title: Teleost Chemokines and Their Receptors

authors: Bird, Steve

subjects: fish

abstract: Chemokines are a superfamily of cytokines that appeared about 650 million years ago, at the emergence of vertebrates, and are responsible for regulating cell migration under both inflammatory and physiological conditions. The first teleost chemokine gene was reported in rainbow trout in 1998. Since then, numerous chemokine genes have been identified in diverse fish species evidencing the great differences that exist among fish and mammalian chemokines, and within the different fish species, as a consequence of extensive intrachromosomal gene duplications and different infectious experiences. Subsequently, it has only been possible to establish clear homologies with mammalian chemokines in the case of some chemokines with well-conserved homeostatic roles, whereas the functionality of other chemokine genes will have to be independently addressed in each species. Despite this, functional studies have only been undertaken for a few of these chemokine genes. In this review, we describe the current state of knowledge of chemokine biology in teleost fish. We have mainly focused on those species for which more research efforts have been made in this subject, specially zebrafish (Danio rerio), rainbow trout (Oncorhynchus mykiss) and catfish (Ictalurus punctatus), outlining which genes have been identified thus far, highlighting the most important aspects of their expression regulation and addressing any known aspects of their biological role in immunity. Finally, we summarise what is known about the chemokine receptors in teleosts and provide some analysis using recently available data to help characterise them more clearly.

text: Teleost Chemokines and Their Receptors Chemokines are a superfamily of cytokines that appeared about 650 million years ago, at the emergence of vertebrates, and are responsible for regulating cell migration under both inflammatory and physiological conditions. The first teleost chemokine gene was reported in rainbow trout in 1998. Since then, numerous chemokine genes have been identified in diverse fish species evidencing the great differences that exist among fish and mammalian chemokines, and within the different fish species, as a consequence of extensive intrachromosomal gene duplications and different infectious experiences. Subsequently, it has only been possible to establish clear homologies with mammalian chemokines in the case of some chemokines with well-conserved homeostatic roles, whereas the functionality of other chemokine genes will have to be independently addressed in each species. Despite this, functional studies have only been undertaken for a few of these chemokine genes. In this review, we describe the current state of knowledge of chemokine biology in teleost fish. We have mainly focused on those species for which more research efforts have been made in this subject, specially zebrafish (Danio rerio), rainbow trout (Oncorhynchus mykiss) and catfish (Ictalurus punctatus), outlining which genes have been identified thus far, highlighting the most important aspects of their expression regulation and addressing any known aspects of their biological role in immunity. Finally, we summarise what is known about the chemokine receptors in teleosts and provide some analysis using recently available data to help characterise them more clearly.

year: 2015-12

title: Unimodal relationship between biomass and species richness of deep-sea nematodes: implications for the link between productivity and diversity

authors: Leduc, Daniel

subjects: Biomass

abstract: Describing large-scale patterns of biological diversity is a first step towards understanding the mechanisms that generate and maintain diversity. The highly diverse deep-sea floor is the largest ecosystem on Earth, but the productivity-diversity relationship in this biome is not well characterized. We investigated this relationship by using biomass of nematodes as a proxy for productivity (particulate organic carbon flux to the seabed). We used sample data collected from the New Zealand and Antarctic regions and combined these with published data from around the globe for broader analyses. There was a significant unimodal relationship between nematode biomass and diversity, i.e. expected number of species, ES(51) both within the New Zealand region and across ocean basins. This relationship remained significant after accounting for the effects of both water depth and nematode abundance. These findings support earlier suggestions of a unimodal productivity-diversity relationship in the deep sea that were based on other proxies (e.g. water depth, modelled particulate organic carbon flux). We argue that the 'productivity context' is of primary importance when determining the strength and nature of the relationship between other environmental factors and diversity. Studies that include either or both extremes of the productivity scale are likely to find that productivity is the main factor limiting deep-sea diversity, whereas those focusing on the intermediate productivity range are more likely to find that other factors (e.g. disturbance, habitat heterogeneity) play a role

text: Unimodal relationship between biomass and species richness of deep-sea nematodes: implications for the link between productivity and diversity Describing large-scale patterns of biological diversity is a first step towards understanding the mechanisms that generate and maintain diversity. The highly diverse deep-sea floor is the largest ecosystem on Earth, but the productivity-diversity relationship in this biome is not well characterized. We investigated this relationship by using biomass of nematodes as a proxy for productivity (particulate organic carbon flux to the seabed). We used sample data collected from the New Zealand and Antarctic regions and combined these with published data from around the globe for broader analyses. There was a significant unimodal relationship between nematode biomass and diversity, i.e. expected number of species, ES(51) both within the New Zealand region and across ocean basins. This relationship remained significant after accounting for the effects of both water depth and nematode abundance. These findings support earlier suggestions of a unimodal productivity-diversity relationship in the deep sea that were based on other proxies (e.g. water depth, modelled particulate organic carbon flux). We argue that the 'productivity context' is of primary importance when determining the strength and nature of the relationship between other environmental factors and diversity. Studies that include either or both extremes of the productivity scale are likely to find that productivity is the main factor limiting deep-sea diversity, whereas those focusing on the intermediate productivity range are more likely to find that other factors (e.g. disturbance, habitat heterogeneity) play a role

year: 2012

title: Te Kotahitanga: Addressing educational disparities facing Māori students in New Zealand

authors: Bishop, Russell

subjects: Effective teaching profile

abstract: The major challenges facing education in New Zealand today are the continuing social, economic and political disparities within our nation, primarily between the descendants of the European colonisers and the Indigenous Māori people. These disparities are also reflected in educational outcomes. In this paper, an Indigenous Māori Peoples' solution to the problems of educational disparities is detailed. Te Kotahitanga is a research and professional development project that seeks to improve the educational achievement of Māori students in mainstream secondary schools. Students ‘voices’ were used to inform the development of the project in a variety of ways: firstly to identify various discursive positions related to Māori student learning; secondly, to develop professional development activities, and thirdly, to create an Effective Teaching Profile. The paper concludes by identifying how implementing the Effective Teaching Profile addresses educational disparities.

text: Te Kotahitanga: Addressing educational disparities facing Māori students in New Zealand The major challenges facing education in New Zealand today are the continuing social, economic and political disparities within our nation, primarily between the descendants of the European colonisers and the Indigenous Māori people. These disparities are also reflected in educational outcomes. In this paper, an Indigenous Māori Peoples' solution to the problems of educational disparities is detailed. Te Kotahitanga is a research and professional development project that seeks to improve the educational achievement of Māori students in mainstream secondary schools. Students ‘voices’ were used to inform the development of the project in a variety of ways: firstly to identify various discursive positions related to Māori student learning; secondly, to develop professional development activities, and thirdly, to create an Effective Teaching Profile. The paper concludes by identifying how implementing the Effective Teaching Profile addresses educational disparities.

year: 2009