A protocol for high-resolution episcopic microscopy and 3D volumetric analyses of the adult mouse brain.

The rapid evolution of different imaging modalities in the last two decades has enabled the investigation of the role of different genes in development and disease to be studied in a range of model organisms. However, selection of the appropriate imaging technique depends on a number of constraints, including cost, time, image resolution, size of the sample, computational complexity and processing power. Here, we use the adult mouse central nervous system to investigate whether High-Resolution Episcopic Microscopy (HREM) can provide an effective means to study the volume of individual subregions within the brain.

Enhanced study of facial soft tissues using a novel large scale histology technique.

The safety and effectiveness of facial cosmetic surgery procedures are dependent on detailed 3D understanding of the complex surgical anatomy of the face. Traditional, small sample size anatomical dissection studies have limitations in providing definitive clarification of the fascial layers of the face, and especially in their relationship with the facial nerve, and their reaction to surgical manipulation. The objective study of large tissue areas is required to effectively demonstrate the broader architecture.

Comparative morphology of the electrosensory system of the epaulette shark Hemiscyllium ocellatum and brown-banded bamboo shark Chiloscyllium punctatum.

We compared the electrosensory system of two benthic elasmobranchs Hemiscyllium ocellatum and Chiloscyllium punctatum. The distribution of the ampullary pores on the head was similar for both species, with a higher density of pores anteriorly and a lower density posteriorly, although C. punctatum generally possessed larger pores.

Developmental asynchrony and antagonism of sex determination pathways in a lizard with temperature-induced sex reversal.

Vertebrate sex differentiation follows a conserved suite of developmental events: the bipotential gonads differentiate and shortly thereafter sex specific traits become dimorphic. However, this may not apply to squamates, a diverse vertebrate lineage comprising of many species with thermosensitive sexual development. Of the three species with data on the relative timing of gonad differentiation and genital dimorphism, the females of two (Niveoscincus ocellatus and Barisia imbricata) exhibit a phase of temporary pseudohermaphroditism or TPH (gonads have differentiated well before genital dimorphism).

Sex determination mode does not affect body or genital development of the central bearded dragon ().

Background: The development of male- or female-specific phenotypes in squamates is typically controlled by either temperature-dependent sex determination (TSD) or chromosome-based genetic sex determination (GSD). However, while sex determination is a major switch in individual phenotypic development, it is unknownhow evolutionary transitions between GSD and TSD might impact on the evolution of squamate phenotypes, particularly the fast-evolving and diverse genitalia. Here, we take the unique opportunity of studying the impact of both sex determination mechanisms on the embryological development of the central bearded dragon ().

Ultrastructure of the ampullary organs of Plicofollis argyropleuron (Siluriformes: Ariidae).

The morphology of ampullary organs in Plicofollis argyropleuron, collected from a southeast Queensland estuary, was examined by light and electron microscopy to assess the morphological characteristics of teleost ampullary organs in environments with fluctuating salinities. This catfish possesses both macroampullae and microampullae. Both have the typical teleost arrangement of an ampullary pore linked by a canal to a single ampulla that is lined with receptor and supportive cells.

Morphology of the teleost ampullary organs in marine salmontail catfish Neoarius graeffei (Pisces: Ariidae) with comparative analysis to freshwater and estuarine conspecifics.

We hypothesized that due to the relative conductivity of the environment, and to maintain sensory function, ampullary organs of marine Neoarius graeffei would differ morphologically from those described previously for estuarine and freshwater conspecifics. Unlike the ampullary systems of N. graeffei from freshwater and estuarine habitats, the ampullary pores of marine specimens occur in two distinct patterns; numerous pores seemingly randomly scattered on the head and ventro-lateral regions of the body, and pores arranged in distinctive vertical lines above the lateral line on the dorso-lateral body of the fish.

Firing the sting: chemically induced discharge of cnidae reveals novel proteins and peptides from box jellyfish (Chironex fleckeri) venom.

Cnidarian venom research has lagged behind other toxinological fields due to technical difficulties in recovery of the complex venom from the microscopic nematocysts. Here we report a newly developed rapid, repeatable and cost effective technique of venom preparation, using ethanol to induce nematocyst discharge and to recover venom contents in one step. Our model species was the Australian box jellyfish (Chironex fleckeri), which has a notable impact on public health.

Morphology of the ampullae of Lorenzini in juvenile freshwater Carcharhinus leucas.

Ampullae of Lorenzini were examined from juvenile Carcharhinus leucas (831-1,045 mm total length) captured from freshwater regions of the Brisbane River. The ampullary organ structure differs from all other previously described ampullae in the canal wall structure, the general shape of the ampullary canal, and the apically nucleated supportive cells. Ampullary pores of 140-205 µm in diameter are distributed over the surface of the head region with 2,681 and 2,913 pores present in two sharks that were studied in detail.

Effects of bound versus soluble pentosan polysulphate in PEG/HA-based hydrogels tailored for intervertebral disc regeneration.

Previous reports in the literature investigating chondrogenesis in mesenchymal progenitor cell (MPC) cultures have confirmed the chondro-inductive potential of pentosan polysulphate (PPS), a highly sulphated semi-synthetic polysaccharide, when added as a soluble component to culture media under standard aggregate-assay conditions or to poly(ethylene glycol)/hyaluronic acid (PEG/HA)-based hydrogels, even in the absence of inductive factors (e.g. TGFβ).

An injectable hydrogel incorporating mesenchymal precursor cells and pentosan polysulphate for intervertebral disc regeneration.

Intervertebral disc (IVD) degeneration is one of the leading causes of lower back pain and a major health problem worldwide. Current surgical treatments include excision or immobilisation, with neither approach resulting in the repair of the degenerative disc. As such, a tissue engineering-based approach in which stem cells, coupled with an advanced delivery system, could overcome this deficiency and lead to a therapy that encourages functional fibrocartilage generation in the IVD.

Squeezers and leaf-cutters: differential diversification and degeneration of the venom system in toxicoferan reptiles.

Although it has been established that all toxicoferan squamates share a common venomous ancestor, it has remained unclear whether the maxillary and mandibular venom glands are evolving on separate gene expression trajectories or if they remain under shared genetic control. We show that identical transcripts are simultaneously expressed not only in the mandibular and maxillary glands, but also in the enigmatic snake rictal gland. Toxin molecular frameworks recovered in this study were three-finger toxin (3FTx), CRiSP, crotamine (beta-defensin), cobra venom factor, cystatin, epididymal secretory protein, kunitz, L-amino acid oxidase, lectin, renin aspartate protease, veficolin, and vespryn.

Structural and molecular diversification of the Anguimorpha lizard mandibular venom gland system in the arboreal species Abronia graminea.

In the past, toxinological research on reptiles has focused principally on clinically important species. As a result, our understanding of the evolution of the reptile venom system is limited. Here, for the first time, we describe the structural and molecular evolutionary features of the mandibular toxin-secreting gland of Abronia graminea, a representative of one of the poorly known and entirely arboreal lineages of anguimorph lizards.

Ampullary organs and electroreception in freshwater Carcharhinus leucas.

The ampulla of Lorenzini of juvenile Carcharhlinus leucas differ histologically from those previously described for other elasmobranchs. The wall of the ampullary canal consists of protruding hillock-shaped epidermal cells that appear to secrete large quantities of a mucopolysaccharide gel. The ampullary organs comprise a long canal sheathed in collagen terminating in an ampulla.

Microampullary organs of a freshwater eel-tailed catfish, Plotosus (tandanus) tandanus.

Whole body studies of Plotosus tandanus revealed that ampullary pores occur over the entire body of the fish, but are in higher concentrations in the head region. These pores give rise to a short canal (50-60 microm) produced by columnar epithelial cells bound together by tight junctions and desmosomes. At the junction of the canal and the ampulla, cuboidal epithelial cells make up the wall.

Distribution and morphology of the ampullary organs of the salmontail catfish, Arius graeffei.

Whole body staining of Arius graeffei revealed that ampullary pores cover the body with their highest densities occurring on the head and lowest densities on the mid-ventral surface. Each ampullary organ consists of a long canal (0.2-1.