1
|
Tetrault E, Swenson J, Aaronson B, Marcho C, Albertson RC. The transcriptional state and chromatin landscape of cichlid jaw shape variation across species and environments. Mol Ecol 2023; 32:3922-3941. [PMID: 37160741 PMCID: PMC10524807 DOI: 10.1111/mec.16975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 04/17/2023] [Accepted: 04/24/2023] [Indexed: 05/11/2023]
Abstract
Adaptive phenotypes are shaped by a combination of genetic and environmental forces, but how they interact remains poorly understood. Here, we utilize the cichlid oral jaw apparatus to better understand these gene-by-environment effects. First, we employed RNA-seq in bony and ligamentous tissues important for jaw opening to identify differentially expressed genes between species and across foraging environments. We used two Lake Malawi species adapted to different foraging habitats along the pelagic-benthic ecomorphological axis. Our foraging treatments were designed to force animals to employ either suction or biting/scraping, which broadly mimic pelagic or benthic modes of feeding. We found a large number of differentially expressed genes between species, and while we identified relatively few differences between environments, species differences were far more pronounced when they were challenged with a pelagic versus benthic foraging mode. Expression data carried the signature of genetic assimilation, and implicated cell cycle regulation in shaping the jaw across species and environments. Next, we repeated the foraging experiment and performed ATAC-seq procedures on nuclei harvested from the same tissues. Cross-referencing results from both analyses revealed subsets of genes that were both differentially expressed and differentially accessible. This reduced dataset implicated notable candidate genes including the Hedgehog effector, KIAA0586 and the ETS transcription factor, etv4, which connects environmental stress and craniofacial morphogenesis. Taken together, these data provide novel insights into the epigenetic, genetic and cellular bases of species- and environment-specific bone shapes.
Collapse
Affiliation(s)
- Emily Tetrault
- Graduate Program in Molecular and Cell Biology, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - John Swenson
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - Ben Aaronson
- Biology Department, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - Chelsea Marcho
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst MA, 01003, U.S.A
| | - R. Craig Albertson
- Biology Department, University of Massachusetts, Amherst MA, 01003, U.S.A
| |
Collapse
|
2
|
Lloyd E, Chhouk B, Conith AJ, Keene AC, Albertson RC. Diversity in rest-activity patterns among Lake Malawi cichlid fishes suggests a novel axis of habitat partitioning. J Exp Biol 2021; 224:238727. [PMID: 33658242 PMCID: PMC8077532 DOI: 10.1242/jeb.242186] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/11/2021] [Indexed: 12/04/2022]
Abstract
Animals display remarkable diversity in rest and activity patterns that are regulated by endogenous foraging strategies, social behaviors and predator avoidance. Alteration in the circadian timing of activity or the duration of rest–wake cycles provide a central mechanism for animals to exploit novel niches. The diversity of the >3000 cichlid species throughout the world provides a unique opportunity to examine variation in locomotor activity and rest. Lake Malawi alone is home to over 500 species of cichlids that display divergent behaviors and inhabit well-defined niches throughout the lake. These species are presumed to be diurnal, though this has never been tested systematically. Here, we measured locomotor activity across the circadian cycle in 11 Lake Malawi cichlid species. We documented surprising variability in the circadian time of locomotor activity and the duration of rest. In particular, we identified a single species, Tropheops sp. ‘red cheek’, that is nocturnal. Nocturnal behavior was maintained when fish were provided shelter, but not under constant darkness, suggesting that it results from acute response to light rather than an endogenous circadian rhythm. Finally, we showed that nocturnality is associated with increased eye size after correcting for evolutionary history, suggesting a link between visual processing and nighttime activity. Together, these findings identify diversity of locomotor behavior in Lake Malawi cichlids and provide a system for investigating the molecular and neural basis underlying variation in nocturnal activity. Summary: Cichlids show a remarkable diversity in morphology and behavior. Cichlid species exhibit differences in strength and polarity of activity rhythms, revealing a new axis of habitat partitioning.
Collapse
Affiliation(s)
- Evan Lloyd
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33401, USA
| | - Brian Chhouk
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Andrew J Conith
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alex C Keene
- Department of Biological Science, Florida Atlantic University, Jupiter, FL 33401, USA
| | - R Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| |
Collapse
|
3
|
Conith AJ, Kidd MR, Kocher TD, Albertson RC. Ecomorphological divergence and habitat lability in the context of robust patterns of modularity in the cichlid feeding apparatus. BMC Evol Biol 2020; 20:95. [PMID: 32736512 PMCID: PMC7393717 DOI: 10.1186/s12862-020-01648-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 07/01/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Adaptive radiations are characterized by extreme and/or iterative phenotypic divergence; however, such variation does not accumulate evenly across an organism. Instead, it is often partitioned into sub-units, or modules, which can differentially respond to selection. While it is recognized that changing the pattern of modularity or the strength of covariation (integration) can influence the range or rate of morphological evolution, the relationship between shape variation and covariation remains unclear. For example, it is possible that rapid phenotypic change requires concomitant changes to the underlying covariance structure. Alternatively, repeated shifts between phenotypic states may be facilitated by a conserved covariance structure. Distinguishing between these scenarios will contribute to a better understanding of the factors that shape biodiversity. Here, we explore these questions using a diverse Lake Malawi cichlid species complex, Tropheops, that appears to partition habitat by depth. RESULTS We construct a phylogeny of Tropheops populations and use 3D geometric morphometrics to assess the shape of four bones involved in feeding (mandible, pharyngeal jaw, maxilla, pre-maxilla) in populations that inhabit deep versus shallow habitats. We next test numerous modularity hypotheses to understand whether fish at different depths are characterized by conserved or divergent patterns of modularity. We further examine rates of morphological evolution and disparity between habitats and among modules. Finally, we raise a single Tropheops species in environments mimicking deep or shallow habitats to discover whether plasticity can replicate the pattern of morphology, disparity, or modularity observed in natural populations. CONCLUSIONS Our data support the hypothesis that conserved patterns of modularity permit the evolution of divergent morphologies and may facilitate the repeated transitions between habitats. In addition, we find the lab-reared populations replicate many trends in the natural populations, which suggests that plasticity may be an important force in initiating depth transitions, priming the feeding apparatus for evolutionary change.
Collapse
Affiliation(s)
- Andrew J. Conith
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003 USA
| | - Michael R. Kidd
- Department of Biology & Chemistry, Texas A&M International University, Laredo, TX 78041 USA
| | - Thomas D. Kocher
- Department of Biology, University of Maryland, College Park, MD 20742 USA
| | - R. Craig Albertson
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003 USA
| |
Collapse
|
4
|
Hulsey CD, Zheng J, Faircloth BC, Meyer A, Alfaro ME. Phylogenomic analysis of Lake Malawi cichlid fishes: Further evidence that the three-stage model of diversification does not fit. Mol Phylogenet Evol 2017; 114:40-48. [DOI: 10.1016/j.ympev.2017.05.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 05/14/2017] [Accepted: 05/30/2017] [Indexed: 01/05/2023]
|
5
|
Wollenberg KC, Veith M, Lötters S. Expanding the understanding of local community assembly in adaptive radiations. Ecol Evol 2013; 4:174-85. [PMID: 24558573 PMCID: PMC3925381 DOI: 10.1002/ece3.908] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/31/2013] [Accepted: 11/07/2013] [Indexed: 11/26/2022] Open
Abstract
Communities are thought to be assembled by two types of filters: by the environment relating to the fundamental niche and by biotic interactions relating to the realized niche. Both filters include parameters related to functional traits and their variation along environmental gradients. Here, we infer the general importance of environmental filtering of a functional trait determining local community assembly within insular adaptive radiations on the example of Caribbean Anolis lizards. We constructed maps for the probability of presence of Anolis ecomorphs (ecology-morphology-behavior specialists) on the Greater Antilles and overlaid these to estimate ecomorph community completeness (ECC) over the landscape. We then tested for differences in environmental parameter spaces among islands for real and cross-fitted ECC values to see whether the underlying assembly filters are deterministic (i.e., similar among islands). We then compared information-theoretic models of climatic and landscape parameters among Greater Antillean islands and inferred whether body mass as functional trait determines ECC. We found areas with high ECC to be strongly correlated with environmental filters, partly related to elevation. The environmental parameters influencing high ECC differed among islands. With the exception of the Jamaican twig ecomorph (which we suspect to be misclassified), smaller ecomorphs were more restricted to higher elevations than larger ones which might reflect filtering on the basis of differential physiological restrictions of ecomorphs. Our results in Anolis show that local community assembly within adaptive island radiations of animals can be determined by environmental filtering of functional traits, independently from species composition and realized environmental niche space.
Collapse
Affiliation(s)
- Katharina C Wollenberg
- Department of Biology School of Science, Engineering and Mathematics, Bethune-Cookman University 640 Dr Mary McLeod Bethune Blvd, Daytona Beach, Florida, 32114
| | - Michael Veith
- Department of Biogeography, Trier University Universitätsring 15, 54296, Trier, Germany
| | - Stefan Lötters
- Department of Biogeography, Trier University Universitätsring 15, 54296, Trier, Germany
| |
Collapse
|
6
|
Kerschbaumer M, Mitteroecker P, Sturmbauer C. Evolution of body shape in sympatric versus non-sympatric Tropheus populations of Lake Tanganyika. Heredity (Edinb) 2013; 112:89-98. [PMID: 24065182 PMCID: PMC3907092 DOI: 10.1038/hdy.2013.78] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 05/27/2013] [Accepted: 07/15/2013] [Indexed: 11/19/2022] Open
Abstract
Allopatric speciation often yields ecologically equivalent sister species, so that their
secondary admixis enforces competition. The shores of Lake Tanganyika harbor about 120
distinct populations of the cichlid genus Tropheus, but only some are sympatric.
When alone, Tropheus occupies a relatively broad depth zone, but in sympatry,
fish segregate by depth. To assess the effects of competition, we studied the partial
co-occurrence of Tropheus moorii ‘Kaiser' and
‘Kirschfleck' with Tropheus polli. A previous study demonstrated via
standardized breeding experiments that some observed differences between Tropheus
‘Kaiser' living alone and in sympatry with T. polli have a genetic
basis despite large-scale phenotypic plasticity. Using geometric morphometrics and neutral
genetic markers, we now investigated whether sympatric populations differ consistently in
body shape from populations living alone and if the differences are adaptive. We found
significant differences in mean shape between non-sympatric and sympatric populations,
whereas all sympatric populations of both color morphs clustered together in shape space.
Sympatric populations had a relatively smaller head, smaller eyes and a more anterior
insertion of the pectoral fin than non-sympatric populations. Genetically, however,
non-sympatric and sympatric ‘Kaiser' populations clustered together to the
exclusion of ‘Kirschfleck'. Genetic distances, but not morphological
distances, were correlated with geographic distances. Within- and between-population
covariance matrices for T. moorii populations deviated from proportionality. It
is thus likely that natural selection acts on both phenotypic plasticity and heritable
traits and that both factors contribute to the observed shape differences. The consistency
of the pattern in five populations suggests ecological character displacement.
Collapse
Affiliation(s)
- M Kerschbaumer
- Department of Zoology, Karl-Franzens-University Graz, Graz, Austria
| | - P Mitteroecker
- Department of Theoretical Biology, University of Vienna, Vienna, Austria
| | - C Sturmbauer
- Department of Zoology, Karl-Franzens-University Graz, Graz, Austria
| |
Collapse
|
7
|
Álvarez-Pérez S, Herrera CM. Composition, richness and nonrandom assembly of culturable bacterial-microfungal communities in floral nectar of Mediterranean plants. FEMS Microbiol Ecol 2012; 83:685-99. [DOI: 10.1111/1574-6941.12027] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 10/01/2012] [Accepted: 10/02/2012] [Indexed: 01/26/2023] Open
Affiliation(s)
- Sergio Álvarez-Pérez
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC); Sevilla; Spain
| | - Carlos M. Herrera
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC); Sevilla; Spain
| |
Collapse
|
8
|
Genetic interactions controlling sex and color establish the potential for sexual conflict in Lake Malawi cichlid fishes. Heredity (Edinb) 2012; 110:239-46. [PMID: 23092997 DOI: 10.1038/hdy.2012.73] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Sex-determining systems may evolve rapidly and contribute to lineage diversification. In fact, recent work has suggested an integral role of sex chromosome evolution in models of speciation. We use quantitative trait loci analysis of restriction site-associated DNA -tag single nucleotide polymorphisms to identify multiple loci responsible for sex determination and reproductively adaptive color phenotypes in Lake Malawi cichlids. We detect a complex epistatic sex system consisting of a major female heterogametic ZW locus on chromosome 5, two separate male heterogametic XY loci on chromosome 7, and two additional interacting loci on chromosomes 3 and 20. Our data support the known chromosomal linkage between orange blotch color and ZW, as well as novel genetic associations between male blue nuptial color and two sex determining regions (an XY and ZW locus). These results provide further empirical evidence for a complex antagonistic sex-color system in this species flock and suggest a possible role for, and effect of, polygenic sex-determining systems in rapid evolutionary diversification.
Collapse
|
9
|
Abstract
The relationship between form and function can have profound effects on evolutionary dynamics and such effects may differ for simple versus complex systems. In particular, functions produced by multiple structural configurations (many-to-one mapping, MTOM) may dampen constituent trade-offs and promote diversification. Unfortunately, we lack information about the genetic architecture of MTOM functional systems. The skulls of teleost fishes contain both simple (lower jaw levers) as well as more complex (jaws modeled as 4-bar linkages) functional systems within the same craniofacial unit. We examined the mapping of form to function and the genetic basis of these systems by identifying quantitative trait loci (QTL) in hybrids of two Lake Malawi cichlid species. Hybrid individuals exhibited novelty (transgressive segregation) in morphological components and function of the simple and complex jaw systems. Functional novelty was proportional to the prevalence of extreme morphologies in the simple levers; by contrast, recombination of parental morphologies produced transgression in the MTOM 4-bar linkage. We found multiple loci of moderate effect and epistasis controlling jaw phenotypes in both the simple and complex systems, with less phenotypic variance explained by QTL for the 4-bar. Genetic linkage between components of the simple and complex systems partly explains phenotypic correlations and may constrain functional evolution.
Collapse
Affiliation(s)
- Nicholas F Parnell
- School of Biology, Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
| | | | | |
Collapse
|