Dataset Information

Degenerative Expansion of a Young Supergene.

ABSTRACT: Long-term suppression of recombination ultimately leads to gene loss, as demonstrated by the depauperate Y and W chromosomes of long-established pairs of XY and ZW chromosomes. The young social supergene of the Solenopsis invicta red fire ant provides a powerful system to examine the effects of suppressed recombination over a shorter timescale. The two variants of this supergene are carried by a pair of heteromorphic chromosomes, referred to as the social B and social b (SB and Sb) chromosomes. The Sb variant of this supergene changes colony social organization and has an inheritance pattern similar to a Y or W chromosome because it is unable to recombine. We used high-resolution optical mapping, k-mer distribution analysis, and quantification of repetitive elements on haploid ants carrying alternate variants of this young supergene region. We find that instead of shrinking, the Sb variant of the supergene has increased in length by more than 30%. Surprisingly, only a portion of this length increase is due to consistent increases in the frequency of particular classes of repetitive elements. Instead, haplotypes of this supergene variant differ dramatically in the amounts of other repetitive elements, indicating that the accumulation of repetitive elements is a heterogeneous and dynamic process. This is the first comprehensive demonstration of degenerative expansion in an animal and shows that it occurs through nonlinear processes during the early evolution of a region of suppressed recombination.

SUBMITTER: Stolle E

PROVIDER: S-EPMC6389315 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Degenerative Expansion of a Young Supergene.

Stolle Eckart E Pracana Rodrigo R Howard Philip P Paris Carolina I CI Brown Susan J SJ Castillo-Carrillo Claudia C Rossiter Stephen J SJ Wurm Yannick Y

Molecular biology and evolution 20190301 3

Long-term suppression of recombination ultimately leads to gene loss, as demonstrated by the depauperate Y and W chromosomes of long-established pairs of XY and ZW chromosomes. The young social supergene of the Solenopsis invicta red fire ant provides a powerful system to examine the effects of suppressed recombination over a shorter timescale. The two variants of this supergene are carried by a pair of heteromorphic chromosomes, referred to as the social B and social b (SB and Sb) chromosomes. ...[more]

PMID: 30576522

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Project description:Exogenic deposits are an important source of rare earth elements (REEs), especially heavy REEs (HREEs). It is generally accepted that microorganisms are able to dissolve minerals and mobilize elements in supergene environments. However, little is known about the roles of microorganisms in the formation of exogenic deposits such as regolith-hosted REE deposits that are of HREE enrichment and provide over 90% of global HREE demand. In this study, we characterized the microbial community composition and diversity along a complete weathering profile drilled from a regolith-hosted REE deposit in Southeastern China and report the striking contributions of microorganisms to the enrichment of REEs and fractionation between HREEs and light REEs (LREEs). Our results provide evidence that the variations in REE contents are correlated with microbial community along the profile. Both fungi and bacteria contributed to the accumulation of REEs, whereas bacteria played a key role in the fractionation between HREEs and LREEs. Taking advantage of bacteria strains isolated from the profile, Gram-positive bacteria affiliated with Bacillus and Micrococcus preferentially adsorbed HREEs, and teichoic acids in the cell wall served as the main sites for HREE adsorption, leading to an enrichment of HREEs in the deposit. The present study provides the first database of microbial community in regolith-hosted REE deposits. These findings not only elucidate the crucial contribution of fungi and bacteria in the supergene REE mineralization but also provide insights into efficient utilization of mineral resources via a biological pathway. IMPORTANCE Understanding the role of microorganisms in the formation of regolith-hosted rare earth element (REE) deposits is beneficial for improving the metallogenic theory and deposit exploitation, given that such deposits absolutely exist in subtropical regions with strong microbial activities. Little is known of the microbial community composition and its contribution to REE mineralization in this kind of deposit. Using a combination of high-throughput sequencing, batch adsorption experiments, and spectroscopic characterization, the functional microorganisms contributing to REE enrichment and fractionation are disclosed. For bacteria, the surface carboxyl and phosphate groups are active sites for REE adsorption, while teichoic acids in the cell walls of G+ bacteria lead to REE fractionation. The above-mentioned findings not only unravel the importance of microorganisms in the formation of supergene REE deposits but also provide experimental evidence for the bioutilization of REE resources.

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Degenerative Expansion of a Young Supergene.

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Degenerative Expansion of a Young Supergene.

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