scholarly journals Drivers of molecular and morphometric variation in Triatoma brasiliensis (Hemiptera: Triatominae): the resolution of geometric morphometrics for populational structuring on a microgeographical scale

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Edgard H. Kamimura ◽  
Maria Carolina Viana ◽  
Maurício Lilioso ◽  
Fernanda H. M. Fontes ◽  
Dayane Pires-Silva ◽  
...  
Keyword(s):  
Mitochondrial Gene ◽  
Northeastern Brazil ◽  
Canonical Variate ◽  
Geographic Scale ◽  
Morphometric Variation ◽  
Mantel Tests ◽  
Variate Analysis ◽  
Semiarid Areas ◽  
The Right ◽  
Source Of Information

Abstract Background The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results. Additionally, we aimed to address the resolution of both markers for delimiting populations in distinct scales. Methods We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the states Rio Grande do Norte (RN) and Paraíba (PB). The geometric morphometry was carried out with 13 landmarks on the right wings (n = 698) and the genetic structure was assessed by sequencing a region of cytochrome b mitochondrial gene (n = 221). Mahalanobis distance (MD) and coefficient of molecular differentiation (ΦST) were calculated among all pairs of populations. The results of comparisons generated MD and ΦST dendrograms, and graphics of canonical variate analysis (CVA). Results Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R2 < 0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic scales. Conclusions We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis. On the other hand, the pattern of morphometric results in micro-geographic scales showed well-defined groups, highlighting the potential of this tool to inferences on the source for infestation.

scholarly journals Drivers of molecular and morphometric variation in Triatoma brasiliensis (Hemiptera: Reduviidae): the resolution of geometric morphometrics for populational structuring in micro-geographic scale

2020 ◽  
Author(s):  
Edgard Kamimura ◽  
Maria Carolina Viana ◽  
Mauricio Lilioso ◽  
Fernanda Fontes ◽  
Dayane Pires-Silva ◽  
...  
Keyword(s):  
Mitochondrial Gene ◽  
Canonical Variate ◽  
Scale Analysis ◽  
Geographic Scale ◽  
Morphometric Variation ◽  
Mantel Tests ◽  
Variate Analysis ◽  
Semiarid Areas ◽  
The Right ◽  
Source Of Information

Abstract Background The protozoan Trypanosoma cruzi circulates in semiarid areas of the northeastern of Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis is the most important Chagas disease vector.Methods We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the Rio Grande do Norte (RN) and Paraíba (PB) States to compare the results of morphometric and genetic variations. The geometric morphometry was carried out with 13 landmarks on the right wings ( N =698) and the genetic structure was assessed by sequencing a region of cytochrome B mitochondrial gene ( N =221). Mahalanobis distance (DM) and molecular differentiation coefficient (Φ ST ) were calculated among all pairs of populations.Results The results of comparisons generated MD and Φ ST dendrograms, and graphics of canonical variate analysis (CVA). Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R 2 <0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic-scales.Conclusions We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis when populations are grouped. On the other hand, the pattern of morphometric results in micro-geographic scales highlights the potential of this tool to infer the source for infestation.

scholarly journals Studying the Shape Variations of the Back, the Neck, and the Mandibular Angle of Horses Depending on Specific Feeding Postures Using Geometric Morphometrics

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 763
Author(s):  
Federica Raspa ◽  
Angela Roggero ◽  
Claudia Palestrini ◽  
Martina Marten Canavesio ◽  
Domenico Bergero ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Management Practices ◽  
Mixed Model ◽  
Principal Component ◽  
Canonical Variate ◽  
Long Term Effects ◽  
Mandibular Angle ◽  
Variate Analysis ◽  
The Right

The effects of specific feeding positions upon the horse’s shape variations of the back and neck postures as well as the variations of the mandibular angle have never been objectively studied. For this reason, geometric morphometrics was applied. Six horses, aged 14 ± 8 years (mean ± standard deviation, SD), were video-recorded while using three different feeding positions: on the ground—control position (CP); neck held 15 ± 3° below withers height with low hay net position (LP); neck held 15 ± 3° above withers height with high hay net position (HP). Data were analyzed using principal component analysis (PCA), multivariate analysis of variance (MANOVA), and partial least squares (PLS). A mixed model procedure was applied to evaluate differences in the magnitude of the mandibular angle. Whilst differences between individual horses were confirmed by canonical variate analysis (CVA), PCA analysis showed that a characteristic feeding position could also be identified on a group level. During the HP hay net position, the back and neck postures as well the mandibular angle were different compared to those exhibited by horses feeding from CP. In LP hay net position, the back posture more closely resembled those exhibited while feeding from CP; however, no similarity between LP and CP was found for neck posture and mandibular angle. Since only a few degrees of variation of the feeding position can influence back and neck postures, this aspect should be further investigated. The right compromise between horse welfare, horse safety, and management practices need to be further explored and long-term effects should be investigated.

Morphometric discrimination among sibling species in the fulva–rudis–texana complex of the ant genus Aphaenogaster (Hymenoptera: Formicidae)

1996 ◽  
Vol 74 (3) ◽  
pp. 528-559 ◽  
Author(s):  
Gary J. Umphrey
Keyword(s):  
Canonical Variate ◽  
Similar Species ◽  
Undescribed Species ◽  
Morphometric Measurements ◽  
Morphometric Variation ◽  
Linear Discriminant ◽  
Interspecific Differences ◽  
Variate Analysis ◽  
Qualitative Characters ◽  
High Degree

The fulva–rudis–texana complex of the ant genus Aphaenogaster includes A. fulva, A. rudis, A. texana, and morphologically similar species. Morphometric and other morphological investigations were conducted on colony representatives of 10 forms (4 likely representing undescribed species) that were previously identified using cytogenetic and electrophoretic markers. In workers, most qualitative characters exhibit such a high degree of size-associated intraspecific variation relative to interspecific differences that they are not reliable for identification. Linear discriminant analysis and canonical variate analysis on 12 morphometric measurements were used to optimize classification and define a morphometric habitus for each form. Two-variable scatterplots clarify the nature of morphometric variation in the complex and provide simple characters that will reliably separate numerous pairs of forms. Indices appear to be of little taxonomic value in this complex. A preliminary key to the workers of the complex summarizes the most important taxonomic characters. This key substantially improves the ability to recognize morphologically most members of the complex, but sometimes only genetic evidence is definitive.

scholarly journals A multivariate analysis of subline divergence in the shape of the mandible in C57BL/Gr mice

1973 ◽  
Vol 21 (2) ◽  
pp. 121-132 ◽  
Author(s):  
Michael Festing
Keyword(s):  
Multivariate Analysis ◽  
Distance Function ◽  
Canonical Variate ◽  
Multivariate Techniques ◽  
Graphical Display ◽  
Classification Analysis ◽  
Variate Analysis ◽  
Pedigree Relationship ◽  
Highly Correlated ◽  
Generalized Distance

SUMMARYThe shape of the mandible in. nine sublines of C57BL/Gr, seven other strains of ‘C57 ancestry’ and four unrelated strains was studied by multivariate techniques. The generalized distance function was used to classify individuals in the groups which they most closely resembled. The degree of misclassification depended on the pedigree relationship between strains and sublines. The generalized distance between pairs of subline centeroids was also highly correlated (r = 0·60) with the number of generations between them. A canonical variate analysis was used to reduce the dimensionality so that a graphical display of the relationships between strains and sublines could be made. The results agreed closely with the classification analysis. It was concluded that the shape of the mandible could be used for subline identification though the accuracy of this technique depends on how closely the sublines are related.

Taxonomic relationships of Nearctic small-footed bats of the Myotis leibii group (Chiroptera: Vespertilionidae)

1984 ◽  
Vol 62 (12) ◽  
pp. 2519-2526 ◽  
Author(s):  
C. G. van Zyll de Jong
Keyword(s):  
Canonical Variate Analysis ◽  
Canonical Variate ◽  
Separate Species ◽  
Taxonomic Relationships ◽  
Morphometric Analyses ◽  
Cranial Measurements ◽  
Variate Analysis ◽  
Myotis Leibii

Crania and bacula of five taxa of small-footed bats of the leibii group, comprising two currently recognised species, Myotis californicus and M. leibii, were studied to elucidate their interrelationships. Canonical variate analysis of 14 cranial measurements shows the existence of three distinct nonoverlapping clusters corresponding to (i) M. californicus, (ii) M. I. ciliolabrum and M. I. melanorhinus, and (iii) M. I. leibii. The results of the morphometric analyses do not support the claim that M. I. leibii and M. I. melanorhinus intergrade in Oklahoma. The taxonomic interpretation of the results is that the western forms of M. leibii represent a separate species M. ciliolabrum (Mcrriam). The bacula of the taxa studied lack distinctive characters that would allow one to discriminate between the species of the leibii group.

scholarly journals An application of canonical variate analysis in profile comparison of dry matter content of white clover between ozone-sensitive and ozone-resistant clones exposed in ambient air conditions

2015 ◽  
Vol 52 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Dariusz Kayzer ◽  
Anna Budka ◽  
Klaudia Borowiak ◽  
Janina Zbierska ◽  
Marta Lisiak
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Profile Analysis ◽  
Ambient Air ◽  
Matter Content ◽  
Canonical Variate Analysis ◽  
Canonical Variate ◽  
Dry Matter Content ◽  
The World ◽  
Variate Analysis

SummaryTropospheric ozone affects plant growth and the yield of main pasture species all around the world. Experiments are usually performed in fully controlled conditions; the number of investigations in ambient air conditions is still limited. Moreover, most investigations of the effect of ozone on white clover biomass production consider one series after the other, including a period without leaves. Hence, based on the recommendations, additional series are proposed and studied here. The responses of sensitive and resistant white clover clones are presented and compared using multivariate analysis of variance and profile analysis. The canonical variate analysis used here makes it possible to present the profile comparison of dry matter content of white clover graphically in Euclidean space. The investigations revealed a difference in response between clones and the necessity of using the additional series.

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