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United States Department of Agriculture

Agricultural Research Service

Research Project: Genetics, Physiology, and Health Research to Improve Catfish Production

Location: Warmwater Aquaculture Research Unit

Title: Intraspecific rDNA variability of Kudoa sp. isolates from blackfin tuna (Thunnus atlanticus) suggests K. crumena and K. thunni are synonymous

Authors
item Griffin, Matt -
item Quiniou, Sylvie
item Bogdanovic, Lewis -
item Ware, Cynthia -
item Esteban, Soto -

Submitted to: Southeast Society of Parasitologists
Publication Type: Abstract Only
Publication Acceptance Date: April 6, 2013
Publication Date: April 10, 2013
Citation: Griffin, M., Quiniou, S., Bogdanovic, L., Ware, C., Esteban, S. 2013. Intraspecific rDNA variability of Kudoa sp. isolates from blackfin tuna (Thunnus atlanticus) suggests K. crumena and K. thunni are synonymous. Southeast Society of Parasitologists. P.23.

Technical Abstract: Numerous myxozoan cysts (~1 mm) were found in the musculature of blackfin tuna (Thunnus atlanticus) harvested off the Caribbean island of St. Kitts. Myxospores were consistent with quadrate members of the Kudoidae, measuring 8.8 (8.2-9.4) µm wide, 7.3 (6.6-8.3) µm thick and 6.2 (5.8-6.9) µm long with 4 uniform drop-like polar capsules measuring 2.7 (2.2-3.2) µm long and 2.0 (1.7-2.2) µm wide. The 18S small-subunit (SSU) and 28S large-subunit (LSU) ribosomal DNA sequences did not result in 100% matches to any published sequences. The SSU sequences (1,786 bp) obtained from 6 individual cysts were identical, demonstrating high homology to K. crumena (99.6%) from yellowfin tuna (Thunnus albacares) and K. thunni (99.0%) from albacore (Thunnus alalunga). Alternatively, 33 unique sequences were obtained for the LSU (~800 bp), demonstrating 0.1 to 5.0% variability between them, although most (60%) demonstrated high homology (>99%) to K. crumena and K. thunni. Comparatively, SSU and LSU sequences of K. crumena and K. thunni differ by 1.6% and 0.6%, respectively. Morphologically, the case isolate was smaller than published descriptions of K. thunni or K. crumena, however, rDNA sequence homology suggests this case isolate and K. thunni are morphologic and genetic variants of K. crumena from different hosts.

Last Modified: 10/20/2014
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