Abstract
Male and female copulatory organs figure prominently in nematode taxonomy, but the associated musculature remains insufficiently explored. The aim of this study was therefore to further our knowledge of the musculature of the vulva and male copulatory organs in nematodes by using phalloidin staining and confocal microscopy to examine two nematode species, Bursaphelenchus mucronatus and Chiloplacus sp. The musculature of the round vulva in Chiloplacus sp. comprises three pairs of radial vulval dilators and another pair of dilators of the anterior inner vulval plate. This arrangement is similar to that of the Rhabditida, but in Chiloplacus the anterior pair appears to have been transformed into the vulval plate muscles. The musculature of the slit-like vulva in B. mucronatus includes dilators of the vulval lips and external vulval flap, constrictors of the vulval slit and posterior transverse muscle bands. The opposing pairs of vulval dilators show quadrilateral symmetry as observed in the Rhabditida, but the constrictors running along the rim of the vulva have no counterparts in other species. The musculature of the male copulatory organ in Chiloplacus sp. comprises two pairs of spicule protractors and retractors and three pairs of gubernacular muscles. In B. mucronatus, as in the other Aphelenchoididae, the gubernaculum is absent and there is one pair of spicule protractors and two pairs of muscles inserted on the saddle (angular bend) of the spicules. The arrangement of the spicule saddle muscles resembles those of the gubernaculum, which may indicate that in this family the gubernaculum has become fused to the spicules. The literature review of muscles of nematode copulatory organs are given in a table for 15 muscle groups; it can be used for phylogenetic reconstruction and classification of the order Rhabditida.
Highlights
Male and female copulatory organs figure prominently in nematode taxonomy, but the associated musculature remains insufficiently explored
Two nematode species were studied: Bursaphelenchus mucronatus Mamiya and Enda, 1979 (European type) and Chiloplacus sp., both belonging to the class Secernentea: order Rhabditida according to the classification of De Ley and Blaxter (2002)
Phalloidin staining for actin, in conjunction with con focal microscopy, is a powerful technique that provides detailed information on morphology and spatial arrangement of muscles
Summary
Male and female copulatory organs figure prominently in nematode taxonomy, but the associated musculature remains insufficiently explored. The aim of this study was to further our knowledge of the musculature of the vulva and male copulatory organs in nematodes by using phalloidin staining and confocal microscopy to examine two nematode species, Bursaphelenchus mucronatus and Chiloplacus sp. The leading role is played by bacterial feeders and entomophilic fungal and plant feeders The latter group includes species of the genus Bursaphelenchus that comprises 130 valid species (based on the authors’ database; Ryss et al, 2005; Ryss and Subbotin, 2017). The most important diagnostic characters of the nematode species are the structures of the anterior and posterior body regions, lateral fields, and copulatory organs These structures have been studied primarily by differential interference contrast (DIC) and SEM, but recently these methods have been increasingly supplemented by confocal microscopy, with its ability to generate accurate three-dimensional (3D) reconstructions from optical sections. Beyond these exam ples, very little confocal research has been published
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
