Fetal Pig Dissection Manual (BIOL 105)

This book is a guide to the basic fetal pig dissection conducted as a part of the Queens College, CUNY Biology Department Bio105 General Biology: Physiology and Cell Biology course. This course is the first half our two-part series for biology majors. The actives are designed to be conducted over a three- 3-hour lab periods which focus on the relationship of form and function of the pig anatomy and physiology. Step by step instructions for the dissection are provided along with some microscopy tasks to look at the histology of key organs. In addition to the full text of the book, we also provide a form with just the assessment portions of the book. This allows students to limit the printed material to just those pages

Histology Atlas: Basic Mammalian Tissue Types (BIOL 105)

This book is a guide to the basic histology lab conducted as a part of the Queens College, CUNY Biology Department Bio105 General Biology: Physiology and Cell Biology course. This course is the first half our two-part series for biology majors. The actives are designed to be conducted over a single 3-hour lab periods which focus on the relationship of form and function of the cellular and organ level anatomy and physiology. Step by step instructions for each slide set are provided for all the key organs. In addition to the full text of the book, we also provide a checklist form with just the assessment portions of the book. This is to help summarize all the information the student should get from the activity

Integration of Nodal and BMP Signals in the Heart Requires FoxH1 to Create Left–Right Differences in Cell Migration Rates That Direct Cardiac Asymmetry

Failure to properly establish the left–right (L/R) axis is a major cause of congenital heart defects in humans, but how L/R patterning of the embryo leads to asymmetric cardiac morphogenesis is still unclear. We find that asymmetric Nodal signaling on the left and Bmp signaling act in parallel to establish zebrafish cardiac laterality by modulating cell migration velocities across the L/R axis. Moreover, we demonstrate that Nodal plays the crucial role in generating asymmetry in the heart and that Bmp signaling via Bmp4 is dispensable in the presence of asymmetric Nodal signaling. In addition, we identify a previously unappreciated role for the Nodal-transcription factor FoxH1 in mediating cell responsiveness to Bmp, further linking the control of these two pathways in the heart. The interplay between these TGFβ pathways is complex, with Nodal signaling potentially acting to limit the response to Bmp pathway activation and the dosage of Bmp signals being critical to limit migration rates. These findings have implications for understanding the complex genetic interactions that lead to congenital heart disease in humans

Integration of Nodal and BMP Signals in the Heart Requires FoxH1 to Create Left–Right Differences in Cell Migration Rates That Direct Cardiac Asymmetry

<div><p>Failure to properly establish the left–right (L/R) axis is a major cause of congenital heart defects in humans, but how L/R patterning of the embryo leads to asymmetric cardiac morphogenesis is still unclear. We find that asymmetric Nodal signaling on the left and Bmp signaling act in parallel to establish zebrafish cardiac laterality by modulating cell migration velocities across the L/R axis. Moreover, we demonstrate that Nodal plays the crucial role in generating asymmetry in the heart and that Bmp signaling via Bmp4 is dispensable in the presence of asymmetric Nodal signaling. In addition, we identify a previously unappreciated role for the Nodal-transcription factor FoxH1 in mediating cell responsiveness to Bmp, further linking the control of these two pathways in the heart. The interplay between these TGFβ pathways is complex, with Nodal signaling potentially acting to limit the response to Bmp pathway activation and the dosage of Bmp signals being critical to limit migration rates. These findings have implications for understanding the complex genetic interactions that lead to congenital heart disease in humans.</p> </div

Jogging laterality phenotypes.

<p>Embryos were scored for laterality of cardiac jogging between 24 and 30 hpf. A–C: Dorsal views of the heart at 24 hpf showing jogging laterality phenotypes by RNA in situ hybridizations using the <i>myl7</i> probe D: WT embryos exhibit primarily left-directed cardiac jog, as do <i>bmp4^Y180</i> mutants (I) lacking both maternal and zygotic <i>bmp4</i> (MZ<i>bmp4</i>). E,F: While WT embryos injected with <i>spaw</i> morpholino <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003109#pgen.1003109-Baker1" target="_blank">[9]</a> and late-zygotic (LZ) <i>oep</i> mutants display randomized jogging laterality, H: MZ<i>bmp4^Y180</i> mutants injected with <i>spaw</i> morpholino lack significant jogging asymmetries. I: Loss of <i>bmp4</i> alone does not affect jogging laterality and resembles WT (D) suggesting Bmp is dispensable for correct jogging when asymmetric Nodal signals are present. J: Jogging laterality in the absence of Spaw is highly sensitive to the level of Bmp4 present, as loss of a single functional copy of <i>bmp4</i> in embryos deficient for Spaw is sufficient to result in predominantly midline jogging phenotypes. K: <i>midway</i> mutants homozygous for a nonsense mutation in the Nodal transcription factor FoxH1 display jogging phenotypes similar to what is observed in embryos lacking both Nodal and Bmp signaling. We note that a discrepancy exists between the randomized jogging of <i>spaw</i> morphants and the predominantly midline jogging of SB-505124-treated embryos (G). As described in more detail in the discussion, these phenotypic differences are likely due to the more global inhibition of TGFβ signaling achieved through drug treatment and we believe reflects the involvement of a second, as yet unidentified, TGFβ ligand in establishing jogging laterality. MO: morpholino. Het: Heterozygotes. Mut: Mutant. Asterisk: jogging data presented supplementary to <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003109#pgen.1003109-Baker1" target="_blank">[9]</a>.</p

Quantitation of Bmp pathway activity by average fluorescence intensity and number of p-Smad1/5/8 positive cells.

<p>Immunofluorescence images for activated Smad1/5/8 (A,B,D,E,G,H,J,K,P–P″) in <i>Tg(myl7:eGFP)</i> embryos (myocardial GFP in B,E,H,K,P–P′″) or in <i>Tg</i>(<i>kdrl</i>:<i>egfp</i>) embryos (endocardial GFP in Q–Q″). C,F,I,L: Schematics of B, E, H and I using IMARIS surface tool. GFP signal in green; p-Smad1/5/8 positive cells are labeled according to intensity using the red (low) to yellow (high) spectrum ranging from an intensity value of 35–65, respectively. All images are dorsal views except for optical cross sections generated in IMARIS along the anterior/posterior axis (P′, Q′) or across the myocardium (P″, Q″). A–C: p-Smad1/5/8 fluorescence intensity is higher on the left of the WT cardiac cone (n = 6). D–F: p-Smad1/5/8 fluorescence intensity on both sides of the cone in <i>spaw</i> morphants is similar to that observed in cells on the left in WT (n = 6). G–I: <i>midway</i> mutants exhibit reduced fluorescence intensities and numbers of p-Smad1/5/8 positive cells, while p-Smad levels elsewhere in the embryo are seemingly unaffected (data not shown, n = 3). J–L: <i>bmp4</i> and <i>spaw</i> double morphants exhibit diminished p-Smad1/5/8 compared with WT (n = 6) but not as severe as observed in <i>midway</i> mutants. M: Comparison of the average fluorescence intensities of p-Smad1/5/8 positive cells on the left and right of the cardiac cone. N: Comparison of the average number of p-Smad1/5/8 positive cells on the left and right of the cardiac cone. O: Comparison of the average number of p-Smad1/5/8 positive cells in the entire cardiac field. P–P″: The myocardium shows little to no overlap of p-Smad1/5/8 positive cells (red) with the green of the myocardium. Q–Q″: Conversely, p-Smad1/5/8 (red) is observed to colocalize with the GFP positive endothelial cells in <i>Tg</i>(<i>kdrl</i>:<i>egfp</i>), indicated with arrowheads in Q′ and Q″, indicating that Bmp signals more strongly to the endocardium. Error bars indicate standard error of the mean. L: Low. H: High. MO: Morpholino. Het: heterozygote.</p

Trajectories and average velocities of migrating cells within the cardiac cone.

<p>A–G: First frame of time lapse movies taken from a dorsal view of <i>Tg(myl7:eGFP)</i> embryos overlaid with cell trajectories. Yellow tracks: left cells. White tracks: center cells. Red tracks: right cells. A: All cells exhibit trajectories directed toward the anterior and left in WT embryos. B: Bilateral expression of <i>spaw</i> in <i>ntl</i> morphants leads to loss of L/R asymmetry in cardiac cell migrations. C–G: L/R directionality is also absent in embryos C: lacking the Nodal ligand <i>spaw</i>; D: treated with the SB-505124 Nodal inhibitor drug E: lacking <i>spaw</i> and one functional copy of <i>bmp4</i>; F: injected with both <i>bmp4</i> and <i>spaw</i> morpholinos; and G: homozygous <i>midway</i> mutants. H: Numbers within each bar indicate the number of cells tracked on the left, center and right for all embryos of each genotype. The number of embryos utilized in analysis is indicated (n = ) for each genotype. WT embryos exhibit differences in average cell velocities along the L/R axis, with left cells migrating significantly faster than right cells. Bilateral exposure to Spaw leads to significant increases in average velocities in left and right cells of <i>ntl</i> morphants, while loss of Spaw and global inhibition of Nodal signaling through drug treatment results in significantly decreased rates of migration. In embryos with diminished Bmp signaling along with loss of Spaw, average cell velocities are significantly increased compared with loss of Spaw alone. Error bars in H indicate standard error of the mean. MO: morpholino. Het: Heterozygotes.</p