Anatomical variation of habitat‐related changes in scapular morphology

The mammalian forelimb is adapted to different functions including postural, locomotor, feeding, exploratory, grooming and defence. Comparative studies on morphology of the mammalian scapula have been performed in an attempt to establish the functional differences in the use of the forelimb. In this study, a total of 102 scapulae collected from 66 species of animals, representatives of all major taxa from rodents, sirenians, marsupials, pilosa, cetaceans, carnivores, ungulates, primates and apes, were analysed. Parameters measured included scapular length, width, position, thickness, area, angles and index. Structures included supraspinous and infraspinous fossae, scapular spine, glenoid cavity, acromium and coracoid processes. Images were taken using computed tomographic (CT) scanning technology (CT‐Aquarium, Toshiba and micro CT‐LaTheta, Hotachi, Japan), and measurement values were acquired and processed using Avizo computer software and CanvasTM 11 ACD systems. Statistical analysis was performed using Microsoft Excel 2013. Results obtained showed that there were differences in morphological characteristics of scapula between mammals with arboreal locomotion and living in forest and mountainous areas and those with leaping and terrestrial locomotion living in open habitat or savannah. Differences were seen in the ratio of maximum length and maximum width, the orientation of scapular spine and the horizontal length of acromion and coracoid processes. The cause for the statistical grouping of the animals and the way the scapular shape covaries with habitat and to the type of locomotion and speed are discussed in detail.     

Muscle fibre distribution in forelimb,hindlimb and trunk muscles in three bat species: The little Japanese horseshoe,greater horseshoe and Egyptian fruit

This study characterised muscle fibres in trunk, forelimb and hindlimb muscles of three bat species: little Japanese horseshoe (Rhinolophus cornutus), greater horseshoe (Rhinolophus ferrumequinum) and Egyptian fruit (Rousettus aegyptiacus). Twenty-seven muscles from trunk, forelimb and hindlimb were dissected, weighed and analysed by immunohistochemistry and sodium didecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and determined their cross-sectional areas (CSA). Results showed that Type IIa and Type IIa/x made the highest proportion of total muscle mass. Moderate proportion was formed by Type IIb. Type I and IIx appeared at very low levels in all bats. Type IIb was the only fibre type detected in patagial muscles in wing membrane of greater horseshoe while other fibre types were not observed. Type I muscle fibres were very few and appeared infrequently in fifteen muscles of Egyptian fruit and in only one muscle in each, greater horseshoe and little Japanese horseshoe. Type IIx was also detected in three muscles in greater horseshoe and only one muscle in Egyptian fruit but none in little Japanese horseshoe. The highest average CSA μm² was detected in Type IIb and values were 734.2μm² for LHB; 1537.9μm² for GHB and 1,720.9μm² for EFB. Lowest and undetermined values were observed for Type I and IIx. These data demonstrate that Type IIa, IIa/x and IIb form significant proportion of adult bat muscle mass and Type IIb is the largest fibre type. The distribution pattern is suggestive of specialised functions of the fibres in relation to orientation and speed of bats during flight.     

Immunoreactivity of cytotoxic T-lymphocyte antigen 2 alpha in mouse pancreatic islet cells

Cells of the pancreatic islets produce several molecules including insulin (beta cells), glucagon (alpha cells), somatostatin (delta cells), pancreatic polypeptide (PP cells), ghrelin (epsilon cells), serotonin (enterochromaffin cells), gastrin (G cells) and small granules of unknown content secreted by the P/D1 cells. Secretion mechanism of some of these molecules is still poorly understood. However, Cathepsin L is shown to regulate insulin exocytosis in beta cells and activate the trypsinogen produced by the pancreatic serous acini cells into trypsin. The structure of the propeptide region of Cathepsin L is homologous to Cytotoxic T-lymphocyte antigen-2 alpha (CTLA-2 alpha) which is also shown to exhibit selective inhibitory activities against Cathepsin L. It was thought that if CTLA-2 alpha was expressed in the pancreas; then, it would be an important regulator of protease activation and insulin secretion. The purpose of this study was, therefore, to examine by immunohistochemistry the cellular localization and distribution pattern of CTLA-2 alpha in the pancreas. Results showed that strong immunoreactivity was specifically detected in the pancreatic islets (endocrine pancreas) but not in the exocrine pancreas and pancreatic stroma. Immunostaining was further performed to investigate more on localization of Cathepsin L in the pancreas. Strong immunoreactivity for Cathepsin L was detected in the pancreatic islets, serous cells and the pancreas duct system. These findings suggest that CTLA-2 alpha may be involved in the proteolytic processing and secretion of insulin through regulation of Cathepsin L and that the regulated inhibition of Cathepsin L may have therapeutic potential for type 1 diabetes.     

Colloid in the anterior pituitary of helmet guinea fowl (<Emphasis Type="Italic">Numida meleagris galeata</Emphasis>): Morphometric analysis and pattern of occurrence in relation to apoptosis

Colloidal accumulations in the pars distalis of helmet guinea fowls at various ages from 1 to 450 days were examined by Periodic acid-Schiff reaction, immunohistochemistry and electron microscopy. Round, ovoid and elongated colloids were observed. Colloids (69.5 ± 2.997) with 0.169 ± 0.014 μm mean diameter were already present in a 1-day-old bird. Numerous colloids were encountered in 450 days old birds (2931.333 ± 29.847) with 2.263 ±  0.078 μm mean diameter of round colloids. A significant difference in the mean colloidal number and diameter between young and adult birds was observed. In young birds (aged 1–30 days) both Periodic acid-Schiff reaction positive colloids and S-100 positive folliculostellate (FS) cells were found to appear first on or near the posterolateral region. In adult birds, FS cells were found to completely surround the colloids. We examined the biochemical components of colloids and the relationship with apoptosis by immunohistochemistry. Results showed that the colloids are composed of clusterin protein. Apoptotic cells detected by single stranded DNA (ssDNA) were abundant and localized preferentially near colloids. To define clearly the type of cells undergoing apoptosis in the anterior pituitary, we performed electron microscopy. Numerous endocrine cells at different stages of apoptosis were found engulfed by FS cells that were in close association with the colloidal accumulations. The occurrence of extremely large number of colloids in relation to apoptotic profiles in anterior pituitary of helmet guinea fowl is discussed.     

Characterization and distribution of an arginine vasotocin receptor in mouse

A cDNA, which has a high homology with teleost Platichthys flesus [Arg8] vasotocin (AVT) receptor (GenBank: AK033957), was found in mouse genome database. Analyses of the deduced amino acid sequence revealed that a cDNA has several features of AVT receptor. We tentatively named it as a mouse vasotocin receptor (MVTR). A two-electrodes voltage clamp technique was applied to characterize the MVTR expressed in Xenopus laevis oocytes. AVT induced Ca2+-dependent Cl- currents in Xenopus oocytes injected with MVTR cRNA. On the other hand, [Arg8] vasopressin, oxytocin and isotocin did not induce such currents. RT-PCR showed that MVTR mRNA was specifically expressed in the brain. In situ hybridization analysis demonstrated significant expression of MVTR mRNA in suprachiasmatic nucleus, arcuate nucleus and medial habenular nucleus of mouse brain. These results suggest that MVTR may mediate a variety of physiological functions in mouse.     

Differential effect of hot water treatment on whole tubers versus cut setts of yam (Dioscorea spp.)

BACKGROUND: The use of thermotherapy or hot water treatment (HWT) is recommended for the management of plant‐parasitic nematodes and other pathogens for a range of planting material, especially vegetatively propagated crops including yams, Dioscorea spp. The sprouting (germination) and consequent viability of yam following HWT, however, appear to be influenced by the post‐treatment method of planting (whole or cut setts) and cultivar. The present study was established to evaluate the sensitivity of the most popular yam cultivars in Benin and Nigeria, West Africa, to HWT at 50–53 °C for 20 min. RESULTS: Sprouting of both setts and whole tubers of most cultivars was affected by HWT. Across experiments, 47% of HWT material, compared with 61% of non‐HWT material, sprouted over 8 weeks. When cut into setts, 41% of HWT or untreated tubers sprouted, compared with 72% of whole tubers. Whole, untreated tubers had highest sprouting rates (84%), and setts following HWT had the lowest (38%). Yam planting material was also not completely free of parasitic nematodes following HWT. The reaction to HWT or cutting was highly cultivar specific. CONCLUSION: Yam cultivars vary in their sensitivity to hot water therapy. Care is therefore advised in selecting yam cultivars for HWT, especially when using cut setts. Copyright © 2009 Society of Chemical Industry