Purification of bone morphogenetic protein derived from bovine bone matrix

Bone morphogenetic protein (BMP) was extracted from the bovine bone matrix and purified by liquid chromatography. The molecular weight of the BMP was 18 kDa by SDS-PAGE, and its pI value was 4.9. Amino acid analysis suggested that the BMP is a polypeptide containing 163 amino acids. In the present study, telopeptide-free type I collagen was used as a carrier of BMP.     

Extrafloral nectary-bearing plant Mallotus japonicus uses different types of extrafloral nectaries to establish effective defense by ants

Extrafloral nectary (EFN)-bearing plants attract ants to gain protection against herbivores. Some EFN-bearing plants possess different types of EFNs, which might have different effects on ants on the plants. Mallotus japonicus (Thunb.) Muell. Arg. (Euphorbiaceae) bears two types of EFNs, including a pair of large EFNs at the leaf base and many small EFNs along the leaf edge. This study aimed to determine the different roles of the two types of EFNs in biotic defense by ants. A field experiment was conducted to investigate the effect of leaf damage on EFN production and on the distribution pattern of ants. After leaf damage, the number of leaf edge EFNs increased in the leaves first-produced. The number of ants on the leaves also increased, and the foraging area of ants extended from the leaf base to the leaf tip. An EFN-covering field experiment revealed that leaf edge EFNs had a greater effect than leaf base EFNs on ant dispersal on leaves. The extended foraging area of ants resulted in an increase of encounter or attack rate against an experimentally placed herbivore, Spodoptera litura. These results suggest that M. japonicus plants control the foraging area of ants on their leaves using different types of EFNs in response to leaf damage, thus achieving a very effective biotic defense against herbivores by ants.

     

Emerging role of podocyte autophagy in the progression of diabetic nephropathy

Glomerular podocytes are pivotal in maintaining glomerular filtration barrier function. As severe podocyte injury results in proteinuria in patients with diabetic nephropathy, determining the pathogenesis of podocyte injury may contribute to the development of new treatments. We recently showed that autophagy is involved in the pathogenesis of diabetes-related podocyte injury. Insufficient podocyte autophagy and podocyte loss are observed in diabetic patients with massive proteinuria. Podocyte loss and massive proteinuria occur in high-fat diet-induced diabetic mice with podocyte-specific autophagy deficiency, with podocytes of these mice and of diabetic rats having huge damaged lysosomes. Sera from diabetic patients and from rodents with massive proteinuria cause autophagy insufficiency, resulting in lysosome dysfunction and apoptosis of cultured podocytes. These findings suggest the importance of autophagy in maintaining lysosome homeostasis in podocytes under diabetic conditions. Impaired autophagy may be involved in the pathogenesis of podocyte loss, leading to massive proteinuria in diabetic nephropathy.     

Improvement of DNA/Metal Particle Adsorption in Tungsten-Based Biolistic Bombardment; Alkaline pH is Necessary for DNA Adsorption and Suppression of DNA Degradation

Tungsten particles have long been used as microcarriers in biolistic bombardment because of their cost-effectiveness compared to alternative gold particles—even if the former have several drawbacks, including their DNA-degrading activity. We characterized tungsten-induced DNA degradation to assess the value of this metal particle and to improve tungsten-based biolistic bombardment. Alkaline pH, low temperature, and high salt concentration were found to diminish tungsten-induced DNA breakdown. The pH was the most influential factor in this phenomenon, both in aqueous solutions and on the particles. Furthermore, alkaline pH greater than 9.4 of an adsorption mixture was found to be essential for DNA binding to metal particles. Based on these findings, we propose a new formula of DNA/tungsten adsorption by using TE buffers that keep alkaline pH (>9.4) of the mixture, in which tungsten-bound plasmid DNA cleavage was suppressed to half the level of that in the conventional DNA-binding condition.     

Ontogenetic changes of habitat selection and thyroid hormone levels in black rockfish (Sebastes schlegelii) reared in captivity

This study examined the ontogenetic change in vertical distribution associated with algae and the thyroid hormone profiles of black rockfish (Sebastes schlegelii) under rearing conditions. Experimental observations on distribution were carried on black rockfish from the newly born larval stage to juveniles 75 days after birth (DAB). Position was categorized by vertical location [upper layer, mid layer and lower layer (LL)] and by association with artificial algae (floating algae, bottom algae and no association). Position of fish was observed four times a day, at 0400 (dawn), 1200 (noon), 1800 (dusk) and 2400 (midnight) hours. The majority of fish (>80%) reached transforming larval stage [17.8 ± 0.7 mm total length (TL)] at 25 DAB and juvenile stage (24.3 ± 0.6 mm TL) at 35 DAB. Newly born larvae were mainly distributed at surface and middle layers, the shift of vertical distribution to the LL occurred between 10 and 25 DAB, and over 98% of the individuals were distributed near the bottom after 35 DAB. Association behavior with algae was first observed from 20 to 30 DAB depending on the time of day. Percentage of fish associated with bottom algae increased from 25 to 40 DAB and reached 50–70% thereafter. Thyroid hormone (T₄) showed two surges at 30 and 50 DAB. The first surge corresponded to the transforming larval stage and the occurrence of association behavior with algae. The results indicate that pelagic larvae settle to the bottom layer before metamorphosis, and association behavior with algae appears at the transforming larval stage. A high T₄ concentration at 30 DAB indicates a close relationship with these morphological and behavioral developments.