Despite the worldwide distribution and pathogenicity of monogenean parasites belonging to the largest helminth genus, Dactylogyrus, there are no complete Dactylogyrinae (subfamily) mitogenomes published to date. In order to fill this knowledge gap, we have sequenced and characterized the complete mitogenome of Dactylogyrus lamellatus, a common parasite on the gills of grass carp (Ctenopharyngodon idella). The circular mitogenome is 15,187 bp in size, containing the standard 22 tRNA genes, 2 rRNA genes, 12 protein-encoding genes and a long non-coding region (NCR). There are two highly repetitive regions in the NCR. We have used concatenated nucleotide sequences of all 36 genes to perform the phylogenetic analysis using Bayesian inference and maximum likelihood approaches. As expected, the two dactylogyrids, D. lamellatus (Dactylogyrinae) and Tetrancistrum nebulosi (Ancyrocephalinae), were closely related to each other. These two formed a sister group with Capsalidae, and this cluster finally formed a further sister group with Gyrodactylidae. Phylogenetic affinity between Dactylogyrinae and Ancyrocephalinae was further confirmed by the similarity in their gene arrangement. The sequencing of the first Dactylogyrinae, along with a more suitable selection of outgroups, has enabled us to infer a much better phylogenetic resolution than recent mitogenomic studies. However, as many lineages of the class Monogenea remain underrepresented or not represented at all, a much larger number of mitogenome sequences will have to be available in order to infer the evolutionary relationships among the monogeneans fully, and with certainty.
Parasitic disease is among the major causes of health problems in marine mammals. However, little information on parasitic species composition and infection levels in finless porpoises (Neophocaena spp.) is available. In this study, we report the first systematic survey on parasitic infections in the East Asian finless porpoise N. asiaeorientalis sunameri (EAFP) living off the Chinese Yellow/Bohai Sea coast. Using both morphological and molecular methods, 5 parasitic helminths were identified: Campula oblonga in the liver and pancreas; Synthesium seymouri in the pyloric stomach and duodenum ampulla; Anisakis pegreffii in the forestomach, main stomach, and esophagus; Halocercus sp. in the lungs; and Crassicauda magna in the mammary glands and muscle. Among these helminths, C. oblonga (80.7%), S. seymouri (80.7%), A. pegreffii (80.7%), and Halocercus sp. (77.4%) were the most prevalent, whereas C. magna (6.5%) were only observed in 2 EAFP individuals. All juvenile and adult EAFPs were parasitized by at least 3 parasites species (C. oblonga, S. seymouri, and A. pegreffii), whereas in neonates, only Halocercus sp. were detected. We observed no significant difference in parasite prevalence between males and females. In addition, A. pegreffii and C. magna represented new infection records in Neophocaena. A pathological examination associated with parasitic lesions in EAFPs showed damage or destruction of cells or tissues to some extent. This study represents the first systematic survey on parasitic infections in EAFPs, providing important and valuable parasitological information for the research and conservation of this coastal marine mammal.
Calonectria leaf blight (CLB) is one of the most important diseases of Eucalyptus trees grown in plantations. This disease poses a serious threat to the sustainability of Eucalyptus plantations in southern China. To better understand the causal agents of CLB, we collected samples of diseased leaves and soil from Eucalyptus plantations from nine regions in Guangdong Province where the disease has become a serious problem. A total of 606 Calonectria isolates were purified from the samples, with 399 and 207 originating from diseased leaves and soils, respectively. Phylogenetic analyses utilizing six gene regions resolved 303 isolates in the C. kyotensis species complex and an equal number of isolates in the C. reteaudii species complex. These two complexes were represented by ten known Calonectria species, including C. aconidialis (12.0%), C. curvispora (0.3%), C. hongkongensis (24.8%), C. ilicicola (0.9%), and C. kyotensis (12.0%) in the C. kyotensis species complex, and C. crousiana (1.0%), C. Guangdongensis (0.3%), C. pseudoreteaudii (40.7%), C. queenslandica (7.3%), and C. reteaudii (0.7%) in the C. reteaudii species complex. Pathogenicity tests showed that all species were capable of causing disease on two tested Eucalyptus genotypes, albeit at varying degrees of aggressiveness. Most isolates (98.3%) in the C. reteaudii species complex were from the diseased leaves, indicating that species in this complex are the main causal agents of CLB outbreak. In addition, a significant number of the C. kyotensis species complex isolates (66.7%) from the soil samples could also cause the disease on Eucalyptus leaves.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.