Molecular characterization and morphological description of cryptic haemoproteids in the laughingthrushes (Leiothrichidae) in the western and eastern Himalaya, India.

Farah Ishtiaq,Vaidas Palinauskas,Megha Rao

doi:10.12688/wellcomeopenres.14675.1

Farah Ishtiaq, Vaidas Palinauskas + Show 1 more

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https://doi.org/10.12688/wellcomeopenres.14675.1

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Abstract

Background: Laughingthrushes (family: Leiothrichidae) consists of diverse and widespread species found in the Indian subcontinent but there is a lack of information on their avian haemosporidians. Methods: We sampled 231 laughingthrushes of 8 species in the western and eastern Himalaya in India. Using parasite morphology and cytochrome b sequences we describe 2 new Haemoproteus species harbored in 3 species of laughingthrushes and report a case of cryptic speciation. Results: First Haemoproteus lineage TROERY01 (GenBank: KY623720) found in Trochalopteron erythrocephalum (27.47%) and Trochalopteron variegatum (2.9%) in mid to high altitude tropical forests in the western and eastern Himalaya, was described as Haemoproteus (Parahaemoproteus) leiothrichus n. sp. (Haemosporida: Haemoproteidae). Second Haemoproteus lineage TROERY02 (GenBank: KY623721) described as Haemoproteus (Parahaemoproteus) homoleiothrichus n. sp. (Haemosporida: Haemoproteidae) was found in T. erythrocephalum (2.19%) and Trochalopteron lineatum (3.84%), albeit in low intensity, only in the western Himalaya. Both H. homoleiothrichus n. sp. and H. leiothrichus n. sp. showed no significant difference in morphological features in blood stages. A genetic divergence of 4.4% along with distinct phylogenetic position indicates that these 2 lineages represent cryptic species. Previously, T. erythrocephalum has been described as an additional host for a morphologically described Haemoproteus timalus in the oriental region. Our described species have several morphological features that are absent in H. timalus. These are, the presence of dumbbell-like shaped mature gametocytes, 'arm' like extensions of gametocytes and lateral displacement of nuclei of infected erythrocytes. Illustrations of blood stages of the new species are given, and phylogenetic analysis with morphologically described Haemoproteus species identifies parasites closely related to the 2 described parasites. Conclusions: The lineages described here have been recorded only in the laughingthrushes so far. These are the first parasites to be described with T. erythrocephalum as a type host from the western and eastern Himalaya in India.

Highlights

Avian haemosporidians are cosmopolitan, vector-borne, and intracellular parasites, first discovered back in 1880 by V
These are the first described species of parasites from the western and eastern Himalayan regions which happen to be morphologically cryptic. Both parasite species appear to be restricted to laughingthrushes
The chestnut-crowned laughingthrush T. erythrocephalum is a south Asian passerine, found in India, Bhutan, China and Nepal, and is one of the most common laughingthrushes seen in the Himalaya (Rasmussen & Anderton, 2005)

Summary

Introduction

Vector-borne, and intracellular parasites, first discovered back in 1880 by V. These parasites are placed in 3 genera: Plasmodium, Haemoproteus or Leucocytozoon (Atkinson & van Riper, 1991). The genus Haemoproteus consists of over 130 species based on morphological descriptions of erythrocytic stages (Valkiūnas et al, 2008). Since the advent of molecular techniques (e.g., Feldman et al, 1995), avian haemosporidians have been used as a popular model system to understand epidemiology and host-parasite co-evolution. Recent studies on avian haemosporidians have recorded the presence of cryptic parasite species (Nilsson et al, 2016; Palinauskas et al, 2015; Sehgal et al, 2006). Nilsson et al (2016), has recently drawn conclusion using molecular techniques that five lineages nested within Haemoproteus majoris, represent five different biological species and are morphologically cryptic

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