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Phenotypic Buffering in a Monogenean: Canalization and Developmental Stability in Shape and Size of the Haptoral Anchors of Ligophorus cephali (Monogenea: Dactylogyridae).

Llopis-Belenguer C, Balbuena JA, Galván-Femenía I, Rodríguez-González A - PLoS ONE (2015)

Bottom Line: Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms.Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation.Geometric morphometrics can be readily applied to other host-monogenean models, affording not only to disentangle the effects of canalization and developmental stability, as shown herein, but to further partition the environmental and genetic components of the former.

View Article: PubMed Central - PubMed

Affiliation: Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain.

ABSTRACT
Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms. Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation. The issue of whether or not they act concurrently as a common developmental buffering capacity has been subject to debate. We used geometric morphometrics to quantify the mechanisms that guarantee phenotypic constancy in the haptoral anchors of Ligophorus cephali. Canalization and developmental stability were appraised by estimating inter- and intra-individual variation, respectively, in size and shape of dorsal and ventral anchors. The latter variation was estimated as fluctuating asymmetry (FA) between anchor pairs. The general-buffering-capacity hypothesis was tested by two different methods based on correlations and Principal Components Analyses of the different components of size and shape variation. Evidence for FA in the dorsal and ventral anchors in both shape and size was found. Our analyses supported the hypothesis of a general developmental buffering capacity. The evidence was more compelling for shape than for size and, particularly, for the ventral anchors than for the dorsal ones. These results are in line with previous studies of dactylogyrids suggesting that ventral anchors secure a firmer, more permanent attachment, whereas dorsal anchors are more mobile. Because fixation to the host is crucial for survival in ectoparasites, we suggest that homeostatic development of the ventral anchors has been promoted to ensure the morphological constancy required for efficient attachment. Geometric morphometrics can be readily applied to other host-monogenean models, affording not only to disentangle the effects of canalization and developmental stability, as shown herein, but to further partition the environmental and genetic components of the former.

No MeSH data available.


Related in: MedlinePlus

Relationship between anchors size and shape variation.Relationship between size and shape intra-individual (Fluctuating asymmetry, FA) (A, B) and inter-individual (C, D) variation in dorsal (A, C) and ventral (B, D) anchors. Trend lines are standard major axis regressions, (shown only in case of significant correlation between the variables of interest).
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pone.0142365.g003: Relationship between anchors size and shape variation.Relationship between size and shape intra-individual (Fluctuating asymmetry, FA) (A, B) and inter-individual (C, D) variation in dorsal (A, C) and ventral (B, D) anchors. Trend lines are standard major axis regressions, (shown only in case of significant correlation between the variables of interest).

Mentions: There was a significant allometric relationship between size and shape in both dorsal and ventral anchors (P< 0.0001 in both cases). However, size accounted for a small fraction of size variation in dorsal and ventral anchors (6.5% and 7.7%, respectively). Inter- and intra-individual (FA) variation in shape were significantly correlated in both dorsal and ventral anchors. As for size, the relationship between inter- and intra-individual variation was only significant in the ventral anchors (Fig 2). Likewise the correlation between intra-individual (FA) shape and size, and between inter-individual variation in shape and size was only significant in the ventral anchors (Fig 3). Only intra-individual (FA) variation in shape was significantly correlated in ventral and dorsal anchors (Fig 4).


Phenotypic Buffering in a Monogenean: Canalization and Developmental Stability in Shape and Size of the Haptoral Anchors of Ligophorus cephali (Monogenea: Dactylogyridae).

Llopis-Belenguer C, Balbuena JA, Galván-Femenía I, Rodríguez-González A - PLoS ONE (2015)

Relationship between anchors size and shape variation.Relationship between size and shape intra-individual (Fluctuating asymmetry, FA) (A, B) and inter-individual (C, D) variation in dorsal (A, C) and ventral (B, D) anchors. Trend lines are standard major axis regressions, (shown only in case of significant correlation between the variables of interest).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4636253&req=5

pone.0142365.g003: Relationship between anchors size and shape variation.Relationship between size and shape intra-individual (Fluctuating asymmetry, FA) (A, B) and inter-individual (C, D) variation in dorsal (A, C) and ventral (B, D) anchors. Trend lines are standard major axis regressions, (shown only in case of significant correlation between the variables of interest).
Mentions: There was a significant allometric relationship between size and shape in both dorsal and ventral anchors (P< 0.0001 in both cases). However, size accounted for a small fraction of size variation in dorsal and ventral anchors (6.5% and 7.7%, respectively). Inter- and intra-individual (FA) variation in shape were significantly correlated in both dorsal and ventral anchors. As for size, the relationship between inter- and intra-individual variation was only significant in the ventral anchors (Fig 2). Likewise the correlation between intra-individual (FA) shape and size, and between inter-individual variation in shape and size was only significant in the ventral anchors (Fig 3). Only intra-individual (FA) variation in shape was significantly correlated in ventral and dorsal anchors (Fig 4).

Bottom Line: Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms.Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation.Geometric morphometrics can be readily applied to other host-monogenean models, affording not only to disentangle the effects of canalization and developmental stability, as shown herein, but to further partition the environmental and genetic components of the former.

View Article: PubMed Central - PubMed

Affiliation: Marine Zoology Unit, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain.

ABSTRACT
Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms. Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation. The issue of whether or not they act concurrently as a common developmental buffering capacity has been subject to debate. We used geometric morphometrics to quantify the mechanisms that guarantee phenotypic constancy in the haptoral anchors of Ligophorus cephali. Canalization and developmental stability were appraised by estimating inter- and intra-individual variation, respectively, in size and shape of dorsal and ventral anchors. The latter variation was estimated as fluctuating asymmetry (FA) between anchor pairs. The general-buffering-capacity hypothesis was tested by two different methods based on correlations and Principal Components Analyses of the different components of size and shape variation. Evidence for FA in the dorsal and ventral anchors in both shape and size was found. Our analyses supported the hypothesis of a general developmental buffering capacity. The evidence was more compelling for shape than for size and, particularly, for the ventral anchors than for the dorsal ones. These results are in line with previous studies of dactylogyrids suggesting that ventral anchors secure a firmer, more permanent attachment, whereas dorsal anchors are more mobile. Because fixation to the host is crucial for survival in ectoparasites, we suggest that homeostatic development of the ventral anchors has been promoted to ensure the morphological constancy required for efficient attachment. Geometric morphometrics can be readily applied to other host-monogenean models, affording not only to disentangle the effects of canalization and developmental stability, as shown herein, but to further partition the environmental and genetic components of the former.

No MeSH data available.


Related in: MedlinePlus