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Nested Levels of Adaptive Divergence: The Genetic Basis of Craniofacial Divergence and Ecological Sexual Dimorphism.

Parsons KJ, Wang J, Anderson G, Albertson RC - G3 (Bethesda) (2015)

Bottom Line: Sexual dimorphisms are also common in species displaying adaptive divergence and can be the result of differential selection between sexes that produce ecological differences between sexes.To enhance our search for candidate genes we take advantage of population genomic data and a genetic map that is anchored to the cichlid genome to determine which genes within our QTL regions are associated with SNPs that are alternatively fixed between species.This study provides a holistic understanding of the genetic underpinnings of adaptive divergence in craniofacial shape.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom Kevin.Parsons@glasgow.ac.uk.

No MeSH data available.


Landmarks, semilandmarks, and deformation grids depicting the first five axes of morphological variation [relative warps (RW)] in F2 hybrids. Across the different axes there are notable differences in craniofacial profile, most obviously in the cranial region quantified using semilandmarks (black dots and lines), but also with regard to the size of the preorbital region, size and positioning of the eye, and depth of the head.
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fig1: Landmarks, semilandmarks, and deformation grids depicting the first five axes of morphological variation [relative warps (RW)] in F2 hybrids. Across the different axes there are notable differences in craniofacial profile, most obviously in the cranial region quantified using semilandmarks (black dots and lines), but also with regard to the size of the preorbital region, size and positioning of the eye, and depth of the head.

Mentions: Variation in the lateral view of the head in F2 hybrids was quantified using a geometric morphometric approach. A total of 14 regular homologous landmarks and 14 sliding semilandmarks were collected on the lateral view of the head (Figure 1). Sliding semilandmarks (Bookstein 1997) make possible the description of shapes combining curves and classic homologous landmarks on the same object, and the incorporation of these data has become standard in the field of morphometrics (Zimmerman et al. 2009; Arnegard et al. 2010). Semilandmarks made it possible to measure the profile of the head from the occipital crest to the dorsal tip of the ascending process of the premaxilla. Landmarks were superimposed by a generalized Procrustes superimposition (GPA) (Rohlf and Slice 1990), whereas semilandmarks were superimposed by allowing them to slide along curves bounded by landmarks to minimize the Procrustes distance among individuals (Bookstein 1997). To minimize the potential effects of allometry from the data we also performed a multiple regression of shape on geometric centroid size to generate landmark data sets based on residuals for further analysis. Landmark data were collected using TPSdig2, GPA was performed using Coordgen6h and multiple regression was performed using Standard6, whereas semilandmarks were slid using tpsRelw (all available at http://www.life.bio.sunysb.edu/morph/).


Nested Levels of Adaptive Divergence: The Genetic Basis of Craniofacial Divergence and Ecological Sexual Dimorphism.

Parsons KJ, Wang J, Anderson G, Albertson RC - G3 (Bethesda) (2015)

Landmarks, semilandmarks, and deformation grids depicting the first five axes of morphological variation [relative warps (RW)] in F2 hybrids. Across the different axes there are notable differences in craniofacial profile, most obviously in the cranial region quantified using semilandmarks (black dots and lines), but also with regard to the size of the preorbital region, size and positioning of the eye, and depth of the head.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528318&req=5

fig1: Landmarks, semilandmarks, and deformation grids depicting the first five axes of morphological variation [relative warps (RW)] in F2 hybrids. Across the different axes there are notable differences in craniofacial profile, most obviously in the cranial region quantified using semilandmarks (black dots and lines), but also with regard to the size of the preorbital region, size and positioning of the eye, and depth of the head.
Mentions: Variation in the lateral view of the head in F2 hybrids was quantified using a geometric morphometric approach. A total of 14 regular homologous landmarks and 14 sliding semilandmarks were collected on the lateral view of the head (Figure 1). Sliding semilandmarks (Bookstein 1997) make possible the description of shapes combining curves and classic homologous landmarks on the same object, and the incorporation of these data has become standard in the field of morphometrics (Zimmerman et al. 2009; Arnegard et al. 2010). Semilandmarks made it possible to measure the profile of the head from the occipital crest to the dorsal tip of the ascending process of the premaxilla. Landmarks were superimposed by a generalized Procrustes superimposition (GPA) (Rohlf and Slice 1990), whereas semilandmarks were superimposed by allowing them to slide along curves bounded by landmarks to minimize the Procrustes distance among individuals (Bookstein 1997). To minimize the potential effects of allometry from the data we also performed a multiple regression of shape on geometric centroid size to generate landmark data sets based on residuals for further analysis. Landmark data were collected using TPSdig2, GPA was performed using Coordgen6h and multiple regression was performed using Standard6, whereas semilandmarks were slid using tpsRelw (all available at http://www.life.bio.sunysb.edu/morph/).

Bottom Line: Sexual dimorphisms are also common in species displaying adaptive divergence and can be the result of differential selection between sexes that produce ecological differences between sexes.To enhance our search for candidate genes we take advantage of population genomic data and a genetic map that is anchored to the cichlid genome to determine which genes within our QTL regions are associated with SNPs that are alternatively fixed between species.This study provides a holistic understanding of the genetic underpinnings of adaptive divergence in craniofacial shape.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, United Kingdom Kevin.Parsons@glasgow.ac.uk.

No MeSH data available.