fluorogenic sir-dna  (Cytoskeleton Inc)

Journal: Environmental Health Perspectives

Article Title: Oocyte Development and Quality in Young and Old Mice following Exposure to Atrazine

doi: 10.1289/EHP11343

Figure Lengend Snippet: Chromosome alignment and segregation in meiosis-I oocytes following atrazine exposure during development. (A) Representative images of MI oocytes, stained for spindles ( α - tubulin , green) and DNA (Hoechst, white), illustrating classes of chromosome misalignment. (B) Quantification of chromosome misalignment in the MI oocytes represented in panel A (data generated from 5 animals from 3 litters in each exposure group; see Excel Table S11). (C) Live-cell images from selected timepoints of meiosis-I stage oocytes showing examples of normal chromosome segregation, NDJ, and lagging segregation. Arrows highlight a NDJ event. The arrowhead highlights lagging chromosomes. (D) Quantification of chromosome missegregation in meiosis-I oocytes. Data generated from 7 animals and 5 litters (unexposed control); and 8 animals and 4 litters (high-dose atrazine), respectively (also see Excel Table S12 for summary data). Numbers of oocytes examined in (B) and (D) are indicated in parentheses above the bars. Error bars represent standard error of a proportion; unidirectional bars are shown for the individual classes to avoid overlaps. Data in (B) and (D) were analyzed with Fisher’s exact tests. Statistical analysis performed in (B) compares the distributions of the three alignment classes shown in (A). All missegregation types were combined for the statistical analysis in (D). Scale bars in (A) and (C) represent 10 μ m . Low, 100 μ g / L atrazine; High, 33 mg / L . Note: MI, metaphase I; NDJ, nondisjunction. * p < 0.05 ; ** p < 0.01 .

Article Snippet: Missegregation was detected in 12.7% of control oocytes (7/55; ), a higher frequency than those reported in the literature ( ≤ 5 % , ), which appeared to be caused by the SiR-DNA fluorogenic DNA label (Spirochrome) used to visualize chromosomes.

Techniques: Staining, Generated

Journal: Environmental Health Perspectives

Article Title: Oocyte Development and Quality in Young and Old Mice following Exposure to Atrazine

doi: 10.1289/EHP11343

Figure Lengend Snippet: Analysis of chromosomal abnormalities and alignment in metaphase-II eggs following atrazine exposure during development. (A) Representative images of MII oocyte chromosomes showing normal euploid (20 pairs of sister chromatids) and aneuploid (21 pairs) nuclei, and a cell with a single free chromatid (20’; magnified in the right-hand side panels) indicative of a premature separation event (predivision). Centromeres (green) were immunostained with CREST, and chromosomes (magenta) were counterstained with DAPI. Scale bars represent 10 μ m (main panels) and 1 μ m (magnified panel). (B) Quantification of chromosomal abnormalities in MII eggs from 3-month-old mice. Numbers of animals used were 8 (from 7 litters ; unexposed control), 4 (from 3 litters ; low dose) and 5 (from 3 litters ; high dose), respectively (also see Excel Table S13 for the summary data). (C) Representative images of MII eggs, stained for spindles ( α - tubulin , green) and DNA (Hoechst, white), illustrating classes of chromosome misalignment. PB1, indicates the position of the first polar body. Scale bars represent 10 μ m (top panels) and 5 μ m (lower panels). (D) Quantification of chromosome misalignment in the metaphase-II eggs represented in (C). 3 animals were used for each exposure group, from 3 (control), 3 (low), and 2 (high) litters, respectively (also see Excel Table S14 for summary data). Numbers of eggs examined in (B) and (D) are indicated in parentheses above the bars. Error bars represent standard error of a proportion; unidirectional bars are shown for the individual classes to avoid overlaps. Data in (B) and (D) were analyzed with Fisher’s exact tests. All missegregation types were combined for the statistical analysis in (B). Statistical analysis performed in (D) compares the distributions of the three alignment classes shown in (C). Low, 100 μ g / L atrazine; High, 33 mg / L . Note: MII, metaphase II; NDJ, nondisjunction. * p < 0.05 ; ** p < 0.01 .

Article Snippet: Missegregation was detected in 12.7% of control oocytes (7/55; ), a higher frequency than those reported in the literature ( ≤ 5 % , ), which appeared to be caused by the SiR-DNA fluorogenic DNA label (Spirochrome) used to visualize chromosomes.

Techniques: Staining

Journal: Environmental Health Perspectives

Article Title: Oocyte Development and Quality in Young and Old Mice following Exposure to Atrazine

doi: 10.1289/EHP11343

Figure Lengend Snippet: Chromosomal abnormalities and alignment in oocytes following atrazine exposure during adulthood. (A) Schematic of atrazine exposure regimen in adult females. (B) Representative images of MI oocyte chromosome preparations showing a normal nucleus with 20 bivalents and a nucleus containing 19 bivalents and 2 univalents (yellow arrows). Chromosomes shown in insets are from the same cell but were in different fields of view. DNA is colored magenta, and centromeres are green. Scale bars represent 10 μ m . (C) Quantification of unconnected univalent chromosomes in chromosome preparations from MI oocytes. Numbers of animals used were 6 (unexposed control), 5 (low dose), and 5 (high dose), respectively (also see Excel Table S19 for summary data). (D) Quantification of chromosome misalignment in metaphase-I oocytes. Numbers of animals used were 4, 3, and 4, respectively (also see Excel Table S20 for summary data). (E) Quantification of chromosomal abnormalities in MII eggs. Numbers of animals used were 7, 6, and 6, respectively (also see Excel Table S21 for summary data). (F) Quantification of chromosome misalignment in metaphase-II eggs. Numbers of animals used were 4, 3, and 4, respectively (also see Excel Table S22 for summary data). (G) Schematic of the discontinuous atrazine exposure regimen. (H) Quantification of chromosomal abnormalities in MII eggs following discontinuous atrazine exposure. Numbers of animals used were 9, 4, and 8, respectively (also see Excel Table S23 for summary data). Numbers of MI oocytes (C,D) and MII eggs (E,F,H) examined are indicated in parentheses above the bars. Error bars represent standard error of a proportion; unidirectional bars are shown in (D–F), and (H) to avoid overlaps. Data were analyzed with Fisher’s exact tests. Statistical analysis performed in (D) and (F) compares the distributions of the three alignment classes. MII chromosomal abnormalities were combined for statistical analyses in (E) and (H). Low, 100 μ g / L atrazine; High, 33 mg / L . Note: MI, metaphase I; MII, metaphase II; ns, not significant. * p < 0.05 ; ** p < 0.01 .

Article Snippet: Missegregation was detected in 12.7% of control oocytes (7/55; ), a higher frequency than those reported in the literature ( ≤ 5 % , ), which appeared to be caused by the SiR-DNA fluorogenic DNA label (Spirochrome) used to visualize chromosomes.

Techniques: