Telomerase activity in Daphnia.

<p>A) Telomeric repeat amplification protocol (TRAP) assay of <i>D</i>. <i>pulex</i> extracts. The amount of cell extract used is indicated above each lane. HI: Heat Inactivated, CE: Cell Extract. TSR8 CT: positive control for PCR step. B) Quantification of the TRAP Assay in 1A. Student T-test was performed, p values are as follows: * = 6.15x10^-6, ** = 6.63x10^-6 (n = 3).</p

Telomerase from <i>Daphnia</i> embryos shows high processivity.

<p>A) TRAP assay from egg stage 1 embryos and 1 week old adults of <i>D</i>. <i>pulex</i> and <i>D</i>. <i>pulicaria</i>. 250 ng of <i>Daphnia</i> extract was used in each lane. B) Quantification of the TRAP assay displayed in 2 A. C) Quantification of the processivity of telomerase from each displayed sample. The p values calculated from student T-tests are as follows: * = 6.15x10^-6, ** = 5.56x10^-6, *** = 0.0005,**** = 1.5x10^-5; # = 0.0002, ## = 0.0002 (n = 4).</p

Comparison of telomerase activity at different ages in <i>D</i>. <i>pulex</i> and <i>D</i>. <i>pulicaria</i>.

<p>A) TRAP assay was performed using <i>Daphnia</i> extracts prepared at indicated ages. Lanes 1–3: <i>D</i>. <i>pulex</i>, lanes 4–6: <i>D</i>. <i>pulicaria</i>. B) Quantification of the TRAP assay displayed in 4 A. C) Quantification of the processivity of telomerase from each displayed sample. Student T-tests were performed, and p values are as follows * = 0.0005, ** = 0.0006, *** = 0.002, # = 0.001, ## = 0.034, ### = 0.0132, #### = 0.029 (n = 4).</p

Telomeric repeat sequence from <i>Daphnia</i> and sequence alignment of <i>Daphnia</i> telomerase (dTERT) with telomerase proteins from other species.

<p>A) Telomeric repeat sequence of <i>Daphnia</i> and other species. <i>H</i>. <i>americanus</i>: <i>Homarus americanus</i>—Lobster, <i>G</i>. <i>pulex</i>: <i>Gammarus pulex</i>—Freshwater amphipod, <i>B</i>. <i>mori</i>: <i>Bombyx mori—</i>Silkworm/moth, <i>A</i>. <i>viridus</i>: <i>Amaranthus viridus</i>—Beetle, <i>M</i>. <i>musculus</i>: <i>Mus musculus</i>—Mouse, <i>H</i>. <i>sapiens</i>: <i>Homo sapiens</i>—Human. B) Identity and similarity percentages of dTERT with TERT from other species. C) <i>D</i>. <i>pulex</i> telomerase reverse transcriptase (DTERT) sequence alignment for the RNA-binding and reverse transcriptase domains. Green Boxes: conserved residues within the RNA binding domain. Black Boxes: conserved residues within the reverse transcriptase domain. Blue boxes: residues within the reverse transcriptase domain that are essential for nucleic acid binding.</p

Life spans and telomere lengths in <i>D</i>. <i>pulex</i> (RW20) and <i>D</i>. <i>pulicaria</i> (LakeXVI-clone11).

<p>A) Survivorship curves of clones RW20 (open squares) and XVI-11 (black circles). Error bars show age-specific standard errors from Kaplan-Meier survival probability estimates. B) Terminal Restriction Fragment (TRF) assay was performed to estimate the average telomere length of the <i>Daphnia</i> at various ages. The age in weeks is indicated above each lane. Lanes 1–3: <i>D</i>. <i>pulex</i>, lanes 4–6: <i>D</i>. <i>pulicaria</i>. M1 and M2: molecular weight markers; lambda HindIII digest and lambda BstEII digest respectively. C) Quantification of 5 A, error bars indicate standard deviation. Student T-tests were performed and p values are as follows: * = 1.03x10^-5, ** = 0.007, *** = 2.48x10^-5 (n = 3).</p