Cryptosporidium is more closely related to the gregarines than to coccidiaas shown by phylogenetic analysis of apicomplexan parasites inferred usingsmall-subunit ribosomal RNA gene sequences
Ra. Carreno et al., Cryptosporidium is more closely related to the gregarines than to coccidiaas shown by phylogenetic analysis of apicomplexan parasites inferred usingsmall-subunit ribosomal RNA gene sequences, PARASIT RES, 85(11), 1999, pp. 899-904
The phylogenetic placement of gregarine parasites (Apicomplexa: Gregarinasi
na) within the Apicomplexa was derived by comparison of small-subunit ribos
omal RNA gene sequences. Gregarine sequences were obtained from Gregarina n
iphandrodes Clopton, Percival, and Janovy, 1991, and Monocystis agilis Stei
n, 1848 (Eugregarinorida Leger 1900), as well as from Ophriocystis elektros
cirrha McLaughlin and Myers, 1970 (Neogregarinorida Grasse 1953). The seque
nces were aligned with several other gregarine and apicomplexan sequences f
rom GenBank and the resulting data matrix analyzed by parsimony and maximum
-likelihood methods. The gregarines form a monophyletic clade that is a sis
ter group to Cryptosporidium spp. The gregarine/ Cryptosporidium clade is s
eparate from the other major apicomplexan clade containing the coccidia, ad
eleids, piroplasms, and haemosporinids. The trees indicate that the genus C
ryptosporidium has a closer phylogenetic affinity with the gregarines than
with the coccidia. These results do not support the present classification
of the Cryptosporidiidae in the suborder Eimerioirina Leger, 1911.