of organ fusion.Methods We inferred the phylogeny of
Lonicera using restriction site–associated DNA sequencing (RADSeq), sampling all major clades and 18 of the 23 subsections. This provided the basis for inferring the evolution of five fusion‐related traits.Results RADSeq data yielded a well‐resolved and well‐supported phylogeny. The two traditionally recognized subgenera (
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Lonicera to date. Our inference of multiple evolutionary shifts in organ fusion provides a solid foundation for in depth developmental and functional analyses. -
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Abstract Fungus‐farming ants (Hymenoptera: Formicidae) have become model systems for exploring questions regarding the evolution of symbiosis. However, robust phylogenetic studies of both the ant agriculturalists and their fungal cultivars are necessary for addressing whether or not observed ant–fungus associations are the result of coevolution and, if so, whether that coevolution has been strict or diffuse. Here we focus on the evolutionary relationships of the species within the ant genus
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