The science of the total environment

β-Catenin (Armadillo in Drosophila) is a multitasking and evolutionary conserved molecule that in metazoans exerts a crucial role in a multitude of developmental and homeostatic processes. More specifically, β-catenin is an integral structural component of cadherin-based adherens junctions, and the key nuclear effector of canonical Wnt signalling in the nucleus. Imbalance in the structural and signalling properties of β-catenin often results in disease and deregulated growth connected to cancer and metastasis. Intense research into the life of β-catenin has revealed a complex picture. Here, we try to capture the state of the art: we try to summarize and make some sense of the processes that regulate β-catenin, as well as the plethora of β-catenin binding partners. One focus will be the interaction of β-catenin with different transcription factors and the potential implications of these interactions for direct cross-talk between β-catenin and non-Wnt signalling pathways.

/pdf/the-many-faces-and-functions-of-b-catenin-2nu9x6ye34.pdf

The many faces and functions of β‐catenin

Hair cortisol as a biological marker of chronic stress: current status, future directions and unanswered questions.

The freshwater cnidarian Hydra was first described in 17021 and has been the object of study for 300 years. Experimental studies of Hydra between 1736 and 1744 culminated in the discovery of asexual reproduction of an animal by budding, the first description of regeneration in an animal, and successful transplantation of tissue between animals2. Today, Hydra is an important model for studies of axial patterning3, stem cell biology4 and regeneration5. Here we report the genome of Hydra magnipapillata and compare it to the genomes of the anthozoan Nematostella vectensis6 and other animals. The Hydra genome has been shaped by bursts of transposable element expansion, horizontal gene transfer, trans-splicing, and simplification of gene structure and gene content that parallel simplification of the Hydra life cycle. We also report the sequence of the genome of a novel bacterium stably associated with H. magnipapillata. Comparisons of the Hydra genome to the genomes of other animals shed light on the evolution of epithelia, contractile tissues, developmentally regulated transcription factors, the Spemann–Mangold organizer, pluripotency genes and the neuromuscular junction.

/pdf/the-dynamic-genome-of-hydra-1holp6l2p7.pdf

The dynamic genome of Hydra

Stress responses play a key role in allowing animals to cope with change and challenge in the face of both environmental certainty and uncertainty. Measurement of glucocorticoid levels, key elements in the neuroendocrine stress axis, can give insight into an animal’s well-being and can aid understanding ecological and evolutionary processes as well as conservation and management issues. We give an overview of the four main biological samples that have been utilized [blood, saliva, excreta (feces and urine), and integumentary structures (hair and feathers)], their advantages and disadvantages for use with wildlife, and some of the background and pitfalls that users must consider in interpreting their results. The matrix of choice will depend on the nature of the study and of the species, on whether one is examining the impact of acute versus chronic stressors, and on the degree of invasiveness that is possible or desirable. In some cases, more than one matrix can be measured to achieve the same ends. All require a significant degree of expertise, sometimes in obtaining the sample and always in extracting and analyzing the glucocorticoid or its metabolites. Glucocorticoid measurement is proving to be a powerful integrator of environmental stressors and of an animal’s condition.

https://www.jstor.org/stable/info/41499891

Measuring stress in wildlife: techniques for quantifying glucocorticoids

A novel method using hair for determining hormonal levels in wildlife

Wnt signaling in hydroid development: formation of the primary body axis in embryogenesis and its subsequent patterning.

Social status and cortisol levels in singing rock hyraxes

http://www.tau.ac.il/~geffene/PDFs/56-Horm_Behav_2006.pdf

Elevated testosterone levels and social ranks in female rock hyrax.

Allorecognition is ubiquitous, or nearly so, amongst colonial invertebrates. Despite the prominent role that such phenomena have played both in evolutionary theory and in speculations on the origin of the vertebrate immune system, unambiguous data on the transmission genetics of fusibility ( i.e. , the ability of two individuals to fuse upon tissue contact) is lacking for any metazoan outside of the phylum Chordata. We have developed lines of the hydroid Hydractinia symbiolongzcarpus (Phylum Cnidaria) inbred for fusibility and here report results of breeding experiments establishing that fusibility segregates as expected for a single locus with codominantly expressed alleles, with one shared allele producing a fusible phenotype. Surveys of fusibility in field populations and additional breeding experiments indicate the presence of an extensive allele series.

https://www.genetics.org/content/genetics/143/2/823.full.pdf

Ofer Mokady

Papers

A novel method using hair for determining hormonal levels in wildlife

Wnt signaling in hydroid development: formation of the primary body axis in embryogenesis and its subsequent patterning.

Social status and cortisol levels in singing rock hyraxes

Elevated testosterone levels and social ranks in female rock hyrax.

Transmission genetics of allorecognition in Hydractinia symbiolongicarpus (Cnidaria:Hydrozoa).