Species of the monogenean genus Thaparocleidus are specific to freshwater siluriform fish. The infection caused by these gill parasites are a major health problem to fish. But, to focus the control strategies of these parasites, first it is important to establish an accurate discrimination by molecular methods. In the present study, phylogenetic and structural analysis of 28S region of ribosomal DNA of T. wallagonius species collected from fish Wallago attu from Meerut (U.P.), India, was carried out. In the first step, we amplified, sequenced 28S region of ribosomal DNA of T. wallagonius to establish the phylogenetic relationship with other species of this genus. T. wallagonius found on gill filaments of fish W. attu, is the most primitive parasite of this genus from India, was unequivocally discriminate from other species of the same genus in this study. A secondary-structure model of the large subunit rDNA was also predicted using a combined comparative and thermodynamic approach. Molecular morphometric and phylogenetic relationship of T. wallagonius are discussed in detailed that based on molecular analysis using bioinformatic tools.

Mus musculus (Rodentia: Muridae) were infected by a nematode belonging to the order Oxyurida. According to external morphological characters it was found to be Aspiculuris tetraptera Schulz, 1924. Present communication deals with molecular characterization of A. tetraptera infecting intestine of Mus musculus in Meerut (U.P.), India. A partial sequence of 18S ribosomal and cytochrome c oxidase subunit 1 (Cox 1) mitochondrial DNA analyses were performed. Sequence corresponding to 18S rRNA and mt Cox 1 gene was identical to sequences reported for A. tetraptera on GenBank. These results confirm the taxonomic validation of A. tetraptera parasitizing Mus musculus. This is the first report of molecular study of A. tetraptera in India.

Three species of genus Bychowskyella Akhmerov (1952), i.e. B. fossilisi Majumdar & Agarwal, 1989, B. tchangi Gusev, 1976 and B. wallagonia (Jain, 1959a) Gusev, 1961, were found to parasitize the gill filaments of siluriform fish in India. This redescription based on light microscopic examination of B. fossilisi, B. tchangi and B. wallagonia provides detailed taxonomic data for these species. We also amplified the 18S ribosomal RNA gene to evaluate the phylogenetic relationships of these three species. The morphological and genetic profiles confirmed the validation and taxonomical relationships of the above-mentioned species belonging to the genus Bychowskyella.

The phylogenetic studies on monogeneans of the genus Thaparocleidus parasitizing W. attu in India was inferred from 18S rDNA gene data. Out of species of Thaparocleidus, one new, T. armillatus sp. n., is described herein which distinguished from its congener species in the shapes and sizes of sclerotized structures and rest of the two species, T. indicus and T. wallagonius are redescribed morphologically as well as validated and confirmed by molecular means also. Besides the above, T. gangus was also included in the molecular analysis as it is recently described on the basis of morphology only. The phylogenetic tree was also reconstructed in order to elucidate the taxonomic status of Thaparocleidus armillatus sp. n., T. indicus, T. wallagonius and T. gangus. This research reports for the first time, the molecular phylogenetic analysis of 18S rDNA gene for four species belonging to the genus Thaparocleidus from W. attu collected off the River Ganga in India. In phylogram, all four species of Thapaocleidus come in a single clade that confirmed their monophyletic status. A very low interspecific variability was observed in T. armillatus sp. n. and T. wallagonius suggesting that these species are highly similar in morphology. Correspondingly, T. indicus and T. gangus also showed low interspecific variability which too signifies their morphological similarities in their sclerotized structures. Our result suggested that all four species taken in the present investigation from India are monophyletic and it is also observed that morphological similarities in the sclerotized structures are well correlated with phylogeny.

A Cellogel procedure for screening the electrophoretic variants of the human red cell glutathione peroxidase ( GPX1 ) was described. Three hundred and ninety eight Dutch persons living in various parts of The Netherlands, 385 individuals born in various states of India, and 72 Jamaicans of African origin living in Birmingham, UK, were screened for GPX1 variants. The Dutch were monomorphic, while one Afro-Jamaican female and two males and one female of the 116 Punjabis were found to be variants indistinguishable from each other in their pattern of electrophoresis. The clear five banded pattern of the variant indicated that the subunit structure of the human red cell glutathione peroxidase is most probably a tetramer and suggested that the variant is the expression of a heterozygote due to alleles at an autosomal locus. The corresponding phenotype was designated tentatively as GPX1 2-1 and the alleles as GPX1 *1 and GPX1 *2 respectively. The variant 2-1 was found to be identical to the "Thomas" variant described by Beutler and West (1974). Thus so far, in addition to the Afro-Americans and Ashkenazi Jews (Beutler et al. 1974), the Punjabis of the Indian subcontinent (this report) were found to exhibit the GPX1 polymorphism due to the GPX1 *2 allele. The data discussed in this paper (which included unpublished observations on several African and non-African populations) suggest that the GPX1 *2 allele is originally an African variant and hint that the present day Punjabis of Indian subcontinent, like Ashkenazi Jews, are "predominantly of Mediterranean origin with some proportion of African ancestry" ( Mourant et al. 1976).

SummaryThe phylogenetic relationships of the nematode species Thelandros scleratus (Oxyurida: Pharyngodonidae) and Physalopteroides dactyluris (Spirurida: Physalopteridae) were analyzed using the ribosomal 18S rRNA and the mitochondrial cytochrome C oxidase subunit genes. The nematodes were recovered from Brook's house gecko, Hemidactylus brooki (Reptilia: Gekkonidae) from Hastinapur, Meerut (U.P.), India. The results demonstrated that T. scleratus shows 100% similarity with another sequence available from the same species and a close relationship (98-99%) with species of Parapharyngodon in both 18S rRNA and cox 1 regions. Regarding the nematode Physalopteroides, analysis showed a close phylogenetic relationship between P. dactyluris and several species of Physaloptera. This is the fi rst sequence of 18S available for any species of the genus Physalopteroides.

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The freshwater shark Wallago attu (Bl. and Schn.) is a frequent silurid in the River Ganga and one of the most commercially exploit fish in India. In a survey on its infection with myxosporeans, spore type belongs to Thelohanellus species was found in the gills, kidney and intestine respectively. Through morphological and molecular investigations, we identified the spore as Thelohanellus wallagoi Sarkar, 1985. They were pyriform in valvular view and slim in sutural view, and had one pyriform polar capsule with four to five turns. The spores measured 8.0 × 4.0 × 2.3 μm. T. wallagoi developed in small cysts in the gill lamellae, whereas cyst and scattered spores of T. wallagoi were also found in the kidney and intestine respectively. The 18S rDNA sequence of T. wallagoi isolates recovered from gills, kidney and intestine were found similar to each other and differed from any other Thelohanellus species available in GenBank and validated its status after 32 years of original description. Phylogenetic analysis signified that T. wallagoi was placed sister to Myxobolus species in the clade that indicated the polyphyletic nature of the genus Thelohanellus.