Parent‐of‐origin effects on carcass traits in Japanese Black cattle

Variances caused by the differential expression of paternally and maternally imprinted genes controlling carcass traits in Japanese Black cattle were estimated in this study. Data on marbling score (BMS), carcass weight, rib thickness, rib‐eye area (REA) and subcutaneous fat thickness (SFT) were collected from a total of 13,115 feedlot steers and heifers in a commercial population. A sire–maternal grandsire model was used to analyse the data, and then, imprinting parameters were derived by replacing the genetic effect of the dam with the effect of the maternal grandsire in the imprinting model to calculate the genetic parameter estimates. The proportions of the total genetic variance attributable to imprinted genes ranged from 8.7% (SFT) to 35.2% (BMS). The remarkably large imprinting variance of BMS was mainly contributed by maternally expressed inheritance because the maternal contribution of the trait was much larger than that of the paternal trait. The parent‐of‐origin effect originating from maternal gene expression was also observed for REA. The results suggested the existence of genomic imprinting effects on the traits of the Japanese Black cattle. Hence, the parent‐of‐origin effect should be considered for the genetic evaluation of Japanese Black cattle in breeding programmes.     

Comparison and phylogenetic analysis of the heat shock protein 70 gene of Babesia parasites from dogs

The heat shock protein 70 (hsp70) genes of Babesia gibsoni, B. canis canis, B. canis vogeli, and B. canis rossi isolated from infected dogs were cloned by polymerase chain reaction (PCR) and sequenced. In the nucleotide sequence and the predicted amino acid sequence of the gene, the parasites were very similar to each other. The nucleotide sequences of the hsp70 gene had more variety than those of 18S nuclear subunit ribosomal DNA (18S rDNA). A phylogenetic analysis of these sequences and comparisons with sequences from other Babesia and Theileria species revealed that all canine babesial isolates analyzed in the present study were closely related to each other and formed one cluster. Additionally, a phylogenetic analysis of Babesia and Theileria species showed that these parasites could be divided into three groups: group A including canine babesial isolates, B. divergens, B. odocoilei, B. bovis, B. caballi, and B. ovis; group B including Theileria annulata, T. orientalis, and T. cervi; and group C including B. microti and B. rodhaini. These results suggested that a phylogenetic analysis of the hsp70 gene sequence might be helpful in classifying Babesia and Theileria species, and that canine babesial isolates might be closely related to each other, indicating their evolution from the same ancestry.     

Characteristics of a self-assembled fibrillar gel prepared from red stingray collagen

A translucent collagen gel was formed from a transparent acidic solution of red stingray collagen by adjusting to physiological ionic strength and pH in phosphate buffer and then incubating at 25–37°C. During fibril formation from red stingray collagen, the turbidity increased when the NaCl concentration was increased at constant pH and the rate of fibril formation was accelerated by higher pH or lower NaCl concentration. The T _m of red stingray collagen fibrillar gel was estimated as 44.3 ± 3.5°C, which was higher than that of the collagen solution, 33.2°C. In addition, red stingray collagen gel maintained its shape without melting and was suitable for culture of mouse stromal cells at 37°C.     

Comanagement for aquaculture: Suggestions from a comparative study between two major production areas of milkfish in the Philippines

ABSTRACT

This study examined if, and how, comanagement is effective in controlling aquaculture industry in the municipalities of Anda and Bolinao in the province of Pangasinan, in the Philippines, the locations of two major production areas of milkfish (Chanos chanos) in the country. Institutional and community analyses conducted in these study sites revealed a unique hierarchy of resource users, as well as unique social and economic problems in aquaculture, distinct from those of capture fishery. It was also indicated that comanagement is seen as a solution for essential practices to be enforced practically and sustainably for the management of this industry. To improve aquaculture governance, it is desired that the comanagement scheme shall include not only the governments and fishers but also business operators who often have large capital and a high degree of power.     

Ontogeny of schooling behavior in the oval squid <Emphasis Type="Italic">Sepioteuthis lessoniana</Emphasis>

In contrast to schooling behavior in fish, which is well documented, the schooling behavior of an evolutionary counterpart, squid, has not been adequately described in the literature. In the current study, we investigated the ontogeny of schooling behavior in the oval squid Sepioteuthis lessoniana reared from hatching to about two months of age. During the two months of development, the distance and angle between nearest-neighbor individuals decreased from 5.3 mantle lengths (ML) to 1.8 ML and from 42.7° to 24.2°, respectively. In addition, the swimming distance of individuals in experimental duration decreased from 530.4 to 79.9 ML, and the relative swimming speed also decreased from 17.1 to 4.6 ML/s during the same period, with increasing synchronized hovering of individuals. These observations clearly suggest that oval squid swim randomly until 20 days after hatching, then form a school 30–60 days after hatching with an inter-individual distance of 2.0 ML. At two months after hatching, oval squid individuals swam in a parallel orientation and formed a belt-shaped arrangement, similar to the adult schooling behavior observed in natural populations.     

Reflection and transmission of visible light by sugi wood: effects of cellular structure and densification

Transmittance and reflectance of visible light by sugi wood (Cryptomeria japonica) were investigated in the longitudinal (L) and tangential (T) directions. Transmittance was the highest in the L direction and reflectance was the highest in the T direction, suggesting that structural anisotropy influences transmittance and reflectance. Intra-ring variations observed with a microspectrometer indicated that T transmittance was higher for latewood than for earlywood, but there was no such trend in for L transmittance in which the highest levels occurred near the annual ring boundaries, on either the earlywood or latewood side, and the lowest at the transition from earlywood to latewood. Dependence of L transmittance on wavelength also showed variations according to the intra-ring position. The increasing of transmittance of earlywood at wavelengths?<?500 nm with increasing wavelength was observed, but this was not confirmed for latewood because of absorption by lignin. These observations supported a previously published finding, which was based on measurements in the radial direction, that the number of internal cell wall reflections, rather than density, determines wood lightness. Indeed, in the L direction, most of the incident light passes through lumens in earlywood and through cell walls in latewood, while it is subjected to numerous internal reflections at the interface between lumens and cell walls. This was further confirmed by the transmittance of earlywood being greatly decreased by radial compression.     

Is it necessary to change the number of samples for different forest types when evaluating plant species richness? A case study in a forested landscape in central Japan

We demonstrate a method for evaluating the appropriate number of samples required to estimate plant species richness in different forest types within a forested landscape. In each of 36 plots (0.1 ha each) from 5 forest types (deciduous broad-leaved secondary forest and 4 categories of coniferous plantation classified according to stand age) in central Japan, 40 quadrats of 1 × 1 m were set in a regular pattern; the total number of quadrats in each forest type ranged from 200 to 400. In each plot, the number of observed species in 40 quadrats ranged from 60 to 80% of the number of species estimated by the rarefaction method for each forest type. Sampling 30 quadrats detected approximately 90% of the observed species in each plot that were detected using 40 quadrats. In specific functional groups (i.e., tall trees and weed species), the ratios of both tall trees and weed species to all species were at equilibrium for 30 or more quadrats. For fewer than 30 quadrats these ratios were highly variable. No significant differences were found among forest types in the ratio of the observed number of species in each plot to the estimated number of species calculated using the rarefaction method, and in sampling efficiency estimated by use of non-parametric estimators. We concluded that the number of samples does not need to be changed according to forest type or plantation stand age in the studied landscape, and that the method used to evaluate the number of samples could be useful.