No abstract

Myxobolus turpisrotundus Zhang, 2009, infects allogynogenetic gibel carp Carassius auratus gibelio (Bloch) and is always regarded as synonymous with Myxobolus rotundus Nemeczek, 1911, since its first report in goldfish Carassius auratus auratus (L.) in China in 1955. In this study, it was comprehensively examined by morphological and molecular biological methods. The round spores of M. turpisrotundus are similar to those of M. rotundus from common bream Abramis brama (L.) in morphology; however, we detected slight differences in morphometry. The ratios of the length and width of the spore to the length and width of the polar capsule of M. turpisrotundus are usually below 2.0 and 1.9, respectively, however these ratios are always above 2.0 and 1.9 in M. rotundus. The plasmodium size of M. turpisrotundus is 600-6,200 microm in diameter and that of M. rotundus is 60-180 microm in diameter. Scanning observation showed the spore surface of M. turpisrotundus was generally pitted. Yet the surface of M. rotundus is smooth. Sequence comparison revealed the small subunit ribosomal RNA gene sequence of M. turpisrotundus did not match any published sequences of M. rotundus (EU710583, 85% over 742 bp; FJ851447, 85% over 742 bp, FJ851448, 85% over 742 bp; FJ851449, 85% over 742 bp). Moreover, phylogenetic analysis showed M. turpisrotundus clustered with the species from allogynogenetic gibel carp with high bootstrap values (100% neighbor-joining, NJ; 100% maximum parsimony, MP) and M. rotundus from common bream composed a new cluster with high bootstrap values (100% NJ, 100% MP). From the morphological and molecular biological data, we gain enough evidences to support the validity of M. turpisrotundus.

During a survey of myxozoan parasites of common carp Cyprinus carpio in Honghu Lake, Hubei Province, China, a parasite was collected that was identified as Myxobolus dispar based on an earlier description from China. However, the small subunit ribosomal DNA of this species shared only 90 % similarity with M. dispar, instead matching M. musseliusae with 100 % identity. To resolve this apparent taxonomic conflict, the validity of M. dispar reported from China was investigated. The species encountered here and in the earlier report from China both bear spores that are notably smaller than those of M. dispar in Europe. In the present study, a mucous envelope was adhered to the posterior of many fresh spores and was observed to expand and surround the spore. This structure has never been reported from fresh spores of M. dispar. Histology showed extravascular plasmodia in the gill filaments in close contact with the cartilaginous ray of the filament, which contrasts with the plasmodia of M. dispar which develop in the arteries of the gill filaments. Phylogenetically, the current species is distinct from M. dispar, instead forming a sister group with M. musseliusae. The data presented here allow us to conclude that the species isolated is M. musseliusae and that prior reports of M. dispar in China are unsubstantiated.

No abstract

Low-density lipoprotein (LDL) from hen egg yolk has high nutritional value and plays an important role in the fields of biology, medicine, and materials. To develop fundamental research about LDL, a highly efficient extraction method is necessary. We found that 30% saturated ammonium sulfate can extract more crude LDL than 40% saturation. We selected polyethylene glycol (PEG; nonionic type) to obtain crude LDL. Three factors were employed, namely, degree of polymerization, concentration of PEG, and pH of egg yolk plasma. The optimized condition was 5% PEG 4,000 and plasma pH 6.0, and the best extraction efficiency was 68.1 ± 0.5 g lipid /100 g DM and 69.9 ± 2.0% protein. The crude LDL oil of PEG precipitation was very significantly higher (P < 0.01) than ammonium sulfate precipitation (ASP), while there was no significant difference in protein, which indicates that PEG can extract more crude LDL. When ascorbic acid was added, hydrosulfuryl (SH) groups and lipids oxidation degree of crude LDL extracted by PEG (PEG-LDL) was very significantly lower than ASP (P < 0.01). We also obtained both purified LDL and yolk immunoglobulin (IgY) with an appropriate purification column. This paper proposes a highly efficient method to extract LDL with high activity using PEG and ensures co-purification of LDL and IgY.