Copepod development rates in relation to genome size and 18S rDNA copy number

Genome ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 750-755 ◽  
Author(s):  
M M White ◽  
I A McLaren
Keyword(s):  
Nuclear Dna ◽  
Rrna Genes ◽  
Cell Level ◽  
Development Rates ◽  
Dna Contents ◽  
Body Sizes ◽  
18S Rrna Genes ◽  
Nuclear Dna Contents ◽  
Copepod Development ◽  
Rdna Copy

It is known that body sizes and temperature-independent developmental durations within two genera of calanoid Copepoda (Crustacea) are positively related to nuclear DNA contents of their somatic nuclei. Evidently because of the constraint of similar cell numbers among the species, (nucleotypic) effects of nucleus size on cell size and on cell-level processes are expressed at the whole-organism level. Here, we show that developmental durations of eight species of five genera are also negatively related to their greatly differing numbers of 18S rRNA genes per unit DNA. We propose that levels of rDNA iteration among copepods have been controlled by natural selection to regulate ribosome concentrations, therefore protein production and development rates, independently of the large variations in genome sizes, which are in turn adapted to regulating cell and therefore body sizes.Key words: Copepoda, rDNA repeats, development rate, iteration, nucleotype.

Innate and acquired variation of nuclear DNA contents of marine copepods

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 602-610 ◽  
Author(s):  
Ruben Escribano ◽  
Ian A. McLaren ◽  
W. C. M. Klein Breteler
Keyword(s):  
First Generation ◽  
Nuclear Dna ◽  
Cell Number ◽  
Development Rate ◽  
Geographical Differences ◽  
Wild Stock ◽  
Significant Treatment ◽  
Dna Contents ◽  
Body Sizes ◽  
Nuclear Dna Contents

Feulgen staining revealed significant geographical differences in mean DNA contents of somatic nuclei of adult female Calanus glacialis and Pseudocalanus acuspes from the Canadian arctic and Nova Scotia; the latter exhibited seasonal differences near Halifax in 1987 but not 1989–1990. Female P. elongatus reared for 96 generations in the laboratory had significantly less DNA per nucleus than did first-generation females from the same North Sea wild stock. Nuclei of C. glacialis reared from juvenile stages (copepodid III) in four food–temperature treatments had significantly more DNA at high food and low temperature. There were also significant treatment effects in P. elongatus and P. acuspes reared from egg to adult. There were always significant differences in DNA contents among females within samples and treatments. Increased variance among nuclei within individual C. glacialis may have resulted from suboptimal laboratory conditions. Body lengths in rearing experiments were positively correlated with nuclear DNA contents in C. glacialis and P. elongatus; there was no correlation of lengths with nucleus number in P. acuspes. Development rate of late-stage C. glacialis was negatively related to nuclear DNA contents. The slight, but significant, differences among females within and among samples and treatments suggest that their DNA contents are both inherent and subject to slight environmental effects. Results are also consistent with earlier indications that body sizes and development rates of copepods, because of restricted variation in cell number, are partly under nucleotypic control.Key words: Copepoda, genome size, intraspecific variation, nucleotypic effects, body size, development rate.

scholarly journals Nuclear DNA contents, rDNAs, and karyotype evolution in subgenus Vicia: III. The heterogeneous section Hypechusa

PROTOPLASMA ◽  
2006 ◽  
Vol 228 (4) ◽  
pp. 167-177 ◽  
Author(s):  
P. Caputo ◽  
M. Frediani ◽  
G. Venora ◽  
C. Ravalli ◽  
M. Ambrosio ◽  
...  
Keyword(s):  
Nuclear Dna ◽  
Karyotype Evolution ◽  
Dna Contents ◽  
Nuclear Dna Contents

Nuclear DNA Contents of Coreopsis nuecensoides and C. nuecensis (Asteraceae), a Progenitor-Derivative Species Pair

1984 ◽  
Vol 145 (2) ◽  
pp. 240-245 ◽  
Author(s):  
H. James Price ◽  
Daniel J. Crawford ◽  
Randall J. Bayer
Keyword(s):  
Nuclear Dna ◽  
Species Pair ◽  
Dna Contents ◽  
Nuclear Dna Contents

Flow cytometric analysis reveals different nuclear DNA contents in cultivated Fonio (Digitaria spp.) and some wild relatives from West-Africa

2007 ◽  
Vol 267 (1-4) ◽  
pp. 163-176 ◽  
Author(s):  
H. Adoukonou-Sagbadja ◽  
V. Schubert ◽  
A. Dansi ◽  
G. Jovtchev ◽  
A. Meister ◽  
...  
Keyword(s):  
West Africa ◽  
Nuclear Dna ◽  
Flow Cytometric Analysis ◽  
Wild Relatives ◽  
Flow Cytometric ◽  
Dna Contents ◽  
Nuclear Dna Contents

Nuclear DNA content of three Eucalyptus species estimated by flow and image cytometry

2009 ◽  
Vol 57 (6) ◽  
pp. 524 ◽  
Author(s):  
Milene Miranda Praça ◽  
Carlos Roberto Carvalho ◽  
Carolina Ribeiro Diniz Boaventura Novaes
Keyword(s):  
Dna Content ◽  
Nuclear Dna ◽  
Methodological Approach ◽  
Nuclear Dna Content ◽  
Image Cytometry ◽  
Eucalyptus Species ◽  
International Consensus ◽  
Mean Values ◽  
Dna Contents ◽  
Nuclear Dna Contents

Previous flow cytometry (FCM) analyses delivered nearly equal mean values of nuclear 2C DNA content for Eucalyptus grandis Hill ex Maiden and E. urophylla S. T. Blake (1.33 pg and 1.34 pg, respectively), whereas E. globulus Labill. presented distinct mean values (1.09, 1.13 and 1.40). These differences have been attributed to the different methodological approach, utilised plant cultivar and presence of intrinsic metabolic compounds that affect fluorochrome fluorescence. In the present study, a FCM and image cytometry (ICM) design, following international consensus criteria, were adopted to reassess the nuclear DNA contents of the above-mentioned Eucalyptus species. Statistical analyses revealed either similar or discrepant nuclear DNA contents, depending on the standard species used and whether FCM or ICM was employed. Our results demonstrated that 2C DNA values obtained by FCM and ICM were most uniform when Solanum lycopersicum was used as a standard. Moreover, the values obtained for E. grandis and E. urophylla were close, but differed as much as 24.63% in relation to previous data, and E. globulus proportionally varied up to 25%. New DNA content values are suggested for these eucalypt species.

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