Name: microdissection and dissociation of the murine oviduct: individual segment identification and single cell isolation
Uploaded: 2021-11-04T13:00:00
Description: Watch this Scientific Journal Video about Microdissection and Dissociation of the Murine Oviduct: Individual Segment Identification and Single Cell Isolation at JoVE.com

This work was supported in part by a DoD Breakthrough Award to AMW (BCRP W81XWH-14-1-0425). KCR was partially supported by intramural fellowships: the Pease Cancer Pre-Doctoral Fellowship and the Mary Galvin Burden Pre-Doctoral Fellowship in Biomedical Sciences and University of California, Riverside, intramural awards: the Graduate Council Fellowship Committee Dissertation Research Grant and the Graduate Division Dissertation Year Program Award. The authors thank Gillian M. Wright and Alyssa M. Kumari for assistance in early troubleshooting of this method.

All animal handling and procedures were approved by the University of California, Riverside institutional animal care and use committee and were in accordance with guidelines from the American Association for Laboratory Animal Care, the United States Department of Agriculture, and the National Institutes of Health. The described method utilized C57BL/6 adult, female mice. All animals were euthanized by decapitation prior to tissue harvesting.
NOTE: An overview of the protocol, which uses a blu...

<ol>
	<li>Stewart, C. A., et al., Kubiak, J. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Mouse oviduct developmemt in Mouse Development: From Oocyte to Stem Cells. , 247-262 (2012).</li><li>Ford, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oviduct+epithelial+cells+constitute+two+developmentally+distinct+lineages+that+are+spatially+separated+along+the+distal-proximal+axis.">Oviduct epithelial cells constitute two developmentally distinct lineages that are spatially separated along the distal-proximal axis.</a> Cell Reports. 36 (10), 109677 (2021).</li><li>Harwalkar, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+and+cellular+heterogeneity+in+the+mouse+oviduct-its+potential+roles+in+reproduction+and+preimplantation+development.">Anatomical and cellular heterogeneity in the mouse oviduct-its potential roles in reproduction and preimplantation development.</a> Biology of Reproduction. 104 (6), 1249-1261 (2021).</li><li>Agduhr, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+the+structure+and+development+of+the+bursa+ovarica+and+the+tuba+uterina+in+the+mouse.">Studies on the structure and development of the bursa ovarica and the tuba uterina in the mouse.</a> Acta Zoologica. 8 (1), 1 (1927).</li><li>Pulkkinen, M. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oviductal+function+is+critical+for+very+early+human+life.">Oviductal function is critical for very early human life.</a> Annals of Medicine. 27 (3), 307-310 (1995).</li><li>Kindelberger, D. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraepithelial+carcinoma+of+the+fimbria+and+pelvic+serous+carcinoma:+Evidence+for+a+causal+relationship.">Intraepithelial carcinoma of the fimbria and pelvic serous carcinoma: Evidence for a causal relationship.</a> American Journal of Surgical Pathology. 31 (2), 161-169 (2007).</li><li>Ghosh, A., Syed, S. M., Tanwar, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+genetic+cell+lineage+tracing+reveals+that+oviductal+secretory+cells+self-renew+and+give+rise+to+ciliated+cells.">In vivo genetic cell lineage tracing reveals that oviductal secretory cells self-renew and give rise to ciliated cells.</a> Development. 144 (17), 3031-3041 (2017).</li><li>Lee, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+candidate+precursor+to+serous+carcinoma+that+originates+in+the+distal+fallopian+tube.">A candidate precursor to serous carcinoma that originates in the distal fallopian tube.</a> Journal of Pathology. 211 (1), 26-35 (2007).</li><li>Kim, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-grade+serous+ovarian+cancer+arises+from+fallopian+tube+in+a+mouse+model.">High-grade serous ovarian cancer arises from fallopian tube in a mouse model.</a> Proceedings of the National Academy of Sciences of the United States of America. 109 (10), 3921-3926 (2012).</li><li>Perets, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformation+of+the+fallopian+tube+secretory+epithelium+leads+to+high-grade+serous+ovarian+cancer+in+Brca;Tp53;Pten+models.">Transformation of the fallopian tube secretory epithelium leads to high-grade serous ovarian cancer in Brca;Tp53;Pten models.</a> Cancer Cell. 24 (6), 751-765 (2013).</li><li>Sherman-Baust, C. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetically+engineered+ovarian+cancer+mouse+model+based+on+fallopian+tube+transformation+mimics+human+high-grade+serous+carcinoma+development.">A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high-grade serous carcinoma development.</a> Journal of Pathology. 233 (3), 228-237 (2014).</li><li>Zhai, Y. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-grade+serous+carcinomas+arise+in+the+mouse+oviduct+via+defects+linked+to+the+human+disease.">High-grade serous carcinomas arise in the mouse oviduct via defects linked to the human disease.</a> Journal of Pathology. 243 (1), 16-25 (2017).</li><li>Karthikeyan, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prolactin+signaling+drives+tumorigenesis+in+human+high+grade+serous+ovarian+cancer+cells+and+in+a+spontaneous+fallopian+tube+derived+model.">Prolactin signaling drives tumorigenesis in human high grade serous ovarian cancer cells and in a spontaneous fallopian tube derived model.</a> Cancer Letters. 433, 221-231 (2018).</li><li>Shao, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differences+in+prolactin+receptor+(PRLR)+in+mouse+and+human+fallopian+tubes:+Evidence+for+multiple+regulatory+mechanisms+controlling+PRLR+isoform+expression+in+mice.">Differences in prolactin receptor (PRLR) in mouse and human fallopian tubes: Evidence for multiple regulatory mechanisms controlling PRLR isoform expression in mice.</a> Biology of Reproduction. 79 (4), 748-757 (2008).</li><li>Alwosaibai, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PAX2+maintains+the+differentiation+of+mouse+oviductal+epithelium+and+inhibits+the+transition+to+a+stem+cell-like+state.">PAX2 maintains the differentiation of mouse oviductal epithelium and inhibits the transition to a stem cell-like state.</a> Oncotarget. 8 (44), 76881-76897 (2017).</li><li>Peri, L. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+class+of+interstitial+cells+in+the+mouse+and+monkey+female+reproductive+tracts.">A novel class of interstitial cells in the mouse and monkey female reproductive tracts.</a> Biology of Reproduction. 92 (4), 102 (2015).</li><li>L&#245;hmussaar, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+the+origin+of+high-grade+serous+ovarian+cancer+using+CRISPR-modification+of+mouse+organoids.">Assessing the origin of high-grade serous ovarian cancer using CRISPR-modification of mouse organoids.</a> Nature Communications. 11 (1), 2660 (2020).</li><li>Chen, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+air-liquid+interphase+approach+for+modeling+the+early+embryo-maternal+contact+zone.">An air-liquid interphase approach for modeling the early embryo-maternal contact zone.</a> Scientific Reports. 7, 42298 (2017).</li><li>Desjardins, P., Conklin, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NanoDrop+microvolume+quantitation+of+nucleic+acids.">NanoDrop microvolume quantitation of nucleic acids.</a> Journal of Visualized Experiments: JoVE. (45), e2565 (2010).</li><li>Schroeder, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+RIN:+an+RNA+integrity+number+for+assigning+integrity+values+to+RNA+measurements.">The RIN: an RNA integrity number for assigning integrity values to RNA measurements.</a> BMC Molecular Biology. 7, 3 (2006).</li><li>McGlade, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-type+specific+analysis+of+physiological+action+of+estrogen+in+mouse+oviducts.">Cell-type specific analysis of physiological action of estrogen in mouse oviducts.</a> The FASEB Journal. 35 (5), 21563 (2021).</li></ol>

The three segments of the oviduct are histologically, morphologically, and functionally distinct1,2,3. The epithelium varies greatly from one end of the oviduct to the other. Ciliated cells dominate at the fimbrial/infundibular end, while secretory cells dominate in the isthmic region1. While this overall gradient has been recognized for some time, recent work has uncovered more distinctions among the ovi...

The murine oviduct is similar in function and morphology to the human fallopian tube1. Both consist of a pseudostratified ciliated epithelium, consisting of two historically described epithelial resident cells: ciliated cells and secretory cells1,2. The oviduct has three classically recognized segments: the infundibulum, the ampulla, and the isthmus. In a recent study, Harwalkar et al.3 investigated oviduct morphology and gene expression leading to the expansion of the categorization of resident epithelial cells to seven distinct populations. In addition, they established the ampullary-isthmus junction as a distinct segment of the oviduct3. The method described herein, which focuses on the infundibulum, ampulla, and isthmus, could easily be extended to include the ampullary-isthmic junction as well2,3. The infundibular region contains the ostium, or opening of the oviduct, and includes the fimbrial region as well as the proximal stalk. Moving toward the uterus, next is the ampulla, and then the isthmus. Ciliated cells are most prominent in the distal end of the region, proximal to the ovary, or infundibulum, while secretory cells are most prominent in the proximal end or isthmus segment1. Unlike the human fallopian tube, the murine oviduct is a coiled structure supported by the mesosalpinx, an extension of the broad ligament peritoneum1,4. In addition, the mouse oviduct is encased in a bursal sac that increases the likelihood of oocyte transfer into the oviduct4. The ampulla is identified as the location of fertilization, from which developing embryos pass into the isthmus before entering the uterus5. Tubal segments are 200-400 &#956;m in diameter and the longer ampullary and isthmus regions are approximately 0.5-1.0 cm in length4. The oviduct distends during the estrous cycle and the ampulla and infundibulum are more distensible than the isthmus1.
Over proliferation of cells, especially secretory cells, characterize precursor lesions to serous tumors found in the pelvic cavity6. These precursor serous intraepithelial lesions arise in the oviduct epithelium solely in the fimbrial region; it is unknown why lesion formation is restricted to this region where normally the predominant cell type is ciliated, not secretory2,7,8. The regionality in terms of normal physiological function, as well as heightened interest in the oviductal origin of ovarian cancer9,10,11,12,13, underscores the importance of separate evaluation of the oviduct segments.
The method described here details the collection of separate oviductal segments for subsequent downstream analyses of segment-specific gene expression and function of dissociated cells. Traditionally, many tissues are processed for whole RNA extraction following either the phenol: chloroform method or an on-column complete extraction method; however, we found that RNA quality was maintained while producing sufficient yield with the described combination method. Utilizing this method, very small functional segments of the oviduct can be processed for downstream analyses rather than investigating the oviduct as a whole, which can mask results representative of the different segments14.
Dissociated murine oviductal cells have rarely been investigated by flow cytometry, most likely due to the limiting cell yield from this tissue. One approach to overcome this problem has been to dissociate cells, grow them in culture, and then stimulate re-differentiation in vitro to obtain appropriate cell numbers for downstream cell analysis15,16,17,18. A limitation to this approach is the time ex vivo and altered microenvironment in culture, both of which likely change gene expression. There is also an assumption that morphological re-differentiation has the same transcriptional and proteomic signature as was present in the intact animal. The current dissociation method was designed to achieve the highest number of epithelial cells in a heterogenous oviductal cell population while maintaining single cell differentiation. Further, the mostly non-enzymatic approach likely limits the loss of cell surface proteins.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.5 mm Stainless steel bead mix</td>
			<td>Next Advance</td>
			<td>SSB05</td>
			<td>Mix 1:1 with 1.4 mm SSB14B, sterilized</td>
		</tr>
		<tr>
			<td>1.4 mm Stainless steel bead mix</td>
			<td>Next Advance</td>
			<td>SSB14B</td>
			<td>Mix 1:1 with 0.5 mm SSB05, sterilized</td>
		</tr>
		<tr>
			<td>1X Dulbecco&#39;s Phosphate Buffered Saline A, pH 7.4 (DPBS)</td>
			<td>Gibco</td>
			<td>21600-010</td>
			<td>Cold, sterile</td>
		</tr>
		<tr>
			<td>25G needle</td>
			<td>BD</td>
			<td>305122</td>
			<td></td>
		</tr>
		<tr>
			<td>60 mm sterile petri dishes</td>
			<td>Corning</td>
			<td>430166</td>
			<td></td>
		</tr>
		<tr>
			<td>70 &#956;m cell meshes</td>
			<td>Fisherbrand</td>
			<td>22-636-548</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent Eukaryote Total RNA 6000 Pico Chip kit</td>
			<td>Agilent 2100 Bioanalyzer</td>
			<td>5067-1513</td>
			<td></td>
		</tr>
		<tr>
			<td>Bead Bullet Blender Tissue Homogenizer</td>
			<td>Next Advance</td>
			<td>BBY24M</td>
			<td></td>
		</tr>
		<tr>
			<td>Bioanlyzer</td>
			<td>Agilent 2100 Bioanalyzer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine serum albumin</td>
			<td>Sigma Aldrich</td>
			<td>A7906</td>
			<td></td>
		</tr>
		<tr>
			<td>Cold plate/pack/surface of choice</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Kept at -20C for dissection</td>
		</tr>
		<tr>
			<td>Dental wax</td>
			<td>Polysciences Inc.</td>
			<td>403</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s Modified Eagle&#8217;s Medium (DMEM)/ Ham&#8217;s F12</td>
			<td>Corning</td>
			<td>10-090-CV</td>
			<td>Prepare dissection medium: DMEM/ Ham&#8217;s F12, 10% FBS, 25 mM Hepes, 1% Pen-Strep</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Corning</td>
			<td>35-015CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine point forceps of choice</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycine</td>
			<td>Sigma Aldrich</td>
			<td>G712b</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG Alexa Fluor 555</td>
			<td>Invitrogen</td>
			<td>A-21422</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Goat anti-rabbit IgG Alexa Fluor 488</td>
			<td>Invitrogen</td>
			<td>A-11001</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Hepes</td>
			<td>Sigma Aldrich</td>
			<td>H-3784</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoescht 33342</td>
			<td>Cell Signaling Technologies</td>
			<td>4082S</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Inverted compound microscope</td>
			<td>Keyence BZ-X700</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse anti-mouse Occludin</td>
			<td>Invitrogen</td>
			<td>33-1500</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Non-enzymatic dissociation buffer</td>
			<td>N/A</td>
			<td></td>
			<td>5 mM EDTA, 1 g/L glucose, 0.4% BSA, 1X DPBS</td>
		</tr>
		<tr>
			<td>Nylon macro-mesh 1 mm x 1 mm</td>
			<td>Thomas Scientific</td>
			<td>1210U04</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma Aldrich</td>
			<td>P-6148</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Pen-Strep</td>
			<td>MP Biomedicals</td>
			<td>10220-718</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolong Gold Antifade Reagent</td>
			<td>Cell Signaling Technologies</td>
			<td>9071S</td>
			<td>Immunocytochemical validation images: antifade mounting medium</td>
		</tr>
		<tr>
			<td>Pronase</td>
			<td>Sigma Aldrich</td>
			<td>10165921001</td>
			<td>Prepare pronase digestion medium: 0.15% Pronase in DMEM/Ham&#39;s F12, sterile</td>
		</tr>
		<tr>
			<td>Propidium Iodide</td>
			<td>Roche</td>
			<td>11 348 639 001</td>
			<td>Viability validation images</td>
		</tr>
		<tr>
			<td>Rabbit anti-mouse Acetylated-Tubulin</td>
			<td>Abcam</td>
			<td>ab179484</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>RBC lysis buffer</td>
			<td>BD Biosciences</td>
			<td>555899</td>
			<td></td>
		</tr>
		<tr>
			<td>RNeasy Mini Kit</td>
			<td>Qiagen</td>
			<td>74134</td>
			<td>Utilized for on-column purification in text.</td>
		</tr>
		<tr>
			<td>Spring form microdissection scissors</td>
			<td>Roboz Surgical</td>
			<td>RS-5610</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile 3 mL bulb pipettors</td>
			<td>Globe Scientific</td>
			<td>137135</td>
			<td></td>
		</tr>
		<tr>
			<td>Toluidine blue</td>
			<td>Alfa Aesar</td>
			<td>J66015</td>
			<td>Prepare toluidine blue solution: 1% in 1X DPBS, sterile</td>
		</tr>
		<tr>
			<td>Tris-Buffered Saline-Tween (TBST)</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Immunocytochemical validation images; 0.1 N NaCl, 10 mM Tris-Cl pH 7.5, 1% Tween 20</td>
		</tr>
		<tr>
			<td>Triton-X-100</td>
			<td>Mallinckrodt Inc.</td>
			<td>3555</td>
			<td>Immunocytochemical validation images</td>
		</tr>
		<tr>
			<td>Trizol RNA Extraction Reagent</td>
			<td>Invitrogen</td>
			<td>15596026</td>
			<td>Referred to as RNA extraction reagent. Nucelase-free water, chloroform and isoproponal are required in supplement of performing Trizol extraction per manufacturer&#39;s guidelines</td>
		</tr>
	</tbody>
</table>

microdissection and dissociation of the murine oviduct: individual segment identification and single cell isolation

Mouse model systems are unmatched for the analysis of disease processes because of their genetic manipulability and the low cost of experimental treatments. However, because of their small body size, some structures, such as the oviduct with a diameter of 200-400 &#956;m, have proven to be relatively difficult to study except by immunohistochemistry. Recently, immunohistochemical studies have uncovered more complex differences in oviduct segments than were previously recognized; thus, the oviduct is divided into four functional segments with different ratios of seven distinct epithelial cell types. The different embryological origins and ratios of the epithelial cell types likely make the four functional regions differentially susceptible to disease. For example, precursor lesions to serous intraepithelial carcinomas arise from the infundibulum in mouse models and from the corresponding fimbrial region in the human fallopian tube. The protocol described here details a method for microdissection to subdivide the oviduct in such a way to yield a sufficient amount and purity of RNA necessary for downstream analysis such as reverse transcription-quantitative PCR (RT-qPCR) and RNA sequencing (RNAseq). Also described is a mostly non-enzymatic tissue dissociation method appropriate for flow cytometry or single cell RNAseq analysis of fully differentiated oviductal cells. The methods described will facilitate further research utilizing the murine oviduct in the field of reproduction, fertility, cancer, and immunology.

The described dissociation protocol yields 100,000-120,000 cells per mouse with pooling of both oviducts. The method is gentle enough to leave multi-ciliated cell borders intact, allowing for a distinction between multi-ciliated cells and secretory cells, and verifying that the digestion method is gentle enough to prevent de-differentiation. Representative immunofluorescence images in Figure 5 show small cell clumps following step 4.2.1, fixed for 3 min in 4% paraformaldehyde (PFA)/ DPBS, wa...

Watch this Scientific Journal Video about Microdissection and Dissociation of the Murine Oviduct: Individual Segment Identification and Single Cell Isolation at JoVE.com

Microdissection and Dissociation of the Murine Oviduct: Individual Segment Identification and Single Cell Isolation

A method for microdissection of the mouse oviduct that allows collection of the individual segments while maintaining RNA integrity is presented. In addition, non-enzymatic oviductal cell dissociation procedure is described. The methods are appropriate for subsequent gene and protein analysis of the functionally different oviductal segments and dissociated oviductal cells.

Mouse model systems are unmatched for the analysis of disease processes because of their genetic manipulability and the low cost of experimental ...

Different oviduct segments have distinct physiological functions and are differentially susceptible to pathological change. Identification of the different segments in a very small mouse oviduct is challenging, as is the production of a good yield of well-differentiated cells by tissue dissociation. In this video, we will demonstrate how to uncoil the mouse oviduct, recognize the different segments so that they can be analyzed individually, and finally, how to produce a relatively high yield of differentiated dissociated cells.A better understanding of the environment specific to the ampulla may improve in vitro fertilization techniques. Also, by contrasting the infundibulum with other segments, we may better understand the infundibulum's propensity for malignant transformation. The single-cell dissociation procedure liberates stromal, as well as epithelial cells from the oviduct.Our method also provides opportunities to separately analyze immune, smooth muscle, and epithelial cell contributions to physiology and pathology of the oviduct. Working under a dissection microscope can be difficult at first. I would advise practicing with a larger tube such as the uterus to ensure that your tools are adequate for the oviduct microdissection.Begin by affixing a piece of dental wax to a Petri dish with adhesive and letting it dry. Then sanitize the dish with 70%ethanol. The surface is now ready for dissection.Immobilize the Petri dish containing the dental wax on the cold platform under a dissection microscope when ready for dissection. Disinfect the ventral surface of the animal with 70%ethanol. Then open the abdominal and pelvic cavity with sterile dissection scissors.Move the gastrointestinal tract to one side to locate the dorsal bihornal uterus. Follow each uterine horn rostrally to locate each oviduct and ovary that are enveloped in the uterine fat pad just below the kidney. Then excise both lateral oviducts with the ovaries and a portion of the distal uterine horn still attached using dissection scissors.Cut each lateral uterine horn with approximately one to two centimeters of the horn still attached to the coiled oviduct and ovary. Submerge the tissue immediately in two milliliters of cold dissection medium, then affix the uterine tissue to the dental wax with a sterile 25 gauge needle to secure tissue for dissection. Clean and dissect the ovarian fat pad and connective tissue to visualize the oviduct clearly.Use a one milliliter syringe to dispense one to two drops of sterile 1%toluidine blue dye solution and incubate for 30 seconds to one minute. Rinse with cold DPBS and then remove all the liquid. Lightly pull the ovary from the coiled oviduct.Cut at the bursal membrane in the broad ligament to remove the ovary from the oviduct without compromising the tubal tissue. Locate the distal fimbrial end of the oviduct found lateral to the uterine tubal junction. Gently pull the tube and cut away at the mesosalpinx with springform micro-scissors to uncoil the oviduct.Cut the tube to produce the infundibular region. Then excise the ampullary region by cutting between turns two and three. Finally, cut the remaining portion to the uterine tubal junction which is the isthmic region.Immediately snap freeze the dissected tissue segments in liquid nitrogen and then add 200 microliters of cold RNA extraction reagent and one-to-one homogenization bead mix to the tissue for RNA isolation. Starting at the fimbrial region, slit the tube longitudinally with springform scissors and use forceps as leverage to expose the luminal epithelium. Mince the slit open portions and the remaining oviduct into approximately one to two millimeter segments.Then add five milliliters of warm non-enzymatic dissociation buffer to the tissue and incubate at 37 degrees Celsius. Fluorescent and phase contrast images of a cell cluster positive for occludin, nuclei, and acetylated tubulin are shown here. Red denotes occludin, blue denotes nuclei, and green denotes acetylated tubulin.The ciliated apical border remains intact throughout the protocol and withstands further digestion to single cells. In these representative images, merged, red, blue, phase contrast, and green channels are shown. After a brief pronase incubation, the majority of cells are single.Propidium iodide staining shows approximately 93%viability in Brightfield, red channel PI positive, and merge. Inset on merge shows an intact ciliated border on a single dissociated cell. Such cells have actively beating cilia.Whole RNA was assessed for yield and quality by microvolume spectrophotometer and bioanalyzer. Results show that this method yields 800 to 1, 200 nanogram RNA per segment except for infundibular samples where pooling from two animals may be necessary for appropriate yield for downstream assays. The presented results for infundibulum are pooled from two animals, totaling four infundibular regions.This protocol successfully achieves pure RNA analyzed with a microvolume spectrophotometer and a bioanalyzer. Samples have a 260 by 280 nanometer absorption ratio between 1.8 and 2, typical of pure RNA nucleotide species. Bioanalyzing the samples showed high RNA integrity with assessed RNA integrity number above seven, appropriate for downstream expression and sequencing analysis.Remember to retain one to two centimeters of the uterine horn to affix the tubal system to the dissection platform. In addition, the use of the toluidine blue dye helps in the fast uncoiling of the oviduct. The faster the uncoiling, the better the preservation and the least amount of RNA degradation.This method is sufficient to obtain RNA of appropriate quality for RNA sequencing allowing individual segment sequencing. The cell dissociation is appropriate for single-cell sequencing or flow cytometry allowing a more precise segment and cell analysis. The method will help move the field beyond whole tube analysis that masks differences at the segment or single cell level.

microdissection-dissociation-murine-oviduct-individual-segment

Research

JoVE Journal

Developmental Biology

Murine Dermal Fibroblast Isolation by FACS

Fibroblasts are the principle cell type responsible for secreting extracellular matrix and are a critical component of many organs and tissues. Fibroblast physiology and pathology underlie a spectrum of clinical entities, including fibroses in multiple organs, hypertrophic scarring following burns, loss of cardiac function following ischemia, and the formation of cancer stroma. However, fibroblasts remain a poorly characterized type of cell, largely due to their inherent heterogeneity. Existing methods for the isolation of fibroblasts require time in cell culture that profoundly influences cell phenotype and behavior. Consequently, many studies investigating fibroblast biology rely upon in vitro manipulation and do not accurately capture fibroblast behavior in vivo. To overcome this problem, we developed a FACS-based protocol for the isolation of fibroblasts from the dorsal skin of adult mice that does not require cell culture, thereby preserving the physiologic transcriptional and proteomic profile of each cell. Our strategy allows for exclusion of non-mesenchymal lineages via a lineage negative gate (Lin-) rather than a positive selection strategy to avoid pre-selection or enrichment of a subpopulation of fibroblasts expressing specific surface markers and be as inclusive as possible across this heterogeneous cell type.

Fibroblast behavior underlies a spectrum of clinical entities, but they remain poorly characterized, largely due to their inherent heterogeneity. Traditional fibroblast research relies upon in vitro manipulation, masking in vivo fibroblast behavior. We describe a FACS-based protocol for the isolation of mouse skin fibroblasts that does not require cell culture.

Fibroblasts are the principle cell type responsible for secreting extracellular matrix and are a critical component of many organs and tissues. Fibroblast ...

Isolation and Characterization of Single Cells from Zebrafish Embryos

The zebrafish (Danio rerio) is a powerful model organism to study vertebrate development. Though many aspects of zebrafish embryonic development have been described at the morphological level, little is known about the molecular basis of cellular changes that occur as the organism develops. With recent advancements in microfluidics and multiplexing technologies, it is now possible to characterize gene expression in single cells. This allows for investigation of heterogeneity between individual cells of specific cell populations to identify and classify cell subtypes, characterize intermediate states that occur during cell differentiation, and explore differential cellular responses to stimuli. This study describes a protocol to isolate viable, single cells from zebrafish embryos for high throughput multiplexing assays. This method may be rapidly applied to any zebrafish embryonic cell type with fluorescent markers. An extension of this method may also be used in combination with high throughput sequencing technologies to fully characterize the transcriptome of single cells. As proof of principle, the relative abundance of cardiac differentiation markers was assessed in isolated, single cells derived from nkx2.5 positive cardiac progenitors. By evaluation of gene expression at the single cell level and at a single time point, the data support a model in which cardiac progenitors coexist with differentiating progeny. The method and work flow described here is broadly applicable to the zebrafish research community, requiring only a labeled transgenic fish line and access to microfluidics technologies.

This protocol describes a method for isolating single cells from zebrafish embryos, enriching for cells of interest, capturing zebrafish cells in microfluidic based single cell multiplex systems, and assessing gene expression from single cells.

The zebrafish (Danio rerio) is a powerful model organism to study vertebrate development. Though many aspects of zebrafish embryonic development have been ...

Isolation of Murine Embryonic Hemogenic Endothelial Cells

The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, and is necessary for the emergence of definitive HSPC from the murine extra embryonic yolk sac, placenta, umbilical vessels, and the embryonic aorta-gonad-mesonephros (AGM) region. The transient nature and small size of this cell population renders its reproducible isolation for careful quantification and experimental applications technically difficult. We have established a fluorescence-activated cell sorting (FACS)-based protocol for simultaneous isolation of hemogenic endothelial cells and HSPC during their peak generation times in the yolk sac and AGM. We demonstrate methods for dissection of yolk sac and AGM tissues from mouse embryos, and we present optimized tissue digestion and antibody conjugation conditions for maximal cell survival prior to identification and retrieval via FACS. Representative FACS analysis plots are shown that identify the hemogenic endothelial cell and HSPC phenotypes, and describe a methylcellulose-based assay for evaluating their blood forming potential on a clonal level.

Hematopoietic stem and progenitor cells (HSPC) derive from specialized (hemogenic) endothelial cells during development, yet little is known about the process by which some endothelial cells specify to become blood forming. We demonstrate a flow-cytometry based method allowing simultaneous isolation of hemogenic endothelial cells and HSPC from murine embryonic tissues.

The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, ...

Identification Of Erythromyeloid Progenitors And Their Progeny In The Mouse Embryo By Flow Cytometry

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where they act as front line sentinels of infection and tissue damage. While other immune cells are continuously renewed from hematopoietic stem and progenitor cells (HSPC) located in the bone marrow, a lineage of macrophages, known as resident macrophages, have been shown to be self-maintained in tissues without input from bone marrow HSPCs. This lineage is exemplified by microglia in the brain, Kupffer cells in the liver and Langerhans cells in the epidermis among others. The intestinal and colon lamina propria are the only adult tissues devoid of HSPC-independent resident macrophages. Recent investigations have identified that resident macrophages originate from the extra-embryonic yolk sac hematopoiesis from progenitor(s) distinct from fetal hematopoietic stem cells (HSC). Among yolk sac definitive hematopoiesis, erythromyeloid progenitors (EMP) give rise both to erythroid and myeloid cells, in particular resident macrophages. EMP are only generated within the yolk sac between E8.5 and E10.5 days of development and they migrate to the fetal liver as early as circulation is connected, where they expand and differentiate until at least E16.5. Their progeny includes erythrocytes, macrophages, neutrophils and mast cells but only EMP-derived macrophages persist until adulthood in tissues. The transient nature of EMP emergence and the temporal overlap with HSC generation renders the analysis of these progenitors difficult. We have established a tamoxifen-inducible fate mapping protocol based on expression of the macrophage cytokine receptor Csf1r promoter to characterize EMP and EMP-derived cells in vivo by flow cytometry.

While infiltrating macrophages are continuously recruited to adult tissues from circulating precursors, resident macrophages seed their tissue during development, where they are maintained without further input from progenitors. The progenitors for resident macrophages were recently identified. Here, we present methods for the genetic fate mapping of the resident macrophage progenitors.

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where ...

The Isolation and Culture of Primary Epicardial Cells Derived from Human Adult and Fetal Heart Specimens

The epicardium, an epithelial cell layer covering the myocardium, has an essential role during cardiac development, as well as in the repair response of the heart after ischemic injury. When activated, epicardial cells undergo a process known as epithelial to mesenchymal transition (EMT) to provide cells to the regenerating myocardium. Furthermore, the epicardium contributes via secretion of essential paracrine factors. To fully appreciate the regenerative potential of the epicardium, a human cell model is required. Here we outline a novel cell culture model to derive primary epicardial derived cells (EPDCs) from human adult and fetal cardiac tissue. To isolate EPDCs, the epicardium is dissected from the outside of the heart specimen and processed into a single cell suspension. Next, EPDCs are plated and cultured in EPDC medium containing the ALK 5-kinase inhibitor SB431542 to maintain their epithelial phenotype. EMT is induced by stimulation with TGF&#946;. This method enables, for the first time, the study of the process of human epicardial EMT in a controlled setting, and facilitates gaining more insight in the secretome of EPDCs that may aid heart regeneration. Furthermore, this uniform approach allows for direct comparison of human adult and fetal epicardial behavior.

The epicardium plays a crucial role in the development and repair of the heart by providing cells and growth factors to the myocardial wall. Here, we describe a method to culture human primary epicardial cells that enables the study and comparison of their developmental and adult characteristics.

The epicardium, an epithelial cell layer covering the myocardium, has an essential role during cardiac development, as well as in the repair response of ...

Cell Dissociation from the Tongue Epithelium and Mesenchyme/Connective Tissue of Embryonic-Day 12.5 and 8-Week-Old Mice

Cell dissociation has been an essential procedure for studies at the individual-cell level and/or at a cell-population level (e.g.,&#160;single cell RNA sequencing and primary cell culture). Yielding viable, healthy cells in large quantities is critical, and the optimal conditions to do so are tissue dependent. Cell populations in the tongue epithelium and underlying mesenchyme/connective tissue are heterogeneous and tissue structures vary in different regions and at different developmental stages. We have tested protocols for isolating cells from the mouse tongue epithelium and mesenchyme/connective tissue in the early developmental [embryonic day 12.5 (E12.5)] and young adult (8-week) stages. A clean separation between the epithelium and underlying mesenchyme/connective tissue was easy to accomplish. However, to further process and isolate cells, yielding viable healthy cells in large quantities, and careful selection of enzymatic digestion buffer, incubation time, and centrifugation speed and time are critical. Incubation of separated epithelium or underlying mesenchyme/connective tissue in 0.25% Trypsin-EDTA for 30 min at 37 &#176;C, followed by centrifugation at 200 x g for 8 min resulted in a high yield of cells at a high viability rate (&#62;90%) regardless of the mouse stages and tongue regions. Moreover, we found that both dissociated epithelial and mesenchymal/connective tissue cells from embryonic and adult tongues could survive in the cell culture-based medium for at least 3 h without a significant decrease of cell viability. The protocols will be useful for studies that require the preparation of isolated cells from mouse tongues at early developmental (E12.5) and young adult (8-week) stages requiring cell dissociation from different tissue compartments.

We have developed a generalized protocol to dissociate a large quantity of high-quality single cells from the epithelium and mesenchyme/connective tissue of embryonic and adult mouse tongues.

Cell dissociation has been an essential procedure for studies at the individual-cell level and/or at a cell-population level (e.g.,&#160;single cell RNA ...

Identification and Isolation of Burst-Forming Unit and Colony-Forming Unit Erythroid Progenitors from Mouse Tissue by Flow Cytometry

Early erythroid progenitors were originally defined by their colony-forming potential in vitro and classified into burst-forming and colony-forming &#34;units&#34; known as BFU-e and CFU-e. Until recently, methods for the direct prospective and complete isolation of pure BFU-e and CFU-e progenitors from freshly isolated adult mouse bone marrow were not available. To address this gap, a single-cell RNA-seq (scRNAseq) dataset of mouse bone marrow was analyzed for the expression of genes coding for cell surface markers. This analysis was combined with cell fate assays, allowing the development of a novel flow cytometric approach that identifies and allows the isolation of complete and pure subsets of BFU-e and CFU-e progenitors in mouse bone marrow or spleen. This approach also identifies other progenitor subsets, including subsets enriched for basophil/mast cell and megakaryocytic potentials. The method consists of labeling fresh bone marrow or spleen cells with antibodies directed at Kit and CD55. Progenitors that express both these markers are then subdivided into five principal populations. Population 1 (P1 or CFU-e, Kit+ CD55+ CD49fmed/low CD105med/high CD71med/high) contains all of the CFU-e progenitors and may be further subdivided into P1-low (CD71med CD150high) and P1-hi (CD71high CD150low), corresponding to early and late CFU-e, respectively; Population 2 (P2 or BFU-e, Kit+ CD55+ CD49fmed/low CD105med/high CD71low CD150high) contains all of the BFU-e progenitors; Population P3 (P3, Kit+ CD55+ CD49fmed/high CD105med/low CD150low CD41low) is enriched for basophil/mast cell progenitors; Population 4 (P4, Kit+ CD55+ CD49fmed/high CD105med/low CD150high CD41+) is enriched for megakaryocytic progenitors; and Population 5 (P5, Kit+ CD55+ CD49fmed/high CD105med/low CD150high CD41-) contains progenitors with erythroid, basophil/mast cell, and megakaryocytic potential (EBMP) and erythroid/ megakaryocytic/ basophil-biased multipotential progenitors (MPPs). This novel approach allows greater precision when analyzing erythroid and other hematopoietic progenitors and also allows for reference to transcriptome information for each flow cytometrically defined population.

Here, we describe a novel flow cytometric method for prospective isolation of early burst-forming unit erythroid (BFU-e) and colony-forming unit erythroid (CFU-e) progenitors directly from fresh mouse bone marrow and spleen. This protocol, developed based on single-cell transcriptomic data, is the first to isolate all the tissue's erythroid progenitors with high purity.

Early erythroid progenitors were originally defined by their colony-forming potential in vitro and classified into burst-forming and colony-forming ...

Processing Gut Cells from Zebrafish Larvae for Single-Cell RNA Sequencing

Gut Isolation from Zebrafish Larvae for Single-cell RNA Sequencing

The gastrointestinal (GI) tract performs a range of functions essential for life. Congenital defects affecting its development can lead to enteric neuromuscular disorders, highlighting the importance to understand the molecular mechanisms underlying GI development and dysfunction. In this study, we present a method for gut isolation from zebrafish larvae at 5 days post fertilization to obtain live,&#160;viable cells which can be used for single-cell RNA sequencing (scRNA-seq) analysis. This protocol is based on the manual dissection of the zebrafish intestine, followed by enzymatic dissociation with papain. Subsequently, cells are submitted to fluorescence-activated cell sorting, and viable cells are collected for scRNA-seq. With this method, we were able to successfully identify different intestinal cell types, including epithelial, stromal, blood, muscle, and immune cells, as well as enteric neurons and glia. Therefore, we consider it to be a valuable resource for studying the composition of the GI tract in health and disease, using the zebrafish.

Author Spotlight: Isolating and Analyzing Intestinal Cells of Zebrafish Larvae for Investigating Transcriptomic Aspects of Gastrointestinal Development 

Here, we describe a method for gut isolation from zebrafish larvae at 5 days post fertilization, for single-cell RNA sequencing analysis.

The gastrointestinal (GI) tract performs a range of functions essential for life. Congenital defects affecting its development can lead to enteric ...

Isolation and Dissociation of Gut from Zebrafish Larvae for FACS Enrichment of Gut Cells

To begin, prepare a 1.8%agarose plate with HEPES Buffered E3 medium or E3.While working under a dissection microscope, place six to 10 anesthetized larvae in a row on the agarose plate. Put one insect pin on the head of each larvae. Then remove the remaining E3 from the plate using a tissue.Using another insect pin, isolate the intestine from a larvae without disturbing any other organs. Ensure proper removal of yolk. Once isolated, inspect the intestine and remove all non-intestinal material, such as skin, fat, or liver.Use tweezers to collect the intestine and transfer it to PBS containing 10%FCS in a microcentrifuge tube placed on ice. Immediately after the dissection of all intestines, centrifuge the microcentrifuge tube at 13, 800 g for 30 seconds. Remove the supernatant, leaving about 100 microliters in the tube to prevent the intestines from drying out.Add 500 microliters of papain solution to the intestines in the tube. Activate the papain by adding 2.5 microliters of one molar cysteine. Then incubate the tube containing the intestines in a water bath at 37 degrees Celsius for 10 minutes.Pipette the contents up and down halfway after five minutes to stimulate enzymatic tissue digestion. Transfer the dissociated cells into a fluorescence-activated cell sorting, or FACS, tube through a pre-wedded 35-micron cell strainer. Wash the strainer several times by adding 0.5 milliliters of PBS containing 10%FCS to a total wash volume of two milliliters.Centrifuge the collected filtrate at 700 g for five minutes at 4 degrees Celsius, and remove the supernatant. Add one microgram per milliliter DAPI to 300 microliters of PBS containing 10%FCS. Add this mixture to the pellet and resuspend to label the dead cells.Then incubate for five minutes on ice to allow their exclusion during subsequent FACS analysis.

Single Cell and Nuclei Extraction from Human Brain Organoids

Generation and Downstream Analysis of Single-Cell and Single-Nuclei Transcriptomes in Brain Organoids

Over the past decade, single-cell transcriptomics has significantly evolved and become a standard laboratory method for simultaneous analysis of gene expression profiles of individual cells, allowing the capture of cellular diversity. In order to overcome limitations posed by difficult-to-isolate cell types, an alternative approach aiming at recovering single nuclei instead of intact cells can be utilized for sequencing, making transcriptome profiling of individual cells universally applicable. These techniques have become a cornerstone in the study of brain organoids, establishing them as models of the developing human brain. Leveraging the potential of single-cell and single-nucleus transcriptomics in brain organoid research, this protocol presents a step-by-step guide encompassing key procedures such as organoid dissociation, single-cell or nuclei isolation, library preparation&#160;and sequencing. By implementing these alternative approaches, researchers can obtain high-quality datasets, enabling the identification of neuronal and non-neuronal cell types, gene expression profiles, and cell lineage trajectories. This facilitates comprehensive investigations into cellular processes and molecular mechanisms shaping brain development.

Author Spotlight: Integrating Organoid Models with Single-Cell and Spatial Transcriptomics Technologies

Here, we introduce a comprehensive protocol for the generation and downstream analysis of human brain organoids using single-cell and single-nucleus RNA sequencing.

Over the past decade, single-cell transcriptomics has significantly evolved and become a standard laboratory method for simultaneous analysis of gene ...