Early Cretaceous trypanosomatids associated with fossil sand fly larvae in Burmese amber

Abstract

Early Cretaceous flagellates with characters typical of trypanosomatids were found in the gut of sand fly larvae, as well as in surrounding debris, in Burmese amber. This discovery supports a hypothesis in which freeliving trypanosomatids could have been acquired by sand fly larvae in their feeding environment and then carried transtadially into the adult stage. At some point in time, specific genera were introduced into vertebrates, thus establishing a dixenous life cycle.Key words: Cretaceous -sand fly larvae -trypanosomatids While trypanosomatids probably existed in the Paleozoic and free-living forms were probably more diverse in the past than today, Paleoleismania proterus Poinar & Poinar (2004a, b) in the Burmese amber sand fly, Palaeomyia burmitis Poinar (2004), shows that sand flies were already transmitting trypanosomatids to vertebrates some 100 million years ago (mya). Attempts have been made to find fossils which show how sand flies may have originally acquired ancient trypanosomatids. Such evidence, which was obtained in a piece of Burmese amber containing two late-instar sand fly larvae, is presented here. MATERIALS AND METHODSThe amber piece containing the fossil sand fly larvae is semicircular in outline, measuring 13 mm along the longest side, 9 mm wide, 4 mm deep, and weighs 0.4 g. Observations, drawings, and photographs were made with a Nikon SMZ-10 R stereoscopic microscope and Nikon Optiphot compound microscope with magnifications up to 1000x. Measurements were obtained by means of a microscopic ocular grid calibrated in microns. The amber piece containing the fossils is deposited in the Poinar amber collection (accession # B-D-24) maintained at Oregon State University.Amber from Burma occurs in lignitic seams in sandstone-limestone deposits in the Hukawng Valley, southwest of Maingkhwan in the state of Kachin (26º20'N, 96º36'E). Palynomorphs obtained from the amber beds have been assigned to the Upper Albian (~ 100-105 mya) of the Early Cretaceous (Cruickshank & Ko 2003). Nuclear magnetic resonance and the structure of wood fibers found embedded in the amber showed that the tree source of Burmese amber is a member of the Araucariaceae, probably Agathis (Poinar et al. 2007). RESULTSThe amber piece contains two sand fly larvae and several fruiting bodies of a coral mushroom (Poinar & Brown 2003, Poinar et al. 2006 (Fig. 1). Both sand fly larvae had voided some of their intestinal contents at the time of preservation, which is typical behavior of mature sand fly larvae just before pupation (Lawyer & Perkins 2000). Both of the larvae also had debris from the feeding substrate, probably the fruiting bodies of the coral mushroom, attached to portions of their bodies. Associated with the expelled fecal matter as well as in the debris attached to the cuticles of both sand flies, were numerous flagellates orientated in a myriad of directions and planes. Similar flagellates surrounded the bases of the fungal fruiting bodies. In order to ascertain whether flagellates were also inside the gut of the...

Phylogenomic Reconstruction Supports Supercontinent Origins forLeishmania

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Leishmania: origin, evolution and future since the Precambrian

“…This fossil dates from the Early Cretaceous (100 Mya) and brought new insights regarding transmission. This discovery revealed an Early Cretaceous sand fly larvae which developed in habitats containing free‐living flagellates with the characteristics of trypanosomatids and suggested that these flagellates were ingested by and probably multiplied inside sand fly larvae (Poinar & Poinar, 2004a, b; Poinar, 2007). Once in an adult sand fly, the flagellates could be transmitted to a vertebrate, thus establishing a continuing cycle between vectors and vertebrates.…”

Sand Fly-Leishmania Interactions: Long Relationships are Not Necessarily Easy

“…Although Leishmania do not invade the midgut cells, close contact between the parasites and these cells i.e., adhesion to epithelial cells through the parasite surface, is well documented [14]. Thus, despite their long evolutionary history (fossil records indicate the presence of flagellates, possibly trypanosomatids, within sand flies in the Early Cretaceous [15]) the relationship between Leishmania and sand flies can be considered an active and intense evolutionary arms-race. In this review we highlight some of the most important events during the development of Leishmania in a suitable sand fly vector, and discuss issues associated with Leishmania -sand fly specificity, metacyclogenesis, and sand fly midgut responses to Leishmania .…”