Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus)

Abstract

Two house mouse subspecies occur in Europe, eastern and northern Mus musculus musculus (Mmm) and western and southern Mus musculus domesticus (Mmd). A secondary hybrid zone occurs where their ranges meet, running from Scandinavia to the Black Sea. In this paper, we tested a hypothesis that the apicomplexan protozoan species Cryptosporidium tyzzeri has coevolved with the house mouse. More specifically, we assessed to what extent the evolution of this parasite mirrors divergence of the two subspecies. In order to test this hypothesis, we analyzed sequence variation at five genes (ssrRNA, Cryptosporidium oocyst wall protein (COWP), thrombospondin-related adhesive protein of Cryptosporidium 1 (TRAP-C1), actin and gp60) in C. tyzzeri isolates from Mmd and Mmm sampled along a transect across the hybrid zone from the Czech Republic to Germany. Mmd samples were supplemented with mice from New Zealand. We found two distinct isolates of C. tyzzeri, each occurring exclusively in one of the mouse subspecies (C. tyzzeri-Mmm and C. tyzzeri-Mmd). In addition to genetic differentiation, oocysts of the C. tyzzeri-Mmd subtype (mean: 4.24 × 3.69 μm) were significantly smaller than oocysts of C. tyzzeri-Mmm (mean: 4.49 × 3.90 μm). Mmm and Mmd were susceptible to experimental infection with both C. tyzzeri subtypes; however, the subtypes were not infective for the rodent species Meriones unguiculatus, Mastomys coucha, Apodemus flavicollis or Cavia porcellus. Overall, our results support the hypothesis that C. tyzzeri is coevolving with Mmm and Mmd.

Subtyping Novel Zoonotic Pathogen Cryptosporidium Chipmunk Genotype I

“…The structure of the gp60 gene was nevertheless similar to the one in C. parvum and C. hominis. The first 19 hydrophobic and hydroxylic amino acids constituted an N-terminal signal peptide with a signal peptide cleavage site between amino acids Ser 19 and Ala 20 , and the last 19 amino acids coded for a transmembrane domain. As in C. parvum, C. hominis, and C. ubiquitum, the hydrophobic C-terminal sequence of the gp60 protein in chipmunk genotype I was likely linked to a glycosylphosphatidylinositol (GPI) anchor (9,13,14).…”

Caracterización molecular de los subtipos de la GP60 de Cryptosporidium parvum y Cryptosporidium hominis alrededor del mundo

“…Both represent the genotype of Cryptosporidium spp. For example, Ia and Ib are subtypes of C. hominis, while IIa and IIb are subtypes that correspond to C. parvum (13). Various groups of subtypes have been identified in these two species: 7 groups of subtypes in C. hominis (Ia-Ig), 6 groups of subtypes in C. meleagridis and 11 subtypes of families in C. parvum (IIa-III) (4); the subtypes of the families IIa and IId have been recognized as zoonotics (14).…”

“…These genotypes are represented as "R2" (R1 represents many subtypes) (11). For example, the subtype IIaA15G2R1 is a subtype of C. parvum (IIa) with 15 repeats of TCA (A) 2 TCG repeats (G) and one ACATCA (13). In humans, as well as, in farms animals, specially in cattle the subtype of the most prevalent family corresponds to the family IIa, specifically IIaA15G2R1 (11).…”

“…El subtipo es identificado por un número romano y una letra minúscula, ambos representan el genotipo de Cryptosporidium spp. Por ejemplo Ia y Ib son subtipos de C. hominis; en tanto que, IIa y IIb son subtipos que corresponden a C. parvum (13). Varios grupos de subtipos han sido identificados en estas dos especies: 7 grupos de subtipos en C. hominis (Ia-Ig), 6 grupos de subtipos en C. meleagridis y 11 subtipos de familias en C parvum (IIa -III) (4); los subtipos de las familias IIa y IId han sido reconocidos como zoonóticos (14).…”

“…En el subtipo de la familia de C. parvum IIa, son pocos los genotipos que poseen dos copias de las secuencias ACATCA justo antes de que el trinucleótido se repita, el cual está representado por "R2" (R1 para muchos subtipos) (11). Por ejemplo, el subtipo IIaA15G2R1 es un subtipo de C. parvum (IIa) con 15 repeticiones TCA (A) 2 TCG repetidas (G) y un ACATCA (13). En humanos; así como, en animales de granja, especialmente en ganado multilocus typing) that increase the precision of the genotyping.…”