scholarly journals The Functional Morphology of Avicularia in Cheilostome Bryozoans

2021 ◽  
Author(s):  
◽  
Michelle Clare Carter
Keyword(s):  
Functional Morphology ◽  
Functional Capacity ◽  
Functional Role ◽  
Metabolic Cost ◽  
Character Traits ◽  
Evolutionary Development ◽  
Tactile Stimuli ◽  
Habitat Differences ◽  
Cheilostome Bryozoans

<p>Avicularia are modified zooids characteristic of cheilostome bryozoans. Through evolutionary time the functional capacity of the polypide has evolved and is now a vestigial feature within the avicularium. The functional role of avicularia in the colony is unclear. Unable to feed, avicularia are dependent on nutrients from the parental or neighbouring zooids and therefore constitute a significant metabolic cost in production and maintenance, a cost which must be met by some reciprocal function. Details on the functional morphology of avicularia are severely lacking with avicularia constituting a large gap in the knowledge of cheilostome biology. By examining their biology, this study will enhance our understanding of the evolution and functional capacity of avicularia. Fundamentally this study will provide insight into the degree of morphological and morphometric divergence among avicularia. The objective of this study was to: (1) conduct a morphological survey of the putative sensory structures associated with the palate (or orificial structures) of avicularia (SEM); (2) conduct an ultrastructural-level study (TEM) of the vestigial polypide from two species of bugulids from disparate habitats; and (3) incorporate a holistic study on the behaviour and functional evolution of character traits in Bugula flabellata. The avicularia from 38 species of cheilostome bryozoans were examined covering 11 superfamilies, 18 families and 29 genera. The results indicate that avicularia are morphologically diverse and display extensive variation in avicularian orifice morphology. Structures associated with the orifice varied from tufts of cilia, simple pores, tubular protuberances, and pores with an organic exude. The adventitious avicularia dominated (83%) and displayed the greatest morphometric diversity compared with interzooidal, vicarious and vibracular types. Within superfamilies, only the catenicellids displayed a significant level of morphometric and anatomical congruence. The density of avicularia within a colony was greatest by combining adventitious and vibracular types (e.g. Caberea). This finding may represent an evolutionary shift towards maximisation of function within a smaller spatial scale. The ultrastructure of the vestigial polypide of the subtidal B. flabellata and deep-sea Nordgaardia cornucopioides revealed disparities suggestive of differing functional roles either as a result of habitat differences or differing stages of evolutionary development. The avicularium of B. flabellata has undergone significant modification in character traits from the plesiomorphic autozooid. The current anatomy and behaviour of this avicularium provides strong evidence for a mechanoreceptive function whereby detection of tactile stimuli from passing invaders is important in the functional role of the bird's-head avicularium of B. flabellata. This study is the first to examine the functional morphology of avicularia in such detail. The techniques used in this study have never been applied to avicularia before allowing numerous features such as the muscles, orificial structures and vestigial polypide anatomy to be discerned. The results indicate that avicularia are morphologically diverse and anatomically equipped to perform a variety of functions. The morphological diversity of avicularia may be of immense ecological importance and represent differing responses to various selective pressures in the environment.</p>

scholarly journals The Functional Morphology of Avicularia in Cheilostome Bryozoans

2021 ◽  
Author(s):  
◽  
Michelle Clare Carter
Keyword(s):  
Functional Morphology ◽  
Functional Capacity ◽  
Functional Role ◽  
Metabolic Cost ◽  
Character Traits ◽  
Evolutionary Development ◽  
Tactile Stimuli ◽  
Habitat Differences ◽  
Cheilostome Bryozoans

<p>Avicularia are modified zooids characteristic of cheilostome bryozoans. Through evolutionary time the functional capacity of the polypide has evolved and is now a vestigial feature within the avicularium. The functional role of avicularia in the colony is unclear. Unable to feed, avicularia are dependent on nutrients from the parental or neighbouring zooids and therefore constitute a significant metabolic cost in production and maintenance, a cost which must be met by some reciprocal function. Details on the functional morphology of avicularia are severely lacking with avicularia constituting a large gap in the knowledge of cheilostome biology. By examining their biology, this study will enhance our understanding of the evolution and functional capacity of avicularia. Fundamentally this study will provide insight into the degree of morphological and morphometric divergence among avicularia. The objective of this study was to: (1) conduct a morphological survey of the putative sensory structures associated with the palate (or orificial structures) of avicularia (SEM); (2) conduct an ultrastructural-level study (TEM) of the vestigial polypide from two species of bugulids from disparate habitats; and (3) incorporate a holistic study on the behaviour and functional evolution of character traits in Bugula flabellata. The avicularia from 38 species of cheilostome bryozoans were examined covering 11 superfamilies, 18 families and 29 genera. The results indicate that avicularia are morphologically diverse and display extensive variation in avicularian orifice morphology. Structures associated with the orifice varied from tufts of cilia, simple pores, tubular protuberances, and pores with an organic exude. The adventitious avicularia dominated (83%) and displayed the greatest morphometric diversity compared with interzooidal, vicarious and vibracular types. Within superfamilies, only the catenicellids displayed a significant level of morphometric and anatomical congruence. The density of avicularia within a colony was greatest by combining adventitious and vibracular types (e.g. Caberea). This finding may represent an evolutionary shift towards maximisation of function within a smaller spatial scale. The ultrastructure of the vestigial polypide of the subtidal B. flabellata and deep-sea Nordgaardia cornucopioides revealed disparities suggestive of differing functional roles either as a result of habitat differences or differing stages of evolutionary development. The avicularium of B. flabellata has undergone significant modification in character traits from the plesiomorphic autozooid. The current anatomy and behaviour of this avicularium provides strong evidence for a mechanoreceptive function whereby detection of tactile stimuli from passing invaders is important in the functional role of the bird's-head avicularium of B. flabellata. This study is the first to examine the functional morphology of avicularia in such detail. The techniques used in this study have never been applied to avicularia before allowing numerous features such as the muscles, orificial structures and vestigial polypide anatomy to be discerned. The results indicate that avicularia are morphologically diverse and anatomically equipped to perform a variety of functions. The morphological diversity of avicularia may be of immense ecological importance and represent differing responses to various selective pressures in the environment.</p>

Introgression does not influence the positive ecological and functional role of dingo populations

2020 ◽  
Author(s):  
Mathew S. Crowther ◽  
Kylie M. Cairns ◽  
Lily M. van Eeden ◽  
Mike Letnic
Keyword(s):  
Functional Morphology ◽  
Functional Role ◽  
Conservation Status ◽  
Preliminary Evidence ◽  
Natural Process ◽  
Domestic Dog ◽  
Eastern Australia ◽  
Canid Species ◽  
The Impact

ABSTRACT The impact of hybridisation between dingoes and domestic dogs, and the subsequent introgression of domestic dog genes into dingo populations, remains a topic of significant impact. It has been claimed, but with little evidence or logical argumentation, that dingoes with significant dog introgression have different effects on agriculture and ecosystems than dingoes with no dog introgression. Introgression is a natural process in evolution, occurring in many species, although this is sometimes human assisted. Canid species in particular show high levels of introgression, due to their genetic and phylogenetic similarities, and human persecution creates scenarios encouraging hybridisation. Dingoes are no exception and demonstrate high levels of introgression of domestic dog genes, particularly in the temperate areas of south-eastern Australia. The available evidence shows that this introgression has minimal effects on the functional morphology of the dingo skull. There is also some preliminary evidence that introgression has not had a major impact on dingo reproductive biology. Studies on the impacts of dingoes on arid, tropical and temperate ecosystems, where levels of introgression vary greatly, all show consistent positive impacts of dingoes, regardless of the amount of domestic dog genes within the dingo population, on these ecosystems. Hence, hybridisation and resultant introgression from domestic dog genes appear to have little effect on aspects of the functional morphology or ecological role of the dingo. Accordingly, introgression does not diminish the conservation status of the dingo.

Expression and functional role of c-Kit and erbB2 in human hepatoblastoma.

2009 ◽  
Vol 221 (03) ◽  
Author(s):  
B Steiger ◽  
I Leuschner ◽  
D Denkhaus ◽  
D von Schweinitz ◽  
T Pietsch
Keyword(s):  
Functional Role

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

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