DNA content in eurasian sturgeon species determined by flow cytometry

Abstract

The nuclear DNA content in 10 species of chondrostean fishes was measured by flow cytometry. The sterlet Acipenser ruthenus blood cells were used as an internal standard. The sterlet DNA content was calculated on the basis of comparison with the Xenopus laeuis blood cells, 2C = 6.30 pg. In the tetraploid A. ruthenus and A. stellatus the DNA content comprises 3.74 pghucleus and is practically invariant; in Huso dauricus it is almost the same, 3.74-3.81 pg; and in A. nudiuentris it is a little higher, 3.88-4.04 pg.In the oldest chondrostean, Pseudoscaphirhynchus kaufmanni, the nuclear DNA content is slightly lower, 2C = 3.46-3.48 pg, and in the American paddlefish Polyodon spathula it is lower still, 3.17 pg. In two octoploid sturgeons, A. baeri and A. gueldenstaedti, the DNA content is twice as high as that of the sterlet, 8.29-8.31 and 7.86-7.88 pg, respectively; a very similar amount, 8.24-8.42 pg, was determined in the hybrid Huso huso x A. ruthenus. In the Sakhalin sturgeon, A. medirostris ( = A . mikadoi), the DNA content is two times higher than in the octoploids, 13.93-14.73 pg; therefore its ploidy may be 16n and the number of chromosomes could be 500. o 1993 Wiley-Liss, Inc.

Metamorphosis inXenopus laevisis not associated with large-scale nuclear DNA content variation

“…To ensure that this staining protocol did not result in artifacts, comparisons with chicken red blood cells as an internal standard [defined as having 2.5·pg·2C -1 (Tiersch and Wachtel, 1991)] were run. The genome size observed for the X. laevis was 6.3·pg·2C -1 , within the reported range of X. laevis (Birstein et al, 1993).…”

First evidence of hybridization between endangered sterlets (Acipenser ruthenus) and exotic Siberian sturgeons (Acipenser baerii) in the Danube River

“…Additionally, both species differ in their number of chromosomes and their ploidy level (Birstein et al 1993;Ludwig et al 2001). Siberian sturgeons have 248 chromosomes, whereas sterlets have 118 chromosomes (reviewed in Birstein et al 1993). Therefore differences of individual allelic number/locus can be used to determine the species.…”

Genetic heterogeneity and ploidy level analysis among different gynogenetic clones of the polyploid gibel carp

“…Comparative karyotype studies were performed in 2002 by Zhou and Gui, and chromosome number difference and karyotypic diversity have been found in various gynogenetic clones of the polyploid fish, suggesting that genome reshuffling might have occurred between these clones (14). Flow cytometry is a powerful and efficient tool in detecting DNA content (15,16), measuring the ratio of DNA-to-RNA content (17), localizing specific genes (18,19), and detecting chromosomal abnormalities (20,21). In this study, five different triploid clones (A, D, E, F, and P), and one artificial multiple tetraploid clone (clone M) were subjected to flow cytometry studies to attempt to answer the following questions: What is the correlation among the DNA contents of each clone?…”