Redescription on Raillietina echinobothrida (Pasquale, 1890) (Cestoda: Davaineidae) and Study of Conserved Domain across Divergent Phylogenetic Lineages of Class Cestoda

Raillietina (Fuhrmannetaa) echinobothrida, (Magnin, 1881) cestode parasite of Gallus gallus domesticus is redescribed on the basis of type material from Aurangabad, Marathawada, Maharashtra, India. The present worms resemble with R. echinobothrida, (Magnin, 1881) in having all essential morphological characters. having scolex oval, rostellum elongated/rounded, presence of four suckers, short neck, mature proglottids are broader than long, testes rounded and excretory canal long tube. But the same differ due to number of testes. Hence it is redescribed. We carried out the phylogenetic analyses to observe molecular resemble of related proteins.


Introduction
Raillietina echinobothrida is a endoparasite, and this tapeworm belonging to the class Cestoda. is is avian gastrointestinal parasite of family Davaineidae (Cestoda: Cyclophyllidea), and is the most pathogenic and prevalent species infecting Gallus domesticus Linnaeus, 1758. R. echinobothrida requires two hosts, birds and ants, for completion of its life cycle. R. echinobothrida is a hermaphrodite worm having both the male and female reproductive organs in its body. e parasite is responsible for 'nodular tapeworm disease' in poultry [1,2].
is tapeworm is responsible for stunted growth of young chicken, also emaciation of adult and decreased egg production of hen. R. echinobothrida does not cause gross pathological damages, but in severe lesions on the intestinal walls and diarrhoea could arise. It ostensibly resulted in ill health [3]. Phylogenetic analyses have become essential to research on R. echinobothrida for the evolutionary tree of life. It shows taxonomical classi cation, identi cation, and naming of organisms, which is usually richly informed by phylogenetics. Multiple sequence alignments are the resource for the annotation of functional units in proteins called as conserved domain. is Conserved domains can be thought of as distinct functional, structural units of a protein from R. echinobothrida. In molecular evolution of R. echinobothrida such domains may have been utilized as building blocks, and may have been recombined in di erent arrangements to modulate protein function, which can be determined by sequence and structure analysis [4,5].

Study cestode
Sixty ve cestode were collected from the intestine of Gallus gallus domesticus from Aurangabad district Maharashtra state, India, during the period Dec-2006 to Dec-2009. irty cestode were preserved in hot 4% formalin and specimen were stained with Haris Haematoxyline and Borax carmine stain and passed through various alcoholic grades. Cleared in xylene, mounted in DPX and drawing are made with aid of camera lucida. All measurements are given in the millimetre [6,7].

Multiple sequence alignment of Cestoda class
Multiple sequence alignment [MSA] is conducted by COBALT that aligns protein sequences of similar Cestoda class using a combination of distance matrix and approximate parsimony methods. Numerical setting method is used to study the relative entropy threshold, in bits, that must be met for an alignment column to be displayed in red. A larger number indicates higher degree of conservation. e relative entropy is computed as: where i is residue type, f i is residue frequency observed in the multiple alignment column, and p i is the background residue frequency.
Identity setting used for only columns with one residue type will be colored in red [10,11].

Journal of Veterinary Science & Technology
aligned sequences that are useful to align highly evolved gene families clearing evolutionary relationships such as multiple actin proteins [12,13]. Trees were obtained by the methods Fast minimum evolution algorithm and Neighbor Joining algorithms. Evolutionary distance is studied by Grishin (protein) model [14,15] and distance between two sequences modelled as expected fraction of amino acid substitutions per site given the fraction of mismatched amino acids in the aligned region and can be computed for fraction of mismatched amino acids larger than 0.75 [5,3].

Results and Description
Observation of R. echinobothrida

Evolutionary distance
is study, 7 β-actin from Cestoda class is summarized to study the evolutionary distance. e identi cation of the origin of β-actin protein, multiple sequences analysis, observing the conserved amino acid residues and reconstruct the phylogenetic tree specify the evolutionary history, relationship of Cestoda with di erent species    (Table 1). Rectangle tree shows rectangular shaped rooted tree, where root is places in the longest edge. Fast minimum evolution algorithm produce un-rooted tree such as ones shown as radial or force in the tabs below. e rooted trees are created by placing a root in the middle of the longest edge (Figure 3). Slanted tree shows similar to rectangle, but with triangular tree shape. Neighbor Joining algorithms produce unrooted tree such as ones shown as radial or force in the tabs below. e rooted trees are created by placing a root in the middle of the longest edge ( Figure 4).

Multiple sequence alignment
Multiple sequence alignment analysis shows columns with no gaps are colour in blue or red. e red colour indicates highly conserved regions and blue indicates less conserved ones.
e Conservation analysis can be used to select a threshold for determining which columns is colour in red ( Figure 5). Multiple sequence alignment identify conserved motifs and to predict functional role in the variable sites as well as conserved sites show the sequence divergence pro le  of these actin proteins, which demonstrate the sequence enrichment strategy of these sequences for adaptation to di erent physiological systems. Here we observed that from all sequences of actin proteins that Cys, Lys, Asp, (Hydrophilic amino acid) Pro, Gly, (hydrophobic amino acid) which is conserved in all peptides having a common ancestor.
at all of these peptides share eight highly conserved cysteine, which were involved in the formation of β-strands are almost conserved. Cysteine (C) is conserved in all sequences at 8 sites.

Conserved domain analysis
Molecular study of Cestoda class species shows one conserved domain is nucleotide-binding domain of the sugar kinase/HSP70/actin superfamily. e nucleotide-binding region residues are conserved and the nucleotide sits in a deep cle formed between the two lobes of the nucleotide-binding domain (NBD). Substrate binding to superfamily members is associated with closure of this catalytic site cle . Functional activities of nucleotide-binding domain, including hexokinases, actin, and HSP70s, are modulated by allosteric e ectors, which may act on the cle closure ( Figure 6).

Conclusion
e presences of various species of the Cestoda were noted on the basis of actual sighting. Above survey with the primary objective of collecting and identifying the species, Sampling for estimation population of available species and understanding the community structure of amphibians in di erent habitat types. Phylogenetic analysis of Cestoda class signi es that nucleotide-binding domain of the sugar kinase protein is important components of Cestoda species, are originated from proteins enriched with di erent sequence speci c substitution strategy for biological needs. Comparative analyses specify that the nucleotide-binding domain of the sugar kinase protein  demonstrates how proteins are generated within the nature's testing ground for tailor-made biologic needs. Tracing the natural protein engineering scheme of sodium/calcium exchanger protein enrich our knowledge which in turn helps to molecular phylogeny.